-■^O'fll 
 
Cornell University Library 
 
 QM 28.Y73 1913 
 
 Handbook of anatomy; being a complete com 
 
 3 1924 003 140 864 
 
 CORNELL. 
 
 UNIVERSITY 
 
 LIBRARY 
 
 GIFT OF 
 J. W. Papez 
 
The original of tiiis book is in 
 tine Cornell University Library. 
 
 There are no known copyright restrictions in 
 the United States on the use of the text. 
 
 http://www.archive.org/details/cu31924003140864 
 
HANDBOOK 
 
 OF 
 
 ANATOMY 
 
 BEING A COMPLETE COMPEN0 OF ANATOMY, 
 
 INCLUDING THE ANATOMY OP THE 
 
 VISCERA AND NUMEROUS 
 
 TABLES 
 
 JAMES K. YOUE'G-. M.D. 
 
 Professor of Orthopaedic Surgery, Philadelphia Polyclinic; eiinical Professor of 
 Orthopaedic Surgery, Woman's Medical College of Pennsylvania ; Associate 
 Professor of Orthopaedic Surgery, University of Pennsylvania ; Fellow 
 of the College of Physicians, of Philadelphia; Fellow of the 
 Philadelphia Academy of Surgery ; Fellow of the Ameri- 
 can Orthopaedic Association; Member of the 
 American Medical Association, etc., etc. 
 
 Fourth revised edition 
 
 WITH 172 ENQRAVINQS, SOME IN COLORS 
 
 PHILADELPHIA 
 
 F. A. DAVIS COMPANY, Publishers 
 1913 
 
Copyright, 1889 
 Copyright, 1905 
 Copyright, 1909 
 Copyright, 1913 
 
 BY 
 
 P. A. DAVIS COMPANY 
 1 Registered at Stationers' Hall, London, Eng.] 
 
 Philadelphia, Pa., U. S. A. 
 
 Press of F. A. Davis Company 
 
 1914-1916 Cherry Street 
 
PREFACE TO FOURTH EDITION. 
 
 Although for over twenty years the book has been in con- 
 stant use by large numbers of students and approved by professors 
 and teachers in leading medical colleges and in Xurses' Training 
 Schools generally, comparatively few errors or omissions of im- 
 portance have been discovered; but in the present edition these 
 liave all been noted and corrected. The appreciative thanks of 
 the author are extended to Dr. A. C. Pole, of Baltimore, for 
 several pertinent suggestions in the preparation of this edition. 
 
 J. K. Y. 
 
 (iii) 
 
PREFACE TO THIRD EDITION. 
 
 In the preparation of this new edition, the author has taken 
 advantage of the opportunity to correct the few clerical errors 
 which must necessarily be found in a comprehensive though 
 condensed work upon Anatomy, and to make such changes as 
 have become necessary through the advances of the science since 
 the publication of the last edition. 
 
 In the section upon the Xervous System the greatest changes 
 will be found, the first part having been rewritten. 
 
 In the description of the Muscular System, the regional 
 grouping has been retained, because it is more practical for the 
 student. 
 
 Attention is directed to the original colored plates of the 
 Arterial System which offer the most complete classification of 
 all the arteries in the smallest space, and also to the original 
 diagrams of the sensory tracts from spinal cord to brain, and 
 the motor tracts from brain to spinal cord. 
 
 The author desires to express his gratitude to the student 
 body of America for their continued confidence in this early 
 literary effort of his, and express the hope that the present edition 
 may be as well received as the others. 
 
 J. K. Y. 
 
 (iv) 
 
PREFACE TO SECOND EDITION. 
 
 The demand for a new editipn has afforded an opportunity 
 to thoroughly revise the text and illustrations, and to add such 
 changes of description and nomenclature as have been intro- 
 duced into modern methods of teaching. 
 
 Whenever it seemed necessary or advisable sections have 
 been entirely rewritten, but the same attention to conciseness and 
 accuracy has been observed as in the former edition. 
 
 The size of the pages has been considerably enlarged and 
 increased in number, and the illustrations increased from 76 to 
 171. Many improved cuts replace those used in the former edi- 
 tion and full-page engraved plates have been inserted in the text 
 where they will be most serviceable. 
 
 In its preparation, the last editions of both Morris and Gray 
 have been freely consulted, so that it can be used with either of 
 these standard works. 
 
 As in the former edition, although prepared particularly 
 for students, sufficient descriptive matter has been added to 
 render it valuable to the busy practitioner, particularly in the 
 sections upon the Viscera, Special Senses, Vascular System, the 
 Nervous System, and Surgical Anatomy. 
 
 Special attention has been given to the anatomy of the brain 
 and nervous system, which will be found to compare favorably 
 with the descriptions in larger works. 
 
 The author has been much gratified to observe the tenacity 
 with which students and physicians have retained the work for 
 reference. 
 
 The author would acknowledge his obligation to Dr. Eichard 
 F. Gerlach, who has distinguished himself by his careful and ' 
 accurate work upon Deaver's "Surgical Anatomy," for valuable 
 assistance upon the revision. 
 
 J. K. Y. 
 
 (V) 
 
PREFACE TO FIRST EDITION. 
 
 The object of this little book is, as its title indicates, to 
 furnish a concise though complete synopsis of human anatomy 
 for the use of students of medicine and others. 
 
 Appreciating, from a personal contact with students, the 
 limited time at their disposal and the unlimited amount of 
 medical material to be digested, the author has endeavored, by 
 well-selected wood-cuts, typographical arrangement, and numer- 
 ous tables, to facilitate the acquisition of a subject as difficult as 
 it is essential, and elegance or diction has therefore been sacri- 
 fieed to conciseness and accuracy. 
 
 In its preparation the last edition of Gray's "Anatomy" 
 [edited by Keen], as the work most largely employed, has been 
 selected as the standard, but Leidy, Quain, Allen, Holden, Henle, 
 SchafEer, Klein, Brown Aids, and others, have been freely used, 
 and on the special subjects Lusk, Spiegelberg, Savage, Schroeder, 
 Budin, Treve's "Surgical Applied Anatomy," and the "Ameri- 
 can System of Dentistry" have been consulted. Although pre- 
 pared particularly for students, sufficient descriptive matter has 
 been added to render it valuable to the busy practitioner, par- 
 ticularly the sections on the Viscera, Special Senses, Vascular 
 System, and Surgical Anatomy. The aim throughout has been 
 to make it as thoroughly complete and accurate as possible, and 
 at the same time readily accessible for reference or study. 
 
 The writer would acknowledge his obligations to l^Icssrs. 
 S. Z. Durborow and C. W. Holly, medical students at the "Uni- 
 versity, for assistance in the correction of proof. 
 
 J. K. Y. 
 
 (vi) 
 
TABLE OF CONTENTS. 
 
 PAGE 
 
 Intboductort 1 
 
 Osteology 3 
 
 The Frontal Bone 8 
 
 Parietals 10 
 
 The Occipital Bone 11 
 
 Temporals 13 
 
 The Sphenoid 17 
 
 The Ethmoid 21 
 
 The Lachrymal 22 
 
 The Malar 23 
 
 The Superior Maxilla 24 
 
 Palate Bones 26 
 
 The Inferior Turbinated Bones 28 
 
 The Vomer 28 
 
 The Inferior Maxilla 29 
 
 The Sutures and Fontanelles 31 
 
 Fossae of Skull 32 
 
 The Orbits 34 
 
 Foramina at the Base of the SkuU 38 
 
 The Sternum 41 
 
 The Ribs 41 
 
 The Spine 43 
 
 The Upper Extremity 47 
 
 The Arm SI 
 
 The Forearm 53 
 
 The Hand 50 
 
 The Lower Extremity ' 59 
 
 The Thigh 63 
 
 The Patella 65 
 
 The I*g 65 
 
 The Foot 68 
 
 Table of Ossification 72 
 
 Abticui-ations and Ligaments Ill 
 
 The Thorax 115 
 
 The Pelvis 118 
 
 (vii) 
 
viii TABLE OF CONTENTS. 
 
 PAGE 
 
 The Mtjsctjlab System 132 
 
 Muscles of the Head 133 
 
 Muscles of the Neck 137 
 
 Vertebral Region 140 
 
 Muscles of the Back 141 
 
 Muscles of the Abdomen 146 
 
 Muscles of the Upper Extremity 149 
 
 Muscles of the Forearm 152 
 
 Muscles of the Hand 155 
 
 Muscles of the Lower Extremity 157 
 
 Muscles of the Leg 161 
 
 Muscles of the Foot 161 
 
 The Fascias 166 
 
 The Heart and Vascular Ststem 170 
 
 The Circulation of the Blood 177 
 
 The Arterial System 173, 177 
 
 Table of thfe Arterial System 200 
 
 The Venous System 206 
 
 The Lymphatic System 214 
 
 The Alimentary Apparatus 218 
 
 The Teeth 219 
 
 The Pharynx 224 
 
 The CEsophagus 225 
 
 The Abdomen 226 
 
 The Peritoneum 228 
 
 The Stomach 231 
 
 The Small Intestine 233 
 
 The Large Intestine 235 
 
 The Pancreas 237 
 
 The Liver 238 
 
 The Ductless Glands 242 
 
 Vocal and Respiratory Apparatus 246 
 
 The Larynx 246 
 
 The Trachea and Bronchi 251 
 
 The Lungs 252 
 
 The Pleurse 255 
 
 The Mediastinum 256 
 
 The Genito-Urinaey Apparatus 257 
 
 The Kidneys 257 
 
 The Bladder 261 
 
 Male Organs 263 
 
 Female Organs 272 
 
 The Mammary Gland 281 
 
TABLE OF CONTENTS. ix 
 
 PAGE 
 
 The Nebvotts System 283 
 
 The Brain 286 
 
 The Cranial Nerves 309 
 
 The Spinal Cord 317 
 
 The Spinal Nerves 318 
 
 Table of Spinal Nerves 328 
 
 The Sympathetic Nervous System 335 
 
 Organs of Special Sense 340 
 
 The Nose 340 
 
 The Eye 343 
 
 Appendages of the Eye 356 
 
 The Ear 359 
 
 The Tongue 371 
 
 The Skin and Appendages 372 
 
 Sdegical Anatomy 374 
 
 Triangles of the Neck 374 
 
 Triangle in Front of Elbow -joint 377 
 
 Scarpa's Triangle 377 
 
 AxiUa 377 
 
 Anatomy of Hernia 379 
 
 Ischio-rectal Region and Perineum 384 
 
 Anatomy of Lateral Lithotomy 390 
 
 Index 391 
 
LIST OF ILLUSTRATIONS. 
 
 FIS. PAGE 
 
 1. Frontal Bone, Outer Surface ^ 
 
 2. Frontal Bone, Inner Surlace 8 
 
 3. Parietal Bone, Outer Surface 9 
 
 4. Parietal Bone, Inner Surface 10 
 
 6. Occipital Bone, Outer Surface 11 
 
 6. Occipital Bone, Inner Surface 12 
 
 7. Left Temporal Bone, Outer Surface 14 
 
 8. Left Temporal Bone, Inner Surface 15 
 
 9. Sphenoid Bone, Upper Surface 18 
 
 10. Sphenoid Bone, Anterior Surface 19 
 
 11. Superior Maxillary Bone 23 
 
 12. Superior Maxillary Bone, Inner Surface 24 
 
 13. Palate Bone 26 
 
 14. Inferior Maxillary Bone 29 
 
 16. Fossae of Skull 33 
 
 16. Facial Portion of Skull 34 
 
 17. Floor of the Cranium 39 
 
 18. A Vertebra 43 
 
 19. Clavicle 47 
 
 20. The Scapula, Inner Surface 49 
 
 21. The Scapula. Outer Surface 50 
 
 22. The Humerus E3 
 
 23. The Ulna and Radius 53 
 
 24. The Carpal Bones 56 
 
 25. Os Innominatum 60 
 
 26. The Femur 63 
 
 27. The Tibia and Fibula, Anterior Surface 66 
 
 28. The Tibia and Fibula, Posterior Surface 66 
 
 29. The Tarsus, Metatarsus, and Phalanges 69 
 
 30. Frontal Bone, Outer Surface 77 
 
 31. Frontal Bone, Inner Surface 77 
 
 32. Parietal Bone, Outer Surface 78 
 
 83. Parietal Bone, Inner Surface 78 
 
 34. Occipital Bone, Outer Surface 79 
 
 35. Occipital Bone, Inner Surface 79 
 
 36. Left Temporal Bone, Outer Surface 80 
 
 37. Left Temporal Bone, Inner Surface 80 
 
 38. Left Temporal Bone, Inferior Surface of the Petrous Portion 81 
 
 39. Section of Left Temporal Bone 81 
 
 40. Sphenoid Bone, Upper Surface 82 
 
 41. Sphenoid Bone, Anterior Surface 82 
 
 42. Ethmoid Bone «3 
 
 43. Nasal Bones 83 
 
 44. Lachrymal Bone 83 
 
 45. Superior Maxillary Bone 84 
 
 46. Superior Maxillary Bone, Inner Surface 84 
 
 47. Vomer 85 
 
 48. Inferior Maxillary Bone 85 
 
 49. Left Half of Interior Maxillary Bone, Inner Surface 85 
 
 BO. Malar Bones 86 
 
 51. Palate Bone (Viewed Posteriorly) 86 
 
 52. Palate Bone (Inner Surface) 86 
 
 63. Inferior Turbinated Bones 86 
 
 54. Nasal Meatuses 87 
 
 B6. The Hyold Bone 87 
 
 56. Facial Portion of Skull 88 
 
 57. Base of Skull, External Surface 59 
 
 68. Sternum and Costal Cartilages 90 
 
 69. The Peculiar Ribs 91 
 
 60. The Vertebral (Column, or Spine 92 
 
 61. A Dorsal Vertebra 93 
 
 (^) 
 
LIST OF ILLUSTRATIONS. xi 
 
 FIO, PAGE 
 
 62. A Cervical Vertebra 98 
 
 63. Seventh Cervical, or Vertebra Prominens 93 
 
 64. The Axis Si 
 
 65. The Atlas 91 
 
 66. Peculiar Dorsal Vertebrae 95 
 
 67. A Iiumbar Vertebra 95 
 
 68. The Sacrum, Anterior Surface 96 
 
 69. The Sacrum, Posterior Surface 96 
 
 70. The Left Clavicle, Upper Surface 97 
 
 71. The Left Clavicle, Under Surface 97 
 
 72. The Scapula, Anterior Surface 98 
 
 73. The Scapula, Posterior Surface 99 
 
 74. The Humerus, Anterior Surface 100 
 
 75. The Humerus, Posterior Surface 100 
 
 76. Ulna and Radius, Anterior Aspect 101 
 
 77. Radius and Ulna, Posterior Aspect 102 
 
 78. Carpus, Metacarpus, and Phalanges, Dorsal Surface 103 
 
 79. Carpus, Metacarpus, and Phalanges, Palmar Surface 104 
 
 80. Os Innominatum, Outer Surface 105 
 
 81.- Os Innominatum, Inner Surface 106 
 
 82. The Femur, Anterior Surface 107 
 
 83. The Femur, Posterior Surface 107 
 
 84. The Tibia and Fibula, Anterior Surface 108 
 
 85. The Tibia and Fibula, Posterior Surface 108 
 
 86. The Tarsus, Metatarsus, and Phalanges, Dorsal Surface 109 
 
 87. The Tarsus, Metatarsus, and Phalanges, Plantar Surface 110 
 
 88. The Thorax 117 
 
 89. The Pelvis 118 
 
 90. The Shoulder 121 
 
 91. The Elbow 123 
 
 92. The Knee 127 
 
 93. The Knee 127 
 
 94. Muscles of the Back 142 
 
 95. Muscles of the Abdomen 147 
 
 96. The Diaphragm 148 
 
 97. Muscles of the Shoulder and Arm 151 
 
 98. Triceps Muscles 151 
 
 99. Posterior Superficial Muscles of the Forearm 153 
 
 100. Muscles of the Anterior Femoral Region 159 
 
 101. Muscles of the Posterior Femoral Region 160 
 
 102. Anterior Muscles of the Leg 162 
 
 103. Posterior Muscles of the Leg 162 
 
 104. Right Side of Heart 171 
 
 106. Diagram of the Foetal Circulation 176 
 
 106. Arteries of the Face 181 
 
 107. Internal Maxillary Artery 183 
 
 108. The Arteries of the Head and Neck Facing 184 
 
 109. The Arteries of the Upper Extremity Facing 187 
 
 110. Abdominal Aorta 193 
 
 111. The Arteries of the Trunk Facing 194 
 
 112. The Arteries of the Lower Extremity Facing 196 
 
 113. Temporary Teeth 221 
 
 114. Permanent Teeth 222 
 
 115. Pharynx, Laid Open from Behind 225 
 
 116. Regions of the Abdomen 226 
 
 117. Abdominal Viscera. Facing 226 
 
 118. The Peritoneum 229 
 
 lis. The Liver 239 
 
 120. Transverse Section of Lobules of Liver 240 
 
 121. Vertical Section of Larynx 247 
 
 122. Heart and Lungs 254 
 
 123. Longitudinal Section of Kidney 258 
 
 124. Diagram of the Course of the Uriniferous Tubules 260 
 
 125. Male Organs of Generation 265 
 
 126. The Testicles and Epididymis 267 
 
 127. Vertical Section of Testicle 269 
 
 128. Internal Female Genitals 273 
 
 129. Female Organs of Generation 275 
 
 130. Section of an Ovary 276 
 
 131. External Female Genitals 278 
 
 132. Surface Anatomy of the Myelencephalon 288 
 
 133. Left Side of Human Cerebrum 291 
 
 134. Convolutions and Fissures of the Median and Tentorial Surfaces ol 
 
 the Right Cerebral Hemisphere 292 
 
Xll 
 
 LIST OF ILLUSTRATIONS. 
 
 PIG. PAGE 
 
 136. Inferior Aspect of Cerebral Hemisphere 293 
 
 136. The Lateral Ventricles and Choroid Plexus 297 
 
 137. Mesial Section of Brain and Brain Stem 300 
 
 138. Interior of Mesencephalon 305 
 
 139. Diagram of Sensory Tracts from Spinal Cord to Brain 306 
 
 140. Diagram of Motor Tracts from Brain to Spinal Cord 307 
 
 141. Scheme of the Nuclei and Root-fibres of the Cranial Nerves 308 
 
 142. Base of Brain and Cranial Nerves 310 
 
 143. Optic, Oculomotor, Trachlear, and Trifacial Nerves Facing 310 
 
 144. Facial and Auditory Nerves 314 
 
 145. Glossopharyngeal, Fneumogastric, Spinal Accessory, and Hypoglossal 
 
 Nerves 315 
 
 146. Section of the Spinal Cord and Membranes 318 
 
 147. Cervical Plexus and Branches 319 
 
 148. Brachial Plexus and Branches 321 
 
 149. Lumbar Plexus and Branches Facing 324 
 
 150. Sacral Plexus and Branches Facing 326 
 
 151. The Sympathetic System Facing 335 
 
 152. The Olfactory Nerves and Nerves of Common Sensation to the Nose... 340 
 
 153. Nasal Meatuses and Accessory Cavities 341 
 
 154. Inner Wall of Orbit and Adjacent Parts 342 
 
 155. Horizontal Section of Right Orbit 343 
 
 106. Antero-posterior Section of Eyeball 344 
 
 157. Vessels of the Eye 347 
 
 158. The Structure of the Human Retina 350 
 
 159. Diagram of the Retinal Vessels 351 
 
 160. The Orbital Muscles 354 
 
 161. The Ophthalmic Artery and Branches 335 
 
 162. The Lachrymal Apparatus 358 
 
 163. External, Middle, and Internal Ear 360 
 
 164. The Auditory Ossicles 364 
 
 165. Organ of Corti 367 
 
 166. Triangles of the Neck 375 
 
 167. The Axilla 378 
 
 168. Dissection of the Inguinal Canal 380 
 
 169. Deep Femoral Region— The Femoral Vessels, etc. (McOrath) 383 
 
 170. Male Perineum, Superficial Dissection 385 
 
 171. Male Perineum, Deep Dissection 386 
 
 172. Female Perineum 388 
 
INTRODUCTORY. 
 
 The term "anatomy," derived from the Greek avd, 
 "through," and refiveo), "to cut," signifies dissection, but has 
 been appropriated under the general term Morphology, to the 
 science which treats of the apparent properties of organized 
 bodies. It is the science of organization and of form. Anatomy 
 is divided into vegetable, M-hich treats of the structures and prop- 
 erties of vegetal bodies ; comparative, which treats of the anatomy 
 of animals ; human, which treats of tlie anatomy of man in 
 a physiological or healthy state; pathological, which treats of 
 the anatomy of the diseased human body, etc. 
 
 Human anatomy is subdivided into general, descriptive, and 
 surgical. 
 
 General anatomy treats of the minute structure or physical 
 elements of the organs of the body. It is also called micro- 
 scopical anatomy, or histology. It comprises four distinct 
 elementary tissues : — 
 
 Epithelial, including mucous membranes, epidermis, glands, etc. 
 Muscular, including striated and nonatriated muscles. 
 Nervous, including the proper nerve elements. 
 
 Connective, including white fibrous, elastic, adipose, cartilage, and 
 bone. 
 
 Descriptive or special anatomy treats of the various proper- 
 ties of the organs arranged into systems; hence the name 
 systematic. It includes : — 
 
 Osteology, the anatomy of the bones. 
 Syndesmology, the anatomy of the joints. 
 Myology, the anatomy of the muscles. 
 Angiology, the anatomy of the vessels. 
 Neurology, the anatomy of the nerves. 
 Splanchnology, the anatomy of the viscera, etc., etc. 
 
 Surgical or topographical anatomy treats of the relative 
 position of organs to one another and to the surrounding parts 
 in special regions of the body, as the axilla, neck, or groin. 
 
 (1) 
 
OSTEOLOGY. 
 
 The frame-work of the body is composed of bones, which 
 constitute the skeleton. This in the adult consists of 306 bones, 
 including the ossieula auditus: Excluding the ear ossicles, the 
 number is 200, or excluding also the two patellse and the hyoid 
 bone the number is 197. Spine (including coccyx and sacrum) 
 26, cranium 8, face 14, ribs, sternum, and os hyoides 26, upper 
 extremity 64, lower extremity 63, ear ossicles, 6. 
 
 The bones of the head number 32, consisting of 
 
 Eight cranial bones, the frontal, 2 parietal, occipital, 2 temporal, the 
 sphenoid and ethmoid bones ; 14 facial bones, 2 lachrymal, 2 nasal, 2 malar, 
 2 superior maxUlae, 2 palate, 2 turbinal, 1 vomer, and 1 inferior maxilla. 
 
 The bones of the trunk number 52, comprising 
 
 Twenty-six vertebrae, 7 cervical, 12 dorsal, 5 lumbar, 1 sacrum and 
 
 1 coc.iyx. 
 
 Twenty-six of the thorax, 7 pairs of true ribs, 3 pairs of false ribs, 
 
 2 pairs of floating ribs, the sternum and os hyoidas. 
 
 The bones of the skull, face, thorax, and vertebral column 
 are Imown as the axial skeleton, and consists of 74 segments. 
 
 The bones of the upper extremity number 64, comprising 
 on either side 
 
 Two shoulder, clavicle and scapula ; 1 arm, humerus ; 2 forearm, 
 radius and ulna ; 8 wrist (carpus), scaphoid, semi-lunar, cuneiform, pisi- 
 form, trapezium, trapezoid, os magnum, and unciform ; 19 hand, 5 meta- 
 carpal and 14 phalanges. 
 
 The bones of the lower extremity number 62, comprising 
 on either side 
 
 One hip, divided into 3 portions, the ilium, ischium, and pubes ; 
 1 thigh, the femur; 2 leg, tibia and fibula ; 1 knee, the patella ; 26 foot, 
 7 tarsal bones, the astragalus, os calcis, scaphoid, cuboid, external, middle, 
 and internal cuneiform ; 5 metatarsal bones, and 14 phalanges. 
 
 The bones of the shoulder girdle, upper extermities, pelvic 
 girdle, and lower extremities are known as the appendicular 
 skeleton, and consists of 126 segments. They are divided into 
 long, short, flat or tabular, and irregular. 
 
 Long hones, such as femur, humerus, or radius, consist of 
 shaft or diaphysis, and two extremities or epiphyses. 
 
 The shaft or diaphysis is a cylindrical tube composed ex- 
 ternally of compact tissue and internally of cancellous tissue, the 
 centre being hollowed out by the medullary canal. 
 
 The epiphyses, or extremities, are expanded for articulation, 
 and are composed of a mass of solid cancellous tissue with a 
 thin coating of compact tissue. 
 
 (3) 
 
4 HUMAN ANATOMY. 
 
 The short bones, as tarsus or carpus, are small, compact, 
 irregular cubes. 
 
 Flat bones J as those of skull and shoulder-blade, afford 
 extensive surfaces for protection or muscular attachment. 
 
 Under irregular or mixed bones are classed the vertebral, 
 sphenoid, maxillary bones, and such that could not be placed 
 under either of the other heads. 
 
 The surfaces of the bones are marked by certain eminences 
 and depressions, which have received the following names : — 
 
 An apophysis is a prominent excrescence formed directly upon 
 a bone, and is distinguished from 
 
 An epiphysis, which has been formed from a distinct centre and 
 separated by cartilage, but afterward united to the bone. 
 
 A head is a rounded, smooth, articular eminence for articulation. 
 
 A condyle is an irregular prominence for muscular attachment. 
 
 A trochanter is a large prominence for the attachment of rotator 
 muscles. 
 
 A tuberosity is a broad, uneven eminence. 
 
 A tubercle is a small tuberosity. 
 
 A spine is a sharp-pointed eminence. 
 
 A line, or ridge, is a rough, narrow elevation, extending some 
 distance. 
 
 Others, from their fancied resemblance to ordinary objects, 
 have received the following names : — 
 
 Coronoid, like a crown ; coracoid, like a crow's beak ; unciform, 
 or hamular, hook-like; malleolar, like a mallet; mastoid, nipple-like; 
 zygoma, yoke-like; pterygoid, wing-like; odontoid, tooth-like; spinous, 
 thorn-like; styloid, pen-like; rostrum, a beak; vaginal, enshea thing; 
 squamous, scaly; conoid, cone-like. 
 
 The cavities of bones are divided into the articular and the 
 non-articular. 
 
 The articular are named acetabulum, measure-like ; glenoid, 
 hollow; cotyloid, cup-like; facet, smooth; trochlear, pulley- 
 like; alveolar, socket-like. 
 
 The non-articular cavities are named notches, fissures, 
 grooves, furrows, fossse, hiatus, foramina, canals, sinuses, aque- 
 ducts, cells, depressions, meatuses, etc. 
 
 Composition of Bone. — Adult human bones have a specific 
 gravity of 1.93, and are composed of about one-third (33.30) 
 organic or animal matter, principally gelatin, and two-thirds 
 inorganic or mineral matter, as follows :— 
 
 Gelatin and blood-vessels, 33.30; phosphate, carbonate, and 
 fluoride of calcium, 64.34; soda, sodium chloride, and mag- 
 nesium phosphate, 2.36 : total, 100. 
 
 Structure of Bone. — In structure they consist of an ivory- 
 like compact substance, inclosing a lamellar, reticular cancellous 
 substance. 
 
OSTEOLOGY. 5 
 
 They are covered with periosteum, and their cavities are 
 Itaed with endosteum and filled with medulla, or marrow. 
 
 Periosteum is a flbro-vascular membrane, composed of two 
 layers, the outer formed chiefly of connective tissue, the inner 
 composed of several layers of elastic fibres, the deepest of which 
 is the "osteogenic," or bone-producing layer. The tendons and 
 ligaments are attached to the periosteum by a mutual interlace- 
 ment of the fibres. 
 
 Endosteum^ medullary membrane or internal periosteum, is 
 a delicate, highly vascular membrane lining the cylindrical cavity 
 of long bones. 
 
 Medulla, or bone-marrow, is of two kinds, the red in the 
 flat and irregular bones, and the yellow in the shafts of adult 
 long bones. The red marrow has few blood-vessels, but many 
 corpuscular elements. These may be divided into three groups : 
 1, red nucleated trae "marrow-cells;" 2, large pinkish cells, 
 "myelo-plaques" of Eobin, supposed to be the source of the red 
 blood-corpuscles; and 3, giant cells , or "osteoclasts." 
 
 The yellow marrow contains numerous blood-vessels, a few 
 "marrow-cells," and a large quantity of fat which imparts to 
 it its color. 
 
 Blood-vessels of Bone. — The arteries consist of three sets: 
 The arteries of the (1) compact and (2) cancellous tissue are 
 derived chiefly from the periosteum, the latter being larger and 
 less numerous. The medullary canal of long bones has (3) one 
 or more nutrient arteries, which penetrate the compact tissue 
 obliquely and divide into two branches, one passing upward, the 
 other downward, in the canal. All the arteries anastomose 
 freely with ?ach other. 
 
 The veins consist of three sets also: 1. The veins of the 
 compact substance are small and join the periosteum. 2. The 
 veins of the cancellous tissue do not accompany the arteries, but 
 in certain localities form large, tortuous channels, as in the 
 diploic veins of the cranium. In the long bones they emerge 
 at the ends near the articular surfaces. 3. The nutrient arteries 
 are accompanied by one or more large veins, which emerge at 
 the nutrient foramen. 
 
 Lymphatics and nerves are numerous in the periosteum and 
 are also found in the substance of the bone. 
 
 Microscopical Appearance. — Microscopically, bone-tissue con- 
 sists of concentric layers, or lamellw, arranged about the course 
 of a vascular or Haversian canal ^/leooo i^ch in diameter. In 
 and between these plates of bone-tissue are minute cavities, or 
 lacunce, each containing a bone-cell, or "osteoblast," and from 
 which diverge in every direction minute canals, or canaliculi. 
 
6 HUMAN ANATOMY. 
 
 connecting the lacuntE with each other and with the Haversian 
 canals. Each canaliculus contains an artery, vein, and lym- 
 phatic (SchafEer). In this manner every part of the osseous 
 substance communicates. 
 
 Development. — The development of bone is effected in two 
 ways — (1) from cartilage, the intra-cartilaginous ; and (2) 
 from membrane, the intra-membranous ; the former occurring 
 at the base of the skull for the protection of vital centres, or 
 in the extremities to secure rigidity of the parts. 
 
 In the intra-cartilaginous the parts are first formed in 
 cartilage and then converted into bone. The process is as fol- 
 lows: The cartilage cells at the "centre of ossification" become 
 enlarged and arranged in rows. The cartilaginous matrix also 
 increases and separates the cells. Lime salts are deposited be- 
 tween the rows of cells, inclosing them in oblong spaces called 
 primary areolce. 
 
 Blood-vessels from the deep or osteogenic layer of the 
 periosteum, carrying numerous osteoblasts (bone-forming cells), 
 and osteoclasts (bone-absorbing cells), pass into the area of 
 calcified cartilage (centre of ossification). The osteoblasts re- 
 place the calcified cartilage, which is absorbed, with new bone, 
 which latter is absorbed in part (tunneled) by the osteoclasts to 
 form the medullary spaces or marrow cavity. 
 
 The walls of the spaces are gradually thickened by suc- 
 cessive layers of osteoblasts, forming lamellae of bone, till noth- 
 ing remains but a channel — ^the Haversian canal. 
 
 The perichondrium having been in the meantime converted 
 into periosteum, the osteogenic, or vascular, layer of this mem- 
 brane furnishes a layer of osteoblasts that form enveloping, cir- 
 cumferential layers of bone. 
 
 Thus, from the osteoblasts all the structures of bone are 
 produced; the remains of a group of cells constitute an Haver- 
 sian canal, the layers deposited by them and the adjacent cells, 
 the lamellse, and the isolated, persistent cells (osteoblasts) form 
 the contents of the lacunse, or "true bone-cells," with their nu- 
 trient canaliculi diverging from them. 
 
 In the intra-mcmhranous form the parts are first formed in 
 membrane, and from one or more centres of ossification lime 
 salts are deposited in radiating spiculse, or osteogenic fibres, in- 
 closing the osteoblasts. 
 
 From these fibres the process spreads, and vessels from the 
 neighboring parts pass into it and form Haversian canals. 
 
 The formation of the lamelltE and the lacunee is essentially 
 the same as in the intra-cartilaginous, and in most bones both 
 processes go on simultaneously. 
 
OSTEOLOGY. 7 
 
 Ossification appears first in the clavicle and inferior maxilla 
 (from fifth to seventh week) and last in the pisiform bone 
 (twelfth year) . The epiphyses ossify from birth and unite from 
 the age of puberty on to maturity, in reverse order to the* ap- 
 pearance of ossification, being regulated, apparently, by the direc- 
 tion of the nutrient artery in the upper extremity toward the 
 elbow and in the lower extremity from the knee. The only 
 exception to this rule is the lower end of the fibula, which ossifies 
 and also becomes united before the upper {vide Table of Ossifi- 
 cation) . In bones with only one epiphysis the artery is directed 
 toward the other extremity. 
 
 1, frontal eminence; 2, superciliary ridge; 3, supra-orbltal arch; 
 4, external angular process; 6, internal angular process; 6, supra- 
 orbital notch; 7, nasal eminence; 8. temporal ridge; 9, nasal spine. 
 
 Growth of Bones. — Long bones grow in thickness from the 
 periosteum and in length from the cartilage between the epiph- 
 yses and the shaft near the extremities. The medullary cavity 
 is at first solid and grows by absorption of the cancellous tissue 
 by the giant cells, or osteoblasts. 
 
 Elat bones grow in thickness from the periosteum and in 
 surface from the borders. Short bones grow from the centre 
 or centres of ossification in all directions. 
 
 THE CRANIAL BONES. 
 
 The cranial bones are eight in number : — 
 
 1 Frontal, 
 
 2 Parietal, 
 1 Occipital, 
 
 2 Temporal, 
 1 Sphenoid, 
 1 Ethmoid. 
 
8 
 
 HUMAN ANATOMY. 
 
 The frontal bone forms the anterior portion of the 
 cranium and consists of two portions, a vertical or frontal por- 
 tion and a horizontal or orbito-nasal portion. 
 
 .The vertical portion consists of two surfaces, external and 
 internal. 
 
 The external surface is convex, and presents the frontal emi- 
 nence on either side of the median line, the superciliary ridges, 
 produced by the frontal sinuses, beneath, below which is the 
 supra-orlital arch, forming the upper boundary of the orbit, and 
 terminating on either side in the external angular process, articu- 
 
 ? r^iyiu, 
 
 FlQ. 2. 
 
 2, foramen csecum; 4, articulates with lesser wing; 6, articulates 
 with ethmoid; 7, anterior and posterior ethmoidal foramina; 9, 
 lachrymal fossa; 10, depression for pulley of superior oblique; 11, 
 frontal sinus. 
 
 lating with the malar bone, and the internal angular process, ar- 
 ticulating with the lachrymal bone, and having at its inner third 
 a notch or foramen, the supra-orbital foramen, for passage of 
 supra-orbital artery, nerve, and vein. 
 
 Ascending from the external angular process is the tem- 
 poral ridge for attachment of temporal fascia. Between the 
 internal angular processes is the nasal notch, for articulation 
 with the nasal bone, and nasal process of superior maxilla, 
 terminating below in the nasal spine, and above it projects the 
 nasal eminence, or glabella, marking the location of the frontal 
 sinuses. 
 
 The posterior or internal surface is concave and lodges the 
 anterior lobes of the brain. 
 
OSTEOLOGY. 9 
 
 In the median line is the frontal crest, which gives attach- 
 ment to the falx cerebri and terminates below in a foramen, 
 the foramen csecum, for passage of a small vein from the nose 
 to the longitudinal sinus. The crest is grooved for longitudinal 
 sinus, and has on either side of it depressions for the Pacchionian 
 bodies. This surface is also grooved for anterior meningeal ar- 
 teries. 
 
 The horizontal portion consists of an external and internal 
 surface. 
 
 The external surface is concave, to form the roof of the 
 orbit, and separated from the opposite side by the ethmoidal 
 notch. 
 
 I .,,,,»-^^%s» 
 
 . iiilill:" », ■■■ / 
 
 Fio. 3. 
 
 1, Superior border; 2, Inferior border for squamous portion of tem- 
 poral; 3, anterior border for frontal bone; 4, posterior border for 
 occipital; 5, parietal eminence; 6, parietal foramen; 7, anterior in- 
 terior angle. 
 
 To the outer side is a deep depression for the lachrymal 
 gland, and to the inner side a slight one for the pulley of 
 superior oblique. 
 
 On the margin of the orbital plate are two notches con- 
 verted into foramina by articulation with the ethmoid, the an- 
 terior ethmoidal canal, for passage of nasal nerve and anterior 
 ethmoidal vessels, and the posterior ethmoidal canal, for passage 
 of posterior ethmoidal vessels. 
 
 The internal surface is marked by the convolutions of the 
 anterior lobes of the brain. 
 
 Between the two plates of the vertical portion are the frontal 
 sinuses, two irregular cavities lined with mucous membrane and 
 opening into the middle meatus of the nose on either side by the 
 infundibulum. 
 
 It articulates with twelve bones, two parietal, sphenoid, 
 ethmoid, nasal, superior maxillary, lachrymal, and malar. 
 
10 HtlMAN ANATOMY. 
 
 Its muscular attachments are three pairs, corrugator super- 
 ciliij orbicularis palpebrarum, and temporal. 
 
 It is developed from membrane by two ossific centres, one 
 for each lateral half. 
 
 Paeietals. — These are two quadrilateral bones forming the 
 superior and lateral walls of the cranium. Each bone consists 
 of two surfaces, four borders, and four angles. 
 
 The external surface is convex and presents the parietal emi- 
 nence a little above the middle, marking the original centre of 
 ossification, the temporal ridge, crossing about the centre for at- 
 tachment of the temporal fascia, and the parietal foramen, near 
 the superior border or sagittal suture, for passage of a vein to 
 the longitudinal sinus. 
 
 *^ ma f* I 4. 
 
 'M--.M 
 
 Fig. 4. 
 
 1, 2, 3, 4, superior, Inferior, anterior, and posterior borders; B, su- 
 perior longitudinal sinus; 6, parietal foramen; 7, anterior inferior 
 angle. 
 
 The internal surface is concave, and presents furrows for 
 the branches of the meningeal arteries, depressions for cerebral 
 convolutions, and Pacchionian bodies; 
 
 A half groove along the superior border for longitudinal 
 sinus, and 
 
 A groove near the posterior inferior angle for the lateral 
 sinus. 
 
 The superior border articulates with its fellow of the oppo- 
 site side, forming the sagittal suture; 
 
 The inferior border articulates from before backward with 
 the sphenoid, squamous, and mastoid portions of temporal bones ; 
 
 The anterior border forms with the frontal bone the coronal 
 suture, and 
 
OSTEOLOGY. 11 
 
 The posterior harder forms with the occipital bone the 
 lambdoid suture. 
 
 Of the angles the anterior inferior is the only important one, 
 being longer and grooved internally by the middle meningeal 
 artery. 
 
 It articulates with five bones — frontal, sphenoid, temporal, 
 occipital, and opposite parietal bones. 
 
 It has but one muscle attached — the temporal. 
 
 It is developed from an ossific centre. 
 
 The occipital forms the posterior inferior portion of the 
 cranium. It presents two surfaces, four angles, and four bor- 
 ders. 
 
 4 f: 
 
 * ' TiBlTiifint^, 
 
 X 
 \ 
 
 IB?''' IW \ 
 
 FlQ. 5. 
 
 2, occipital protuberance; 3, crest; i, iDterlor curvefl line; 8, fora- 
 men magnum; 6, condyle; 7, posterior condyloid foramen; 8, an- 
 terior condyloid foramen; 9, jugular process; 11, basilar process; 12, 
 tubercles tor check ligaments. 
 
 The external and posterior surface is irregularly convex, and 
 presents 
 
 The occipital protuberance (also called external to dis- 
 tinguish it), for insertion of ligamentum nuchas, descending 
 from which to the foramen magnum is 
 
 The occipital crest, for tendinous attachment, and diverg- 
 ing on either side, above and below, are 
 
 The superior curved line, for attachment of occipito fron- 
 talis, trapezius, and other muscles; and 
 
 The inferior curved line for attachment of rectus capitis 
 posticus, major and minor. 
 
 Anteriorly it presents a large aperture. 
 
12 
 
 HUMAN ANATOMY. 
 
 The foramen magnum, transmitting the medulla oblongata 
 and its coverings, the vertebral arteries, and the spinal accessory 
 nerves. 
 
 A little in front and on either side of the foramen magnum 
 are the condyles for articulation w^ith the atlas, the inner border 
 of each condj'le presenting a tubercle ior the check ligament. 
 
 Externally to each condyle are the jugular processes, afford- 
 ing attachment for the rectus capitis lateralis, and forming by its 
 articulation with the fibrous portion of the temporal bone the 
 jugular foramen, or foramen lacerum posterius, transmitting the 
 internal jugular vein, glosso-pharyngeal, pneumogastric, and 
 
 <j '■'^ " '<*«' 
 
 £Sr 
 
 Fio. 6. 
 
 1, cerebral fossa; 2, cerebellar fossa; S, superior longitudinal 
 Binus; 4, occipital sinuses; 6, lateral sinus; 6, toroular Heropblll; 
 7, foramen magnum; 8, jugular process; 9, posterior condyloid fora- 
 men; 13, jugular fossa; 14, inferior petrosal sinus. 
 
 spinal accessory nerves, and meningeal branches of the ascending 
 pharyngeal and occipital arteries. 
 
 In front of the condyles on either side are the openings of 
 the anterior condyloid foramen, for passage of hypoglossal nerve 
 and meningeal branch from the ascending pharyngeal artery; 
 and behind, the posterior condyloid foramen, for passage of a 
 small vein to the lateral sinus. 
 
 In front of the foramen magnum is the basilar process, 
 articulating with the sphenoid bone, and grooved on its under 
 surface by the pharyngeal spine for the insertion of the tendinous 
 raphe and superior constrictor of the pharynx. 
 
OSTEOLOGY. 13 
 
 The internal surface is irregularly concave and divided by 
 a crucial ridge, or occipital cross, into four fossse, the upper, for 
 the posterior lobes of the cerebrum, and the lower, for the lateral 
 lobes of the cerebellum. Its centre is marked by an eminence, 
 the internal occipital protuberance, which is hollowed out to 
 correspond to the torcular Herophili, or confluence of the sinuses. 
 
 The upper division of the crucial ridge affords attachment 
 for the falx cerebri, being grooved for the great longitudinal 
 sinus; the lower extremity, called also the internal occipital 
 crest, affords attachment for the falx cerebelli, being grooved 
 for the occipital sinus; and the lateral divisions afford attach- 
 ment for the tentorium cerebelli and are grooved for the lateral 
 sinuses. 
 
 The internal surfaces of the jugular processes are grooved 
 for the lateral sinuses. 
 
 In front of the foramen magnum is the basilar groove, 
 lodging the medulla oblongata and part of the pons Varolii. Its 
 lateral borders (the basilar process) are grooved for the inferior 
 petrosal sinus. 
 
 The superior angle articulates with the parietal bones, the 
 inferior angle articulates with the sphenoid, and the lateral 
 angles are wedged in between the mastoid portion of the tem- 
 poral and the posterior inferior angle of the parietal. 
 
 This bone has four foramina — foramen magnum, anterior 
 and posterior condyloid, and foramen lacerum posterius. 
 
 It articulates with six bones — two parietal, two temporal, 
 the sphenoid, and the atlas. 
 
 The muscular attachments are twelve (13) : occipito-fron- 
 talis, trapezius, sterno-mastoid, complexus, splenius capitis, ob- 
 liquus superior, rectus capitis, posticus major and minor, rectus 
 lateralis, rectus anticus major and minor, and constrictor pharyn- 
 gis superior. 
 
 It is developed from seven (7) ossific centres: four for 
 the tabular, or supra-occipital, or occipital portion proper; one 
 for each condyloid, or external occipital portion, and one for the 
 basilar, or hasi-ocdpital portion. 
 
 Temporals. — These are situated at the side and base of the 
 cranium, and consist of three portions — ^the squamous, mastoid, 
 and petrous. 
 
 The squamous portion is scale-like, and overlaps the parietal 
 bone. Its external surface, convex behind, concave in front, pre- 
 sents from before backward the following : — • 
 
 The zygoma, or zygomatic process, an arched process of 
 bone articulating with the zygomatic process of the malar bone, 
 and affording attachment above to the temporal fascia and below 
 
14 HUMAN ANATOMY. 
 
 to the masseter muscle. It is connected to the body of the bone 
 by three roots, the anterior root of which ends in the eminentia 
 articularis, a process of bone in front of the glenoid cavity, and 
 presents at its junction a tubercle for the external lateral liga- 
 ment ; the middle root terminates at the Glaserian fissure, and 
 the posterior root forms the posterior portion of temporal ridge 
 and gives attachment to the retrahens aurem. 
 
 The glenoid fossa is a marked depression hollowed out for 
 articulation of the condyle of the lower jaw. It is bounded in 
 
 FlO. 7. 
 
 1, temporal fossa; 2, squamous portion; 3, for masseter muscle; 
 4, zygoma: 5. tubercle of zygoma; 6, eminentia articularis; 7, glenoid 
 fossa; 8, Glaserian fissure; 9, petrous portion; 10, meatus audltorlua 
 externus; 11, stylo-hyoideus; 12, stylo-glossus; 13, styloid process; 
 14, mastoid portion; 15, sterno-mastoid ; 16, retrahens aurem; 17, 
 splenlus ca;pitis; 18, trachelo-mastoid; 19, mastoid foramen; 20, 
 auditory process; 21, digastrlcus; 22, mastoid process; 23, vaginal 
 process, 
 
 front by the eminentia articularis, to the outer side by the 
 middle root, and behind by the vaginal process. It is divided 
 into two portions by the Glaserian fissure, the anterior being 
 separated from the auditory process by the post-glenoid tubercle — 
 rudimentary in man — and the posterior being formed by the 
 tympanic plate, a thin plate of bone forming the front wall of 
 the tympanum. 
 
 The Glaserian fissure communicates with the tympanum, 
 transmits the tympanic branch of the internal maxillary artery, 
 and lodges the processus gracilis of the malleus. 
 
OSTEOLOGY. 15 
 
 In the angle between the squamous and petrous portions the 
 chorda tympani nerve passes from the tympanum through the 
 ca'iial of Huguier. 
 
 The internal surface of the squamous portion presents the 
 markings of the convolutions, and grooves for the ramifications 
 of the middle meningeal artery. The mastoid portion is convex, 
 rough, and nipple-like, and presents, externally, the following : — 
 
 The mastoid foramen^ near the posterior border, transmits a 
 branch of the occipital artery to the dura mater and a small vein 
 to the lateral sinus; 
 
 Fig. 8. 
 
 1, .lateral sinus; 2, mastoid foramen; 3, middle meningeal artery; 
 4, zygoma; 5, superior petrosal sinus; 6, petrous portion; 7, meatus 
 auditorius internus; 8, carotid canal; 9, aquseductus cochles; 10, 
 aquBeductus vestibuli; 11, stylo-pharyngeus. 
 
 The mastoid process^ a prominent projection, composed of 
 the mastoid cells, and affording insertion for the splenius capitis, 
 sterno-mastoid, and trachclo-mastoid muscles. 
 
 To its inner side is a groove, the digastric groove, for attach- 
 ment of the digastric muscle, and still more internally the occip- 
 ital groove, for the accommodation of the occipital artery. 
 
 The internal surface is concave, and presents a groove, the 
 fossa sigmoidea, for the lateral sinus, in the bottom of which . 
 is the opening of the mastoid foramen. 
 
 The petrous portion is pyramidal in shape, intensely hard, 
 and contains the internal ear. It projects downward, forward, 
 and inward, and presents for examination a superior, posterior, 
 and inferior surface. 
 
16 HUMAN ANATOMY. 
 
 The superior or anterior surface is united to the squamous 
 portion by the temporal suture and presents the following : — _ 
 
 An eminence, marking the position of the superior semicir- 
 cular canal; 
 
 A depression, forming the roof of the tympanum; 
 
 The hiatus Fallopii, transmitting a branch of the middle 
 meningeal artery and the petrosal branch of the Vidian nerve 
 to the aqueduct of Fallopius; 
 
 Foramen for the smaller petrosal nerve; 
 
 Orifice of the carotid canal, transmitting the carotid plexus 
 of the sympathetic and the internal carotid artery ; and 
 
 Depression for Gasserian ganglion of the trifacial nerve. 
 
 The posterior surface presents about its middle 
 
 The meatus auditorius internus, at the bottom of which is 
 the lamina crihrosa, a perpendicular plate of bone^ and numerous 
 foramina for the exit of the auditory nerve and the auditory 
 branch of the basilar artery^ one of which is the commencement 
 of the aquffiductus Fallopii for the facial nerve. 
 
 Posteriorly to the internal meatus is the aquwductus ves- 
 tibuli, lodging a process of dura mater, and transmitting an 
 artery and vein, and between them another small depression for 
 the same purpose. 
 
 The inferior or iasilar surface presents, from within out- 
 ward, the following: — 
 
 A rough, quadrilateral surface, for attachment of the tensor 
 tympani and levator palati muscles; 
 
 The opening of the carotid canal, transmitting the carotid 
 plexus of the sympathetic and the internal carotid artery; 
 
 Aquceductus cochlecB, transmitting a vein to the. internal 
 jugular vein from the cochlea; 
 
 Jugular fossa, forming the jugular foramen (foramen 
 lacerum posterius) by articulation with the occipital bone, and 
 transmitting the internal jugular vein, the glosso-pharyngeal, 
 pneumogastrie, and spinal accessory nerves, and meningeal 
 branches of the ascending pharyngeal and occipital arteries; 
 
 Foramen for Jacolson's nerve, the tympanic branch of the 
 glosso-pharyngeal ; 
 
 Foramen for entrance of Arnold's nerve, the auricular 
 branch of the pneumogastrie ; 
 
 Jugular surface for articulation with jugular process on oc- 
 cipital bone ; 
 
 The vaginal process, extending from the mastoid process to 
 the carotid canal, and ensheathing 
 
 The styloid process, affording attachment for the stylo- 
 maxillary and stylo-hyoid ligaments and the stylo-hyoideus, stylo- 
 pharyngeus, and stylo-glossus muscles; 
 
OSTEOLOGY. 17 
 
 The stylo-mastoid foramen, for exit of facial nerve ; 
 
 The auricular fissure, for the exit of Arnold's nerve, the 
 auricular branch of the pneumogastric. 
 
 The base of the petrous portion presents 
 
 The external auditory meatus, the canal leading into the 
 tympanum, and 
 
 The auditory process, a lamina of bone formiag the greater 
 part of its walls. 
 
 Borders. — The superior border affords attachment to the 
 tentorium cerebelli, and has a groove for the superior petrosal 
 sinus. The posterior border forms part of the jugular fossa. 
 The anterior border articulates with the spinous process of the 
 sphenoid. Between the squamous and petrous portions are two 
 canals, separated by the processus cochleariformis, for the tensor 
 tympani muscle above and the Eustachian tube below. 
 
 Muscular attachments are fifteen: — 
 
 To 'the squamous portion, 2 — the temporal and masseter; 
 to the mastoid portion, 6 — stemo-mastoid, occipito-frontalis, 
 splenius capitis, trachelo-mastoid, retrahens aurem, and digas- 
 tricus; to the styloid portion, 3 — stylo-hyoideus, stylo-pharyn- 
 geus, and stylo-glossus ; and to the petrous portion, 4 — levator 
 palati, tensor palati, tensor tympani, and stapedius. 
 
 , Its ossific centres are ten (10), 1 for the squamous portion, 
 including the zygoma, 1 for auditory process, 6 for petrous and 
 mastoid portions, and 2 for the styloid process. 
 
 The sphenoid is wedged in between the bones at the base 
 of the skull anteriorly and resembles a bat with extended wings. 
 It consists of 
 
 A body, 2 Lesser wings, and 
 
 2 Greater wings, 2 Pterygoid processes. 
 
 It presents 
 
 12 Foramina, 12 Pairs of muscles, and 
 
 12 Articulations, 14 Centres of ossification, 
 
 and is in every respect the most important bone of the cranium, 
 entering into the formation of 
 
 5 Cavities — 2 Zygomatic, 
 
 1 Anterior cerebral, 3 Spheno-maxillary, 
 
 2 Middle cerebral, 4 Nasal, and 
 
 3 Orbital, S Fissures — 
 
 4 Pharyngeal, 1 Spheno-maxillary, 
 
 5 Nasal, • 2 Pterygoid-maxillary, and 
 
 ^ Fossw — 3 Sphenoidal or foramen la- 
 
 1 Temporal, cerum anterior. 
 
18 HUMAN ANATOMY. 
 
 The body is a hollow cube and presents upper, lover, ante- 
 rior, and posterior surfaces. 
 
 The upper surface of the body presents from before back- 
 ward the following points: — 
 
 Ethmoidal spine, for articulation with the cribriform plate 
 of the ethmoid; 
 
 Optic groove, lodging the optic commissure and terminating 
 in the optic foramen; 
 
 Olivary' process, a small, olive-like eminence behind the 
 optic groove ; 
 
 Pituitary fossa, or sella turcica, for the pituitary body; 
 
 Fig. 9. 
 
 1, olivary process; 2, ethmoid spine; S, optic foramen; 4, lesser 
 wing; 5, anterior clinoid process; 6, posterior clinoid process; 7, 
 carotid groove; 8, Vidian canal; 9, hamular process; 10, pituitary 
 fossa; 11, sphenoidal fissure; 12, foramen rotundum; 13, foramen 
 ovale; 14, foramen spinosum; 15, spinous process; 16, pterygoid 
 process. 
 
 Middle clinoid process, one on either side bounding the 
 pituitary fossa; 
 
 Dorsum sellce, or dorsum ephippii, a quadrilateral plate of 
 bone, bounding the pituitary fossa behind, and notched on either 
 side for the passage of the sixth cranial nerves ; 
 
 Posterior clinoid processes are the terminations of the dor- 
 sum sellse on either side and afford attachment to the tentorium 
 cerebelli ; 
 
 Declivity, or clivu^ Blumenbachii, supporting the upper part 
 of the pons Varolii ; 
 
 Carotid or cavernous groove, lodging the cavernous sinus 
 and the internal carotid artery ; 
 
 Lingula, a ridge of bone to the outer side of the cavernous 
 sinus. 
 
OSTEOLOGY. 
 
 19 
 
 The lower surface presents : — 
 
 Rostrum, the eontiniiation down-ward of the ethmoidal crest, 
 for articulation with the alae of the vomer ; 
 
 Vaginal processes, a thin plate of bone on either side articu- 
 lating with the edges of the vomer ; and 
 
 Groove, converted into the ptery go-palatine canal by articu- 
 lation with the sphenoidal process of the palate bone for trans- 
 mission of the pharyngeal nerve and pterygo-palatine vessels. 
 
 The anterior surface presents : — 
 
 Ethmoidal crest, a thin plate of bone articulating with the 
 ethmoid ; 
 
 Openings of sphenoidal cells or sinuses partially closed by 
 the sphenoidal turbinated bones or pyramids of Wistar, two 
 curved plates of bone absent in infancy but derived as a pair 
 of cones from the ethmoid. The sphenoidal cells open into the 
 
 Fig. 10. 
 
 1, tensor palati; 2, Vidian canal; 3, pterygoideus internus; 4, 
 pterygo-palatine canal; 5, vaginal process; 6, superior constrictor ot 
 pharynx; 7, scaphoid fossa; 8, pterygoid fossa. 
 
 superior meatus of the nose, but occasionally into the posterior 
 ethmoidal sinuses. 
 
 The posterior surface articulates with the basilar process of 
 the occipital and becomes united to it between the eighteenth and 
 twenty-fifth year. 
 
 GEEATER WINGS OF THE SPHENOID. 
 
 The superior surfaces of the great wing, deeply concave, 
 forms part of middle fossa of skull and presents the following : — 
 
 Foramen rotundum, for second division of fifth nerve ; fora- 
 men ovale, for third division of fifth, small meningeal artery, 
 and small petrosal nerve; foramen Vesalii, for small vein, and 
 foramen spinosum, for passage of middle meningeal artery. 
 
 The exterior surface is convex and presents : — 
 
 Pterygoid ridge, dividing the bone into two portions ; 
 
20 HUMAN ANATOMY. 
 
 Spinous process, for attachment of tensor palati muscle, and 
 the internal lateral ligament of the lower jaw. 
 
 The anterior or orbital surface enters into the formation of 
 the orbit and presents numerous external orbital foramina for 
 passage of branches of the deep temporal arteries. 
 
 The circumference of the greater wing forms part of the 
 sphenoidal fissure and articulates with the frontal bone in front 
 and laterally with the parietal, squamous, and petrous portions 
 of the temporal bone. 
 
 The lesser wings, or processes of Ingrassias, project on 
 either side from the superior surface of the body, to which they 
 are attached by two roots. 
 
 The upper surface forms part of the anterior fossa of the 
 slniU. The lower surface forms part of the orbit and the upper 
 border of the sphenoidal fissure, or foramen lacerum anterius, 
 transmitting the third and fourth ophthalmic divisions of the 
 fifth and sixth cranial nerves, orbital branch of the middle 
 meningeal artery, a recurrent branch of the lachrymal artery, the 
 ophthalmic vein, and filaments from the cavernous plexus. 
 
 The anterior clinoid process is formed by the inner extrem- 
 ity of the posterior border. 
 
 Between the two roots is the optic foramen, transmitting 
 the optic nerve and ophthalmic artery. 
 
 The pterygoid processes are two wing-like processes descend- 
 ing from the junction of the greater wings with the body. 
 
 Each process presents the following : — 
 
 An external pterygoid plate, for attachment of the external 
 pterygoid muscle ; 
 
 The pterygoid fossa lies between the two plates and affords 
 attachment for the internal pterygoid muscle; 
 
 The internal pterygoid plate, terminating below in a hook- 
 like process — the hamular process — for the tendon of the tensor 
 palati muscle; 
 
 The scaphoid fossa, at the base of the internal plate, afEord- 
 ing origin for the tensor palati muscle and presenting just above 
 it the posterior opening of the Vidian canal for the Vidian ves- 
 sels and nerves ; 
 
 An angular interval between the two plates articulates with 
 tuberosity or pterygoid process of the palate bone. 
 
 The fokamina are : Opticum, lacerum anterius, rotundum, 
 Vesalii, ovale, spinosum, and two canals — Vidian and pterygo- 
 palatine; articulate with twelve bones — two malar, two palate, 
 vomer, and all of cranium. Its muscular attachments are 
 twelve pairs — external and internal pterygoid, temporal, tensor 
 palati, laxator tympani, superior constrictor, levator palpebrae, 
 
OSTEOLOGY. 21 
 
 obliquus superior ; superior, inferior, internal and external recti. 
 Its ossiFic CENTRES are fourteen, as follow : Body, 2 anterior and 
 2 posterior; external pterygoid plates and greater wings, 2; in- 
 ternal pterygoid plates, 2; lingula, 2; lesser wings, 2; spheno- 
 turbinals, 2. 
 
 The ethmoid is a spongy, cubical bone, consisting of a 
 perpendicular lamella, a horizontal or cribriform plate, and two 
 lateral masses. 
 
 The horizontal or cribriform plate presents from before 
 backward the following points : — 
 
 Two projections completing the foramen ccecum, the com- 
 mencement of the longitudinal sinus ; 
 
 Crista galli, affording attachment to the falx cerebri; 
 
 Foramina crihrosa, three 'rows, transmitting filaments of 
 the olfactory body; 
 
 Fissure for passage of the nasal branch of the ophthalmic 
 nerve. 
 
 The perpendicular plate assists in forming the nasal septum, 
 articulating in front with the crest of the nasal bones and the 
 frontal bone and behind with the sphenoid and vomer. It is 
 usually inclined to one side. 
 
 The lateral masses are composed of the ethmoidal cells. 
 
 The upper surface presents two notches, converted into fo- 
 ramina by articulation with the frontal bone — 
 
 The anterior ethmoidal foramen, transmitting the anterior 
 ethmoidal artery and nasal nerve, and 
 
 The posterior ethmoidal foramen, transmitting the posterior 
 ethmoidal artery and vein. 
 
 The outer surface presents 
 
 The OS planum, a smooth plate of bone forming the inner 
 wall of the orbit, and projecting downward from it is 
 
 The unciform process, a hook-like plate of bone closing the 
 upper part of the opening of the antrum. 
 
 The inner surface forms part of the nasal fossa, and presents 
 
 The superior turbinated bone, forming the upper boundary 
 of the superior meatus, into which open the sphenoidal and pos- 
 terior ethmoidal cells, and the 
 
 Middle turbinated bone, forming the upper boundary of the 
 middle meatus of the nose, into which open the anterior eth- 
 moidal cells, the frontal cells through the infundibulum, and the 
 antrum Highmorianum. 
 
 It articulates with fifteen bones — two sphenoidal turbinated, 
 sphenoid, frontal, and eleven of the face, the two nasal, two 
 lachrymal, two superior maxillse, two palate, two inferior turbi- 
 nated, and the vomer. 
 
22 HUMAN ANATOMY. 
 
 It has no muscular attachments. 
 
 Its ossific centres are three — one for the lamella and one for 
 each lateral mass. 
 
 BONES OF THE FACE. 
 
 The bones of the face are fourteen in number — six pairs and 
 two single bones: Two lachrymal, two nasal, two malar, two 
 superior maxillary, two palate, two turbinal, one vomer, and one 
 inferior maxillary. 
 
 The lachrymal are two small, thin bones forming part 
 of the inner wall of the orbit and the lachrymo-nasal duct, and 
 named, from their resemblance to a finger-nail, the ossa unguis. 
 
 Bach presents externally : — 
 
 The lachrymal crest affords attachment for the tensor tarsi 
 and separates the anterior surface from the groove; 
 
 The groove forms part of the lachrymal groove and lodges 
 the lachrymal sac; 
 
 The hamular process, or, when separate, called the lesser 
 lachrymal hone, projects downward and articulates with the 
 lachrjrmal tubercle of the superior maxilla. 
 
 Internally : — 
 
 A furrow, corresponding to the lachrymal crest on the ex- 
 ternal surface; 
 
 The internal surface enters into the formation of the middle 
 meatus, closing in the anterior ethmoidal cells. 
 
 It articulates with four bones — the frontal, ethmoid, supe- 
 rior maxilla, and inferior turbinated. 
 
 The only muscular attachment is the tensor tarsi. 
 
 It is developed from one ossific centre. 
 
 The nasal bones are two irregularly quadrate bones form- 
 ing together the bridge of the nose. 
 
 The outer surface, covered by the compressor nasi and pyr- 
 amidalis nasi muscles, presents 
 
 A foramen, transmitting a small vein. 
 
 The inner surface presents 
 
 A groove or canal for a branch of the nasal nerve. 
 
 The inferior border, the most important, has attached to it 
 the lateral cartilage of the nose, and presents 
 
 A spine, forming, with its fellow, the nasal angle, a notch 
 for exit of the branch of the nasal nerve which grooves the pos- 
 terior surface. 
 
 It articulates with four bones — frontal, ethmoid, superior 
 maxilla, and its fellow. 
 
 It has no muscular attachments. It is developed from one 
 centre. 
 
OSTEOLOGY. 23 
 
 The malar bones are two quadrilateral bones forming the 
 prominence of the cheek. They enter into the formation of the 
 orbit and the zygomatic and temporal fossae. 
 
 Each bone has four processes — zygomatic, maxillai^, fron- 
 tal, and orbital. 
 
 The external surface has attached to it the zygomatic mus- 
 cles (major and minor), and presents 
 
 A foramen to its outer side for the malar branch of the 
 temporo-malar nerve and a foramen to its inner side for the 
 temporal branch of the temporo-malar. 
 
 The internal surface articulates with the superior maxilla, 
 has attached to it the masseter and temporal muscles, and pre- 
 sents the internal openings of the foramen given above. 
 
 1, malar process; 2, nasal process; 3, orbital process; 4. Infra- 
 orbital foramen; 6, Infraorbital groove; 6, lachrymal tubercle; i, 
 incisor teeth; c, canine; b, bicuspid; m, molars. 
 
 The zygomatic process forms, with ttie zygomatic process 
 of the temporal bone, the zygoma. 
 
 The maxillary process is triangular and roughened for ar- 
 ticulation with the superior maxilla. 
 
 The frontal process is articulated with the external angular 
 process of the temporal bone. 
 
 The orbital process, the most important, articulates by its 
 upper surface with the greater wing of the sphenoid, forming 
 part of the outer wall of the orbit; the under surface forms 
 part of the temporal fossa, while the posterior margin forms part 
 of the spheno-maxillary fissure. The superior surface presents 
 two temporo-malar canals, transmitting temporo-malar branches 
 of the superior maxillary nerve. 
 
24 HUMAN ANATOMY. 
 
 It articulates with four bones— the frontal, sphenoid, tem- 
 poral, and superior maxilla. 
 
 Its muscular attachments are five— the masseter, temporal, 
 zygomaticus major and minor, and the levator labii superions. 
 
 It is developed from one ossific centre. 
 
 The sdperioe maxilla is the largest bone of the face, 
 excepting the lower jaw, and one of the most important, assisting 
 in the formation of three cavities, the mouth, nose, and orbit; 
 two fissures, the spheno-maxillary and pterygo-maxillary ; and 
 two fossae, the spheno-maxillary and zygomatic. It consists of a 
 body and four processes — the nasal, the malar, the palatine, and 
 the alveolar (Pig. 11) . 
 
 Fig. 12. 
 
 1, antrum; 2, nasal process; 3, superior turbinated bone; 4, 
 middle meatus; 5, inferior crest; 6, inferior meatus; 11, posterior 
 palatine canal; 15. anterior nasal spine; 16, anterior palatine canal; 
 18, palate process. 
 
 The body is excavated to form the maxillary sintis or antrum 
 Highmorianum, a large, irregular triangular cavity, with its 
 base directed inward, its apex upward and outward, projecting 
 into the malar process. 
 
 Its posterior wall presents the posterior dental canals, trans- 
 mitting the posterior dental vessels and nerves. 
 
 The external or facial surface (Fig. 11) of the body presents 
 the following points : — 
 
 Incisive fossa, or myrtiform fossa, for the origin of the 
 depressor alaa nasi : 
 
 Canine fossa, for origin of levator anguli oris; 
 
 Canine eminence, over the position of the canine tooth ; 
 
 Infraorbital foramen, for the exit of the infraorbital nerve 
 and artery. 
 
OSTEOLOGy. 25 
 
 The internal surface of the body presents: — 
 
 Palate process^ separating the mouth from the nasal fossa; 
 
 Orifice of antrum Higlimorianum, before alluded to; 
 
 Groove completing the posterior palatine canals behind; 
 
 Deep groove in front, forming, with the inferior turbinated 
 bone and lachrymal, the lachrymal canal for lachrymo-nasal duct; 
 
 Inferior turbinated crest for the turbinated bone. 
 
 The superior orbital surface presents: — 
 
 Infraorbital groove about the middle for the infraorbital 
 artery and nerve; 
 
 Anterior dental canal, one of the divisions of the infra- 
 orbital canal, transmitting the anterior dental vessels and nerve. 
 
 The posterior or zygomatic surface presents : — 
 
 Posterior dental canals, transmitting posterior dental nerves 
 and vessels; 
 
 Maxillary tuberosity, articulating with the tuberosity of the 
 palate bone; 
 
 Groove, converted into posterior palatine canal by the palate 
 bone for posterior palatine vessels and nerves. 
 
 The nasal process projects upward to articulate with the 
 frontal bone, its external surface smooth, affording attachment 
 to several muscles, its internal surface forming part of the outer 
 wall of the nose. It presents the following : — 
 
 Superior turbinated crest, for the middle turbinated bone 
 of the ethmoid; 
 
 Inferior turbinated crest below, for the inferior turbinated 
 bone; 
 
 Groove at the posterior margin, forming part of the lachry- 
 mal canal; 
 
 Lachrymal tubercle, at the junction of the nasal process with 
 the orbital surface. 
 
 The malar process projects upward and outward to articu- 
 late with the malar bone. 
 
 The palatine process projects from the internal surface of 
 the bone to form part of the roof of the mouth and the floor of 
 the nose. It presents: — 
 
 Anterior palatine canal or fossa, divided into four canals; 
 
 Foramina of Stenson, one on either side, transmit the an- 
 terior branch of the descending palatine artery; 
 
 Foramina of Scarpa, one in front and behind, transmit the 
 naso-palatine nerves; 
 
 Suture in the anterior part showing original separation of 
 the incisive or intermaxillary bone; 
 
 Posterior palatine groove for the posterior palatine vessels, 
 and anterior palatine nerves from Meckel's ganglion; 
 
26 HUMAN ANATOMY. 
 
 Nasal crest for the vomer, and 
 
 Anterior nasal spine projecting from the anterior extremity 
 of the crest. 
 
 The alveolar process forms the curved, spongy portion for 
 the insertion of the upper teeth. It presents 
 
 The alveoli or sockets of varying depths, eight in the adult, 
 five in the child. 
 
 It articulates with nine (9) bones — the' ethmoid, frontal, 
 lachrymal, nasal, malar, inferior turbinated, palate, vomer, and 
 its fellow of the opposite side. 
 
 Its muscular attachments are nine — the levator labii supe- 
 rioris alseque nasi, levator labii superioris proprius, levator anguli 
 oris, compressor naris, depressor alffi nasi, orbicularis palpe- 
 brarum, inferior obliquus, masseter, and buccinator. 
 
 FlQ. 13. 
 
 1, torizontal plate; 2, vertical plate; 3, tuberosity; 4, crest; B, 
 post-nasal spine; 6, inferior turbinated crest; 7, spheno-palatine fora- 
 men; 8. zygomatic surface; 9. sphenoidal surface. 
 
 It is developed from four centres : one for incisive bone, or 
 pre-maxilla; one for palate process, or pre-palatine ; one for 
 the maxillary portion, including the orbital and facial portion; 
 and one for the malar portion. 
 
 Each palate-bone is a thin, L-shaped bone, consisting of 
 an inferior or horizontal plate and a superior or vertical plate. 
 
 Each bone assists in forming three cavities — the outer wall 
 and floor of the nose, the roof of the mouth, and floor of the 
 orbit ; two fossse — the pterygoid and spheno-maxillary ; and one 
 fissure — ^the spheno-maxillary. 
 
 The horizontal plate is quadrilateral. Its inferior surface 
 presents 
 
 A ridge for the aponeurosis of the tensor palati muscle ; 
 
 A groove entering into the formation of the posterior pala- 
 tine canal; 
 
 Accessory palatine foramina for posterior descending pala- 
 tine nerves. 
 
OSTEOLOGY. 27 
 
 Its posterior border presents 
 
 The posterior nasal spine for the azygos UTulse muscles. 
 
 The internal border articulates with its fellow and presents 
 
 A crest for the vomer. 
 
 The vertical plate projects upward and inward, terminating 
 above in two well-marked processes — the orbital and sphenoidal 
 processes. 
 
 The internal surface forms part of the outer wall of the 
 nasal fossa, and presents 
 
 An inferior turbinated crest for the inferior turbinated 
 bone; 
 
 A superior turbinated crest for the middle turbinated bone, 
 separating the middle from the inferior meatus of the nose. 
 
 The external surface forms part of the spheno-maxillary 
 fossa and covers part of the orifice of the antrum. 
 
 It presents at the posterior part 
 
 A groove, converted by the superior maxilla into a canal, 
 the posterior palatine, for the passage of the descending palatine 
 vessels and the descending palatine branches from Meckel's gan- 
 glion. 
 
 The anterior border presents 
 
 The maxillary process, closing part of the orifice of the 
 antrum. 
 
 The pterygoid process, or tuberosity of the palate, at its 
 lower part wedged in between the pterygoid plates of the sphe- 
 noid, and giving origin to part of the superior constrictor and 
 the internal pterygoid muscles. 
 
 Foramina of accessory descending palatine canals, for pos- 
 terior descending branches from Meckel's ganglion. 
 
 The ORBITAL PROCESS, a large, hollow, triangular process, is 
 so called from its forming part of the orbit. 
 
 It presents 
 
 The anterior or maxillary articular surface for superior 
 maxilla ; 
 
 The posterior or sphenoidal articular surface for sphenoid; 
 
 The internal or ethmoidal articular surface for ethmoid ; 
 
 A superior or orbital surface, a smooth portion entering into 
 the formation of the orbit ; 
 
 An external or zygomatic surface, also smooth, forming part 
 of the zygomatic fossa. 
 
 The sphenoidal process is a small, thin plate of bone 
 which articulates by its upper surface with the sphenoidal tur- 
 binated bone; its inner surface forms part of the nasal fossa, 
 and its outer surface articulates with the pterygoid process of 
 the sphenoid and forms part of the spheno-maxillary fossa. 
 
28 HUMAN ANATOMY. 
 
 The anterior border forms part of the spheno-palatine fora- 
 men, which passes between the orbital process and the sphenoidal 
 process. 
 
 It articulates with six (6) bones — ethmoid, sphenoid, supe- 
 rior maxillary, vomer, inferior turbinated, and fellow of the 
 opposite side. 
 
 Its muscular attachments are azygos uvulse, tensor palati, 
 internal and external pterygoid, and superior constrictor. It 
 has one ossific centre at the Junction of the plates. 
 
 The infekioe turbinated bones are small, scroll-like 
 bones, situated on the outer wall of the nasal fossa, separat- 
 ing the middle from the inferior meatus. Each presents two 
 surfaces and three processes, the lachrymal, ethmoidal, and 
 maxillary. 
 
 The internal surface is lined in the recent state with the 
 mucous membrane of the nose. 
 
 The external surface is attached to the superior maxilla and 
 palate-bone, and presents above the three processes. 
 
 The lachrymal process forms part of the lachrymal canal, 
 articulating with the superior maxilla and the lachrymal bone. 
 
 The ethmoidal process articulates with the hook-like process 
 of the ethmoid bone. 
 
 The maxillary process projects outward and downward from 
 the ethmoidal process, and narrows the orifice of the antrum. 
 
 It articulates with four bones — ethmoid, palate, superior 
 maxillary, and lachrymal. 
 
 Muscular attachments, none. It has one ossific centre. 
 
 The vomer is a thin, triangular plate of bone, contributing 
 to form part of the sseptum nasi. It is usually bent to one side. 
 
 The superior border presents a groove with overlapping 
 larninae, or vaginal processes, for articulation with the rostrum 
 and vaginal processes of the sphenoid. 
 
 The inferior border articulates with the crests of the supe- 
 rior maxilliE and palate-bones. 
 
 The posterior border is smooth and free, forming the pos- 
 terior nasal septum. 
 
 The lateral surfaces present 
 
 Furrows for blood-vessels, and 
 
 Naso-palatine grooves for the naso-palatine nerves, which 
 descend to the foramina of Scarpa. 
 
 It articulates with six bones — the ethmoid, sphenoid, two 
 palate, and two superior maxillse. 
 
 It has no muscular attachments. It is developed from a 
 single ossific centre, although it begins as two cartilaginous 
 laminae, which coalesce. 
 
OSTEOLOGY. 
 
 29 
 
 The inferior maxilla is the largest bone in the face. It 
 consists of a body and two rami. 
 
 The body is the horizontal, horseshoe-like portion, contain- 
 ing the lower teeth. 
 
 The external surface presents from before backward : — 
 
 Symphysis, a vertical median line indicating the junction of 
 the vaginal halves ; 
 
 Mental process, a triangular prominence constituting the 
 chin; 
 
 Incisive fossa, for the origin of the levator labii inferioris; 
 
 Mental foramen, for the exit of the mental nerve and artery; 
 
 Fig. 14. 
 
 1, body; 2, ramus; 3, symphysis; 5, mental foramen; 6, external 
 oblique line; 7, facial groove; 8, angle; 9, internal oblique line; 10, 
 coronoid process; 11, condyle; 12, sigmoid notch; 13, inferior dental 
 foramen; mylo-hyoid groove; 1, Incisors; c, canine; b, bicuspids; 
 m, molars. 
 
 External ohlique line, running backward and upward from 
 the mental process, for the attachment of the depressor anguli 
 oris and depressor labii inferioris. 
 
 The internal surface presents from before backward : — 
 
 Genial tubercles, four in number, for attachment of the 
 genio-hyoglossi muscles above and the genio-hyoidei below ; 
 
 Sublingual fossa, for the sublingual gland; 
 
 Internal oblique line (mylo-hyoidean), for the attachment 
 of the superior constrictor, the mylo-hyoid muscles, and the 
 ptery go-maxillary ligament ; 
 
 Submaxillary fossa, for the submaxillary gland. 
 
 The superior or alveolar border presents sixteen cavities (ten 
 in childhood) for the teeth. 
 
 The inferior border is grooved posteriorly for the facial 
 artery. 
 
30 HUMAN ANATOMY. 
 
 The ramus or horizontal portion on either side is somewhat 
 quadrilateral, and presents the following points: — 
 
 The internal surface of ramus; 
 
 Foramen of inferior dental canal, for inferior dental vessels 
 and nerve; 
 
 Mylo-hyoidean groove, described above; 
 
 Spine, for attachment of the internal lateral ligament of 
 the lower jaw. 
 
 The upper border is surmounted by two processes, the coro- 
 noid and the condyloid processes, separated by the sigmoid notch. 
 
 The coronoid process is in front, and afEords attachment for 
 the temporal muscle. 
 
 The condyloid process articulates with the glenoid fossa of 
 the temporal bone, being supported upon a constricted portion, 
 the neck, which receives the insertion of the external pterygoid 
 muscle, and presents to its outer side a tubercle for the external 
 lateral ligament of the lower jaw. 
 
 The sigmoid notch is crossed by the masseteric vessels and 
 nerve. 
 
 The lower border presents : — 
 
 Angle of the jaw, the point of junction of the ramus with 
 the body; 
 
 Rough surface, for attachment of the stylo-maxillary liga- 
 ment, and on its inner side the internal pterygoid muscle, and 
 on its outer side the masseter. 
 
 It articulates with the two temporal bones. 
 
 The muscular attachments are fifteen pairs; to the external 
 surface, six — depressor anguli oris, depressor labii inferioris, 
 levator labii inferioris, orbicularis oris, platysma myoides, and 
 buccinator; from the internal surface of the body, five — the 
 genio-hyoglossus, genio-hyoid, mylo-hyoid, digastric, and supe- 
 rior constrictor; and to the ramus, four — the masseter, internal 
 and external pterygoids, and temporal. 
 
 It has two ossific centres, one for each lateral half, devel- 
 oped partly from membrane, partly from cartilage, being pre- 
 ceded in time only by one bone — ^the clavicle. 
 
 Changes in Lower Jaw.— Certain changes occur in the size 
 and shape of the lower jaw as age advances. 
 
 At birth the body is shell-like, containing sockets for the 
 ten temporary teeth, the mental foramen is large and opens 
 beneath first molar, and the coronoid process is large and at right 
 angles to base. 
 
 In adults the base and alveolar process are equal in size, 
 the mental foramen opens midway between upper and lower 
 borders, and the rami are at nearly right angles to base. 
 
OSTEOLOGY. 31 
 
 In advanced age the loss of the teeth and alveolar borders 
 greatly reduces the body, the mental foramen opens near the 
 alveolar border, and the rami are united at very obtuse angles 
 with the base. 
 
 The htoid bone, or lingual bone, is a small U-shaped bone 
 situated at the base of the tongue, consisting of a body, two 
 greater and two lesser cornua. 
 
 It is supported by the stylo-hyoid ligament from the styloid 
 processes of the temporal bones. 
 
 The anterior surface is divided by a crucial ridge into four 
 depressions for muscular attachments, and its centre presents a 
 tubercle. 
 
 The posterior surface is in relation with the epiglottis, being 
 separated by the thyro-hyoid membrane. 
 
 The upper and lower borders afEord attachment to muscles, 
 and the lateral surfaces are mounted with cartilage for articula- 
 tion with the greater cornua. 
 
 The greater cornua, or thyro-hyals, project backward, afford 
 attachment to the hyoglossus, thyro-hyoid, and middle constrictor 
 of the pharynx, and terminate behind in a tubercle for the at- 
 tachment of the thyro-hyoid ligament. 
 
 The lesser cornua, or cerato-hyals, are two tuber-like pro- 
 jections attached at the junction of the body with the greater 
 cornua, and receiving the insertion of the stylo-hyoid ligaments. 
 They do not articulate with any bone. 
 
 Its muscular attachments are ten — the lingualis, hyoglossus, 
 genio-hyoglossus, middle constrictor, stylo-, mylo-, genio-, sterno-, 
 thyro-, omo- hyoid ; also aponeurosis of digastric and stylo-hyoid 
 ligament. 
 
 Ossific centres, five — one for body and one for each horn. 
 
 The Sutures and Pontanelles. — The sutures are divided 
 into three sets, those of the vertex, side, and base of the skull. 
 
 At the vertex of the skull there are three : — 
 
 Sagittal, or inter-parietal; 
 Coronal, or fronto-parietal; 
 Lambdoid, or occipito-parietal. 
 
 At the side of the skull are three : — 
 
 Spheno-parietal ; 
 Squamo-parietal, or squamous; 
 Masto-parietal. 
 
 At the base of the skull are nine : — 
 
 Basilar, in centre, 
 
 Petro-ocoipital, "\ 
 
 Masto-occipital, I „„ „,!,„_ .,. 
 
 Petro-sphenoidal, f °" ^'^^^e' »'^«- 
 
 Squamo-sphenoidal, J 
 
32 HUMAN ANATOMY. 
 
 The sutures of the face are very numerous, but the most 
 important are : — 
 
 Zygomatic, at the temporo-malar junction; 
 
 Transverse, passes from one external angular process to the other, 
 and connects the frontal with the malar ethmoid, sphenoid, lachrymal, 
 superior maxillary, and nasal bones; 
 
 Intermaxillary, the median suture between the superior maxillse; 
 
 Symphysis, the remains of a fcetal suture. 
 
 The fontanelles are six membranous intervals in the infant's 
 skull corresponding to the four angles of the parietal bones. 
 The anterior, larger and lozenge-shaped, is at the junction of 
 sagittal and coronal sutures ; the posterior, smaller and triangu- 
 lar, is at the junction of sagittal and lambdoid sutures ; and the 
 four lateral are at anterior and posterior inferior angles of 
 parietal bones. 
 
 The Wormian, or supernumerary, are irregular bones inter- 
 posed in intervals between the cranial bones, chiefly in the course 
 of the lambdoid suture. From their triangular form they are 
 called "ossa triqueta." 
 
 Congenital fissures from an arrest of ossification also occur, 
 the most common being the parietal and sagittal fissures 
 (Treves). 
 
 FOSS.ffl OF SKULL. 
 
 The fosssB at the lateral regior of the skull are temporal, 
 zygomatic, and spheno-maxillary. 
 
 Temporal Fossa. — Deeply concave in front, convex behind, 
 it is formed by parts of five bones — frontal, malar, sphenoid, 
 temporal, and parietal. It is bounded above and behind by 
 temporal ridge; in front by the sphenoid, malar, and frontal; 
 below and externally by zygoma and pterygoid ridge on greater 
 wing of sphenoid. It is crossed by six sutures — spheno-malar, 
 spheno-parietal, squamo-parietal, squamo-sphenoidal, coronal, 
 and transverse facial. It opens below into the zygomatic fossa, 
 is filled by the temporal muscle, and lodges the deep temporal 
 vessels. 
 
 Zygomatic Fossa. — This irregular cavity contains parts of 
 temporal, external and internal pterygoid muscles, and is bounded ' 
 above by pterygoid ridge of sphenoid and squamous portion of 
 temporal, below by alveolar border of superior maxilla, in front 
 by tuberosity of superior maxillary, behind by border of pterygoid 
 process, externally by zygoma and ramus of lower jaw, and in- 
 ternally by external pterygoid plate. It is traversed by two fis- 
 sures — spheno-maxillary and pterygo-maxillary. 
 
OSTEOLOGY. 
 
 33 
 
 The spJieno-maxillary fissure connects the zygomatic, tem- 
 poral, and spheno-maxillary fossae, and transmits the infraorbital 
 artery, ascending branches of Meckel's ganglion, the superior 
 maxillary nerve, and its orbital branch. 
 
 It is bounded above by great wing of sphenoid, below by 
 superior maxilla and part of palate bone ; internally it opens into 
 pterygo-maxillary fissure, and externally part of malar bone. 
 
 Fig. 15. 
 
 1, median suture; 2, anterior palatine foramen; 3, posterior pala- 
 tine foramen; 4, posterior nasal spine; 5, vomer; 6, hamular process; 
 7, pterygo-palatine canal; 8, external plate; 9, scaphoid fossa; 10, 
 foramen ovale; 11, foramen spinosum; 12, foramen lacerum medium; 
 13, zygoma; 14, basilar suture; 15, glenoid fossa; 16, external audi- 
 tory meatus; 17, mastoid process; 18, styloid process; 19, carotid 
 foramen; 20, foramen lacerum posterius; 21, occipital condyles; 22, 
 basilar process; 23, foramen magnum; 24, occipital crest; 25, inferior 
 curved lilies. 
 
 The ptery go-maxillary fissure connects the zygomatic and 
 spheno-maxillary fossae, passing vertically between pterygoid 
 process of sphenoid and superior maxillary bone, and transmits 
 branches of internal maxillary artery. 
 
34 
 
 HUMAN ANATOMY. 
 
 The spheno-maxillary fossa is a triangular cavity, bounded 
 above by body of sphenoid and orbital plate of palate-bone, within 
 by vertical plate of palate, in front by superior maxillary, and 
 behind by pterygoid process of sphenoid. It has communicating 
 with it 
 
 Three fossas — orbital, nasal, and zygomatic; 
 
 Three fissures — sphenoidal, spheno-maxillary, and pterygo- 
 maxillary ; 
 
 Two cavities — cranial and buccal; and 
 
 Five foramina — foramen rotundum. Vidian, and pterygo- 
 palatine posteriorly; spheno-palatine, on inner wall, and pos- 
 terior palatine canal, and (sometimes) accessory posterior pala- 
 
 FiQ. 16. 
 
 2, nasal eminence; 3, supraorbital ridge; 4, lachrymal bone; 5, 
 ethmoid bone; 6, infraorbital groove: 7, lachrymal groove: 9, infra- 
 orbital foramen; 10, malar foramina. 
 
 tine canals below. It contains internal maxillary artery, superior 
 maxillary nerve, and Meckel's ganglion. 
 
 The orbits are two pyramidal cavities, situated between 
 the nose and external angular processes, the forehead and face, 
 their bases outward and forward, their apexes converging toward 
 the body of the sphenoid bone. They contain the eye and its 
 appendages, and are each formed by seven bones — frontal, eth- 
 moid, sphenoid (entering into both cavities), and superior maxil- 
 lary, lachrymal, malar, and palate (separate in each). The 
 roof, concave, presents: — 
 
 Externally, depression for lachrymal gland ; 
 
 Internally, depression for pulley of superior oblique, and 
 
OSTEOLOGY. 35 
 
 Posteriorly, a suture between lesser wing and frontal bone. 
 
 It is formed by the orbital plate of frontal and lesser wing of 
 sphenoid. 
 
 The floor is short and flat, and presents: — 
 
 Internally, a depression for inferior oblique muscle; 
 
 Middle, the infraorbital groove for nerve and artery; 
 
 Externally, suture of superior maxillary and malar, and 
 
 Posteriorly, suture between palate and superior maxillary. 
 
 It is formed by orbital processes of malar and superior 
 maxilla and orbital surface of palate. 
 
 Inner wall presents crest of lachrymal bone, lachrymal 
 groove, and sutures between ethmoid and sphenoid, and ethmoid 
 and lachrymal. 
 
 It is formed by lachrymal, parts of ethmoid, and sphenoid 
 and nasal process of superior maxilla. 
 
 The outer wall presents suture between malar and sphenoid 
 and orifices of malar canals. It is formed by orbital plate of 
 sphenoid and orbital process of malar. 
 
 The angles of the orbit are four, — superior internal and 
 external, inferior internal and external. 
 
 They present the following : — 
 
 Superior internal angle; 
 
 Poramen ethmoidal anterior, transmitting anterior eth- 
 moidal vessels and nasal nerve; 
 
 Poramen ethmoidal posterior, transmitting posterior eth- 
 moidal artery and vein; 
 
 Suture between frontal and ethmoid, and frontal and lach- 
 rymal ; 
 
 Superior external angle; 
 
 Sphenoidal fissure, or foramen lacerum anterius, transmit- 
 ting third, fourth, ophthalmic division of fifth and sixth nerves ; 
 orbital branch of middle meningeal artery, filaments of cavernous 
 plexus of sympathetic, recurrent branch of lachrymal artery, and 
 ophthalmic vein and process of dura mater. 
 
 Suture between great wing of sphenoid and malar bone. 
 
 Inferior internal angle; 
 
 Suture between superior maxillary and palate bones, uniting 
 with lachrymal and os planum of ethmoid; 
 
 Inferior external angle; 
 
 Spheno-maxillary fissure, for passage of superior maxillary 
 nerve and its orbital branch, infraorbital vessels, and ascending 
 branches from Meckel's ganglion. 
 
 The ciKCUMFERENCE is bounded : — 
 
 Inner side by nasal process of superior maxilla and internal 
 angular process of frontal; 
 
36 HUMAN ANATOMY. 
 
 Outer side by external angular process of frontal and malar 
 bone; 
 
 Above by supraorbital arch; 
 
 Below by lachrymal, superior maxilla, and malar, 
 
 Tt presents sutures malo-maxillary below; 
 
 Sutures fronto-malar to outer side; 
 
 Sutures fronto-maxillary to inner side; 
 
 Supraorbital notch or foramen above, for passage of supra- 
 orbital nerve, artery, and vein, and forms part of lachrymal 
 groove. 
 
 The apex presents : — 
 
 Optic foramen, for passage of optic nerve and ophthalmic 
 artery. 
 
 Each orbit presents nine (9) openings, as follows : — 
 
 1. Supraorbital foramen for passage of supraorbital artery, 
 vein, and nerve; 
 
 3. Infraorbital canal for infraorbital nerve and artery ; 
 
 3. Anterior ethmoidal foramen for anterior ethmoidal ar- 
 tery, vein, and the nasal nerve; 
 
 4. Posterior ethmoidal foramen for posterior ethmoidal ar- 
 tery and vein; 
 
 5. Malar foramina, for malar and temporal branches of 
 temporo-malar nerve; 
 
 6. Lachrymal canal, for lachrymo-nasal duct ; 
 
 7. Spheno-maxilldry fissure, for infraorbital vessels, supe- 
 rior maxillary nerve and its orbital branches, and ascending 
 branches from spheno-palatine (Meckel's) ganglion; 
 
 8. Foramen lacerum anteriu^ (or sphenoidal fissure), for 
 third, fourth, ophthalmic division of fifth and sixth nerves, oph- 
 thalmic vein, branches of lachrymal and meningeal arteries, fila- 
 ments of the sympathetic nerve, and a process of dura mater for 
 enpheathing of the nerve; 
 
 9. Optic foramen, for optic nerve and ophthalmic artery. 
 The nasal foss^ consist of two large cavities separated 
 
 from each other by the sceptum nasi, and opening in front by 
 the anterior nares, and behind into the pharynx by the posterior 
 nares. 
 
 They are formed by fourteen bones — ^the frontal, ethmoid, 
 sphenoid, and all the bones of the face except the lower jaw 
 and malar. 
 
 They have each four sinuses opening into them — ^the eth- 
 moidal and antrum of Highmore (maxillary) on either side, the 
 sphenoidal behind and the frontal above, and communicate with 
 the mouth by the anterior palatine canal, with the orbit by the 
 
OSTEOLOGY. 37 
 
 lachrymal canal, with the spheno-maxillary fossae by the spheno- 
 palatine foramen, and with the cranium by the olfactory fo- 
 ramina. 
 
 They are each bounded by an outer, inner, upper, and lower 
 wall. 
 
 The outer wall is divided by the middle turbinated process of 
 the ethmoid and the inferior turbinated bone into the superior, 
 middle, and inferior meatmes of the nose. 
 
 The superior meatus, the smallest, has three orifices opening 
 into it — 
 
 The posterior ethmoidal cells ; 
 
 The sphenoidal sinuses, opening behind the superior tur- 
 binated bone, and 
 
 The spheno-palatine foramen, for transmission of spheno-- 
 palatine vessels and superior nasal and naso-palatine nerves. 
 
 The middle meatus has two orifices — 
 
 The infundihulum, communicating with the frontal sinuses, 
 and through them with the anterior ethmoidal cells, and the' 
 orifice of the antrum or maxillary sinus. 
 
 The inferior meatus, the smallest, has two orifices — 
 
 The lachrymal canal, for lachrymo-nasal duct, and the an- 
 terior palatine canals, for anterior branches of descending pala- 
 tine arteries (foramina of Stenson) and naso-palatine nerves 
 (foramina of Scarpa). 
 
 The inner wall, or sseptum nasi, is formed, by the vomer, 
 vertical plate of the ethmoid, and the triangular cartilage of the 
 nose, with portions of the following bones: nasal spine of the 
 frontal, rostrum of the sphenoid, and the crests of the nasal, 
 palate, and superior maxillary bones. It is grooved by the naso- 
 palatine and other nerves. 
 
 The upper wall or roof presents the following from before 
 backward : — 
 
 The nasal slit in the cribriform plate, for passage of nasal 
 nerve, a branch of ophthalmic; 
 
 The olfactory foramina, for olfactory filaments, and 
 
 Openings or orifices posteriorly of the sphenoidal sinuses. 
 
 The lower wall or floor presents from before backward: — 
 
 The anterior nasal spine; 
 
 The anterior palatine canals, given above ; 
 
 Crest or ridge for vomer; 
 
 Suture between superior maxillary and palate-bone, and 
 
 Posterior nasal spine. 
 
38 HUMAN ANATOMY. 
 
 FORAMINA AT THE BASE OF THE SKULL. 
 
 Antbeior fossa presents one single foramen and four in 
 pairs : — 
 
 Foramen ccecum transmits a small vein to the superior 
 longitudinal sinus; 
 
 Ethmoidal fissure transmits nasal branch of ophthalmic 
 nerve ; 
 
 Olfactory foramina, for filaments of olfactory bulb ; 
 
 Anterior ethmoidal transmit anterior ethmoidal artery and 
 nasal nerve; 
 
 Posterior ethmoidal transmits posterior ethmoidal artery 
 and vein. 
 
 Middle fossa presents nine (9) pairs: — 
 
 Optic foramen transmits the optic nerve and ophthalmic 
 artery ; 
 
 Foramen lacerum anterius, or sphenoidal fissure, transmits 
 •third, fourth, three branches of the (third) ophthalmic division 
 of the fifth and sixth nerves, orbital branch of the middle 
 meningeal, recurrent branch from the lachrymal artery, fila- 
 ments of the sympathetic and ophthalmic vein; 
 
 Foramen rotundum transmits second division of fifth or 
 superior maxillary; 
 
 Foramen Vesalii transmits a small vein; 
 
 Foramen ovale transmits third division of fifth or inferior 
 maxillary nerve, small petrosal nerve, and small meningeal 
 artery ; 
 
 Foramen spinosum transmits middle or great meningeal 
 artery ; 
 
 Foramen lacerum medium transmits the internal carotid 
 artery, carotid plexus, a branch of ascending pharyngeal artery, 
 and the Vidian or large petrosal nerve; 
 
 Foramen for lesser petrosal nerve, and 
 
 Hiatus Fallopii transmits petrosal branch of middle menin- 
 geal artery and petrosal branch of the Vidian nerve. 
 
 Posterior fossa presents six pairs and one single one : — 
 
 Meatus auditorius internus transmits auditory artery, facial 
 and auditory nerves; 
 
 Aqumductus vestibuU transmits small artery and vein and 
 lodges a process of dura mater; 
 
 Foramen lacerum posterius, or jugular foramen, transmits 
 inferior petrosal sinus and lateral sinus, forming the internal 
 jugular vein, glosso-pharyngeal, pneumogastric, and spinal ac- 
 cessory nerves, and meningeal branches of ascending pharyngeal 
 and occipital arteries; 
 
OSTEOLOGY. 
 
 39 
 
 Groosa Jbr Ssu^t. Ungitud.0imta 
 droavmafar ArttM-. M»-ningtalA\ 
 Womtnen Ceteiimi- 
 CrUta- CattC- 
 Silt fir Viudt vtfn- 
 
 /mteruiT XtkmaidnlTut, 
 
 QrifUit* fir Olfnotery n^nti 
 
 £crttrt»w £&miid»l H 
 
 ffptfa TenMSM. 
 Oftie Oraii- 
 Olivary 
 Jbtterlar Clinoid^rai 
 
 JKddU CttaoH gme- 
 faaUriar Clinoid -^rea. 
 
 TorS laaerum medium^. 
 O-r^flifM tf e^rffttd Catuil 
 
 Jfftatat Aaditiwr. Ijetfrnur- 
 
 ,8Ut firr Dwra^Xater- 
 
 jSitp. JPttvoatU groove 
 
 Mar. Jaetram paattriuM- 
 
 jMttrior CondylotdTtfa 
 
 Ai{Ufduat. VettibuU- 
 
 £Ht.^M§ttlnqsal GrffowA- 
 
 FIG. 17. 
 Floor ol the cranium, 
 
40 HUMAN ANATOMY. 
 
 Mastoid foramen transmits small vein to the lateral sinus 
 and small artery from occipital to the dura mater; 
 
 Anterior condyloid foramen transmits meningeal branch 
 from ascending pharyngeal artery and hypoglossal nerve; 
 
 Posterior condyloid foramen transmits posterior condyloid 
 vein; 
 
 Foramen magnum transmits vertebral arteries, medulla ob- 
 longata and its membranes, and the spinal accessory nerves. 
 
 OTHER FORAMINA OF SKULL. 
 
 The external surface of the hose presents seven pairs : — 
 
 Palatal portion: — 
 
 Incisive foramina transmit nerves and vessels to the incisor 
 teeth ; 
 
 Foramina of Stenson transmit the anterior branch of the 
 posterior palatine vessels; 
 
 Foramina of Scarpa transmit the right and left naso-pala- 
 tine nerve; 
 
 Posterior palatine foramina transmit posterior palatine ves- 
 sels and descending palatine nerve ; 
 
 Accessory palatine foramina transmit posterior palatine 
 nerves ; 
 
 Pterygo-palatine canals transmit ptery go-palatine vessels, 
 and the 
 
 Pterygoid or Vidian canal transmits the Vidian artery and 
 nerve. 
 
 Lateral portion presents nine pairs : — 
 
 Opening of the Eustachian tube; 
 
 Opening of the tensor tympani canal transmits the tensor 
 tympani muscle; 
 
 Olaserian fissure transmits the tympanic branch of the in- 
 ternal maxillary artery and lodges the processus gracilis of the 
 malleus ; 
 
 Canal of Iluguier transmits cliorda tympani nerve; 
 
 Foramen for Jacohson's nerve, the tympanic branch of the 
 glosso-pharyngeal nerve; 
 
 Foramen for Arnold's nerve, the auricular branch of the 
 pneumogastric nerve; 
 
 Opening of aqumductus cochlece transmits a vein from the 
 cochlea to internal jugular vein; 
 
 Auricular fissure transmits exit of Arnold's nerve; 
 
 Stylo-masioid foramen transmits the facial nerve and stylo- 
 mastoid artery. 
 
OSTEOLOGY. 41 
 
 Anteeioe REGioiT presents three pairs : — 
 
 Supraorbital foramen, or notch, transmits supraorbital ar- 
 tery, vein, and nerve; 
 
 Infraorbital foramen transmits infraorbital artery and 
 nerve, and 
 
 Mental foramen transmits mental nerve and artery. 
 
 BONES OF THE TRUNK. 
 
 The STERNUM, or breast-bone, is a long, narrow, sword-like 
 bone occupying the anterior part of the thorax and consisting 
 of three portions: manubrium (handle), gladiolus (blade), 
 xyphoid or ensiform appendix (point). Its anterior surface is 
 irregularly flat, posterior surface slightly concave. 
 
 Manubrium is thick and triangular, and presents above 
 the interclavicular notch, on either side of which are facets for 
 articulation of clavicles. Laterally it presents an articular facet 
 for the cartilage of the first rib and a half of one for part of 
 second costal cartilage. 
 
 Gladiolus is the longest, narrowest portion, and presents 
 •about its centre, between the third and fourth segments, the 
 sternal foramen, and laterally facets for half of the second and 
 for the third, fourth, fifth, and sixth costal cartilages. 
 
 Ensiform appendix is cartilaginous in youth and varies 
 much in size and shape. 
 
 It articulates with the clavicles and seven costal cartilages 
 on side. 
 
 Its ossific centres are six — one each for the manubrium and 
 appendix and four for the gladiolus, or body. 
 
 Its muscular attachments are ten — sterno-mastoid, sterno- 
 hyoid, sterno-thyroid, pectoralis major, triangularis sterni, ob- 
 liquus extemus and intemus, transversalis, rectus, and dia- 
 phragm. 
 
 The eibs, twelve on each side, form a series of narrow elas- 
 tic arches on each side of the thorax, constituting the chief part 
 of the thorax. They are divided into seven vertebrosternal, true 
 or sternal, each of which join the sternum by a separate costal 
 cartilage; three vertebro-chondral, or false, the cartilages of 
 which join each other and with the seventh before uniting with 
 the sternum, and two vertebral, free or floating, which have 
 no sternal attachment. 
 
 Each rib consists of a head, neck, tubercle, and body. 
 
 The head presents facet (except the first, tenth, eleventh, 
 and twelfth) for articulation with the bodies of the contiguous 
 
42 HUMAN ANATOMY. 
 
 dorsal vertebrse, separated by a ridge for tbe interarticiilar liga- 
 ment. 
 
 The nech or constricted portion is smooth in front and 
 presents a rough surface behind for the middle costo-transverse 
 ligament, and a rough crest above for the anterior costo-trans- 
 verse ligament. 
 
 The tubercle or tuberosity (wanting in eleventh and twelfth) 
 presents an articular surface for articulation with the transverse 
 process of the vertebra below, and a non-articular surface for 
 attachment of the posterior costo-transverse ligament. 
 
 The shaft or body is flat, thin, and twisted on itself. Its 
 anterior extremity presents an oval depression for costal cartilage. 
 
 The internal surface is smooth, concave, and presents in 
 front of the angle a ridge, forming the side of the groove on the 
 inferior border. 
 
 The external surface is rough, convex, and presents a little 
 in front of the tubercle a bend or angle marked by a prominent 
 line, and near the sternal extremity another bend, the anterior 
 angle, marked by an oblique line. 
 
 The superior border is round and thick, and presents an 
 external and internal lip for external and internal intercostal 
 muscles. 
 
 The inferior border at its posterior third presents a groove 
 for the intercostal vessels and nerve, and at its anterior two- 
 thirds is sharp and thin. 
 
 Peculiar Ribs.- — The peculiar ribs are the first, second, tenth, 
 eleventh, and twelfth. 
 
 The first is short, broad, and has no angle, and but one 
 facet on the head. Its upper surface is marked by two parallel 
 grooves, the anterior for the subclavian vein, the posterior for 
 the artery, separated by a tubercle for insertion of scalenus an- 
 ticus muscle, — an important guide in ligation of the subclavian 
 artery. 
 
 The second resembles the first in being flattened and not 
 twisted. The tubercle and angle are slight and almost coincide 
 in position. The outer surface of the shaft presents near its 
 middle a rough eminence for the second and third portions of the 
 serratus magnus. 
 
 The tenth rib has but one facet for articulation with the 
 tenth dorsal vertebra. 
 
 The eleventh has single facet on head, slight angle, but no 
 tubercle or neck. 
 
 The twelfth, single facet, but no angle, tubercle, or neck. 
 
 The ribs articulate with twelve vertebrse behind and twelve 
 costal cartilages in front. 
 
OSTEOLOGY. 43 
 
 Muscular attachments are twenty — scalenus anticus, medius, 
 and posticus, peetoralis minor, intercostals, serratus magnus, ob- 
 liquus extemus, transversalis, quadratus lumborum, diaphragm, 
 latissimus dorsi, serratus posticus, superior and inferior; sacro- 
 lumbalis, musculus accessorius ad ilio-costaleni, levatores costa- 
 rum, longissimus dorsi, cervicalis ascendens, and infracostales. 
 
 They are developed from thirty-four ossific centres, each 
 rib having one centre each for its head, shaft, and tubercle, 
 except the eleventh and twelfth, which have but two centres, not 
 having any tubercles. 
 
 VERTEBRA. 
 
 The SPINE, or vertebral column, is a flexible column com- 
 posed of twenty-six bones (thirty-three vertebrae), as follows: 
 
 Fig. 18. 
 
 1, body; 2, demi-facet for rib; 3, superior articular processes; 
 5, Intervertebral notch; 6, spinous process; 7, facet for tubercle on 
 transverse process; 9, inferior articular processes. 
 
 seven cervical, twelve dorsal, five lumbar, sacrum, and coccyx. 
 Each vertebra consists of a body, and an arch composed of two 
 pedicles and two laminte, supporting seven processes — one spi- 
 nous, two transverse, and four articular. 
 
 The body (centrum), the large, solid, anterior portion, is 
 generally half-cylindrical, concave behind, convex in front and 
 sides. Its upper and lower surfaces are broad and rough, for 
 attachment of interarticular cartilages. Its posterior surface has 
 large foramen for exit of veins. 
 
 The pedicles project backward (except the cervical, which 
 project obliquely outward), and present four intervertebral 
 notches, two each, above and below. These, when articulated, 
 form interarticular foramina for exit of spinal nerves and pas- 
 sage of blood-vessels. 
 
44 HTJMAN ANATOMY. 
 
 The lamince are two broad, flat plates of bone, projecting 
 backward and inward from the pedicles, to complete the verte- 
 bral arch and inclose the spinal foramen. Their upper and 
 lower margins are rough for attachment of the ligamenta sub- 
 flava. 
 
 The spinous processes vary much in size and shape in the 
 different regions. They project backward from the junction 
 of the laminse, and afford attachment for muscles. 
 
 The transverse processes project, one on each side, from 
 the junction of the lamina with the pedicles, and in the cervical 
 region from the sides of the body also, inclosing the foramen 
 for the vertebral artery. 
 
 The articular processeSj four in number, project one above 
 and below on each side, from the junction of the laminae and 
 pedicles. The two superior project upward and more or less 
 backward, the inferior downward and more or less forward, 
 articulating with the corresponding processes of the adjoining 
 vertebra. 
 
 The spinal foramen is a large, triangular canal, inclosed 
 by the body in front, the pedicles laterally, and the laminse be- 
 hind for the passage of the spinal cord and its membranes. 
 
 The cervical vEETEBEiE are- characterized by small body, 
 concave above, convex below, the anterior margin overlapping the 
 one below; short and bifid transverse process, perforated at 
 base by foramen for vertebral artery; oblique articular processes 
 — superior convex directed upward and backward, inferior con- 
 cave downward and forward ; short spinous process, bifid, placed 
 horizontally ; long and narrow lamina, inclosing large, triangular 
 spinal canal. 
 
 The peculiar cervical vertebra are first, second, and seventh. 
 
 The first or atlas is ring-like, without either body or spinous 
 process, and consists of an anterior and posterior arch and two 
 lateral masses. The anterior arch, convex in front, presents 
 tubercle for longus colli muscles and behind articulates with 
 odontoid process of axis. The posterior arch is deeply grooved 
 above for transmission of vertebral artery and suboccipital nerves, 
 and terminates behind in a rudimentary spine. It articulates 
 above with condyles of occipital, below with axis. The trans- 
 verse process is short and contains a foramen. 
 
 The axis, so-called from the pivot-like odontoid process, 
 which projects, from the upper part of its body to articulate with 
 the anterior arch and transverse ligament of atlas. 
 
 The seventh resembles the dorsal series, its spinous process 
 being long, not bifid, and prominent; hence its name, "vertebra 
 prominens." To it is attached the ligamentum nuchas. 
 
OSTEOLOGY. 45 
 
 The dorsal veetebr^ have large, heart-shaped bodies, flat 
 above and below. Laterally are demi-articular facets for heads 
 of ribs; long, strong, transverse processes, marked by facet, for 
 tubercle of rib; vertical articular processes, superior backvrard, 
 inferior forward ; long, triangular, overlapping spinous process ; 
 small, and nearly circular, spinal canal. 
 
 The peculiar dorsal vertebrw are: first, which resembles 
 cervical, and have distinct facet for head of first rib, and half-one 
 for half of second head; tenth, eleventh, and twelfth, one facet 
 for head of rib ; and eleventh and twelfth, no facet on transverse 
 processes for tubercle of rib. 
 
 The lumbar vbrtebeje are the largest, and have trans- 
 versely oval body, flat above and below; long, thin, transverse 
 processes, representing ribs; vertical processes interlocking with 
 adjacent vertebrse; large, triangular spinal canal. 
 
 The last lumbar is peculiar in having body thicker in front, 
 shorter and stronger transverse process, and inferior articular 
 processes wider apart, and directed forward. 
 
 Muscular attachments to atlas, ten — rectus anticus minor, 
 rectus lateralis, rectus posticus minor, obliquus superior and 
 inferior, splenius colli, levator anguli scapulee, interspinous, and 
 intertransverse. To axis, ten — the last five of preceding, and 
 obliquus inferior, rectus posticus major, semi-spinalis colli mul- 
 tifidus spinse, scalenus posticus, and transversalis colli. 
 
 To the remaining vertebrae are attached anteriorly ten (10) 
 muscles, and posteriorly twenty-two (22) [vide Spinal Muscles, 
 p. 107]. 
 
 Development. — The ossific centres for each vertebra are 
 three primary, one for the body and one for each side, and five 
 secondary epiphyses, as follows : one for tip of each spinous and 
 transverse process, and the remaining two are thin plates on 
 articular surfaces. 
 
 The exceptions to this rule are: atlas, with two primary 
 centres and one epiphysis; the axis, with three extra centres for 
 odontoid process ; the seventh cervical, with one extra centre for 
 each transverse process, and the lumbar vertebrae, two additional 
 centres for tubercles. 
 
 The sacrum is a large, wedge-shaped bone, base above, apex 
 below, with expanded lateral masses and alse, composed of five 
 consolidated sacral vertebrae, and forming the posterior wall of 
 pelvis. 
 
 The hose articulates with the last lumbar vertebra. Its 
 anterior edge forms the promontory or sacra-vertebral angle, on 
 each side of which is a smooth triangular surface, the ala. Be- 
 hind the articulating surface is the sacral canal, and on either 
 side are the superior processes. 
 
46 HUMAN ANATOMY, 
 
 The apex is small and articulates with the coccyx. 
 
 The anterior concave surface presents four ridges, indicating 
 the original separations, which terminate externally in eight 
 anterior sacral foramina, with wide, shallow grooves, for the 
 exit of the anterior sacral nerves. To the outer side of these 
 foramina is the lateral mass for origin of pyriformis muscle. 
 
 The posterior surface presents rudimentary spinous articu- 
 lar and transverse processes, the laminse of the last two segments 
 being deficient.* On the other side of the spinous process is a 
 broad, shallow concavity, the sacral groove, for the origin of the 
 erector spinge muscle, and external to the articular processes are 
 four posterior sacral foramina for the exit of posterior sacral 
 nerves. 
 
 The lateral surfaces have each a rough articular surface for 
 articulation, with ossa innominata, and below presents a deep 
 notch on each side of the apex, which is converted by articulation 
 with the transverse process of the coccyx into the fifth sacral 
 foramen, for exit of anterior division of the fifth sacral nerve. 
 
 The sacral canal, continuous above with the spinal foramen 
 of the vertebrjE, runs through the centre. Large and triangular 
 above, small and flattened below, its lower posterior wall is de- 
 ficient. It lodges the sacral nerves, and out of it pass the an- 
 terior and posterior sacral foramina. 
 
 It articulates with four bones, — ^two ossa innominata, last 
 lumbar vertebra, and coccyx. 
 
 Muscular attachments are seven — ^iliacus, pyriformis, coccyg- 
 eus, gluteus maximus, latissimus dorsi, multifidus spinse, and 
 erector spinse. 
 
 Its ossific centres are thirty-five, as follows : bodies, includ- 
 ing interarticular plates, three each (15) ; arches, two each (10) ; 
 lateral masses, six (6) ; epiphyseal plates of lateral surfaces, 
 four (4). Total, 35. 
 
 The coccyx is a small triangular bone, resembling a 
 cuckoo's beak, and composed of four rudimentary vertebrae more 
 or less co-ossified. 
 
 The base articulates with the sacral apex, being prolonged 
 upward into two cornua to complete the fifth posterior sacral 
 foramen for exit of posterior branch of fifth sacral nerve. 
 
 Laterally the base is prolonged into rudimentary transverse 
 processes, completing with the notch of the sacrum the fifth 
 anterior sacral foramina for exit of the anterior branch of fifth 
 sacral nerve. 
 
 * The articular processes of the fourth and fifth unite to form the 
 sacral cornua for articulation with the cornua of the coccyx. 
 
OSTEOLOGY. 47 
 
 The anterior concave surface supports the rectum and gives 
 attachment to levator ani muscle and anterior sacro-eoceygeal 
 ligament. 
 
 The posterior convex surface presents rudimentary, articular 
 processes and transverse grooves. 
 
 The apex is rounded, occasionally bifid, or deviated to one 
 side, and affords attachment to the levator ani and sphincter 
 ani muscles. 
 
 The muscular attachments are coccygei, gluteus maximus, 
 extensor coccygeus (occasionally present), levator and sphincter 
 ani. 
 
 Its os^ific centres are four — one for each segment. 
 
 THE UPPER EXTEEJIITY. 
 
 The upper extremity consists of the arm, forearm, and 
 hand. It is attached to the trunk by the shoulder girdle formed 
 
 Fig. 19. 
 
 1, sternal extremity; 2, costal facet for first rib; 5, acromial extrem- 
 ity; 6, 6, deltoid muscle; 7, 7, trapezius muscle. 
 
 by the clavicles and scapulae and contains the following bones : 
 Clavicle, scapula, humerus, radius, ulna, eight carpus, five meta- 
 carpus, and fourteen phalanges. 
 
 The clavicle, or collar- or key- bone, is a long bone, curved 
 horizontally like the italic letter /, extending almost horizontally 
 between the sternum and acromial process of scapula. Its inner 
 two-thirds are cylindrical and convex in front, its outer third 
 flattened from above downward and concave in front. It con- 
 sists of a body, or shaft, and outer, or acromial, and inner, or 
 sternal extremities. 
 
 The shaft presents in its outer third the following points : — 
 
 Superior surface, rough impression in front for deltoid mus- 
 cle, rough impression behind for trapezius ; 
 
 Anterior border, occasionally deltoid tubercle about the 
 centre for attachment of deltoid; 
 
 Inferior surface, conoid tubercle at the posterior border for 
 conoid ligament; oblique Iiii,e extending outward and forward 
 from this for attachment of trapezoid ligament. 
 
48 HUMAN ANATOMY. 
 
 The inner two-thirds is prismatic and presents three surfaces 
 and three borders: — 
 
 Anterior surface, divided by line into upper rough surface 
 for sterno-mastoid muscle and lower for pectoralis major; 
 
 Posterior or cervical surface, gives attachment to sterno- 
 hyoid muscle and presents foramen for nutrient artery. 
 
 Inferior or subclavian surface presents : — 
 
 Facet, continuous with sternal articular surface, for car- 
 tilage of first rib ; 
 
 Rhomboid impression for costo-clavicular or rhomboid liga- 
 ment; 
 
 Subclavian groove for attachment of subclavian muscle; 
 
 Longitudinal line, frequently dividing the groove into two 
 parts, for intermuscular septum of the muscle. 
 
 Anterior border separates the anterior and posterior sur- 
 faces and limits the attachment of the pectoralis major. 
 
 Superior border gives attachment to the sterno-mastoid 
 muscle. 
 
 Posterior or subclavian border is short and concave, extend- 
 ing from the rhomboid impression to the conoid tubercle and 
 giving attachment to the subclavian fascia. 
 
 The acromial extremity presents an oval facet for articula- 
 tion with the acromial process of the scapula and a rough circum- 
 ference for acromio-clavicular ligaments. 
 
 The sternal extremity is triangular, and presents a facet for 
 cartilage of sternal articulation and rough circumference for 
 sterno-clavicular ligaments. 
 
 The clavicle articulates with three bones — ^the sternum, 
 scapula, and first costal cartilage. 
 
 The muscular attachments are seven — subclavius, platysma, 
 sterno-hyoid, sterno-mastoid, trapezius, pectoralis major, and del- 
 toid. 
 
 Its ossific centres are two — one each for body and sternal 
 end. 
 
 The scapula, or shoulder-blade, is a large, fiat, triangular 
 bone situated on the upper postero-lateral aspect of the thorax 
 from the second to seventh rib, inclusive. 
 
 It consists of a body, head, neck, acromion, and coracoid 
 processes, and presents two surfaces, three borders, and three 
 
 The anterior surface, or venter, presents : — 
 Subscapular fossa, a concave triangular surface for attach- 
 ment of subscapular muscles, marked by 
 
 Oblique ridges, for the tendinous intersections of the muscle; 
 Marginal surface, for attachment of serratus magnus ; 
 
OSTEOLOGY. 49 
 
 Subscapular angle, a transverse depression at the upper part 
 for the thickest part of the muscle. 
 
 The posterior surface, or dorsum, presents : — 
 
 Spine, a bony ridge passing upward, forward, and outward, 
 dividing it unequally into two fossse, affording attachment to 
 the trapezius muscle above and the deltoid below, and terminat- 
 ing above in the acromion process; 
 
 Supraspinous fossa above the spine, for the origin of the 
 supra-spinatus muscle; 
 
 Infra-spinous fossa below, for the origin of the infra-spiaa- 
 tus muscle; 
 
 ^ 
 
 Fig. 20. 
 
 1, 1, 1. oblique ridges; 3, superior border; 4, superior angle; 5, 
 supra-scapular notch: 6, coracoid process; 7, acromial process; 10, 
 glenoid fossa; 14, inferior angle. 
 
 Nutrient foramen, near the upper part of infra-spinous 
 fossa, for nutrient artery. 
 
 The marginal surface extends from the glenoid cavity down- 
 ward and backward to an inch above inferior angle, its inner 
 side formed by 
 
 An elevated ridge, for the attachment of the aponeurosis 
 between the iaf ra-spinatus and two teres muscles ; its outer side 
 by the axillary border. It is divided by an oblique line into two 
 parts, the upper for the teres minor and the lower for the teres 
 major muscles, and crossed by a groove near the upper part for 
 the dorsalis scapulse vessels; 
 
 A smooth, triangular surface at the root of the spine over 
 which the trapezius glides. 
 
50 
 
 HUMAN ANATOMY. 
 
 The superior harder, shortest, presents : — ■ 
 
 Supra-scapular notch at the base of the coracoid process, 
 converted into a foramen [supra-scapular] by the transverse liga- 
 ment, for the passage of the supra-scapular nerve (the artery 
 passing above) ; 
 
 Origin of omo-hyoid muscle from this border just internal 
 to notch. 
 
 External or axillary border, thickest, presents : — 
 
 Bough impression, just below glenoid cavity, for origin of 
 long head of triceps muscle, and below, 
 
 Fig. 21. 
 
 1, supra-splnous fossa; 2, Intra-spinous fossa; S, superior border; 
 4, supra-scapular notch; 5, axillary border; 6, head; 7, inferior 
 angle; 8, neck; 9, vertebral border; 10, spine; 11, surface for tra- 
 pezius; 12, acromion process; 13, nutrient foramen; 14, coracoid 
 
 process. 
 
 Longitudinal groove, for origin of part of subscapularis. 
 
 Internal, vertebral border (base), longest, presents: — 
 
 Anterior lip, for insertion of serratus magnus ; 
 
 Posterior lip, for attachment above of supra-spinatus, below 
 infra-spiaatus. 
 
 The superior angle, gives attachment to part of levator 
 angulas scapulas; 
 
 The inferior angle, for attachment of teres major, and gome- 
 times part of latissimus dorsi. 
 
 The anterior or external angle is thickest, and forms the 
 head. 
 
OSTEOLOGY. 51 
 
 The head is connected to the body of the scapula by a con- 
 stricted portion, the nech, from the anterior surface of which 
 arises the coracoid process. It presents 
 
 The glenoid cavity or fossa^ a shallow, pyriform, articular 
 depression, deepened in the recent state by the glenoid ligament, 
 for the head of the humerus. To its upper part or apex is 
 attached the long head of the biceps muscle. 
 
 The acromion peooess, forming the summit of the 
 shoulder, is a triangular process, projecting forward, outward, 
 and upward to overarch the glenoid cavity. It gives attachment 
 by its upper surface to the platj'sma and deltoid and by its inner 
 margin to the trapezius. It presents 
 
 An apex, for attachment of coraeo-acromial ligament; 
 
 Articular facet, just behind the apex for the clavicle. 
 
 The ookacoid process (like a crow's beak) arches forward, 
 upward, and inward above the glenoid cavity. It presents : — 
 
 Attachment for pectoralis minor muscle from the anterior 
 border near the tip ; 
 
 Apex, for attachment of coraco-brachialis and short head of 
 biceps ; 
 
 Rough impression at the inner side of the root for the 
 conoid ligament, and from it 
 
 A ridge running outward and forward for the trapezoid 
 ligament. 
 
 It articulates with the clavicle and humerus. 
 
 Its muscular attachments are 18 : platysma, supra- and 
 infra- spinatus, subscapular, deltoid, trapezius, omo-hyoid, ser- 
 ratus magnus, levator anguli scapulas, rhomboideus major and 
 minor, triceps, teres major and minor, biceps^ coraco-brachialis, 
 pectoralis minor, and latissimus dorsi. 
 
 Its ossific centres are seven — one each for body, posterior 
 border, and inferior angle, and two each for acromion and cora- 
 coid processes. 
 
 The humerus, or arm-bone, the largest and longest bone 
 of the upper extremity, consists of a shaft, head, neck, greater 
 and lesser tuberosities, and lower extremity. 
 
 The shaft, cylindrical above, flattened and prismoid below, 
 becomes twisted in the middle, and presents 
 
 A rough triangular surface about the middle of its outer sur- 
 face for insertion of the deltoid muscle, and a 
 
 Musculo-spiral groove for the musculo-spiral nerve and supe- 
 rior profunda artery, on each side of which arise the external and 
 internal heads of the triceps muscle. 
 
 The upper extremity presents 
 
52 HUMAN ANATOMY. 
 
 The head, forming nearly a sphere, projecting upward, back- 
 ward, and inward, articulating with the glenoid cavity ; 
 
 The anatomical neck, immediately beneath, is slightly 
 grooved for the attachment of the capsular ligament; 
 
 Greater tuberosity, external to the head and lesser tuberosity, 
 with three facets from before backward for attachment of supra- 
 spinatus, infra-spinatus, and teres minor muscles; 
 
 Lesser tuberosity, smaller but more prominent than greater, 
 is anterior to head, for the subscapular muscle ; 
 
 Bicipital groove, passes downward and inward between the 
 two tuberosities and lodges the long tendon of biceps ; 
 
 The anterior bicipital ridge, bounds the groove in front and 
 receives insertion of pectoralis major muscle; 
 
 The posterior bicipital ridge, receives the latissimus dorsi 
 and teres major; 
 
 The surgical nech, including the head, neck, and both tuber- 
 osities ; 
 
 A rough impression near the centre of the inner border for 
 the coraco-brachialis muscle ; 
 
 Nutrient canal, below and directed toward the lower ex- 
 tremity. 
 
 The lower extremity presents from within outward the fol- 
 lowing : — 
 
 Internal condi/loid ridge, extending upward from the con- 
 dyle; 
 
 Internal condyle, more prominent than external, gives ori- 
 gin to the flexors and pronator radii teres ; 
 
 Epitrochlea, an eminence separating the trochlea from the 
 internal condyle ; 
 
 Trochlea, a pulley-like articulating surface for greater sig- 
 moid cavity of ulna ; 
 
 Coronoid fossa, a small depression bounding the trochlea in 
 front, and receiving the coronoid of the ulna in flexion; 
 
 Olecranon fossa, a larger depression behind, and receiving 
 the olecranon process of ulna in extension; 
 
 Supra-trochlear foramen, sometimes formed by perforation 
 of one fossa into the other ; 
 
 Radial head, or capitellum, a smooth, rounded eminence ar- 
 ticulating with cup-like depression on head of radius; 
 
 External condyle, less prominent, gives rrigin to the ex- 
 tensors and supinators; 
 
 External condyloid ridge, extending upward on the shaft 
 from the condyle. 
 
 It articulates with three bones — scapula, radius, and ulna. 
 
OSTEOLOGY. 
 
 53 
 
 Its muscular attachments are twenty-five — subscapularis, 
 supra- and infra- spinatus, teres major and minor, pectoralis 
 major, latissimus dorsi, deltoid, coraco-brachialis, brachialis an- 
 ticus, triceps, pronators and flexors to inner condyle, pronator- 
 radii teres, flexor carpi radialis, palmaris longus, flexor sublimus 
 digitorum, flexor carpi ulnaris, supinators and extensors to outer 
 condyle, supinator longus, extensor carpi radialis longior and 
 
 Fig. 22. 
 
 1, shaft; 2, head; 3, neck; 4, 
 greater tuberosity; 5, lesser tuber- 
 osity; 6, posterior bicipital groove; 
 7, impression for deltoid; 8, bicipital 
 groove; 10, nutrient foramen; 11, 
 capitelliun; 12, trochlea; 13, external 
 condyle; 14, internal condyle; 15 
 and 16, external and internal supra- 
 condyloid ridges. 
 
 Fig. 23. 
 
 1, shaft of ulna; 2, greater sig- 
 moid cavity; 3, lesser sigmoid cavity; 
 4, olecranon; 5, coronoid process; 
 6, nutrient foramen; 7, interosseous 
 borders; 8, head of ulna; 9, styloid 
 process of ulna; 11, head of radius; 
 12, neck of radius; 13, tuberosity of 
 radius; 14, shaft of radius; 15, car- 
 pal extremity of radius; 16, styloid 
 process of radius. 
 
 brevior, extensor communis digitorum, extensor minimi digiti, 
 extensor carpi ulnaris, anconeus and subanconeus, supinator 
 ' brevis. 
 
 Its ossiflc centres are seven — one each for head, shaft tuber- 
 osities, condyles, radial head, and trochlear portion. 
 
 The ulna is a long bone to the inner side of the forearm, 
 and consists of a shaft and an upper and lower extremity. It 
 forms the greater part of the articulation with the humerus, but 
 
54 HUMAN ANATOMY. 
 
 does not enter into the formation of the wrist-joint, being ex- 
 cluded by the interarticular fibro-cartilage. 
 
 The shaft is prismatic aboye, smooth and rounded below, and 
 presents : — 
 
 Anterior surface, gives attachment to the deep flexors and 
 pronator quadratus ; 
 
 Nutrient foramen on anterior surface, directed upward to- 
 ward the elbow-joint; 
 
 Posterior surface marked above by an ollique line for part 
 of supinator brevis, above which is smooth triangular surface for 
 anconeus muscle, and the lower third for extensor muscles of the 
 thumb ; 
 
 External harder, shr.rp in middle two-thirds, for attachment 
 of interosseus membrane. 
 
 The upper extremity is large and irregular, and presents : — 
 
 Olecranon process (head of elbow), projects upward and 
 forward, its apex being received into the olecranon fossa of the 
 humerus in extension of tlie forearm; its upper border has rough 
 impression for the triceps muscle ; its lateral borders are grooved 
 for external and internal lateral ligaments; 
 
 Coronoid process, smaller than olecranon, projects forward 
 from anterior surface, being received into coronoid fossa of hu- 
 merus in flexion. 
 
 Its upper surface forms part of the great sigmoid cavity. 
 
 Its under surface has rough impression for insertion of 
 brachialis anticus, and has, at its junction with the shaft, the 
 tubercle of the ulna for the oblique ligament. 
 
 Its outer surface is the lesser sigmoid cavity. 
 
 Its inner surface gives attachment to the internal lateral 
 ligament, and the flexor digitorum sublimis, flexor profundus 
 digitorum, and one head of pronator radii teres. 
 
 Greater sigmoid cavity is a large, semi-lunar depression 
 between the olecranon and coronoid processes, divided into tsvo 
 unequal lateral parts by an elevated ridge. It is continuous on 
 the outer side with the lesser sigmoid cavity and articulates with 
 the trochlear surface of the humerus. 
 
 Lesser sigmoid cavity is an oval, concave, articular depres- 
 sion, external to the coronoid process, for articulation with the 
 head of the radius. Its prominent extremities give attachment 
 to the orbicular ligament. 
 
 The lower extremity is small and cylindrical and presents :— 
 
 Head, an external, rounded, articular process, for the tri- 
 angular fibro-cartilage below and the sigmoid cavity of the radius 
 externally; 
 
OSTEOLOGY. 65 
 
 Styloid process, projects from the posterior and internal part 
 of the extremity, its apex gives attachment to the internal lateral 
 ligament of the wrist, and it is marked at its root by a depression 
 between it and the head, for attachment of the fibro-cartilage ; 
 
 Groove, upon the posterior surface, for passage of extensor 
 carpi ulnaris. 
 
 It articulates with two bones — ^humerus and radius. 
 
 Its muscular attachments are sixteen — ^brachialis anticus, 
 triceps, anconeus, flexor and extensor carpi ulaaris, pronator radii 
 teres, flexor sublimus and profundus digitorimi, pronator quad- 
 ratus, supinator brevis, extensor indicis, extensor ossis metacarpi, 
 extensor secundi intemodii poUicis, and flexor longus pollicis. 
 
 Its ossific centres are three — one each for shaft, olecranon, 
 and inferior extremity. 
 
 The radius is a long bone, shorter than the ulna, situated 
 on the outer side of the forearm, the upper end small, the shaft 
 slightly curved, and the lower end expanded to form part of the 
 wrist-joint. It consists of shaft, upper and lower extremity. 
 
 The shaft is prismoid, slightly curved, and presents 
 
 An internal border, sharp and prominent, for interosseous 
 membrane ; 
 
 An anterior border, marked at its upper third by an oblique 
 line, for attachment of flexor longus pollicis, supinator brevis, 
 and flexor sublimis digitorum ; 
 
 Anterior surface, affords attachment above for flexor longus 
 pollicis, below for pronator quadratus, and presents at the junc- 
 tion of middle and upper two-thirds a nutrient foramen directed 
 upward ; 
 
 Posterior surface gives attachment at upper third to supina- 
 tor brevis, and at middle third to extensors of thumb. 
 
 The upper extremity presents : — 
 
 Head — a cup-like cylindrical cavity, for articulation with 
 capitellum of humerus, and on its side an articulating surface 
 for lesser sigmoid cavity of ulna and orbicular ligament, which 
 nearly surrounds it ; 
 
 Nech, the constricted portion below the head; 
 
 Bicipital tuberosity, below and to inner side, divided by a 
 vertical line into a rough surface posteriorly, for attachment of 
 biceps tendon, and smooth surface anteriorly for bursa. 
 
 The lower extremity, large, expanded, and quadrilateral, 
 presents : — 
 
 Carpal articular surface, smooth, concave, triangular depres- 
 sion divided by an antero-posterior ridge into an outer facet for 
 scaphoid bone and inner for semi-lunar; 
 
66 
 
 HUMAN ANATOMY. 
 
 Sigmoid cavity, a shallow concavity at inner side of carpal 
 end, for articulation with ulnar head ; 
 
 Styloid process, projects obliquely downward from the ex- 
 ternal surface, for attachment by its apex to external lateral liga- 
 ment of wrist-Joint, and by its base to insertion of supinator 
 longus muscle. Its outer surface is marked by two grooves for 
 extensors of thumb ; 
 
 The posterior surface of the lower extremity is also marked 
 by three grooves from withoiit inward for the following: ext. 
 carpi radialis longior and brevior in first, ext. secundi internodii 
 in second, and ext. indicis, ext. communis digitorum, and ext. 
 minimi digiti in third innermost. This surface has also attach- 
 ment of posterior ligament of wrist. 
 
 Fig. 24. 
 
 -1, ulna; 2, radius; 3, flbro-cartilage; 4, 5, 6, 7, 8, metacarpal 
 bones; S, scaphoid: L, semi-lunar; C, cuneiform; P, pisiform; R, 
 trapezium; T, trapezoid; M, os magnum; U, unciform. 
 
 It articulates with four bones — humerus, ulna, scaphoid, and 
 semi-lunar. 
 
 Its muscular attachments are ninfr — biceps, supinator longus 
 and brevis, flexor digitorum sublimis, flexor longus pollicis, pro- 
 nator quadratus, extensor ossis metacarpi pollicis, ext. primi in- 
 ternodii pollicis, and pronator radii teres. 
 
 Its ossific centres are three — one each for shaft and each 
 extremity. 
 
 The Hand. — The bones of the hand consist of eight carpus, 
 five metacarpus, and fourteen phalanges; total, twenty-seven 
 bones. 
 
 The carpus consists of eight small bones arranged in two 
 rows — first, or proximal row, from the radial side inward are 
 
OSTEOLOGY. 57 
 
 scaphoid, semi-lunar, cuneiform, and pisiform; the second, or 
 distal row, in same order are trapezium, trapezoid, os magnum, 
 and unciform. 
 
 Scaphoid (boat-shaped), largest of first row, convex above, 
 concave below, articulates with five bones, as follows: superior 
 surface, with radius; inferior, with trapezium and trapezoid; 
 internal, with semi-lunar above and os magnum beneath. The 
 external surface has attachment of external lateral ligament of 
 wrist. 
 
 Semi-ldnae (half -moon), crescentic in outline, presents 
 articulating surfaces for five bones, as follows : superior convex 
 surface with radius, inferior concave facet with os magnum and 
 unciform, quadrilateral internal facet with cuneiform, and ex- 
 ternal with scaphoid. 
 
 CuNEiFOEM is wedge-shaped, the base, directed outward, 
 articulates with the semi-lunar, apex with the interarticular fibro- 
 cartilage of wrist-joint, inferior surface with unciform, and 
 anterior with pisiform; in all, three bones. 
 
 Pisiform (pea-like) is a small, pea-shaped bone articulating 
 with anterior surface of cuneiform, and affording attachment to 
 annular ligament and two muscles, flexor carpi ulnaris, abductor 
 minimi digiti. 
 
 Trapezium (a table), a very irregular bone, articulates 
 above by concave surface with scaphoid ; below, by surface con- 
 cave from side to side, convex from before backward, with first 
 metacarpal, by internal surface with trapezoid, inferior with 
 second metacarpal. Its dorsal surface is rough; its palmar 
 grooved by flexor carpi radialis tendon. Muscular attachments 
 are three — flexor ossis metacarpi, flexor brevis pollicis, and ab- 
 ductor pollicis. 
 
 Trapezoid, smallest of second row, is wedge-shaped, apex 
 palmar; articulates with four bones — superior surface with sca- 
 phoid, inferior with second metacarpal, external with trapezium, 
 internal with os magnum and interosseous ligament. 
 
 It has one muscular attachment for flexor brevis pollicis. 
 
 Os MAGNUM, or CAPITATE, the largest carpal bone, consists 
 of a body, neck, and head. The latter projects from the supe- 
 rior surface and articulates with the scaphoid and semi-lunar. 
 The inferior surface articulates with second, third, and fourth 
 metacarpal bones ; the external with trapezoid, and internal with 
 unciform ; in all seven bones. 
 
 Muscular attachment for flexor brevis pollicis. 
 
 TJnoifoem (hook-like), a wedge-shaped bone, so named 
 from the hook-like process, projecting from its anterior surface, 
 below its articulation with fourth and fifth metacarpals, and 
 
58 HUMAN ANATOMY, 
 
 above its articulation with semi-lunar. This process gives at- 
 tachment to annular ligament, flexor brevis minimi digiti, flexor 
 ossis metacai-pi minimi digiti, and is grooved for passage of other 
 flexor tendons. External surface articulates with os magnum 
 and internal with cuneiform. 
 
 Muscular attachments are those to unciform process. Each 
 carpal bone is developed from a single ossific centre. 
 
 Table of Articulations of Carpal Bones. — Scaphoid, five; 
 semi-lunar, five; cuneiform, three; pisiform, one; trapezium, 
 four; trapezoid, four; os magnum, seven; unciform, five. 
 
 The metacarpus are five long bones, resembling each other, 
 and presenting a shaft and two extremities. Anterior surface is 
 concave, posterior convex; superior extremity irregular for ar- 
 ticulation with carpal bones and with the adjoining bones; in- 
 ferior extremity presents rounded head for articulation with 
 phalanges. The first metacarpal for thumb is supported on 
 trapezium, articulates with first phalanx, and has three muscles 
 attached — first dorsal interosseus, fiexor, and extensor ossis meta- 
 carpi pollicis ; the second metacarpal by three, trapezium, trape- 
 zoid, and OS magnum, articulates also with third metacarpal and 
 second phalanx, and has five muscles attached- — first and second 
 dorsal interosseus, first palmar interosseus, fiexor carpi radialis, 
 and extensor carpi radialis longior; the third metacarpal sup- 
 ported by OS magnum, articulates also with second and fourth 
 metacarpal and third phalanx, and has five muscles attached — 
 fiexor brevis pollicis, extensor carpi radialis brevior, adductor 
 pollicis, and second and third dorsal interosseus. The fourth 
 metacarpal is supported on os magnum and unciform, articulates 
 with third and fifth metacarpal and fourth phalanx, and has 
 three muscles attached — second palmar and third and fourth dor- 
 sal interosseus. The fifth metacarpal, supported on unciform, 
 articulates with fourth metacarpal and fifth phalanx, and has five 
 muscles attached — flexor ossis metacarpi minimi digiti, flexor 
 and extensor carpi ulnaris, and fourth dorsal and third palmar 
 interosseus. 
 
 Ossific centres are two for each bone, one each for shaft 
 and head, except thumb, which has one each for shaft and 
 base, resembling the phalanges. 
 
 Phalanges. — Each finger has three phalanges, except the 
 thumb, which has but two. Palmar surface concave, dorsal con- 
 vex ; the superior extremity articulates with head of metacarpal, 
 and the inferior, concave from side to side, convex from before 
 backward, articulates with second phalanx, which presents an 
 opposite arrangement, except in the thumb, where it articulates 
 with ungual or terminal phalanx. 
 
OSTEOLOGY. 59 
 
 The second phalangeal articulation is the same, and the 
 ungual phalanx presents a rough, arrow-shaped extremity. 
 
 The muscular insertions to the first row are : to thumb four, 
 flexor brevis, abductor and adductor pollicis, and extensor primi 
 intemodii ; to index two, first palmar and dorsal interosseus ; to 
 middle two, second and third dorsal interossei; to ring two, 
 second palmar and fourth dorsal interosseus; to little three, 
 flexor brevis and abductor minimi digiti and third palmar inter- 
 osseus. 
 
 The insertions to second row are: extensor secundi inter- 
 nodii and flexor longis pollicis; and to each of the others four, 
 extensor communis digitorum, flexor sublimis digitorum, with 
 the addition of extensor indicis to index and extensor minimi 
 digiti to little. 
 
 The insertions to third row are: extensor communis digi- 
 torum and flexor profundus. 
 
 Ossific centres are two for each bone, one each for shaft 
 and base. 
 
 THE LOWER EXTREMITY. 
 
 The lower extremity consists of the thigh, leg, and foot. It 
 is connected to the trunk by the pelvic girdle formed by the hip 
 bones and sacrum, and contains the following bones: os inno- 
 minatum, femur, patella, tibia, fibula, seven tarsus, five meta- 
 tarsus, and fourteen phalanges. 
 
 The OS innominatum, or hip-bone, is a large, irregular bone 
 forming the lateral and anterior walls of the pelvis, and consist- 
 ing of three bones, ilium, ischium, and pubes, united about 
 puberty. It presents 
 
 The acetabulum or cotyloid cavity, a deep, cup-shaped cavity, 
 for articulation of the head of the femur — the ischium forming 
 a little more than two-fifths, the ilium a little less than two- 
 fifths, and the pubes one-fifth. The bottom of the cavity presents 
 a circular depression, lodging a mass of fat, and giving attach- 
 ment by its edges to the ligamentum teres, and continuous below 
 with a deep notch, the cotyloid notch, for attachment of cotyloid 
 and part of ligamentum teres, converted into a foramen by the 
 transverse ligament for the entrance of the nutrient vessels and 
 nerves. The margin of the acetabulum is deepened by a fibro- 
 cartilaginous ring. 
 
 The obturator, or thyroid foramen, is an aperture large and 
 ovoidal in the male, small and triangular in the female, situated 
 on the anterior inferior surface between the ischium and pubes. 
 It is closed, in the recent state, by a strong membrane attached 
 to its margins except above externally, where a foramen exists 
 for obturator vessels and nerve. 
 
GO 
 
 HUMAN ANATOMY. 
 
 The ilium, broad, flat, and triangular, forms the greater 
 part of the bone, its base above, its apex at the acetabulum. 
 
 The external surface, or dorsum, concave in front and be- 
 hind, presents from below upward 
 
 A groove, just above the acetabulum, for the reflected tendon 
 of the rectus femoris muscle; 
 
 The inferior curved line, marking the lower border of the 
 gluteus minimus; 
 
 The middle curved line, the longest of the three, marking the 
 lower border of the gluteus medius ; and 
 
 FlQ. 25. 
 
 1, Ilium; 2, Ischium; 3, pubes; 4, crest of Ilium; 5, S, and 7, 
 middle, inferior, and superior curved lines; 8 and 9, anterior superior 
 and inferior spinous processes; 10 and 11, posterior superior and 
 inferior spinaus processes; 12, spine of ischium; 13, great ^ sacro- 
 sciatic notch; 14, lesser sacro-sciatic notch; 15, tuberosity of ischium; 
 16, ramus of ischium and pubes; 17, horizontal ramus of pubes; 19, 
 acetabulum; 20, obturator foramen. 
 
 The superior curved line, the shortest marks the lower an- 
 terior border of the gluteus maximus, and from the surface below 
 which arise a few fibres of the pyriformis. 
 
 The upper expanded border forms the crest of the ilium, 
 terminating in front in 
 
 The anterior superior spinous process, giving origin to the 
 sartorius and tensor vaginse fem6ris muscles and Poupart's liga- 
 ment, below which is 
 
 The anterior inferior spinous process, for the ilio-femoral 
 ligament, and the straight tendon of the rectus femoris muscle; 
 and behind in 
 
OSTEOLOGY. 61 
 
 The posterior superior spinous process, for the oblique band 
 of the sacro-iliac ligament, and part of the multifidns spins 
 muscle, below which is — 
 
 The posterior inferior spinous process, for attachment of 
 the great sacro-sciatic ligament. 
 
 Between the superior and inferior spinous processes, both 
 anteriorly and posteriorly, is a notch, the former for partial at- 
 tachment of the sartorius and passage of the external cutaneous 
 nerve. 
 
 The internal concave surface, or venter, presents 
 
 The internal iliac fossa, lodging the iliacus muscle, and hav- 
 ing a nutrient foramen at its lower part ; 
 
 Ilio-pectineal line, limiting the fossa below, and separating 
 the false from the true pelvis ; 
 
 Rough surface, divided into two parts — an upper part for 
 posterior sacro-iliac ligaments, and lower auricular surface for 
 articulation with sacrum. 
 
 The ischium forms the outer back part of pelvis, and con- 
 sists of a body, tuberosity, and ascending ramus. 
 
 The external surface of the body forms a little more than 
 two-fifths of the acetabulum, and presents 
 
 A groove below, for the tendon of the obturator extemus. 
 
 The internal surface is concave and smooth, and forms the 
 lateral wall of the true pelvis. 
 
 The posterior border presents 
 
 The spine of the ischium, projecting downward, backward, 
 and inward, from below the centre, for attachment of the gemel- 
 lus superior, coccygeus, and levator ani muscles, and lesser sacro- 
 sciatic ligament; 
 
 Great sacro-sdatic notch, a deep notch above the spine con- 
 verted into a foramen by the lesser sacro-sciatic ligament, trans- 
 mitting the pyriformis muscle, superior gluteal nerve, gluteal 
 vessels, sciatic vessels and nerves, and the internal pudic vessels 
 and nerves; 
 
 Lesser sacro-sciatic notch, below the spine, and between it 
 and the tuberosity, converted into a foramen by the great sacro- 
 sciatic ligament, transmitting the obturator internus muscle and 
 nerve, the internal pudic vessels and nerves. The lowest portion 
 of the body presents : — 
 
 Tuberosity (tuber ischii), with 
 
 An outer lip, for attachment of part of adductor magnus, 
 and quadriceps femoris; 
 
 Inner lip, for part of great sacro-sciatic ligament, erector 
 penis, and transversus perinsei ; 
 
 Groove, on inner lip, for internal pudic vessels and nerve ; 
 
62 HUMAN ANATOMY. 
 
 Intermediate surface, for semi-membranosus, semi-tendino- 
 Bus, biceps, adductor magmis, gemellus inferior, and great sacro- 
 sciatic ligament. 
 
 The ascending ramus passes upward and inward from the 
 tuberosity to join the descending ramus of the pubes, forming 
 part of the inner margin of the obturator foramen. It gives 
 attachment to gracilis, obturator externus, part of adductor mag- 
 nus, erector penis, and transversus perinsei. 
 
 The pubes forms the anterior part of the pelvis, and con- 
 sists of a body, horizontal ramus, and descending ramus. 
 
 The body is quadrilateral, and presents 
 
 An anterior surface, for attachment of adductor longus and 
 brevis, and part of gracilis, adductor magnus, and obturator ex- 
 ternus ; 
 
 Posterior surface, forming anterior wall of true pelvis and 
 giving attachment to levator ani and part of obturator internus; 
 
 Spine, upon the upper border, for Poupart's ligament and 
 outer pillar of external abdominal ring ; 
 
 Ilio-pectineal line, continuous with that on ilium ; 
 
 Crest, along the upper border, internal to the spine; 
 
 Angle, at the junction of the inner border with the crest and 
 giving attachment to internal pillar of external ring ; 
 
 Symphysis, the internal oval border roughened by several 
 ridges for articulation with opposite bone. 
 
 The horizontal ramus joins the ilium, forming the upper 
 part of the obturator foramen, and presents at its lower border a 
 
 Groove, for the obturator vessels and nerve. 
 
 The descending ramus is flat and thin, and joins the ascend- 
 ing ramus of the ischium. 
 
 Each innominate bone articulates with three bones — ^the sa- 
 crum, femur, and its fellow of- the opposite side. 
 
 Its muscular attachments are thirty-three — [ilium], latissi- 
 mus dorsi, tensor vaginee femoris, obliquus externus, erector 
 spinee, transversalis, quadratus lumborum, gluteus minimus, 
 medius, and maximus, rectus, pyriformis, iliacus, multifidus 
 spinse, sartorius; [ischium], obturator externus and internus, 
 gemellus superior, coccygeus, levator ani, semi-membranosus and 
 semi-tendinosus, biceps, quadratus femoris, adductor magnus, 
 gemellus inferior, erector penis, and transversus perinsei; 
 [pubes], pyramidalis, obliquus internus and externus, psoas par- 
 vus, pectineus, adductor longus and brevis, gracilis, and com- 
 pressor urethrge. 
 
 Its ossific centres are eight — one primary for each division 
 and five epiphyses, one each for crest of ilium, symphysis, tuber- 
 osity of ischiumj anterior spinous process, and acetabulum. 
 
OSTEOLOGY. 
 
 63 
 
 fV" 
 
 The femur, or thigh-bone, is the largest, longest, and 
 strongest bone in the body. In the erect position it inclines 
 toward its fellow at the knee, being widely separated above, form- 
 ing the sides of a triangle, the base of which is greater in females 
 ±rom the greater breadth of the pelvis. In consists of a shaft, an 
 upper and lower extremity. 
 
 The shaft, expanded above and 
 below, curved and twisted, convex in 
 front, concave behind, is nearly cyl n- 
 drical throughout, and presents: — 
 
 Smooth anterior surface, for origin 
 of crureus and subcrureus musclis ; 
 
 Lateral surfaces, covered by the 
 vasti externus and intern us ; 
 
 The posterior surface, rough and 
 prominent, has its 
 
 Nutrient foramen between the mid- 
 dle and lower two-thirds directed up- 
 ward ; 
 
 Linea aspera, a rough, prominent, 
 longitudinal crest descending from the 
 trochanters along the middle third, bi- 
 furcating and diverging at the inferior 
 extremity to the condyles, inclosing 
 
 The popliteal space, a smooth, tri- 
 angular space, on which rests the pop- 
 liteal artery, and which is 
 
 Grooved at its inner margin by the 
 femoral artery. 
 
 The outer and inner lip of the linea 
 aspera give attachment to the vasti ex- 
 terni and interni, three adductors, pec- 
 tiiieus, biceps, and gluteus maximus. 
 
 The upper extremity presents the 
 following : — 
 
 The head, forming two-fifths of a 
 sphere, articulates with the acetabulum, 
 having a central oval depression for the 
 ligamentum teres ; 
 
 iV^ecfe^ pyramidal, with excavated surfaces, connects the head 
 with the shaft, the angle of its obliquity to the shaft varying 
 much from puberty to old age, being, in the adult, about 130° ; 
 
 The great trochanter, a large, rough, quadrilateral eminence, 
 directed upward, outward, and backward, its external surface 
 marked by a diagonal liae for insertion of gluteus medius ten- 
 
 FlO. 26. 
 
 1, shaft of femur; 2, 
 head; 3, necK; 4, great 
 trochanter; 6, anterior 
 trochanteric line;. 6, les- 
 ser trochanter; 7 and 8, 
 external and internal 
 condyles: 10, groove for 
 popliteus muscle; 9 and 
 11, external and internal 
 tuberosities. 
 
64 HUMAN ANATOMY. 
 
 don, its outer surface smooth for the passage of the gluteus maxi- 
 mus tendon, separated by a bursa, and its superior surface marked 
 by three impressions, from behind forward, for pyriforniis, obtu- 
 rator internus, and gemelli muscles. The gluteus minimus is 
 attached to the anterior border; 
 
 Digital or trochanteric fossa, to the inner side of the great 
 trochanter, for insertion of obturator externus tendon ; 
 
 The lesser trochanter, a small, conical projection at the base 
 of the neck posteriorly, and giving attachment to the tendon 
 of psoas magnus muscle, the iliacus being inserted below ; 
 
 Anterior intertrochanteric line, connects the trochanters in 
 front and gives attachment at its upper part to the capsular liga- 
 ment; 
 
 Posterior intertrochanteric line, a much more prominent 
 ridge, connects them behind ; 
 
 Tubercle of the femur, a prominence at the junction of the 
 neck with the great trochanter, is the meeting-place of five mus- 
 cles — two gemelli, obturator internus, gluteus minimus, and 
 vastus externus; 
 
 Tubercle of the quadratus, about the centre of the posterior 
 intertrochanter line, for the quadratus femoris; 
 
 Linea quadrati, passes vertically downward from the middle 
 of the posterior line, and gives attachment to part of adductor 
 magnus and quadratus femoris. 
 
 The inferior extremity, large and cuboidal in form, pre- 
 sents : — 
 
 External condyle, shorter and broader than the internal, has 
 behind its centre the outer tuberosity for the external lateral liga- 
 ments of the knee, and a groove below the tuberosity for the 
 tendon of the popliteus muscle. It also gives origin to the outer 
 head of the gastrocnemius, above which arises the plantaris mus- 
 cle; 
 
 The internal condyle, longer by half an inch and more 
 prominent (so as to bring them on the same horizontal plane 
 owing tb the obliquity of the shaft), has on the inner surface the 
 inner tuberosity for the internal lateral ligament; 
 
 Adductor tubercle, at the summit of the internal condyle, 
 marks the termination of the inner ridge of the linea aspera, and 
 gives attachment to tendon of adductor magnus ; 
 
 Depression, above the articular surface of the internal con- 
 dyle posteriorly, for the origin of the inner head of gastrocne- 
 mius; 
 
 Iritercondyloid notch, separates the condyles behind, and 
 lodges the crucial ligaments; 
 
OSTEOLOGY. 65 
 
 Trochlea is a smooth surface between the condyles in front 
 and articulates with the patella in front. The inferior surfaces 
 of both condyles are smooth, continuous in front, covered with 
 cartilage in the recent state, for articulation with the head of the 
 tibia. The femur articulates with three bones — ianominatum, 
 tibia, and patella. 
 
 Its muscular attachments are twenty-three (33) — ^two vasti, 
 three adductors, gluteus maximus, medius, and minimus, pyri- 
 formis, obturator externus and iatemus, two gemelli, quadratus 
 femoris, psoas magnus, iliacus, biceps, peetineus, crureus, sub- 
 crureus, gastrocnemius, plantaris, and popliteal. 
 
 Its ossific centres are five — ^three primary, one each for shaft 
 and each extremity, and one epiphysis for each trochanter. 
 
 The patella is a flat, triangular bone, sesamoid in origin, 
 developed in the tendon of the quadriceps extensor, forming the 
 knee-cap, and entering into the formation of the knee-joint. 
 
 The convex anterior surface is roughened by apertures for 
 nutrient vessels. 
 
 The posterior or internal surface is divided by a vertical and 
 transverse ridge into three surfaces — two smooth, articular facets, 
 for either condyle of femur above, the outer being deeper and 
 broader, and a rough surface below (apex) for ligamentum 
 patellae. 
 
 The superior harder gives attachment to the rectus and 
 crureus muscles, the internal and external lateral borders to the 
 vasti iuternus and externus. 
 
 It articulates with the femur. 
 
 Its muscular attachments are four muscles — rectus femoris, 
 crureus, vastus externus, and vastus internus. 
 
 It is developed from a single ossific centre. 
 
 The tibia, or shin-bone, extends on the internal aspect of 
 the leg from the knee to ankle, and consists of a shaft, upper and 
 lower extremity. 
 
 The shaft is triangular, prismoid, with the base above. 
 
 Its anterior iorder and internal surface are subcutaneous, 
 the former forming the shin or crest of the tibia. 
 
 The posterior surface presents above an oblique line for the 
 lower border of the popliteal muscle and fascia, and origin of the 
 soleus, and parts of flexor longus digitorum and tibialis posticus 
 muscles. 
 
 It presents just below the oblique line a nutrient canal, the 
 largest in the skeleton, directed downward. 
 
 Its external border, or interosseous ridge, is thin, for attach- 
 ment of interosseous membrane. 
 
 The external surface and internal borders are covered by 
 muscles. . 
 
66 
 
 HUMAN ANATOMY. 
 
 The superior expanded surface presents : — 
 
 Head J consisting of two lateral tuberosities, having each 
 upon their upper surfaces a smooth, concave, ovoidal articulating 
 facet for the condyles of the femur, separated by 
 
 The spinous process of the tibia, in front and behind which 
 is impression for crucial ligaments, and laterally tubercles for 
 the extremities of the semi-lunar cartilages; 
 
 FlQ. 27. 
 
 1, shaft o( tibia; 2 and 3, inner anfl 
 outer tuberosities; 4, spine; 6, tuber- 
 cle; 6, crest or shin; 7, lower ex- 
 tremity; 8, internal malleolus; 9, 
 shaft of fibula; 10, head of fibula; 11, 
 external malleolus. 
 
 Fig. 28. 
 
 1 and 2, articular surfaces; 3, In- 
 sertion of seml-membranosus; 5, ob- 
 lique line; 6, nutrient foramen; 7, 
 shaft of tibia; 9 and 14, grooves for 
 flexors; 13, external malleolus. 
 
 Tubercle, on the anterior surface of the head, between the 
 tuberosities, for the insertion of ligamentum patellae ; 
 
 Popliteal notch, separating the tuberosities posteriorly, for 
 attachment of posterior crucial ligament; 
 
 Transverse groove, on the posterior surface of the inner 
 tuberosity, for insertion of semi-membranosus tendon ; 
 
 Facet, upon the posterior surface of the outer tuberosity, for 
 articulation of the head of the fibula. 
 
OSTEOLOGY. 67 
 
 The inferior extremity, smaller than the superior, is quadri- 
 lateral, and presents in front a smooth surface for extensor ten- 
 dons, behind a groove for flexor longus pollicis tendon, externally, 
 a rough, triangular, articular surface, for fibula, and internally 
 
 The internal malleolus, which projects downward, and ar- 
 ticulates by its outer surface with the astragalus. 
 
 Its inner surface is smooth and subcutaneous ; its posterior 
 border is grooved for the tendons of the tibialis posticus and 
 flexor longus digitorum muscles, and to its tip is attached the in- 
 ternal lateral ligament. 
 
 It articulates with three bones — femur, flbula, and astraga- 
 lus. 
 
 Its muscular attachments are twelve — ^ligamentum patellce, 
 popliteus, soleus, flexor longus digitorum, tibialis posticus, semi- 
 membranosus and tendinosus, gracilis, sartorius, tibialis anticus, 
 and extensor longus digitorum, biceps. 
 
 It is developed from three ossific centres, one each for shaft, 
 upper and lower extremities. 
 
 The fibula, or peroneal bone, is a long, slender bone on the 
 outer aspect of the leg, and consists of a shaft, upper and lower 
 extremity. 
 
 The shaft is prismoidal, four-sided, twisted on itself, and 
 arched backward. Its antero-internal border, or interosseous 
 ridge, gives attachment to the interosseous membrane. The 
 postero-internal border, called also ohlique line, and the other 
 surfaces and borders give attachment to all the muscles except the 
 biceps. 
 
 Nutrient foramen, about the middle of the anterior internal 
 surface, is directed downward. 
 
 The superior extremity presents a neck, supporting a 
 rounded, irregular head, which articulates by a flattened facet on 
 its inner surface with the tibia, and is prolonged upward on its 
 outer side by the styloid process, giving attachment to the biceps 
 tendon and the external lateral ligament of the knee. 
 
 The inferior extremity expands into the external malleolus, 
 with its convex internal surface for articulation with astragalus, 
 outer convex surface subcutaneous, and posterior border deeply 
 grooved for tendons of peroneus longus and brevis muscles. 
 
 To the summit is attached the middle fasciculus of the ex- 
 ternal lateral ligament, and to rough depressions in front and 
 behind the anterior and posterior fasciculi. 
 
 It articulates with two bones, tibia and astragalus. 
 
 Its muscular attachments are nine — soleus, biceps, three 
 peront'i, tibialis posticus, flexor longus halliicis, and extensor 
 longus digitorum and hallucis. 
 
68 HUMAN ANATOMY. 
 
 It is developed from three ossific centres, one each for shaft, 
 head, and malleolus. 
 
 THE FOOT. 
 
 The bones of the foot consist of seven tarsns, five metatarsus, 
 and fourteen phalanges. 
 
 The tarsal bones are — calcaneum, astragalus, cuboid, sca- 
 phoid, and internal, middle, and external cuneiform. 
 
 They may be arranged into two series, anterior and posterior, 
 the calcis and astragalus behind, and all the others in front of 
 the calcaneo-cuboid, astragalo-scaphoid joint [Chopart's]. 
 
 Calcaneum, or os calcis, the largest, is irregularly cuboidal. 
 
 The superior surface presents two articular surfaces for the 
 astragalus, separated by a groove for the calcaneo-astragaloid 
 ligament, and internally a projecting process, the sustentaculum 
 tali, for calcaneo-cuboid ligament. The inferior surface, rough 
 and excavated, presents two tubercles, an outer and inner tubercle, 
 for muscles and ligaments. 
 
 Internal surface is concave, for passage of flexor longus, and 
 tibialis posticus tendons, and plantar vessels and nerves. 
 
 External surface presents tubercle for external lateral liga- 
 ment of ankle and grooves for peroneal tendons. 
 
 Posterior surface, projecting behind, presents a smooth sur- 
 face above for bursa and rough below for attachment of tendo 
 Achillis. 
 
 It articulates with astragalus and cuboid. 
 
 Muscular attachments are eight — tendo Achillis, plantaris, 
 tibialis posticus, abductor pollicis and minimi digiti, flexor 
 brevis, digitorum and accessorius, extensor brevis digitorum. 
 
 Astragalus is an irregular, short bone, consisting of body, 
 neck, and head. The quadrilateral body presents four articular 
 surfaces, above for lower extremity of tibia and internal mal- 
 leolus and external malleolus; below two surfaces for os calcis, 
 separated by deep groove for interosseous calcaneo-astragaloid 
 ligament; posteriorly it presents a deep groove for flexor longus 
 pollicis tendon; and anteriorly, the rounded convex head sup- 
 ported on nech articulates with scaphoid, and rests upon calcaneo- 
 Ecaphoid ligament. 
 
 It articulates with four bones — tibia, fibula, scaphoid, and 
 OS calcis. It has no muscular attachments. 
 
 Cuboid (cube-like) is a small, pyramidal bone, between the 
 OS calcis and the fourth and fifth metatarsal bones on the outer 
 side of the foot. 
 
 The upper or dorsal surface is rough for ligamentous attach- 
 ment; the lower or plantar surface is grooved for tendon of pero- 
 
OSTEOLOGY. 69 
 
 neiis longus, behind which is a ridge for the long ealcaneo-cuboid 
 ligament, terminating externally in the tuberosity of the cuboid. 
 
 The external surface has a deep notch, the outer extremity of 
 the peroneal groove. 
 
 The posterior surface has triangular facet for os calcis, the 
 anterior has two facets, separated by a ridge for the fourth and 
 fifth metatarsals, and the internal surface has broad, square facet 
 for external cuneiform, and sometimes a smaller facet for sca- 
 phoid. 
 
 Fia. 29. 
 
 1. OS calcis; 2. 2, outer and Inner tuberosity; S, groove for flexor 
 loDgus poUicis; 4, head of astragalus; 6, tubercle ot scaphoid; 7, 8, 
 9, internal, middle, and external cuneiform bones; 10, cuboid; 11, 
 groove for peroneus longus; 12, 12, metatarsal bones; 13, 11, 16, 
 phalanges. 
 
 It articulates with four and occasionally with five bones. 
 
 It has one muscular attachment — part of flexor brevis pol- 
 licis. 
 
 Scaphoid, or navicular bone, is a boat-like bone placed be- 
 tween astragalus and three cuneiform bones. 
 
 Its posterior concave surface articulates with head of as- 
 tragalus, its anterior convex surface has three facets for cunei- 
 form bones; its internal border presents the tuberosity of the 
 scaphoid for insertion of tibialis posticus, the only muscular at- 
 tachment. Its other borders are roughened for ligamentous at- 
 tachment. 
 
70 HUMAN ANATOMY. 
 
 It articulates with four bones — astragalus and three cunei- 
 forms. 
 
 The cTineiform bones are named from their position the in- 
 ternal, middle, and external. 
 
 The internal cuneifoem, the largest, has its base below, 
 and articulates anteriorly with first metatarsal, posteriorly with 
 scaphoid, and externally with second metatarsal and middle 
 cuneiform. The plantar surface presents tuberosity for insertion 
 of part of tibialis posticus and antieus tendons, the only muscular 
 attachments. It articulates with four bones — scaphoid, middle 
 cuneiform, first and second metatarsals. 
 
 The middle cuneifokm, the smallest, has its base upward, 
 and articulates posteriorly with scaphoid, anteriorly by a tri- 
 angular facet with second metatarsal, and laterally with internal 
 and external cuneiforms. It has no muscles attached. 
 
 The external cuneiform, intermediate in size, and more 
 regular, articulates posteriorly with scaphoid, anteriorly with 
 third metatarsal, internally with middle cuneiform and second 
 metatarsal, and externally with cuboid and fourth metatarsal. 
 
 Muscular attachments are for flexor brevis pollicis and 
 tibialis posticus. 
 
 The metatarsal bones have the same general form as the 
 metacarpal bones of hand, each consisting of shaft, head, and 
 base. 
 
 The shaft is prismoid and curved, with concavity below, con- 
 vexity above. 
 
 The head is rounded for articulation with phalanges, and has 
 tubercles laterally for ligaments and a groove below for tendon 
 of long flexor. 
 
 The base is wedge-shaped for articulation with the tarsus 
 and with each other. 
 
 The first and strongest articulates at base with internal 
 cuneiform, at head with phalanx and second metatarsal, and has 
 three muscular attachments — for tibialis antieus, peroneus lon- 
 gus, and first dorsal interosseous. 
 
 The second is wedged in by base between three cuneiform 
 bones, articulates with second phalanx, first and third metatarsi, 
 and has three muscular attachments — for adductor hallucis, first 
 and second interosseous. 
 
 The third articulates with external cuneiform below and sec- 
 ond and third metatarsi and third phalanx, and has four muscu- 
 lar attachments — for adductor hallucis, first plantar, and second 
 and third dorsal interossei. 
 
 The fonrih articulates at base with external cuneiform and 
 cuboid and at extremity with third and fifth metatarsal and 
 
OSTEOLOGY. 71 
 
 fourth phalanx, and has four muscular attachments — for ad- 
 ductor hallucis, third and fourth dorsal, and second plantar 
 interossei. 
 
 The fifth has marked tubercle on outer side. It articulates 
 with cuboid, fourth metatarsal, and fifth phalanx, and has five 
 muscular attachments — for flexor brevis minimi digiti, peroneus 
 brevis and tertius, fourth dorsal, and third plantar interosseus. 
 
 The phalanges have same general characteristics as in 
 hand, but are compressed from side to side instead of from before 
 backward. The muscular insertions to first row are — to great 
 toe, transversus pedis, extensor brevis digitorum, adductor, ab- 
 ductor, and flexor brevis hallucis ; to second, first and second dor- 
 sal interosseus; to third, third dorsal and first plantar inter- 
 osseus; to fourth, fourth dorsal and second plantar interosseus; 
 to fifth, abductor and flexor brevis minimi digiti and third 
 plantar interosseus. To second row — ^to great toe, flexor and 
 extensor longus hallucis ; to remaining toes, extensor longus and 
 brevis digitorum, flexor brevis digitorum, and lumbricales. To 
 third row, or ungual phalanges — flexor longus and extensor 
 longus and brevis digitorum. 
 
 The ossiflc centres are one each for the tarsus, excepting the 
 OS calcis, which has an epiphysis for posterior part, and two each 
 for metatarsals and phalanges. These latter are arranged in 
 phalanges, one each for shaft and base, and in metatarsals, one 
 each for shaft and head, excepting great one, which has one each 
 for shaft and base. 
 
 Sesamoid bones are small, osseous masses, cartilaginous in 
 early life, developed in the tendons to relieve pressure. They are 
 of two kinds — those over articular surfaces of joints, as patella ; 
 and those applied to the surfaces of bones, as in tendon of pero- 
 neus longus in the groove of cuboid bone. 
 
72 
 
 HUMAN ANATOMY. 
 
 Name. 
 
 VEKTEBEiE. 
 
 Atlas (3). 
 Axis (G). 
 
 Seventh Cervical. 
 
 Lumbar Verte- 
 
 brse (2). 
 Sacrum (35). 
 
 15. 
 
 10. 
 
 0. 
 4. 
 
 Coccyx (7). 
 
 Cranial 
 Bones. 
 
 Occipital (7). 
 
 Parietal (1). 
 
 TABLE OF OSSIFICATION. 
 
 Centres. 
 
 3 Primary: — 
 
 1 for each lamina. 
 1 for each process. 
 1 for body. 
 
 4 Secondary Centres: — 
 
 1 for ea,ch transverse process. 
 
 2 for end of spinous process. 
 2 Additional Plates: — 
 
 1 epiphyseal plate on upper and 
 under surface of body. 
 
 1 for each lateral mass. 
 
 1 epiphysis for anterior arch. 
 
 1 for lower part of body. 
 
 1 for each lamina. 
 
 2 for lateral processes. 
 
 1 for apex of odontoid process. 
 1 for anterior and costal part of 
 transverse process. 
 
 1 for each tubercle of superior 
 articular process. 
 
 3 — 1 for each body 
 
 and upper and lower epiphys- 
 eal plate. 
 
 2 — 1 for each arch. 
 
 2 for each lateral mass of the first 
 three vertebrae. 
 
 Each lateral surface has one epi- 
 physeal articulation and ad- 
 joining edge. 
 
 1 for each piece. 
 
 1. 
 
 2. 
 
 3. 
 
 4. 
 
 4 for tabular or epi-occipital. 
 1 for each condylar portion. 
 
 1 for basilar portion. 
 
 From membrane. 
 
 Single centre at parietal eminence. 
 
 Time of 
 
 Appearance. 
 
 Cth week. 
 8th week. 
 I6th year. 
 
 21st vear. 
 
 AH unite by 30th 
 
 year. 
 8th week. 
 1st year. 
 6th month. 
 
 6th foetal month. 
 
 Cth foetal month ; 
 joins 5th or 6th 
 year. 
 
 8th or 9th week, 
 loth year, and 
 
 unites 18th or 
 
 20t'h year. 
 6th or 8th month; 
 
 joins 2d to 6th 
 
 year. 
 
 18th to 25th year. 
 
 Birth. 
 
 5th to 10th year. 
 lOlh to 15th year. 
 15th to 20th year. 
 
 8th foetal week. 
 
 4th to 6th year; 
 joined to sphe- 
 noid 18th to 
 25th year. 
 
 7th to 8th foetal 
 week. 
 
OSTEOLOGY. 
 
 73 
 
 Name. 
 Frontal (2). 
 
 Temporal (10). 
 Sphenoid (14). 
 
 Ethmoid (3). 
 
 Face. 
 Nasal. 
 
 Superior Max- 
 llliB (4). 
 
 Lachrymal. 
 Malar. 
 Palate. 
 
 Inferior Turbi- 
 nated, 
 
 Vomer. 
 Inferior Maxilla. 
 
 Body. 
 Hjoid (5). 
 
 Centres. 
 
 1 for each lateral portion. 
 From membrane. 
 
 1 for squamous process. 
 
 1 for auditory process. 
 6 for petro-raastoid. 
 
 2 for styloid process. 
 8 for post-sphenoid. 
 
 1 for each greater wing and ex- 
 ternal pterygoid plate. 
 1 for each internal pterygoid plate. 
 
 Time of 
 Appearance. 
 
 7th to 8th week. 
 
 United by 4th- 
 year. 
 
 2d month. 
 
 Later. 
 
 5th or 6th month. 
 
 2 for posterior part of body. 
 
 1 for base ap- 
 
 
 pears before 
 birth and one 
 
 
 after birth. 
 
 1 for each lingula. 
 
 
 6 for pre-sphenoid: — 
 1 for each lesser wing. 
 
 Appear from 8th 
 week to third 
 
 2 for anterior portion of body. 
 1 for each spheno-turbinal. 
 
 year, and union 
 of all parts is 
 
 
 accomplished 
 by the 20th 
 
 
 year, and with 
 occipital, 18th 
 to 25th year. 
 
 1 for each lateral mass. 
 
 4th to 5th foetal 
 
 
 month. 
 
 1 for lamella. 
 
 Unite about 2d 
 
 
 year. 
 
 1 for each bone. 
 
 6th week. 
 
 1 pre-maxilla. 
 
 1 pre-palatine portion. 
 
 Very early. 
 Antrum appears 
 about fourth 
 
 
 fcetal month. 
 
 1 maxillary portion. 
 1 malar 
 
 
 A single centre. 
 
 7th week. 
 
 Single centre. 
 
 6th week. 
 
 Single centre at junction of plates. 
 
 2d foetal month. 
 
 Single centre. 
 
 Middle of foetal 
 
 
 life. 
 
 Single centre, but two faminae. 
 
 8th week. 
 
 Probably several centres ; at birth 
 consists of two halves. 
 
 Very early, be- 
 ing second in 
 
 
 order. 
 
 1 for body and for each comua. 
 
 3 months after 
 
 
 birth. 
 
74 
 
 HUMAN ANATOMY. 
 
 Name. 
 Sternum (6). 
 
 Ribs (3). 
 
 Upper 
 
 exteemitt. 
 
 Clavicle (2). 
 Scapula (7). 
 
 Humerus (7). 
 
 Ulna (3). 
 Badiua (3). 
 
 Carpus. 
 
 Centres. 
 
 1 for manubrium. 
 
 4 for gladiolus. 
 
 1 for ensiform appendix. 
 
 1 for each shaft, head, and tuber- 
 cle, excepting the last two, 
 which have but 2, the tuber- 
 cles being absent. 
 
 1 for shaft. 
 
 1 for sternal extremity. 
 
 1 for body. 
 
 2 for coracoid process. 
 2 for acromion process. 
 1 for posterior border. 
 1 for inferior angle. 
 
 1 for shaft. 
 
 1 for head. 
 
 1 for tuberosities. 
 
 1 for radial head. 
 
 1 trochlear portion. 
 1 for each condyle. 
 
 1 for shaft. 
 
 1 for olecranon. 
 
 1 for lower extremity. 
 
 1 for shaft. 
 
 1 for upper extremity. 
 1 for lower extremity. 
 
 Each has single centre: — 
 Os magnum. 
 Unciform. 
 Cuneiform. 
 
 Trapezium and semi-lunar. 
 Scaphoid. 
 Trapezoid. 
 Pisiform. 
 
 Time of 
 Appearance. 
 
 Middle of foetal 
 
 life. 
 
 Before vertebrae. 
 Epiphysis for 
 tubercle ap- 
 pears from 
 16th to 20th 
 year, and 
 unites about 
 25th. 
 
 About 30th day. 
 2d month. 
 
 Completed b e - 
 tween 20 th and 
 25th year. 
 
 8th week. 
 
 Upper extremity 
 ossifies 2d to 
 4th year. 
 
 Complete about 
 
 20th year. 
 8th week. 
 10th year. 
 4th year. 
 Soon after hu- 
 merus. 
 6th year; unites 
 
 17th to 18th 
 
 year. 
 2d year ; unites 
 
 20th year. 
 Upper extremity 
 
 joins 16th year; 
 
 lower, 20th 
 
 year. 
 
 1st year. 
 1st year. 
 3d year. 
 5th year. 
 6th year. 
 8th year. 
 12th year. 
 
OSTEOLOGY. 
 
 75 
 
 Name. 
 Metacarpus (2). 
 
 Phalanges (2). 
 
 LOWEB 
 
 EXTBEMITT. 
 
 Os Inuominata 
 (8). 
 
 Femur (5) 
 
 Patella. 
 
 Tibia (3). 
 
 Fibula (3). 
 
 Centres. 
 
 Centres for each: — 
 1 for shaft and 
 
 1 for each distal extremity ex- 
 cept thumb, which has one 
 each for shaft and base. 
 
 1 for each shaft and base. 
 
 3 Primary: — 
 Ilium. 
 
 Ischium. 
 Pubes. 
 5 Secondary: — 
 1 crest of ilium. 
 1 anterior inferior spinous proc- 
 ess. 
 1 tuber isehii. 
 1 symphysis pubis. 
 1 acetabulum. 
 
 1 for shaft. 
 1 for upper extremity. 
 1 for lower extremity. 
 1 for great trochanter. 
 1 for lesser trochanter. 
 
 Single centre. 
 
 1 for shaft. 
 
 1 upper extremity. 
 
 1 lower extremity. 
 
 1 for shaft. 
 
 1 upper extremity. 
 
 1 lower extremity. 
 
 Time of 
 Appearance. 
 
 8th or 9th week. 
 3d year, and 
 
 unites about 
 
 20th year. 
 
 8th week, and 
 unites 18th to 
 20th year. 
 
 Same as verte- 
 brse, 6th week. 
 3d month. 
 4th or 5th month. 
 
 Puberty. 
 
 13th or 14th year; 
 completed 25th 
 year. 
 
 5th week. 
 
 End of 1st year. 
 
 9th foetal month. 
 
 4th year. 
 
 13th or 14th year. 
 
 Inferior extrem- 
 ity. The last 
 is not united 
 before the 20th 
 year. 
 
 3d to 6th year; 
 completed 
 about puberty. 
 
 7th week. 
 Birth; unites 
 
 20th year. 
 2d year ; unites 
 
 18 th year. 
 
 8th foetal week. 
 
 4th year. 
 
 2d year; the 
 lower unites 
 first — about 
 20th year. 
 
76 
 
 HUMAN ANATOMY. 
 
 Name. 
 
 Centres. 
 
 Time of 
 Appearance. 
 
 
 
 Tarsus. 
 
 4 OS calcis: — 
 
 
 
 1 for body and 
 
 6th foetal month. 
 
 
 1 for posterior extremity. 
 
 
 
 1 each for the following: — 
 
 
 
 Cuboid. 
 
 9th month. 
 
 
 Astragalus. 
 
 7th « 
 
 
 Scaphoid. 
 
 4th year. 
 
 
 Internal cuneiform. 
 
 3d " 
 
 
 Middle 
 
 4th " 
 
 
 External 
 
 1st '• 
 
 Metatarsus. 
 
 1 for each shaft 
 
 7th week. 
 
 
 and digital extremity, 
 
 3d year. 
 
 
 except great toe, which is 
 
 
 
 same as thumb. 
 
 
 Phalanges (2). 
 
 1 for each shaft and proximal ex- 
 
 
 trcmity. 
 
OSTEOLOaY. 
 
 77 
 
 Fig. 30. 
 Frontal bone, outer surtacOb 
 
 «^ Sap Maxdi ^^^^^^l^f^Yl^^^^' '^FrontaZ Sinut 
 
 Fig. 31. 
 Frontal bone, inner surface. 
 
78 
 
 HUMAN ANATOMY. 
 
 
 FIG. 32. 
 Parietal bone, outer surface. 
 
 rMl-I«fcrJ{: 
 
 ■hit InJiT.SMjU 
 
 FIQ. 
 
 Parietal bone, inner surface. 
 
OSTEOLOGY. 
 
 79 
 
 Occipital bone, outer surface. 
 
 
 Fio. 35. 
 Occipital bone, inner surface. 
 
8C0 
 
 HUMAN ANATOMY. 
 
 fa 4 fen 
 
 Fig. 36. 
 Left temporal bone, outer surface. 
 
 ■oQ^rtP- t.tt,i 
 
 J)cpTC::.LMt fn VumiiuiCrr 
 
 Ojilrm.71^ for SfiaJIff PctTCSJci-Ntti* 
 BrulU thisstd lArouifJi Cztatj^ CtiM.'J 
 
 FiQ. 37. 
 Left temporal bone, inner surface. 
 
OSTEOLOGY. 
 
 81 
 
 
 STYLO-PMARYMCED5 
 
 Umijh ^tuidrilaUTnl Surface 
 Vfr-nivq of ta.ruti<l caind- 
 Caniil/Jbr Ja£obfon\ nerve 
 Ai^urdiif.TMS Cur/Uct£- 
 CaTin-L fi^r Ariwldi Tierve 
 JuffuJar Jo S3 a. 
 Vagi nal- process 
 SiylmJ. p races^ 
 Stif}o-ma,-^rmd foravicT. 
 JiKjiil/tT Si'.rfacc 
 
 Fig. 38. 
 Left temporal bone, inferior surface of the petroas portion. 
 
 Fig. 39. 
 
 Section of the temporal bone (natural size) through the middle 
 ear. Fallopian canal, mastoid antrum, and cells, showing dense bone 
 between the antrum and cells, with no communication between them: 
 1, drumhead; 2, tip of the mallet handle; 3, anvil, showing the long 
 cms at the right for articulation with the stirrup, and the short proc- 
 ess at the left which serves the purpose of an anchor to the bone; 4, 
 head of the mallet; 5, tensor- tympani muscle and tendon; 6, dense 
 bone where pneumatic spaces are usually found; 7, pneumatic cells in 
 the tip of the mastoid process; 8, Fallopian canal, for the facial nerve; 
 fl, the stirrup. At the right of 9 and at the left, of the anvil is the 
 aditus ad antrum, connecting the tympanum with the antrum. 
 
82 
 
 HUMAN ANATOMY. 
 
 ^FiMU CU^^id 
 
 laramm Optiei 
 
 jTummi.n Bctusi'hi.-m- 
 m OfoU ■ 
 
 Fig. 40. 
 Sphenoid bone, upper surface. 
 
 ^tvT^Jo'td 
 
 LAXATOR TYMFANI 
 
 Pia. 41. 
 Sphenoid bone, anterior surface. 
 
OSTEOLOGY. 
 
 83 
 
 VitJt tnf.'turbinateU 6. 
 
 Fig. 42. 
 EthmoicI bone. 
 
 tvCth frontal B, 
 
 •Ojpotitt hon*. 
 
 (Outer surface.) 
 
 Pig. 43. 
 Nasal bones. 
 
 iAFronba 
 
 vnith 
 
 TrotteaT i^piti^ 
 
 orexi 
 
 vrifh 
 
 J'lateifElJimoii, 
 
 groove for luitainerao 
 
 (Inner surface.) 
 
 Fig. 44. 
 Lachrymal bone. 
 
844 
 
 HUMAN ANATOMY. 
 
 T^IioehTymat tubtftle. 
 
 TbNns ecu II 
 
 ■Incisive fossa- 
 
 , i^J^^~^ Posterior Jifnlal CaaaJa 
 
 £iastUa.ru Tulercsi^, 
 
 Fig. 45. 
 
 Superior maxillary bone. 
 
 marfad in aadin^ 
 
 
 t.Nia9at&)int 
 
 BritiU 
 pdatsd through 
 Ant.ffnlat, CmioI 
 
 Fig. 46. 
 Superior maxillary, Inner surface. 
 
OSTEOLOGY. 
 
 85 
 
 FIG. 48. 
 Inferior maxillary bone 
 
 :mo-Hve-aio3SXis 
 
 'CENIO-HY0IDEV9 
 
 B dy 
 
 Pig. 49. 
 
 Left half of inferior maxillary bone, inner surface. 
 
HUMAN ANATOMY. 
 
 
 (Outer surface.) 
 
 (Inner surface.) 
 
 Fig. 50. 
 Malar bones. 
 
 Sitfr trier Jtfjai 
 
 FIG. 51. 
 Palate bone (viewed posteriorly). 
 
 MOBIZONTAL ftATE 
 
 Fig. 52. 
 Palate bone (inner surface). 
 
 (Inner suiface.) 
 
 (Outer surface.) 
 
 Fig. 53. 
 Inferior turbinated bones. 
 
OSTEOLOGY. 
 
 87 
 
 S,00f 
 
 I — 'Nato-lnehnfinal Cnitirl 
 
 A7it.Naia.l Sj 
 
 eaJatt 1'toc of Sup ftoji 
 
 ihlatu I^oc. ofT iaU- 
 
 Poit.Na.aaL £pi. u, 
 
 ^Tit. Pahuim Canal 
 
 Outer Wail 
 
 I, ftfh wijrruiL 
 Uneifinmi-toa rf diUa 
 -Pa Into 
 
 Fig. 54. 
 Nasal meatuses. 
 
 r/ii/ro'hywdi. 
 
 Qoaio-huoid Stemu-hyoul. 
 
 Pig. 55. 
 The byoid bone. 
 
HUMAN ANATOMY. 
 
 TEHD3 oeULt 
 
 
 Grcffv» fitr I'aclobt af 
 
 Fig. 56. 
 Facial portion of skull. 
 
OSTEOLOGY. 
 
 89 
 
 \^^=JkiJismiU A'Tii palat vcss. 
 
 Aeeetaory palatini 
 Frrmntna. , 
 
 "TltTt/gu-poilatln* C. 
 
 ■FMaTygu/ea.lSpiTu.fiiT»^r. CONBTKICS 
 
 ' [U««Euce Ciihliit.' 
 
 *r. laeara mjaawttftur. 
 CaiuUfurAmolUi- A 
 
 Fig. B7. 
 Base ol skull, external surface. 
 
90 
 
 HUMAN ANATOMY, 
 
 Uimn-ciiiBa. imctoid 
 
 Fig. 68. 
 Sternum and costal cartilages. 
 
OSTEOLOGY. 
 
 91 
 
 J^sK, /' 
 
 
 FlQ. 59. 
 
 \Tbe peculiar ribs. 
 
92 
 
 HUMAN ANATOMY, 
 
 
 Q 
 
 O 
 C 
 
 2- 
 
 /3 
 
 ^^ '^O'.K^X 
 
 Fig. 60. 
 The vertebral column, or splno. 
 
OSTEOLOGY. 
 
 93 
 
 Suffrhi Artie. Aoettt__ 
 
 Htvit.faett kr hrad efXih 
 
 Ftuetfii- TtiheiclgofSJh- 
 
 DemiJaMtfir1uii.df ^JtH 
 Infer. ArticFTOo. 
 
 FIG. 61. 
 A dorsal vertebra. 
 
 AiiterinrTuhrelf of Trant.T'TW. .. 
 
 Foramen far Vertebral Art 
 BrteiiffrTiilerjilf n/Trant.Froi 
 
 FlO. 62. 
 
 A cervical vertebra. 
 
 'amveric J?Toei3a. 
 
 J^tr^n ATttcibLa.r ProeesS 
 nferiorAjticiila r Frocesa 
 
 Fig. 63. 
 Seveoth cervical, or vertebra promlneoa. 
 
94i 
 
 HUMAN ANATOJiy. 
 
 Odontoid Fi'os , 
 
 Sough Suff.fff CAteh Li^ 
 Ajtu. Surf./fr Tratu.tiyf — 
 
 Spfa.hva. 
 
 Artir. Sar/.farAtla» 
 
 ■h-Boif 
 
 Fig. 64. 
 The axis. 
 
 TuOerc//!- 
 
 Trmts.Froct- 
 
 Vorteiral Arts 
 
 Groove fer V^ro^A Art f 
 
OSTEOLOGY. 
 
 95 
 
 
 Ii»nUf*«iO aitia 
 
 l—OSEjmltrt/aeJl 
 
 An tntire/iui^ 
 No.fae*t en 7>u nc AM 
 
 An fittir^/aett 
 K Safa4tteaTia**.JI> 
 ' Inftr.Artie.Pret 
 
 Fig. 66. 
 Peculiar dorsal vertebraa. 
 
 St^en Aptie^ Prac. 
 
 Fio. 67. 
 A lumbar vertebra. 
 
96 
 
 HUMAN ANATOMY. 
 
 J'raTjujntory 
 
 Fig. 68. 
 The sacrum, anterior surface. 
 
 Fig. 69. 
 The sacrum, posterior surface. 
 
OSTEOLOGY. 
 
 97 
 
 ^i,.r„,.,i«i&f.'' 
 
 S/^rTiat ExtrtmUij 
 
 Fig. 70. 
 The lett clavicle, upper surlaco. 
 
 FIG. 71. 
 The lett clavicle, under surface. 
 
98 
 
 HUMAN ANATOMY. 
 
 FlQ. 72. 
 The scapula, anterior surface. 
 
OSTEOLOGY, 
 
 99 
 
 Cernema 
 
 v''"'-* 
 ^a:^*^. 
 
 Fig. 73. 
 The scapula, posterior surface. 
 
noo 
 
 HUMAN ANATOMY. 
 
 ';? 
 
 ATreoAL 
 
 ■uiumB utvii 
 
 FIC3. 74. 
 The humerus, anterior surface. 
 
 Fig. 75. 
 
 The humerus, posterior 
 surface. 
 
OSTEOLOGY. 
 
 101 
 
 R M.0 t It a 
 
 IttOII DICITORUH- 
 tUOLIMIB 
 
 ^rlcxan 
 
 Stylaui jfrsceat 
 
 Pig. 76, 
 Ulna and radius, anterior aspect. 
 
 HETMAWI rsLMCia 
 IHTHNsaiirOUlCIf 
 
102 
 
 HUMAN ANATOMY. 
 
 FLCxon DiotTOBS 
 
 ^UT. CARPI K D, 
 
 CJtT.CAftPt ItAD.BKKVIi 
 1BT. BKOUKDI INTSRNODU NtLlDt^ 
 
 fir tXt. CARPI IJLNAB. 
 
 Fig. 77. 
 Radius and ulna, posterior aspect. 
 
OSTEOLOGY. 
 
 103 
 
 
 'l^Jtuir 
 
 Fig. 78. 
 Carpus, metacarpus, and phalanges, dorsal surface. 
 
104 
 
 HUMAN ANATOMY. 
 
 fi.niDR.cAIIPl ULnAitia 
 
 M.EXOR BUEVIS minimi DICITI 
 
 fLEXen OSSIS MBTftCARPI 
 MINIMI DICITI 
 
 Metaear/iu* 
 
 
 PiQ. 79. 
 Carpus, metacarpus, and phalanges, palmar surface. 
 
OSTEOLOGY. 
 
 105 
 
 aueujis Mvcjuai 
 
 Fig. 80. 
 Os innominatum, outer surface. 
 
106 
 
 HUMAN ANATOMY. 
 
 Fig. St. 
 Os innominatum, inner surface. 
 
OSTEOLOGY. 
 
 107 
 
 Via. 82. 
 
 Tbe temur, anterior 
 surface. 
 
 Fio. 83. 
 
 Tbe lemur, posterior 
 surlace. 
 
108 
 
 HUMAN ANATOMY. 
 
 ^e aa 
 
 Bl^M>l^ 
 
 XKUraal M«It,Btuw 
 
 Fio. 84. 
 
 The tibia and fibula, anterior 
 surface. 
 
 '^3jlTKUt 
 
 Fig. 85. 
 
 The tibia and fibula, posterior 
 surface. 
 
OSTEOLOGY. 
 
 109 
 
 ruxBi UHen rouicii 
 
 Ifetataratefi 
 
 .IRCVIl OICITonul* 
 
 iiy«# 
 
 tXT. lANDHS rOLblGIB 
 
 Fig. 86. 
 The tarsus, metatarsus, and phalanges, dorsal surface. 
 
110 
 
 HUMAN ANATOMY, 
 
 
 riaijiui tHTiouM 
 
 Fig. 87. 
 Thn tarsus, metatarsus, and phalanges, plantar surface. 
 
ARTICULATIONS AND LIGAMENTS. 
 
 The bones of the skeleton are connected together by articu- 
 lations or joints. 
 
 These consist essentially of the expanded extremities of 
 bones, covered with cartilage, often separated by interarticular 
 fibro-cartilage, held together by ligaments, and lined by synovial 
 membrane. 
 
 The bone entering into the articular lamella differs from 
 ordinary bone by its extreme density, w^ithout Haversian canals, 
 its lacunae being much larger, and without canaliculi. It is not 
 perforated by blood-vessels. 
 
 Cartilage is a whitish, highly elastic, non-vascular structure, 
 forming in the foetus the greater part of the skeleton, and found 
 in the adult chiefly in the joints, the walls of the thorax, and 
 certain orifices, as the nostrils, ears, etc. 
 
 It is either temporary, becoming ossified later, or permanent, 
 remaining unossifled. The latter is divided into three varieties : 
 articular, in joints covering the ends of the bones ; costal, form- 
 ing part of the thorax; and reticular, arranged in plates or 
 lamellae to maintain the shape of parts. 
 
 Fibro-cartilage consists of a mixture of cartilaginous with 
 white fibrous tissue. There are four varieties : — 
 
 (a) Interarticular, interposed between the joint surfaces; 
 (i) Connecting, binding bones together as in pubes; 
 (c) Circumferential, deepening cavities, as glenoid cavity of 
 shoulder; and 
 
 (dj Stratiform, lining grooves for tendons. 
 
 Synovial membranes are of three kinds: articular, lining 
 the cavities of movable joints throughout except the surface of the 
 cartilage ; bursal, irregular cavities interposed at convenient posi- 
 tions to alleviate friction; from their contents they may be 
 either mucous or sjmovial ; and vaginal synovial membranes, or 
 sheaths, surrounding tendons and diminishing friction. 
 
 Synovia is a transparent, viscid liquid, albuminous in :ts 
 nature. 
 
 The articulations consist of three (3) classes: diarthrosis, 
 movable; synarthrosis, immovable; and amphiarthrosis, mixed. 
 
 (Ill) 
 
112 HUMAN ANATOMY. 
 
 1. The diarthrosis are subdivided into: — 
 
 Arthrodia, gliding-joint, as superior tibio-fibular ; 
 
 Enarthrosis, ball-and-socket joint, as shoulder and hipj 
 
 Ginglymus, hinge-joint, as knee and ankle; 
 
 Trochoides, a ring surrounding a pivot, as atlo-axoid joint, and 
 superior radio-ulnar. 
 
 Condyloid, elliptical cavity receiving an ovoid head, as wrist-joint. 
 
 Reciprocal reception, a concavo-convex articulation, as carpo-meta- 
 carpal joint of thumb. 
 
 2. Synarthrosis^ surface, immovably connected by fibrous 
 membrane without synovial membrane. 
 
 They are divided into: — 
 
 Sutura, bones interlocking with one another; 
 
 Schindylesis, a fissure in one bone receiving a plate of bones, as 
 between vomer and sphenoid; 
 
 Gomphosis, a socket with a pivot inserted, as in alveolar cavities 
 for teeth. 
 
 Synchondrosis, a temporary joint in which the connecting medium 
 is cartilage. 
 
 The sutura may be either true, sutura vera, or false, sutura 
 notha, the former having three divisions: dentata, tooth-like 
 processes, as interparietal suture; serrata, saw-like edges, as iu- 
 terf rental suture; limbosa, dentated processes and beveled mar- 
 gins, as f ronto-parietal ; the latter two divisions: — 
 
 Squamosa, overlapping beveled margins, and 
 
 Harmonia, by union of roughened surfaces, as intermaxillary 
 suture. 
 
 3. AmpMarthrosis, bony surfaces connected by fibro-carti- 
 lage, with or without synovial membrane, as between vertebral 
 bodies, and pubic symphysis. 
 
 Motions in Joints. — Joints admit of four (4) distinct 
 varieties of motion : — 
 
 (a) Gliding movement, between contiguous surfaces; 
 (■ftj Angular movement, as flexion, extension, adduction, and ab- 
 duction ; 
 
 (c) Circumduction, as in true enarthrosis; 
 
 (d) Rotation on its own axis, as between the atlas and axis. 
 
 Temporo-maxillart is formed by condyle of lower jaw, 
 below articulating with glenoid cavity of the temporal bone and 
 eminentia articularis above. It is a double arthrodial joint. 
 
 Ligaments. — External Lateral. — Origin, tubercle on outer 
 edge of zygoma; insertion, outer side of neck of condyle. 
 
 Internal Lateral. — Origin, spinous process of sphenoid; in- 
 sertion, lower circumference of inferior dental foramen. 
 
ARTICULATIONS AND LIGAMENTS. lib 
 
 Capsular. — Origin, circumference of articulation ; insertion, 
 neck of condyle. 
 
 Interarticular fibro-cartilage is within cavity; external 
 pterygoid muscle attached to its inner edge. 
 
 Synovial membrane is divided into two by cartilage. 
 
 Intermaxillary ligament passes from external pterygoid 
 process to corouoid. 
 
 Stylo-maxillary Ligament. — Origin, styloid process; inser- 
 tion, inner surface of angle. of jaw. Nerves are derived from the 
 auriculo-temporal and masseteric branches of the inferior maxil- 
 lary. 
 
 Articulations of Vertebral Column. — These are formed 
 between the contiguous surfaces of the vertebral bodies and ar- 
 ticular processes, inclosed lq capsular ligaments, and connected 
 with the following ligaments : — 
 
 The anterior common ligament extends from the front of 
 the body of the axis down the anterior surface of the spine to 
 the sacrum, being expanded opposite, and attached to each inter-' 
 vertebral connecting fibro-cartilage; 
 
 The posterior common ligament descends along posterior 
 surfaces of bodies from axis to sacrum within spinal canal. It 
 also expands opposite and adheres to intervertebral substance ; 
 
 Intervertebral substance, disks of varying size, twenty-seven 
 in number, composed of decussating fibres of fibro-cartilage, ar- 
 ranged in crescentie laminae with central, semi-pulpy substance, 
 separate the vertebrae ; 
 
 Ligamenta subflava descend in pairs, twenty-three on either 
 side, from one lamina to another,«from axis to sacrum, inclosing 
 spinal canal; 
 
 Supraspinous ligament, strong cord descending from one 
 vertebra to another, from vertebra prominens (seventh cervical) 
 to sacrum. Its continuation in cervical region forms ligamentum 
 nuchce; 
 
 Interspinous stretch between spinous processes throughout 
 dorsal and lumbar regions ; 
 
 Intertransverse, between transverse processes in lower dorsal 
 and lumbar regions. 
 
 The arteries are derived from ascending cervical and verte- 
 bral in cervical, iatercostals in dorsal, and lumbars in lumbar 
 regions. 
 
 The nerves are from spinal nerves in each region. 
 
 Atlo-axoid articulation consists of four joints, the two 
 lateral joints being arthrodia, and that between the odontoid 
 process and arch of atlas and transverse ligament — a diarthrosis 
 
114 HUMAN ANATOMY. 
 
 rotatoria — ^being double, one in front, atlo-odontoid, and one be- 
 hind, odonto-transverse. The ligaments are: — 
 
 Anterior atlo-axoid, two — superficial and deep, connecting 
 anterior borders together; 
 
 Posterior atlo-axoid, connecting the arches of the atlas and 
 axis posteriorly, and pierced laterally by the second spinal nerve ; 
 
 Capsular, two, connecting the articulating processes later- 
 ally, and lined with synovial membrane; 
 
 Transverse, or cruciform, arises from the tubercle on one 
 side of the lateral mass, passes across the back of odontoid proc- 
 ess to be inserted into the opposite tubercle. 
 
 The arteries are from vertebral, nerves from second cervical, 
 or from loop between it and suboccipital. 
 
 OcciPiTO-ATLOiD. — Anterior occipito-atloid — two, super- 
 ficial and deep, connecting the tubercle and upper border of an- 
 terior arch of atlas with basilar process and margin of foramen 
 magnum of occiput. 
 
 Posterior occipito-atloid (membranous), connects the upper 
 border of posterior arch of atlas with posterior margin of fora- 
 men magnum. 
 
 Lateral ligaments, two bands connecting transverse process 
 of atlas with jugular process of occipital. 
 
 Capsular ligaments connect the articular processes of atlas 
 with condyles of occiput. 
 
 ' The arteries are from vertebral; nerves, from suboccipital. 
 
 OcciPiTO-AxoiD. — Occipito-axoid is a broad band, the con- 
 tinuation of posterior common ligament, extending from the 
 body of the axis to basilar grooye of occipital. 
 
 Odontoid, OT check, pass upward and outward from the sum- 
 mit of the odontoid process, to be inserted into the inner side of 
 the occipital condyles. 
 
 Ligamentum suspensonum, or central occipito-odontoid, 
 arises from the centre of the transverse ligament at the apex of 
 the odontoid process, and passes upward, to be inserted into the 
 anterior margin of the foramen magnum. 
 
 Occipito-cervical, or cervico-hasilaris, arises from the bodies 
 of the third cervical and axis, and is inserted into the basilar 
 groove of occipital. 
 
 The arteries are from vertebral; the nerves from suboc- 
 cipital. 
 
 Capsular ligaments. — Throughout the spine the articula- 
 tions between the facets of the articular processes are surrounded 
 by capsular ligaments, making twenty-five pairs in all. 
 
 CosTO-VEKTEBRAL ARTICULATIONS. — The costo-vertcbral 
 have each a double arthrodia between the head of the rib and the 
 
ARTICULATIONS AND LIGAMENTS. 115 
 
 bodies of the two adjacent vertebrse, except the first, tenth, 
 eleventh, and twelfth ribs, which have each but a single joint. 
 
 Anterior Gosto-vertehral, or Stellate Ligament. — Origin, 
 head of the rib ; insertion, into body of vertebra above and below, 
 and interarticular cartilage between. 
 
 Interarticular costo-vertehral is within the capsular liga- 
 ment, from the crest on the head of the rib to the intervertebral 
 substance. 
 
 Capsular ligament surrounds the articular surfaces. 
 
 Gosto-transverse articulations are united by three ligaments 
 — anterior, middle, and posterior cos to-transverse ligaments — 
 extending between the tubercles of the ribs to the transverse proc- 
 ess below. Arteries, the intercostals ; nerves, anterior branches 
 of spinal. 
 
 CosTO-STEENAL ARTICULATIONS. — These are connected by 
 arthrodia excepting the first, which is a synarthrodia. 
 
 Anterior chondro-sternal ligaments connect the chondral 
 and sternal surface in front; 
 
 Posterior chondro-sternal connect them behind. 
 
 Capsular ligaments surround all, and synovial membranes 
 are present in all but the first, while the second has an inter- 
 articular cartilage interposed. 
 
 The chondro-xiphoid ligament connects the cartilage of the 
 seventh, and sometimes the sixth rib with the xiphoid appendix. 
 
 Interchondral and Costo-chondral Articulations. — The ribs 
 are connected with their cartilages by the periosteum covering 
 them. The cartilages of the sixth, seventh, and eighth ribs, and 
 sometimes the fifth and ninth, are connected by anterior and 
 posterior inter-chondral ligaments, held together by capsular 
 ligaments and lined with synovial membrane. 
 
 Ligaments of Sternum. — The first and second portions of 
 the sternum are articulated by an amphiarthrodial joint, some- 
 times a diarthrodial joiat, connected by the anterior intersterrml 
 and posterior intersternal ligaments^ and lined with synovial 
 membrane. 
 
 The third portion, or ensiform cartilage, is united to the 
 gladiolus by a synarthrodial joint. 
 
 TiiE thorax. 
 
 The thorax is a conical osteo-cartilaginous framework, 
 formed by the dorsal vertebree behind, the ribs, intercostal mus- 
 cles, and costal cartilages laterally, and the sternum in front. 
 
 The apex, or superior opening, is bounded behind by the 
 first dorsal vertebra, laterally by the first rib, and in front by the 
 upper border of the sternum. 
 
116 HUMAN ANATOMY. 
 
 It transmits the following structures: — 
 
 CEsophagus, trachea, thoracic duct (on left side), lymphatic ves- 
 sels of right side of chest and of surface of liver, innominate artery 
 (right side), left common carotid artery, left subclavian artery, right 
 and left superior intercostal arteries, right and left internal mammary 
 arteries, thyroidea ima artery (if present), right and left inferior thy- 
 roid veins, right and left innominate veins, right and left phrenic nerves, 
 right and left pneumogastric nerves and their cardiac branches, left 
 recurrent laryngeal nerve, right and left first dorsal nerves, right and 
 left sympathetic nerves and their cardiac branches, apices of lungs and 
 pleurae, remains of thymus, and deep cervical fascia passing to peri- 
 cardium. 
 
 The longus colli, sterno-hyoides, and sterno-thyroides on both 
 sides also pass through it. 
 
 The inferior opening is formed by the last dorsal vertebra 
 behind, the last rib laterally, and the ensiform cartilage in front. 
 It is filled in by the diaphragm. 
 
 The cavity of the thorax contains the following structures : 
 the heart and great vessels, trachea, bronchi, and lungs, azygos 
 and bronchial veins, internal mammary arteries, pneumogastric, 
 phrenic, and splanchnic nerves, thoracic duct, cESophagus, lym- 
 phatic vessels, and glands {vide mediastinum). 
 
 Spine and Pelvis. — Sacra-vertebral articulation. In addi- 
 tion to those of the spine, given above, there are two ligaments 
 connecting the last lumbar vertebra with the sacrum: — - 
 
 Lumbosacral ligament, arising from the transverse process 
 of the last lumbar vertebra, and inserted into the base of the 
 sacrum ; 
 
 Ilio-lumbar ligament, arising from the apex of the trans- 
 verse process of the last lumbar vertebra, and inserted into the 
 crest of the ilium. The arteries are from last lumbar, ilio- 
 lumbar, and lateral sacral. The nerves are branches of fourth 
 and fifth lumbar and sympathetic. 
 
 Sacro-iliac articulation, between the articular surfaces of 
 the sacrum and ilium, is an amphiarthrodial joint connected by 
 
 The anterior sacro-iliac ligament, crossing between anterior 
 surfaces of the two bones; 
 
 Posterior sacro-iliac ligament, the stronger, passes in dif- 
 ferent directions between the posterior surfaces of the two bones, 
 firmly binding them together. One of these, stronger than the 
 others, passes from the posterior superior spinous process to the 
 third sacral transverse process. It is called 
 
 The oblique sacro-iliac ligament. 
 
 The arteries are from gluteal, sacral, spinal, and ilio-lum- 
 bar; the nerves from lumbo-sacral and posterior sacral cords. 
 
ARTICULATIONS AND LIGAMENTS. 117 
 
 Sacro-iscMatic Articulation. — The os innominatum and sa- 
 crum are united by two important ligaments — ^the great sacro- 
 sciatic (posterior) ligament, and the lesser sacro-sciatic (or an- 
 terior) ligament. 
 
 The great sacro-sciatic ligament arises from the fourth and 
 fifth transverse tubercles of the sacrum, from spine of ilium, 
 sacrum, and coccyx, and passes downward, outward, and forward, 
 to be inserted into the inner margin of tlie tuberosity of the 
 ischium, being prolonged forward as the falciform ligament 
 protecting the internal pndic veins and nerves. 
 
 FIQ. 88. 
 
 1, manubrium; 2, gladiolus; 3, xiphoid appendix; 4. first dorsal 
 vertebra; 6, last dorsal vertebra; 6, first rib. 
 
 It converts the sacro-sciatic notch into the lesser sacro- 
 sciatic foramen, transmitting the obturator internus muscle and 
 nerve, the internal pudic vessels and nerves. 
 
 The lesser sacro-sciatic ligament arises from the lateral 
 margin of the sacrum and coccyx, and is inserted into the spine 
 of the ischium. It converts the sacro-sciatic notch inio the 
 greater sacro-sciatic foramen, transmitting the pyriformis mus- 
 cle, gluteal vessels, superior gluteal nerve, sciatic vessels and 
 nerves, and the internal pudic vessels and nerves. 
 
 Sacro-coccygeal articulation is an amphiarthrodial joint, 
 resembling the vertebral, having an interarticular £bro-cartilage, 
 and connected together by 
 
118 
 
 HUMAN ANATOMY. 
 
 An anterior sacro-coccygeal ligament, and 
 
 A posterior sacro-coccygeal ligament, continuations respect- 
 ively of the anterior and posterior common ligaments. 
 
 Lateral sacro-coccygeal, intertransverse^ and intercornual 
 ligaments connecting the rudimentary transverse processes and 
 the cornua together. 
 
 The arteries are from lateral and median sacral; 
 
 The nerve branches of coccygeal, fifth sacral, and posterior 
 divisions of fourth sacral. 
 
 Pubic Aeticulation. — This is an amphiarthrodial joint, 
 known also as the symphysis pubis. 
 
 It is connected by the 
 
 Anterior pubic ligament in front ; 
 
 _^s-yL 
 
 Fig. 89. 
 
 A A, antero-posterior diameter; B B, transverse diameter; C C, 
 oblique diameter; 1, sacro-iliac ligament; 2, anterior or lesser sacro- 
 Bciatic ligament; 3, posterior or great sacro-sciatic ligament. 
 
 Superior pubic ligament above; 
 
 Posterior pubic ligament behind ; 
 
 Subpubic ligament below, forming the boundary of the pubic 
 
 arch. 
 
 Within the joint an interposed fibro-cartilage separates the 
 bones. 
 
 The obturator membrane, or ligament, closes the obturator 
 foramen, and affords attachment for the external and internal 
 obturator muscles and allows passage at its upper outer part, for 
 the obturator vessels and nerves. 
 
 THE PELVIS. 
 
 The pelvis is a strong, bony basin, formed at the lower end 
 of the vertebral column by the articulation of the sacrum and 
 coccyx posteriorly with the ossa innominata laterally. 
 
ARTICULATIONS AND LIGAMENTS. 119 
 
 It is divided into a false and true pelvis by tlie ilio-pectineal 
 line. 
 
 The false pelvis is situated above the ilio-pectineal line, and 
 corresponds to the expanded iliac fossae, being bounded laterally 
 by the ossa ilii, and having in front and behind wide intervals. 
 
 The true pelvis includes all that portion below the linea ilio- 
 pectinea, and presents a cavity, superior circumference or inlet, 
 and an inferior circumference or outlet. 
 
 The inlet is heart-shaped, being bounded behind by the 
 promontory of the sacrum, laterally by the linea ilio-pectinea, and 
 in front by the crest and spine of the pubes. 
 
 Its principal diameters in the female are: — 
 
 Anteroposterior, from symphysis to vertebral angle, four and 
 three-fourths inches; transverse, across the widest part, five and one- 
 fourth inches; and oblique, from the ilio-pectineal eminence in front to 
 the sacro-iliac symphysis behind, five inches. In the male, these meas- 
 urements are about three-fouiths of an inch less in every diameter. 
 
 It transmits the following structures : — 
 
 Viscera and Ducts. 
 
 1. Small intestine. 5. Urachus and obliterated hypo- 
 
 2. Rectum. gastric arteries. 
 
 3. Vasa deferentia (in male), 6. Uterus (pregnant). 
 
 round ligaments (in female). 7. Bladder (distended). 
 
 4. Ureters. 8. Peritoneal coverings. 
 
 1. Superior hsemorrhoidal. 6. Obturator (from deep epigas- 
 
 2. Internal iliac. trie). 
 
 3. Sacra media. 7. Ovarian. 
 
 4. Ilio-lumbar. 8. Pubic branches from external 
 
 5. Branches of vasa intestini ten- epigastric aiteries. 
 
 uis. - 9. Lymphatic vessels. 
 
 Nerves. 
 
 1. Sympathetic. 3. Obturator. 
 
 2. Branches from hypogastric 4. Lumbosacral cord. 
 
 plexus. 
 
 The co.vity of the pelvis is bounded behind by the sacrum and 
 coccyx, in front by the symphysis, and laterally by the body of 
 the ischium, forming a curved canal, widest in the middle. It 
 contains, in the recent state, the organs of generation, rectum, 
 bladder, and their vessels, nerves, ducts, etc. Its axis corre- 
 sponds to the concavity of the sacrum and coccyx. 
 
 Its depth in front, at the symphysis, is about one and a half 
 m the middle axial line, three and a half behind, in males four 
 and a half to possibly five and a half. 
 
120 HUMAN ANATOMY. 
 
 The outlet of the pelvis is bounded. by three prominences, the 
 tuber ischii laterally and the coccyx behind; separated by three 
 notches, the subpubic arch in front and the sacro-sciatic notches 
 posteriorly. 
 
 Its principal diameters are : transverse, three and a half in 
 male, four and three-fourths in female; antero-posterior and 
 oblique, three and one-fourth in male, five in female. 
 
 In the erect position the pelvis is placed at an angle of from 
 sixty degrees to sixty-five degrees with the ground. 
 
 Differences of Sex. — The male pelvis is characterized by 
 the strength of the bones, by prominent muscular impressions, 
 by the depth and narrowness of the cavity, the large obturator 
 foramen, and the acute angle of the subpubic arch. 
 
 The female pelvis is characterized by the lightness of the 
 bones, the slight muscular impressions, by the shallow expanded 
 iliac fossae, the increased size of the cavity in every diameter, and 
 the obtuse angle of the subpubic arch. 
 
 ARTICULATIONS OF THE UPPER EXTREMITY. 
 
 The sterno-clavicular articulation is an arthrodial joint, 
 formed between the sternal end of the clavicle and the sternum 
 and first rib, being divided into two cavities by an interartieular 
 fibro-cartilage. Its ligaments are: — 
 
 Anterior sterno-clavicular^ is a broad band passing between 
 the articular margins, attached to the interartieular cartilage 
 and two synovial membranes, and forming the front part of the 
 capsular ligament; 
 
 Posterior sterno-clavicular, passes over the posterior aspect 
 of the joint and corresponds to the former; 
 
 Interclavicular, passes from the sternal end of the' clavicle 
 on one side across the supra-sternal notch to the clavicle of the 
 opposite side; 
 
 Gosto-clavicular, or rhomioid, passes from the rhomboid 
 impression on the inferior surface of the clavicle to the upper sur- 
 face of the first costal cartilage. 
 
 The synovial membranes form two sacs separated by the in- 
 terartieular cartilage. 
 
 The arteries are from muscular branch of supra-scapular 
 and contiguous muscular branches; 
 
 The nerves, from descendens noni. 
 
 AcEOMio-CLAvicuLAR ARTICULATION is an arthroidal joint 
 formed between the acromial extremity of the clavicle and the 
 acromial process of the scapula. Its ligaments are: — 
 
ARTICULATIONS AND LIGAMENTS. 
 
 121 
 
 The superior acromio-clavicvlar, connect the adjoining parts 
 of the superior surfaces of the claTicle and acromion process; 
 
 Inferior acromio-clavicular, connecting the inferior sur- 
 faces ; 
 
 Goraco-clavicular, consists of two parts : — 
 
 Trapezoid, broad, square, arises from upper surface of cora- 
 coid process, and is inserted into oblique line on under surface 
 of clavicle; and 
 
 Conoid, behind and internal, arises from base of coracoid 
 process, and is inserted into conoid tubercle on under side of 
 clavicle and a line internal to it. 
 
 Fig. 90. 
 
 1, superior acromio-clavicular ligaments; 2, coraco-clavicular liga- 
 ments; 3, coraco-acromial ligaments; 4, transverse ligament; 6, 
 capsular ligament; 6, coraco-bumeral ligament; 7, tendon of biceps. 
 
 The capsular ligament covers the anterior and posterior sur- 
 faces of the joint, uniting above and below with the superior 
 and inferior acromio-clavicular ligaments. 
 
 The arteries are from anterior circumflex, acromial thoracic, 
 and supra-scapular. 
 
 The nerves are anterior circumflex and supra-scapular. 
 
 The scapula has, also. 
 
 The coraco-acromial, arising from the outer border of the 
 coracoid process and inserted into the summit of the acromion, 
 and 
 
 Transverse, a ligamentous band bridging the supra-scapular 
 notch, converting it into a foramen for supra-scapular nerve. 
 
122 HUMAN ANATOMY. 
 
 The shoulder-joint is an enarthrodial joint, formed 
 above by the glenoid cavity of the scapula and below by the head 
 of the humerus. Its ligaments are — glenoid, coraco-humcral, 
 and capsular. 
 
 The glenoid surrounds the edge, deepens the glenoid cavity, 
 and is continuous above with the long head of the biceps tendon. 
 
 The capsular ligament, extensive and loose, arises above it 
 from circumference of glenoid cavity behind the ligament, is 
 attached below to the anatomical neck of humerus, and is pierced 
 by tendons of two or three muscles. 
 
 The coraco-humeralj or accessory, is a fibrous band which 
 extends obliquely downward and outward from the coracoid proc- 
 ess to the anterior part of great tuberosity, strengthening the 
 capsular ligament. 
 
 The synovial membrane is extensive and reflected upon the 
 tendons of biceps, infra-spinatus, and sub-seapularis muscles. 
 
 Its arteries are derived from the subscapular, supra-scapular, 
 dorsalis scapulas, anterior and posterior circumflex ; 
 
 Its nerves, from the subscapular, supra-scapular, and cir- 
 cumflex. 
 
 The elbow-joint is a ginglymoid articulation formed 
 above by the lower extremity of humerus, below by upper ex- 
 tremities of ulna and radius. Its ligaments are external and 
 internal lateral, anterior and posterior ligaments. 
 
 External lateral arises from external condyle of humerus and 
 is inserted into outer margin of ulna. Internal lateral, much 
 stronger, consists of two portions; anterior arises from fore 
 part of internal condyle to be inserted into coronoid process, and 
 posterior from back part of condyle to inner margin of olec- 
 ranon. 
 
 Anterior ligament arises above coronoid fossa, and is in- 
 serted into coronoid process of ulna and orbicular ligament. 
 
 Posterior ligament, attached above olecranon fossa, and be- 
 low to olecranon process of ulna. The anterior and posterior 
 ligaments become continuous with the lateral to encircle the 
 joint. 
 
 The arteries are derived from superior and inferior pro- 
 funda, anastomotica magna, posterior interosseous recurrent, an- 
 terior and posterior ulnar recurrent, and radial recurrent. 
 
 The nerves, from median, ulnar, musculo-cutaneous, and 
 musculo-spiral. 
 
 The eadio-ulnar articulations are three — the superior, 
 middle, and inferior. 
 
 The superior radio-ulnar is a diarthrosis rotatoria, formed 
 by the inner side of the head of radius and lesser sigmoid cavity 
 
ARTICULATIONS AND LIGAMENTS. 
 
 123 
 
 of ulna. Its synovial cavity comnmnicates with the elbow-joint 
 and it is held together by the orbicular, or annular ligament, at- 
 tached in front and behind to the lesser sigmoid cavity and sur- 
 rounding the head of radius. Its arteries and nerves are the 
 same as fqr elbow. 
 
 The middle radio-ulnar articulation consists of the oblique 
 or round ligament, passing from tubercle of ulna to below 
 tuberosity of radius, and the interosseous passing between the 
 bones, deficient above for passage of posterior interosseous ves- 
 
 FiG 91. 
 
 1, anterior ligament; 2 and 2, anterior and posterior portions of 
 Internal lateral; 3, orbicular ligament; 4. oblique; 5. interosseous 
 membrane. 
 
 sels, and perforated below for anterior vessels. Its arteries are 
 from anterior interosseous; its nerves, from anterior and pos- 
 terior interosseous. 
 
 Inferior radio-ulnar consists of anterior and posterior radio- 
 ulnar ligaments, passing from one to the other in front and back 
 of wrist, and triangular interarticular fibro-cartilage, interposed 
 between head of ulna and cuneiform bone, and binding the radius 
 and ulna firmly together.. Its arteries are from anterior and 
 posterior interosseous and carpal; its nerves, from median and 
 posterior interosseous. 
 
124 HUMAN ANATOMY. 
 
 The radio- carpal, or wrist-Joint, is a condyloid joint con- 
 sisting of an elliptical cavity formed by the radius and triangular 
 cartilage, into which fits the convex surfaces of the scaphoid, 
 semi-lunar, and cuneiform below. Its ligaments are external 
 and internal lateral, anterior and posterior radio-carpal. 
 
 External lateral passes from the styloid process of radius to 
 the scaphoid, os magnum, and trapezium. 
 
 Internal lateral passes from the styloid process of uhia to 
 the cuneiform, pisiform, and annular ligament. 
 
 The anterior radio-carpal is a broad membrane attached 
 above to the anterior margia of the radius, its styloid process and 
 ulna, and below to cuneiform, semi-lunar, scaphoid, and os mag- 
 num, strengthened by a band extending from styloid process of 
 ulna to semi-lunar and cuneiform. 
 
 The posterior radio-carpal is attached to dorsal margin of 
 radius, and below to cuneiform, semi-lunar, and scaphoid. The 
 anterior and posterior radio-carpal belong to tlie annular liga- 
 ment (mrfe fascias). 
 
 Its arteries are the anterior and posterior carpal, derived 
 from the radial and ulnar, anterior and posterior interosseous, 
 and ascending branches from the deep palmar arch. 
 
 Its nerves are derived from the median, ulnar, and posterior 
 interosseous. 
 
 The carpal articulations are arthrodial, and consist of three 
 sets. The first row is held together by two palmar, two dorsal, 
 and two interosseous; the second row by three dorsal, three 
 palmar, and three interosseous; and the two rows are held to- 
 gether by a palmar, dorsal, internal and external lateral ligament. 
 
 First Eow. — The palmar and dorsal ligaments connect the 
 scaphoid and semi-lunar, and semi-lunar and cuneiform together 
 on the front and back. 
 
 The interosseovs connect the semi-lunar with the scaphoid 
 and cuneiform. 
 
 The pisiform bone has a separate capsular ligament and 
 an interosseous ligament connecting it to the fifth metacarpal 
 bone and cuneiform. 
 
 Second Eow. — The palmar and dorsal ligaments connect 
 the trapezium with the trapezoid, and the os magnum with the 
 trapezoid and unciform, on the front and back of the wrist. 
 
 The interosseous connect the adjacent surfaces of the trape- 
 zium and trapezoid, and the os magnum with the trapezoid and 
 unciform. 
 
 Two Rows Together. — The palmar and dorsal connect 
 the bones of the first with the second rows on the front and back 
 
AETTCULATIONS AND LIGAMENTS. 125 
 
 of the wrist. The internal lateral passes on the ulnar side be- 
 tween the cuneiform and unciform. The external lateral, 
 stronger, passes on the radial side between the scaphoid and 
 trapezium. 
 
 The anterior annular ligament contributes strength to these 
 joints. 
 
 The arteries are: Carpal of anterior interosseous, anterior 
 and posterior carpals of radial and ulnar, carpal of deep palmar 
 arch, interosseous recurrent, and terminal branches of anterior 
 and posterior interosseous. 
 
 The nerves are from median, ukiar, and posterior inter- 
 osseous. 
 
 The carpo-metacarpal articulations are each arthrodial 
 joints, held together by dorsal, palmar, interosseous, and capsular 
 ligaments, except the thumb, which has only capsular. 
 
 The capsular ligament of the thumb surrounds the margins 
 of the articular surfaces of the first metacarpal and trapezium, 
 and is lined by a separate synovial sac. 
 
 The palmar and dorsal carpo-metacarpal connects the carpus 
 and metacarpus on the palmar and dorsal surface. 
 
 The interosseous connect the adjoining inferior angles of 
 OS magnum and imciform with the contiguous surfaces, fourth 
 and fifth metacarpal bones. 
 
 The synovial membranes of the wrist consist of five distinct 
 sacs : First, memirana sacciformis lines lower end of ulna, sig- 
 moid cavity of radius, and upper surface of triangular cartilage; 
 second, lower surface of radius and cartilage and upper surface 
 of first row of carpus; third, between margins of carpus and 
 carpo-metacarpal joints ; fourth, between carpo-metacarpal joint 
 of thumb ; and fifth, between pisiform and cuneiform. 
 
 Intermetacarpal Articulation. — The bases of the metacarpal 
 bones, except the thumb, articulate with one another by ar- 
 throdial joints, lined by synovial membrane continuous with the 
 carpal sac and connected together by palmar, dorsal, and inter- 
 osseous ligaments. The digital extremities are connected by a 
 transverse ligament across the anterior surface, continuous with 
 anterior metacarpo-phalangeal ligament. 
 
 The metacarpo-phalangeal and phalangeal are of the 
 condyloid variety, like the wrist-joint, allowing of motion in 
 every direction except laterally. They are each connected by one 
 anterior and two lateral ligaments, the posterior ligament being 
 substituted by the extensor tendon, which crosses the dorsum of 
 the joint. 
 
 The arteries and nerves are from the digitals. 
 
126 HUMAN ANATOMY. 
 
 AETICULATIONS OF THE LOWER EXTREMITY. 
 
 The hip-joint is a true enarthrodial articulation, formed 
 above by deep cup-like cavity of acetabulum, below by promi- 
 nent spherical head of femur. Its ligaments are the capsular, 
 ilio-femoral, teres, cotyloid, and transverse. 
 
 The capsular ligament, dense and strong, is attached above 
 to margin of acetabulum and cotyloid ligament, and below to 
 the spiral line in front and to the neck behind. It is strength- 
 ened by several accessory bands, the pubo-femoral, ilio-trochan- 
 teric, ischio-capsular, and ilio-femoral. Of these the latter is the 
 most important, arising above from anterior inferior spine, and 
 attached below to spiral line, and has received the name of 
 Y-ligament of Bigelow. 
 
 The ligamentum teres, or round ligament, is a strong tri- 
 angular band, its base arising from the bottom of acetabulum and 
 margins of cotyloid notch externally, its apex inserted below and 
 behind centre of head of femur. 
 
 The cotyloid ligament encircles and deepens the acetabulum, 
 and at the inner side, under the name of the transverse ligament, 
 it bridges over the cotyloid notch, converting it into a foramen 
 for the passage of nutrient vessels to the joint. 
 
 There are numerous bursa about the joint, with one of 
 which, beneath the ilio-psoas muscle, the synovial membrane 
 often communicates. 
 
 Its arteries are derived from the sciatic, internal and ex- 
 ternal circumflex, obturator, and gluteal. 
 
 Its nerves are derived from the great sciatic, obturator, 
 accessory obturator, and the sacral plexus. 
 
 The knee-joint is a ginglymoid articulation, formed above 
 by condyles of femur, below by head of tibia, and in front by 
 patella. 
 
 Its ligaments are divided into two sets, the external, con- 
 sisting of anterior, posterior, internal lateral, two external lat- 
 erals, and capsular; and internal, consisting of anterior, pos- 
 terior, two semi-lunar fibro-cartilages, transverse, coronary, 
 ligamentum mucosura, and ligamenta alaria. Its joint surface 
 is the most extensive in the body. 
 
 External Set. — Anterior, or ligamentum patella, is the 
 tendinous portion of extensors of thigh between patella and 
 tubercle of tibia. The posterior, or ligamentum posticum Wins- 
 lowii, derived principally from the tendon of semi-membranosus, 
 arises from inner tuberosity of tibia, passes upward and outward 
 to be inserted into external condyle of femur. 
 
ARTICULATIONS AND LIGAMENTS. 
 
 127 
 
 The internal lateral is a flat and broad ligament arising 
 from back part of inner condyle of femnr, descends forward to 
 be inserted into inner tuberosity of tibia, covering in its course 
 the inferior internal articular artery and nerve, part of tendon 
 of semi-membranosus, and attaching itself to the internal semi- 
 lunar fibro-cartilage. 
 
 The long external lateral ligament, round and strong, arises 
 from tuberosity on outer part of external condyle, and descends 
 forward to the head of fibula. The short external lateral liga- 
 ment is an accessory, not very constant, band, descending pos- 
 teriorly to the preceding. 
 
 Fig. 93. 
 
 2, anterior crucial ligament; 3, 2, quadriceps extensor: 3, patella: 
 
 posterior crucial ligament; 4, trans- 4, ligamentum patelto; 6, bursa; 7, 
 verse ligament; 6, 7, internal and ex- 8, 9, synovial membrane of iinee-joint: 
 ternal semi-lunar cartilages; 8, liga- 10, anterior crucial ligament, 
 menta patellse; 9, bursa patellae ; 10. 
 anterior superior tibio-flbular liga- 
 ment. 
 
 The capsular ligament fills up the intervals between the 
 preceding ligaments, and is strengthened by bands from fascia 
 lata, vasti, crureus, semi-membranosus, biceps, and sartorius 
 tendons. 
 
 Internal Set. — Crucial ligaments are two strong, short, 
 interosseous, crossing each other from before backward. The 
 anterior, or external, arises from inner posterior part of condyle 
 of femur, and descends forward and inward to be inserted into 
 front of spine of tibia and internal semi-lunar cartilage. 
 
 The posterior, or internal, arises from outer fore part of 
 inner condyle of femur, descends downward, backward, and out- 
 ward to spine of tibia. 
 
128 HUMAN ANATOMY. 
 
 The semi-lunar fibro-cartilages consist of two crescentic 
 laKiinse of interarticular cartilage, resting upon the upper ar- 
 ticular surface of tibia, which serve to deepen its surface. 
 
 The internal is attached by its inner border to internal 
 lateral ligament and to head of tibia by coronary ligaments, its 
 extremities attached in front of anterior crucial ligament and 
 behind the spine. 
 
 The external, more circular, is connected to edge of tibial 
 head by coronary ligaments, its extremities being inserted behind 
 and in front of the tibial spine. 
 
 In other words, the ends of the semi-lunar cartilages are all, 
 except the anterior end of internal, attached to the tibia between 
 the crucial ligaments. 
 
 A band of fibres passing from the anterior margin of ex- 
 ternal cartilage to the internal has received the name of tram- 
 verse ligament. 
 
 The knee is lined by the most extensive synovial membrane 
 in the body, covering both surfaces throughout and extending 
 up between quadriceps tendon and surface of femur. 
 
 Below the patella in front is a duplicature of synovial mem- 
 brane, inclosing some adipose tissue, which has received the 
 name of ligamentum mucosum, and extending from it are two 
 fringes — the ligamenta alaria. 
 
 On either side in the popliteal space behind are bursse, 
 which often communicate with joint. 
 
 There are also bursse over the patellse, above and beneath 
 the ligamentum patellee, and between the inner hamstring and 
 head of tibia. 
 
 The arteries of the knee-joint are derived from the anasto- 
 motica magna, the articular branches of the popliteal (five), and 
 the recurrent branch of the anterior tibial. 
 
 Its nerves are derived from the anterior crural, obturator, 
 external and internal popliteal nerves. 
 
 The tibio-fibulae articulations are three— superior, 
 middle, and inferior. The superior is an arthrodial joint between 
 fibular head and outer tuberosity of tibia, and consists of an- 
 terior and posterior ligaments stretching on either side of the 
 outer tuberosity, downward and backward, to the head of the 
 fibula. The arteries are some of the knee; the nerves, from 
 external popliteal. 
 
 The middle consists of an interosseous membrane between 
 the bones, connecting them firmly together, deficient above, for 
 passage forward of anterior tibial artery and below for anterior 
 peroneal vessels. 
 
 The inferior is an arthrodial joint between contiguous in- 
 
ARTICULATIONS AND LIGAMENTS. 129 
 
 ferior surfaces of tibia and fibula, and consists of four: the 
 interosseous, continuous with that above; the anterior inferior 
 tihio-fihular, extending downward and outward between tibia and 
 fibula in front; the posterior inferior tibio-fibular, occupying 
 a similar position behind; and the transverse, a long narrow 
 band, passing between external malleolus and tibia. The syno- 
 vial membrane is continuous with that of ankle-joint. The 
 arteries and nerves are the same as those to the ankle. 
 
 The AiTKLE-JOiNT is a ginglymoid articulation, formed be- 
 tween the lower extremity and malleolus of tibia on the inner 
 side, the malleolus of the fibula on the outer side, and the as- 
 tragalus below. Its ligaments are anterior, posterior, external, 
 and internal lateral. 
 
 The anterior tilio-tarsal ligament consists of a broad set of 
 irregular fibres, attached above to lower margin of tibia, below 
 to astragalus. The posterior tibio-tarsal ligament passes trans- 
 versely between back part of tibia and astragalus. 
 
 The internal lateral, or deltoid, has two layers — ^the super- 
 ficial triangular, its apex arising from malleolus, its base spread 
 out from before backward to be attached to scaphoid and infe- 
 rior calcaneo-scaphoid ligament, the sustentaculum, and inner 
 side of astragalus; and the deep, a short, round cord passing 
 from internal malleolus to astragalus. 
 
 The external lateral ligament consists of three distinct 
 fasciculi, anterior, middle, and posterior, arising from near sum- 
 mit of external malleolus, and being inserted respectively into 
 the front of astragalus, the outer surface of os calcis, and the 
 back of astragalus. 
 
 The arteries of the ankle-joint are derived from the malleo- 
 lar branches of the peroneal and anterior tibial. 
 
 Its nerves are branches of the anterior and posterior tibial 
 nerves. 
 
 The articulations of the taksal bones consist of those 
 of the first row, those of the second row, and of the two rows 
 with each other. 
 
 First Eow. — The astragalus articulates with the calcaneum 
 by two distinct surfaces separated by the interosseous groove, and 
 firmly connected by the external and posterior calcaneo-astraga- 
 loid ligaments, and the interosseus. The external calcaneo- 
 astragaloid ligament passes vertically downward from the outer 
 surface of astragalus to outer surface of calcaneum. The pos- 
 terior is a short, narrow, oblique band connecting the posterior 
 border of astragalus to the os calcis. 
 
 The interosseus is a strong, short ligament passing vertically 
 and obliquely downward between the two bones, the principal 
 bond of union. 9 
 
130 HUMAN ANATOMY. 
 
 The arteries of the first row are tarsal from dorsalis pedis, 
 external malleolar froni anterior tibial, and branches of peroneal 
 from posterior tibial. 
 
 Nerves, from posterior tibial, or plantar. 
 
 The second row are firmly held together by dorsal, plantar, 
 and interosseous ligaments. The two former unite the dorsal 
 and plantar surfaces and the interosseous, four strong bands 
 connect the scaphoid and cuboid, the internal and middle, the 
 middle and external cuneiforms, and the external cuneiform 
 and cuboid. 
 
 The arteries of the second row are from plantars and meta- 
 tarsals. Nerves, from anterior tibial, and internal and external 
 divisions of posterior tibial nerves. 
 
 The two eovsts of the taesus are connected with each 
 other by three sets of ligaments, first between os calcis and 
 cuboid, consisting of superior and internal calcaneo-cuboid, long 
 and short calcaneo-cuboid; second, between os calcis and sca- 
 phoid, consisting of superior and inferior calcaneo-scaphoid ; and 
 third, between astragalus and scaphoid, consisting of a single 
 superior astragalo-scapTioid ligament, a band passing from neck 
 of astragalus to upper surface of scaphoid. 
 
 Calcaneo-cuboid. — The superior passes between dorsal sur- 
 faces of OS calcis and cuboid. The internal, passing from os 
 calcis to inner side of cuboid, is one of the main bonds of union 
 between the two rows of tarsus. 
 
 The inferior firmly connects the bones below, the ligamen- 
 tum longcB plantce passing from os calcis forward to the plantar 
 surface of the cuboid, and sending fibres forward to bases of 
 second, third, and fourth metatarsal bones; the ligamentum 
 breve plantce passing from fore and under surface of os calcis to 
 under surface of cuboid. The two preceding are important in 
 preserving the arch of the foot. 
 
 The superior and inferior calcaneo-scaphoid pass above and 
 below these bones, firmly connecting them. 
 
 The arteries of the mediotarsal joints are derived from the 
 anterior tibial, tarsal, metatarsal, or external plantar. 
 
 Nerves, from external branch of anterior tibial. 
 
 The takso-metataesal articulations are firmly held to- 
 gether by dorsal and plantar ligaments, and connected with one 
 another by interosseous bands, three in number, passing between 
 internal cuneiform and second metatarsal bone, external cunei- 
 form and second metatarsal, and external cuneiform and third 
 metatarsal. 
 
 The arteries are from metatarsal, dorsalis pedis, and deep 
 plantar arch; 
 
ARTICULATIONS AND LIGAMENTS. 131 
 
 The nerves, from anterior tibial, and internal and external 
 plantars. 
 
 Intermetatarsal Articulations. — The bases of all except the 
 first are connected by dorsal plantar and interosseous ligaments, 
 and the distal extremities are connected by the transverse meta- 
 tarsal ligament. 
 
 The synovial membeanes concerned in these articulations 
 are six: (1) between calcaneo-astragaloid articulation, posterior 
 to interosseous membrane; (2) anterior calcaneo-astragaloid 
 and astragalo-scaphoid ; (3) ealcaneo-cuboid; (4) between mid- 
 dle and external cuneiform, scaphoid, and three cuneiforms, 
 middle and external cuneiform, and second and third metatarsal, 
 and between cuboid and external cuneiform and scaphoid; (5) 
 between internal cuneiform and first metatarsal; and (6) be- 
 tween cuboid and fourth and fifth metatarsal bones. 
 
 The metataeso-phalakgeal articulation's are each con- 
 nected by two lateral and a plantar ligament, and the phalangeal 
 articulations are the same, the extensor tendons acting as dorsal 
 ligaments. They resemble in every respect the articulations in 
 the hand {vide hand) . 
 
THE MUSCULAR SYSTEM. 
 
 Ti-iB muscles constitute 45 per cent, of the bodj'-weight and 
 are the active agents of locomotion. 
 
 They consist of two kinds — the non-striated or involuntary, 
 and the stbiated, or voluntary. The latter, being usually under 
 the control of the will (the heart being a notable exception), have 
 also received the name of voluntary, and the former, not under 
 the control of the will, involuntary. 
 
 Microscopically, their structure is as follows : — 
 
 N on-striated muscular tissue is made up of elongated, con- 
 tractile, nucleated fibre-cells. They consist of minute fibres in 
 bundles, inclosed in extremely delicate sheaths of connective 
 tissue. 
 
 They are held together by an albuminous cement and col- 
 lected by connective tissue, into groups or masses, one-tenth to 
 one five-hundredth of an inch in length. 
 
 Non-striated muscular tissue is highly vascular and is sup- 
 plied with nerves from the sympathetic. 
 
 Striated muscular tissue is made up of spindle-shaped fibres 
 of from one and a half to two inches in length and one two- 
 hundredth to one six-hundredth of an inch in diameter. They 
 are held together in bundles by the endomysium, a delicate fibro- 
 connective tissue. These bundles are collected into groups by 
 the perimysium, a stronger connective-tissue band, forming the 
 fasciculi of the fully formed muscle. Striated muscular tissue is 
 also highly vascular. 
 
 The parts of an individual fibre are — first, the sarcolemma, 
 a very delicate, transparent, elastic sheath; second, the mem- 
 branes of Krausc, which appear as dark lines stretching across 
 the fibre at regular intervals, forming the third, or the compart- 
 ments of Krause, which contain the muscular substance. The 
 latter contain the multi-nucleated muscle-cells. 
 
 The striated muscular fibres of the heart differ somewhat 
 from the preceding, being branched, and dividing and subdivid- 
 ing longitudinally to form an intricate net-work. 
 
 The muscles are connected to cartilages, ligaments, bones, 
 and skin, either directly or by aponeuroses or tendons. 
 
 Aponeuroses are dense, white, fibrous membranes, serving to 
 connect the muscles with the structures to be acted upon. 
 
 Tendons are white, fibrous, glistening cords. They are com- 
 posed of white, fibrous tissue, arranged into bauds or bundles. 
 (132) 
 
THE MUSCULAR SYSTEM. 133 
 
 They are attached to the perichondrium, periosteum, ligaments, 
 and subcutaneous tissue by a mutual interlacement of fibres. 
 
 Classification. — Muscles are classified according to region 
 of the body, their physiological action, or from their embryo- 
 logical development. The former arrangement is retained here 
 for practical purposes. 
 
 Names of Muscles. — They have received their names : — 
 
 1. From the arrangement of their fibres they have received the 
 names of radiated, penniform, bipenniform, etc. 
 
 2. From their uses they are called extensors, adductors, etc. 
 
 3. From their direction, oblique, rectus, transversalis, etc. 
 
 4. From the number of insertions, as triceps, biceps, etc. 
 
 5. From their form, as rhomboid, deltoid, etc. 
 
 6. From their attachment, as occipito-frontalis, sterno-hyoid, etc. 
 
 The origin refers to the fixed extremity; the insertion, to 
 the movable point. 
 
 Muscles of the Head. 
 
 cranial eegion. 
 Occipito-frontalis. — Origin, by two bellies, one from 
 outer tv7o-thirds of superior curved line of the occipital bone 
 and base of the mastoid process of the temporal, the other from 
 corrugator supercilii, orbicularis palpebrarum, and pyramidalis 
 nasi fibres; insertion, into fibrous aponeurosis covering the ver- 
 tex of the skull ; action, raises the eyebrows and used chiefly as a 
 muscle of facial expression ; nerves, supraorbital, small occipital, 
 facial, and posterior auricular branch of facial. 
 
 AURICULAE REGION. 
 
 Attollens Aurem. — Origin, from aponeurosis of occipito- 
 frontalis ; insertion, into the surface of the pinna ; action, raises 
 the ear ; nerve, occipitalis minor. 
 
 Atteahens Aurem. — Origin, from edge of occipito-fron- 
 talis aponeurosis ; insertion, into anterior part of helix ; action, 
 draws the ear upward and forward ; nerve, facial. 
 
 Eetrahens AuREii. — Origin, from mastoid portion of tem- 
 ' poral bone ; insertion, into lower part .of concha ; action, draws 
 the ear backward ; nerve, posterior auricular branch of facial. 
 
 palpebral region. 
 Orbicularis Palpebrarum. — Origin, from nasal process of 
 superior maxilla, internal angular process of frontal, and from 
 front and sides of tendo-palpebrarum ; insertion, into skin of 
 the cheek, eyelids, forehead, and temple, blending with the cor- 
 rugated supercilii and the occipito-frontalis ; action, sphincter of 
 the eyelids ; nerve, facial. 
 
134 HUMAN ANATOMY. 
 
 Tbndo Palpebeakum (Tendo Oculi). — Origin, nasal proc- 
 ess of superior maxilla; insertion^ inner part "of tarsal cartilage. 
 
 CoKEUGATOE SuPEEOiLii. — Origin, superciliary ridge; in- 
 sertion, into orbicularis about the middle of the orbital arch; 
 action, draws eyebrows inward and downward and wrinkles the 
 forehead; nerve, facial. 
 
 Tensor Taesi. — Origin, from crest and orbital surface of 
 lachrymal gland ; insertion, into tarsal cartilages near the puncta 
 lachrymalia; action, draws the lachrymal canals inward and 
 against the globe of the eye; nerve, facial. 
 
 ORBITAL REGION. 
 
 Levator Palpebr^ Supeeioeis. — Origin, from lesser wing 
 of the sphenoid, near the optic foramen ; insertion, superior bor- 
 der of tarsal cartilage; action, elevates the upper eyelid; nerve, 
 third cranial, or motor oculi. 
 
 Eectds Superior. — Origin, sheath of the optic nerve and 
 upper margin of optic foramen; insertion, into upper surface 
 of sclerotic coat ; acitow, rotates the eyeball upward ; nert)e, third 
 cranial. 
 
 Eegtus Inferior. — Origin, from lower and inferior part 
 of optic foramen (ligament of Zinn) ; insertion, into lower sur- 
 face of sclerotic; action, rotates the eyeball downward; nerve, 
 third cranial. 
 
 Eegtus Inteenus. — Origin, same as rectus inferior; inser- 
 tion, into inner surface of sclerotic; action, rotates the eyeball 
 inward; nerve, third cranial. 
 
 Eectus Externus. — Origin, by two heads — lower from liga- 
 ment of Zinn and lower margin of sphenoidal fissure, upper from 
 outer margin of optic foramen; insertion, into outer surface of 
 sclerotic; nerve, abducens, or sixth cranial. Passing between 
 the two heads are the ophthalmic vein, the third, nasal branch 
 of fifth, and sixth nerves. 
 
 Superior Oblique. — Origin, from inner margin of optic 
 foramen: its tendon passes through a pulley near the internal 
 angular process of the frontal bone; insertion, into sclerotic, 
 between external and superior recti, midway between entrance 
 of optic nerve and the cornea; action, rotates the eyeball on its 
 axis; nerve, fourth, or patheticus. 
 
 Inferior Oblique. — Origin, orbital plate of superior 
 maxilla; insertion, near that of superior oblique, between ex- 
 ternal and superior recti; action, rotates the eyeball on its axis; 
 nerve, third cranial. 
 
THE MUSCULAR SYSTEM. 135 
 
 NASAL EEGION. 
 
 Pteamidalis Xasi ok Peoceeus. — Origin, from the occipi- 
 to-f I'ontalis ; insertion, into the compressor nasi-; action, lowers 
 the inner angle of the eyebrows; nerve, facial. 
 
 Levatoe Labii Supeeioeis Al^qdb Nasi. — Origin, nasal 
 process of superior maxilla; insertion, the ala of the nose and 
 upper lip, blending with the levator labii oris proprius and or- 
 bicularis; action, dilates the nostril and elevates the upper lip; 
 nerve, facial. 
 
 DiLATOK Naeis Posteeioe.- — Origin, nasal notch of superior 
 maxilla; insertion, into skin at the margin of the nostril. 
 
 Dilator Naris Anteeioe. — Origin, from cartilage of the 
 ala ; insertion, into the skin of nose ; action, dilates the nostrils ; 
 nerve, facial. 
 
 CoMPEESSOE Nasi. — Origin, superior maxilla, near, the in- 
 cisive fossa ; insertion, into fibro-cartilage of the nose, continuous 
 with the pyramidalis nasi aponeurosis and its fellow; action, 
 dilates the nostril ; nerve, facial. 
 
 CoMPEESSOR Narium Minor. — Origin, from alar cartilage; 
 insertion, into the skin of the end of the nose ; action, dilates the 
 nostril; nerve, facial. 
 
 Depressor Alje Nasi. — Origin, incisive fossa of superior 
 maxilla ; insertion, into the ala of the nose ; action, contracts the 
 nostril ; nerve, facial. 
 
 maxillary REGION. 
 
 Levator Labii Supeeioeis (Proprius). — Origin, above in- 
 fraorbital foramen to malar and superior maxilla ; insertion, into 
 the upper lip ; action, elevates the upper lip ; nerve, facial. 
 
 Levator Anguli Oris. — Origin, from canine fossa; inser- 
 tion, into the angle of the mouth, blending the depressor anguli 
 oris, orbicularis, and zygomatici; action, draws the angle inward 
 and raises it; nerve, facial. 
 
 Ztgomaticus MxsoiL.— Origin, from malar bone ; insertion, 
 into angle of mouth, blending with depressor anguli oris and 
 orbicularis. 
 
 Ztgomaticus Minor. — Origin, from malar bone ; insertion, 
 at the angle of the mouth, blending with the levator superioris; 
 action, draws the lip outward and upward; nerve, facial. 
 
 Levator Labii Infeeioeis. — Origin, from incisive fossa of 
 lower jaw; insertion, into the skin of the chin; action, raises the 
 lower lip; nerve, facial. 
 
136 HUMAN ANATOMY. 
 
 Depressor Labii Inferioris. — Origin, from external ob- 
 lique line of lower jaw; insertion, into skin of lower lip, blending 
 with its fellow and the orbicularis; action, lowers the angle of 
 the mouth ; nerve, facial. 
 
 Depressor Anguli Oris. — Origin, external oblique line of 
 lower jaw; insertion, into the angle of the mouth, continuous 
 with the orbicularis and risorius at its insertion and the platysma 
 at its origin; action, depresses the angle of the mouth; nerve, 
 facial. 
 
 Orbicularis Oris. — Origin, by accessory fibres (accessorii 
 orbicularis superioris and inferioris and naso-labialis), from 
 superior and inferior maxillary borders and nasal septum ; inser- 
 tion, into the buccinator and adjoining muscles, forming the 
 sphincter of the mouth ; action, closes the lips ; nerve, facial. 
 
 Buccinator. — Origin, from pterygo-maxillary ligament 
 and the posterior alveolar processes of the upper and lower jaw; 
 insertion, into orbicularis oris; action, compresses and con- 
 tracts tiie cheeks; nerves, facial and buccal branch of the in- 
 ferior maxillary nerve. 
 
 Risorius (Santoeini). — Origin, from fascia of masseter 
 muscle , insertion, at angle of the mouth ; action, draws back the 
 angles of the mouth, — ^the "smiling" muscle; nerve, facial. 
 
 Masseter: Superficial Portion. — Origin, inner surface 
 of zygoma and malar process of superior maxilla; insertion, into 
 the ramus and angle of the lower jaw. 
 
 Deep Portion. — Origin, posterior border and inner surface 
 of the zygoma ; insertion, into the ramus and coronoid process of 
 the jaw; action, raises the lower jaw, and the superficial portion 
 assists in drawing it forward ; nerve, inferior maxillary. 
 
 Temporal. — Origin, from the temporal fascia and the tem- 
 poral fossa ; insertion, into the coronoid process of the lower jaw ; 
 action, raises and draws backward the lower jaw ; nerve, inferior 
 maxillary. 
 
 Internal Pterygoid. — Origin, from pterygoid fossa and 
 the tuberosity of the palate-bone; insertion, into the inner side 
 of the ramus and angle of the lower jaw; action, draws forward 
 and raises the lower jaw; the accessory triturating muscle of 
 mastication ; nerve, inferior maxillary. 
 
 External Pterygoid. — Origin, by two heads — the lower 
 from the tuberosities of the palate and superior maxilla and from 
 the external pterygoid plate, the upper from the pterygoid ridge 
 on the greater wing of the sphenoid ; insertion, into the front of 
 the neck of the lower jaw and inner side of interarticular car- 
 tilage; action, draws the jaw forward; triturating muscle of 
 mastication; nerve, inferior maxillary. 
 
THE MUSCULAR SYSTEM. 137 
 
 Muscles of the Eak {vide Ear). 
 Muscles of the Neck. 
 
 SUPEEFICIAL cervical REGION. 
 
 Plattsma Mtoides. — Origin, from the deep fascia over the 
 trapezius, deltoid, and pectoral muscles, and from the clavicle 
 and acromion ; insertion, into the lower jaw and skin of the face ; 
 action, wrinkles the skin of the neck and protects the air-passages 
 and blood-vessels from external pressure, — rudimentary in man; 
 nerves, branch of superficial cervical plexus and the facial. 
 
 Sterno-cleido-mastoid. — Origin, by two heads — sternal 
 portion from the fore and upper part of the manubrium sterni, 
 the clavicular portion from the inner third of the upper border 
 of the clavicle, leaving a triangular interval; insertion, into the 
 mastoid process and outer two-thirds of the superior curved line 
 of the occipital bone; action, rotates and depresses the head; 
 nerves, spinal accessory and branches of the cervical plexus. 
 
 INFRA-HTOID REGION. 
 
 Stbrno-htoid. — Origin, from upper and back part of the 
 manubrium sterni and inner extremity of the clavicle ; insertion, 
 into the lower border of the os hyoides ; action, 'depresses the 
 hyoid bone; nerve, branch from the loop of communication be- 
 tween the descendens and communicans noni. 
 
 Sterno-thykoid. — Origin, posterior surface of manubrium 
 sterni; insertion, into oblique line of the surface of the thyroid 
 cartilage; action, depresses the larynx; nerve, branch from the 
 communicating loop above. 
 
 Thtro-htoid. — Origin, from the oblique line on the sur- 
 face of the thyroid cartilage; insertion, into the greater cornu 
 and body of the hyoid bone; action, elevates the larynx; nerve, 
 hypoglossal. 
 
 Omo-htoid. — Origin, from the upper border of the scapula 
 and the transverse ligament; insertion, into the lower border of 
 the OS hyoides; its centre is tendinous and bound down to the 
 cartilage of the first rib by a process of the deep cervical fascia; 
 action, depresses the hyoid bone and draws it backward; nerve, 
 from the communicating loop above. 
 
 SUPRA-HTOID region. 
 
 Digastric. — Origin, by two bellies — posterior from digas- 
 tric groove of mastoid process of the temporal bone, anterior 
 
138 HUMAN ANATOMY. 
 
 from a depression in tlie lower border of the ]"aw near the sym- 
 physis; the tendon is held to the hyoid bone by an aponeurotic 
 loop and pierces the stylo-hyoid; action, raises the tongue and 
 hyoid bone ; nerve, mylo-hyoid branch of the inferior dental and 
 facial. 
 
 Stylo-hyoid. — Origin, from outer surface of styloid proc- 
 ess ; insertion, into the body of the hyoid bone ; action, retracts 
 and elevates the hj'oid bone ; nerve, facial : near its insertion it is 
 perforated by the tendon of the digastric. 
 
 MYLO-HYOiD.^Ori^in, from the mylo-hyoid ridge of the 
 inferior maxilla from last molar to symphysis ; insertion, into a 
 fibrous raphe in the median line, extending from the hyoid bone 
 to the chin and into the body of the hyoid bone; action, draws 
 forward and elevates the hyoid bone and forms part of the floor 
 of the mouth; nerve, mylo-hyoid branch of the inferior dental. 
 
 Genio-hyoid. — Origin, from inferior genial tubercle of the 
 internal surface of the symphysis of the jaw; insertion, into the 
 front of the body of the hyoid bone; action, same as the mylo- 
 hyoid; nerve, hypoglossal. 
 
 MUSCLES of the TONGUE. 
 
 Gbnio-hyoglossus. — Origin, from superior genial tubercle 
 of the interiTal surface of the symphysis of the jaw; insertion, 
 by fan-like expansion into the whole length of the inferior sur- 
 face of the tongue, the side of the pharynx, and the body of the 
 hyoid bone; action, retracts and protrudes the tongue; nerve, 
 the hypoglossal. 
 
 Hypoglossus. — Origin, body and greater comu of the hyoid 
 bone; insertion, between the lingualis and styloglossus into the 
 side of the tongue; action, renders the tongue convex from side 
 to side ; nerve, hypoglossal. 
 
 Styloglossus. — Origin, from stylomaxillary ligament and 
 styloid process of the temporal; insertion, into the side of the 
 tongue, blending with the hyoglossus and lingualis; action, re- 
 tracts and elevates the tongue; nerve, hypoglossal. 
 
 Lingualis. — Consists of four portions — superficial, inferior, 
 transverse, and vertical. It lies between the genio-hyoglossus 
 and the hyoglossus, extending from the apex to the base of the 
 tongue; action, renders the tongue convex from before back- 
 ward ; nerve, the chorda tympani. 
 
 palato-glossus (constrictor isthmi faucium) (vide pala- 
 tal region). 
 
THE MUSCULAR SYSTEM. 139 
 
 PHARYNGEAL AND PALATAL EEGION. 
 
 CoNSTEiCTOE SUPERIOR. — Origin, from margin of internal 
 pterygoid plate and its hamular process ; from pterygo-maxillary 
 ligament, part of the alveolar process of the lower jaw and side 
 of the tongue, tendon of the tensor palati, and part of the palate- 
 hone ; insertion, into the median raphe and the pharyngeal spine 
 of the basilar process of the occipital bone ; action, constricts the 
 pharynx; nerves, pharyngeal plexus and glosso-pharyngeal. 
 
 Constrictor Medius. — Origin, from the stylo-hyoid liga- 
 ment, greater and lesser cornna of the hyoid bone; insertion, 
 into the median fibrous raphe, blending with its fellow of oppo- 
 site side; action, constricts the pharynx; nerves, pharyngeal 
 plexus and glosso-pharyngeal. 
 
 Constrictor Inferior. — Origin, from the sides of the thy- 
 roid and cricoid cartilages; insertion, into the fibrous raphe of 
 the pharynx; action, contracts the pharyngeal canal; nerves, 
 external laryngeal, glosso-pharyngeal, pharyngeal plexus. 
 
 Stylo-phartngeus. — Origin, from base of the styloid proc- 
 ess; insertion, into the constrictor muscles, palato-pharyngeus, 
 and posterior border of the thyroid cartilage ; nerves, pharyngeal 
 plexus and glosso-pharyngeal. 
 
 Levator Palati. — Origin, cartilaginous portion of Eusta- 
 chian tube and apex of the petrous portion of the temporal 
 bone; insertion, into the back part of the soft palate, blending 
 with its fellow of the opposite side; action, elevates the soft 
 palate ; nerve, descending palatine from Meckel's ganglion, from 
 the facial. 
 
 Tensor Palati, or Cieoumelexus. — Origin, from spine of 
 the sphenoid, vaginal portion of temporal bone, cartilage of 
 Eustachian tube, and scaphoid fossa at base of internal pterygoid 
 plate ; insertion, into the palate-bone and the soft palate ; action, 
 renders tense the palate ; nerve, a branch from the otic ganglion. 
 
 AzYGOS UvuL^, OR LEVATOR. — Origin, from aponeurosis of 
 soft palate and posterior nasal spine; insertion, into the uvula; 
 action, raises the palate; nerves, descending palatine branches 
 and Meckel's ganglion, from the facial. 
 
 Palato-glossus (Constrictor Isthmi Fauoium). — Ori- 
 gin, from soft palate on either side of the uvula ; insertion, into 
 the dorsum and side of the tongue, blending with the fibres of the 
 styloglossus — this muscle forms the anterior pillar of the fauces ; 
 action, constricts the fauces; nerves, palatine branches of Meck- 
 el's ganglion. 
 
140 HUMAN ANATOMY. 
 
 Palato-phartngeus. — Origin, by two portions, from soft 
 palate; insertion, into posterior border of thyroid cartilage and 
 pharynx; this muscle forms the posterior pillar of the fauces; 
 action, closes the posterior nares ; nerves, palatine branches from 
 Meckel's ganglion. 
 
 VERTEBRAL REGION. 
 
 Eeotus Capitis Anticus Major. — Origin, by four tendons 
 from transverse processes of the third, fourth, fifth, and sixth 
 cervical vertebrse; insertion, basilar process of occipital bone; 
 action, flexes the head; nerves, suboccipital and deep internal 
 branches of cervical plexus. 
 
 Rectus Capitis Anticus Minor. — Origin, from root of 
 transverse process and, anterior part of the lateral mass of the 
 atlas; insertion, basilar process of occipital, behind the former; 
 action, flexes the head ; nerves, suboccipital and deep branches of 
 the cervical plexus. 
 
 Eeotus Lateralis. — Origin, superior surface of the trans- 
 verse process of the atlas ; insertion, inferior surface of the jugu- 
 lar process of the occipital; action, draws the head laterally; 
 nerves, suboccipital and deep internal branches of the cervical 
 plexus. 
 
 Longus Colli. — Origin, from three portions, superior ob- 
 lique portion from anterior tubercles of the transverse processes 
 of the third, fourth, and fifth cervical; insertion, tubercle on 
 the anterior arch of atlas; inferior oblique portion, origin, from 
 anterior surface of the bodies of the first two or three dorsal ver- 
 tebra; insertion, anterior tubercles of the transverse processes 
 of the fifth and sixth cervical; vertical portion, origin, from 
 the anterior surface of the bodies of the lower three cervical and 
 upper three dorsal bodies of the second, third, and fourth cervical 
 vertebrae; action, rotates and flexes the cervical portion of the 
 vertebrse; nerves, anterior branches of the lower cervical nerve. 
 
 Scalenus Anticus. — Origin, from the tubercle of the first 
 rib ; insertion, into the anterior tubercles of the transverse proc- 
 esses of the third, fourth, fifth, and sixth cervical vertebra; 
 action, flexes and rotates the vertebral column; nerves, anterior 
 branches of the lower cervical nerve. 
 
 Scalenus Medius. — Origin, upper surface of the first rib, 
 behind the groove for the subclavian artery ; insertion, into the 
 transverse processes of the lower six cervical vertebrae; action, 
 rotates and flexes the vertebral column; nerves, the anterior 
 branches of the lower cervical nerve : the posterior thoracic, long 
 thoracic nerve, or external respiratory nerve of Bell, has its 
 
THE MUSCULAR SYSTEM. 141 
 
 origin in the substance of this muscle, by union of two roots from 
 fifth and sixth cervical nerves. 
 
 Scalenus Posticus. — Origin, from the outer surface of the 
 second rib, behind the serratus magnus ; insertion, into the pos- 
 terior tubercles of the transverse processes of the lower two or 
 three cervical vertebrse; action, flexes and rotates the spine; 
 nerves, anterior branches of the lower cervical nerves. 
 
 Of these muscles the scalenus medius is the longest and 
 largest, and the scalenus posticus the smallest. 
 
 Muscles of the Larynx and Epiglottis {vide Larynx) . 
 
 Muscles oe the Trunk. 
 
 muscles op the back. 
 
 First Layer. 
 
 Trapezius. — Origin, from inner third of superior curved 
 line of the occipital bone, the ligamentum nuehfe, the spinous 
 processes of the seventh cervical, and all the dorsal vertebrae; 
 insertion, into the outer third of the posterior border of the 
 clavicle, the inner margin of the acromion process, and the crest 
 of the spine of the scapula ; action, with head fixed elevates point 
 of shoulder, with shoulders fixed together draws head backward, 
 or singly draws head to corresponding side; adducts, rotates 
 inward, and depresses humerus ; nerves, cervical plexus and spinal 
 accessory. 
 
 Ligamentum NucHiE. — Origin, from external occipital 
 protuberance ; insertion, spinous processes of, the cervical verte- 
 brse, from the second to the seventh. This ligament is rudi- 
 mental in man, and in the lower animals sustains the head. 
 
 Latissimus Doesi. — Origin, by an aponeurosis from the 
 spinous processes of the six lower dorsal, the lumbar and sacral 
 vertebrse, the supraspinou.s ligament, the crest of the ilium, and 
 the three or four lower ribs ; insertion, into the inner lip of the 
 bicipital groove of the humerus, in front of the teres major, and 
 a little above the pectoralis major; the tendon of this muscle 
 twists completely on itself, so that the superior fibres become the 
 inferior; action, draws the arm backward and downward, or, 
 fixing the arm, raises the lower ribs and draws the trunk forward ; 
 nerve, subscapular. 
 
 Second Layer. 
 Levator Anguli Scapulje. — Origin, from three to five 
 tendons from the posterior tubercles of the transverse processes 
 of the three or five upper cervical vertebrae ; insertion, into pos- 
 terior border of the scapula, at the root of the spine; action. 
 
142 
 
 HUMAN ANATOMY. 
 
 elevates the angle of the scapula; nerve, interior division of the 
 third and fourth cervical nerves. 
 
 Ehomboideus Mtso^.— Origin, from spinous processes of 
 seventh cervical and first dorsal vertebrae and the- ligamentum 
 nuchffi ; insertion, into root of the spine of the scapula ; action, 
 draws the inferior angle upward and backward; nerves, branches 
 from the fifth cervical nerve. 
 
 FiQ. 94. 
 
 Muscles of the back: 1, trapezius; 2, 4, latissimus dorsl; 10, leva- 
 tor anguli scapulsB; 11, rhomboideus minor; 12, rbomboideus major; 
 13, 14, splenius capitis et colli; 16, vertebral aponeurosis; 16, serratus 
 posticus inferior. 
 
 Ehomboideus Major. — Origin, from supraspinous liga- 
 ment and spinous processes of four or five upper dorsal vertebrse ; 
 insertion, by a tendinous arch attached above near the spine and 
 below to the inferior angle of the scapula; action, draws the 
 
THE MUSCULAR SYSTEM. 143 
 
 inferior angle upward and backward; nerves ^ branches of the 
 fifth cervical. 
 
 Third Layer. 
 
 Seeratus Posticus SuPEEiOR.-^Ong'iw, from spinous proc- 
 esses of the two or three upper dorsal and last cervical vertebras, 
 and from the ligamentum nuchse; insertion, into upper borders 
 of the second to the fifth ribs inclusive ; action, assists in respira- 
 tion; nerves, external branches of the posterior division of the 
 cervical. 
 
 Seeeatus Posticus Infeeioe. — Origin, from spinous proc- 
 esses and interspinous ligaments of two or three upper lumbar 
 and two lower dorsal vertebra; insertion, into lower borders of 
 the four lower ribs, external to their angles ; action, elevates the 
 ribs; assists in respiration; nerves, external branches of the 
 posterior divisions of the lower dorsal. 
 
 Splenius. — Origin, from spinous processes of last cervical 
 and six upper dorsal vertebrae, the lower half of the ligamentum 
 nuchse, and the supraspinous ligament ; insertion, by two heads — 
 splenius capitis into the occipital bone, ]ust below the superior 
 curved line and the mastoid process of the temporal bone ; sple- 
 nius colli into posterior tubercles of the transverse processes of 
 the three or four upper cervical vertebrae; action, separately, 
 rotates the head and draws it to the other side; together, draw 
 the head backward; nerves, external branches of the posterior 
 divisions of the cervical. 
 
 Fourth Layer. 
 
 Ekectoe Spin^. — Origin, from sacro-iliac groove and from 
 a broad tendon attached internally to the spinous processes of 
 the lumbar and two or three lower dorsal vertebrae and supra- 
 spinous ligament; externally, the crest of the ilium and the 
 posterior part of the sacrum; insertion, by two parts — 1, sacro- 
 lumbalis (ilio-costalis), inserted into bhe angles of the six or 
 seven lower ribs; this muscle has two accessory portions, (a) 
 musculus aecessorius ad sacro-lumbalem : origin, from angle of 
 six lower ribs ; insertion, angles of six upper ribs ; (h) cervicalis 
 ascendens : origin, angles of the four or five upper ribs ; inser- 
 tion, into the posterior tubercles of the fourth to the sixth cer- 
 vical vertebrae, inclusive; 2, longissimus dorsi; insertion, into 
 the transverse processes of all the dorsal vertebrae, and from the 
 seventh to the eleventh ribs, inclusive, between their angles and 
 tubercles ; action, bends the trunk backward and erects the spine ; 
 nerves, external branches of the posterior divisions of the lumbar 
 and dorsal. 
 
144 HUMAN ANATOMY. 
 
 Thansversalis Colli (or Ceevicis). — Origin, transverse 
 processes of six upper dorsal vertebra; insertion, into tlie pos- 
 terior tubercules of the transverse processes of the second to the 
 sixth cervical vertebrse inclusive; nerves, external branches of 
 the posterior divisions of the cervical. 
 
 Trachelo-mastoid. — Origin, from articular processes of 
 three or four lower cervical, and from the transverse processes 
 of the third to the sixth dorsal vertebrse; insertion, into the pos- 
 terior margin of the mastoid process, below the sterno-mastoid 
 and the splenius; action, steadies the head; nerves, external 
 branches of the posterior divisions of the cervical. 
 
 Spinalis Dorsi. — Origin, spinous processes of last two dor- 
 sal and first two lumbar vertebrae ; insertion, into spinous proc- 
 esses of the dorsal vertebrse, blending with the semi-spinalis 
 dorsi ; action, erects the spinal column ; nerves, external branches 
 of the posterior divisions of the cervical. 
 
 Spinalis Ceevicis. — Origin, from the spinous processes of 
 the fifth to the seventh cervical vertebrse; insertion, into the 
 spinous process of the axis; action, steadies the neck; nerves, 
 same as above; this muscle is absent in 20 per cent, of the 
 subjects. 
 
 CoirPLEXus OR Semispixalis Capitis. — Origin, by seven 
 tendons from transverse processes of the upper three dorsal and 
 seventh cervical and articular processes of the fourth, fifth, and 
 sixth cervical; insertion, .into the occipital bone, between the 
 curved lines ; action, separately, rotates and draws the head to one 
 side ; together, draw the head directly backward ; nerves, sub- 
 occipital, great occipital, and internal branches of the posterior 
 divisions of the cervical. 
 
 Fifth Layer. 
 
 Sejii-spinales Dorsi. — Origin, from transverse processes 
 from the fifth to eleventh dorsal vertebrse; insertion, into the 
 spinous processes of the lower two cervical and upper four dorsal 
 vertebrse; action, erects the spinal column; nerves, internal 
 branches of the posterior divisions of the cervical. 
 
 Semi-spinales Ceevicis. — Origin, from transverse processes 
 of lower four cervical and upper four dorsal vertebrse ; insertion , 
 into spinous processes of the second to the fifth cervical verte- 
 brse; action, erects the spinal column; nerves, same as above. 
 
 MuLTTFiDUS SPIN.E. — Origin, from the transverse processes 
 of the dorsal region, the articular processes in the cervical and 
 lumbar region, the posterior superior of the ilium, posterior 
 sacro-iliac ligaments, and from the aponeurotic arch of the erec- 
 tor spinas; insertion, each fasciculus is attached to the lamina' 
 
THE MUSCXJLAR SYSTEM. 145 
 
 and spinous process of the vertebrae above; action, preserves the 
 erect condition of the spine; nerves, internal branches of the 
 posterior divisions of the cervical, dorsal, lumbar, and sacral 
 nerves. 
 
 EoTATOHES Spin^. — Eleven on either side. Origin, from 
 upper part of transverse process; insertion, into outer surface 
 and lower border of the laminae of the verteljrae above, from the 
 first and second dorsal to the eleventh and twelfth; action, ro- 
 tates the spinal column; nerves, anterior branches of the pos- 
 terior divisions of the dorsal. 
 
 Sdpraspinales. — Origin and insertion, the spinous proc- 
 esses in the cervical region of the vertebrae; action, extends 
 cervical spine; nerves, internal branches of the posterior divi- 
 sions of the cervical. 
 
 Interspinales. — Consist of muscular bands in pairs be- 
 tween the spinous processes of the adjoining vertebras : six pairs 
 in the cervical region, three pairs in the dorsal, four or five in the 
 lumbar; action, extend the spine; nerves, internal branches of 
 the posterior divisions of the cervical, dorsal, and lumbar. 
 
 Extensor Cocotgis. — Origin, from the first piece of the 
 coccyx, or last bone of the sacrum ; insertion, into the lower ex- 
 tremity of the coccyx; action, rudimental in man. 
 
 Inteeteansversales. — Are small, muscular bands between 
 the transverse processes: in the cervical region seven pairs, in 
 the dorsal twelve pairs, in the lumbar region four pairs ; action, 
 flex the spine laterally ; nerves, internal branches of the posterior 
 division of the cervical, dorsal, and lumbar. 
 
 Eeotus Capitis Posticus Major. — Origin, from the spi- 
 nous process of the axis; insertion, into inferior curved line of 
 the occipital bone; action, rotates the atlas and the cranium; 
 nerve, the suboccipital. 
 
 Eectus Capitis Posticus Minor. — Origin, from the tu- 
 bercle of the posterior arch of the atlas; insertion, below the 
 inferior curved line of the occipital bone; action, draws the 
 head backward; nerve, suboccipital. 
 
 Obliquus Capitis Inferior. — Origin, spinous process of 
 the axis; insertion, lower back portion of the transverse process 
 of the atlas; action, rotates the atlas and the cranium; nerves, 
 suboccipital and great occipital. 
 
 Obliquus Capitis Superior. — From upper surface of the 
 transverse process of the atlas; insertion, between the curved 
 lines of the occipital bone to the outer side of the complexus; 
 action, rotates the atlas ; nerves, suboccipital and great occipital. 
 
146 
 
 HUilAN ANATOMY. 
 
 MUSCLES OF THE ABDOillNAL-THOKAOIC REGION. 
 
 Obliquus Exteenus. — Origin, lower borders of the eight 
 lower ribs; insertion, the lowermost miiscular fibres, into the 
 anterior half of the iliac crest; the other muscular fibres, by a 
 broad aponeurosis, which joins the anterior half of the aponeu- 
 rosis of the internal oblique to form the anterior walls of the 
 sheath of the rectus, above into the ensiform cartilage, below 
 into the symphysis pubis. In the median line it blends with 
 its fellow of the opposite side to form the linea alba. A slit 
 in its lower portion above the pubic spine is called the external 
 abdominal ring. The lower thickened portion of the aponeu- 
 rosis stretching between the anterior superior iliac spine and 
 the pubic spine is called Poupart's ligament. A reflection from 
 it to the ilio-pectineal line is called Gimbernat's ligament ; action, 
 flexes the pelvis on the thorax, or vice versa, and compresses the 
 viscera; nerves, lower intercostal, ilio-hypogastrie, and ilio-in- 
 guinal. 
 
 Obliqdus Inteenus. — Origin, from the outer half of Pou- 
 part's ligament, from the anterior two-thirds of the crest of the 
 ilium, and the posterior lamellae of the lumbar fascia ; insertion, 
 above to the lower four costal cartilages, below, conjointly with 
 the tendon of the transversalis, into the os pubis and linea ilio- 
 pectinea, to form the conjoined tendon, and into the median 
 line (linea alba) by an aponeurosis extending from the sternum 
 and seventh and eighth costal cartilages to the pubis. This apo- 
 neurosis at its lower fourth consists of two united laminas passing 
 in front of the rectus muscle, but in its upper three-fourths it 
 divides, one lamina passing in front of the rectus and joining 
 the aponeurosis of the external oblique, the other passing behind 
 and joining the aponeurosis of the transversalis; action, same as 
 the externus ; nerves, same as externus. 
 
 Teansveesalis. — Origin, from outer third of Poupart's 
 ligament and anterior three-fourths of the crest of the ilium, 
 from the inner surface of the cartilages of the six lower ribs, and 
 from the spinous and transverse processes of the lumbar verte- 
 bras; insertion, by the conjoined tendon into the linea ilio-pee- 
 tinea and crest of the os pubis; action and nerves, same as the 
 externus. 
 
 Eectus Abdominis. — Origin, by two tendons — the outer 
 from the crest of the pubis, the inner interlacing with its fellow 
 of the opposite side; insertion, into the cartilages of the fifth, 
 sixth, and seventh ribs; action, depresses the thorax, flexes the 
 vertebral column, and, acting from above, flexes- the pelvis upon 
 the vertebral column. 
 
THE MUSCtlLAR SYSTEM. 
 
 147 
 
 Ptraiiidalis. — Origin, from the os pubis and anterior pubic 
 ligament; insertion, into the linea alba, midway between the 
 OS pubis and umbilicus. 
 
 QuADKATUS Ldmboeum. — Origin, by two portions — ^pos- 
 terior portion, from crest of the ilium and ilio-lumbar ligament; 
 
 Fig. 95. 
 
 Muscles of abdomen: 12, external oblique; 16, rectus abdominis; 
 internal oblique; 17, pyramidalis; 19, quadratus lumborum. 
 
 IS. 
 
 insertion, into lower border of the last rib and transverse proc- 
 esses of the three lower lumbar vertebrae; origin, anterior por- 
 tion, from upper border of the transverse processes of the lumbar 
 vertebrae, from the third to the fifth ; insertion, into one-half the 
 lower margin of the last rib and apices of upper four lumbar 
 vertebrse; action, draws down and fixes the last rib and assists 
 in inspiration and expiration. 
 
148 
 
 HUMAN ANATOMY. 
 
 MUSCLES 01' THE THORAX. 
 
 Intercostales Bxterni. — Eleven pairs on either side. 
 Origin, from the outer border of the groove on the lower border 
 of each rib, from the cartilage to the tubercle; insertion, into 
 upper border of the rib below; action, raises the ribs; nerve, 
 intercostal. 
 
 Intercostales Interni. — Origin, inner lip of the groove 
 on the lower border of each rib ; insertion, into the upper border 
 of the rib below; action, pulls the ribs upward; nerve, inter- 
 costal. 
 
 Diaphragm: 1, 2, 3, central oordilorm tendon; 4, middle leaflet; 
 5, ligamentura arcuatum externum; 6, ligamentum arcuatum in- 
 ternum; 8, right crua; 10, left crus; 11, aortic opening; 12, oesopha- 
 geal opening; 13, opening for vena cava; 14, psoas magnus; 15, quadra- 
 tus lumborum. 
 
 Ikfracostales (Subcostales). — Origin, inner surface of 
 rib ; insertion, into the inner surface, from the first to the third 
 rib below; action, inspiratory muscles; nerve, intercostal. 
 1 Triangularis Sterni. — Origin, lower part of the back of 
 the sternum and back of ensiform cartilage and inner surface of 
 sternal end of the costal cartilages of the three or four lower 
 ribs; insertion, into the border and inner surfaces of the costal 
 cartilages, from the second to the sixth rib inclusive (it is con- 
 tinuous below with transversalis abdominis muscle) ; action, 
 draws down the costal cartilages; nerve, intercostal. 
 
THE MUSCULAR SYSTEM. 149 
 
 Levatores Costaeum. — Twelve on either side. Origin, 
 from transverse processes of seventh cervical and eleven upper 
 dorsal vertebrae; insertion, into upper surface of the rib below, 
 between the angle and tubercle; action, raises the ribs; nerve, 
 the intercostal. 
 
 DIAPHRAGMATIC EE6I0N. 
 
 Diaphragm. — Origin, inner surface of ensiform cartilage, 
 cartilages and bony portions of siz or seven lower ribs in front, 
 and from two aponeurotic arches, the ligamentum arcuatum ex- 
 ternum and internum and the lumbar vertebras behind; inser- 
 tion, into the circumference of the central or cordiform tendon; 
 action, the principal muscle of inspiration and expulsion; nerves, 
 the phrenic, and phrenic plexus of the sympathetic. 
 
 THE openings IN THE DIAPHRAGM. 
 
 The aortic opening is placed posteriorly between the two 
 crura, in front of the spine. It transmits the aorta, thoracic 
 duct, and vena azygos major, and sometimes the left sympa- 
 thetic nerve. 
 
 The oesophageal opening is in front of the decussation of 
 the crura, a little to the left and in front of the aortic opening. 
 It transmits the oesophagus and pneumogastric nerves. 
 
 The foramen quadratum, or opening for the vena cava, is 
 placed at the highest part of the central tendon, a little to the 
 right. It transmits the vena cava and maintains its patency. 
 The crus on each side transmits the sympathetic and greater and 
 lesser splanchnic nerves, and in addition the left transmits the 
 vena azygos minor. 
 
 JICSCLES OF THE PERIXEUM (vide PERIXEUM). 
 
 Muscles of the Upper Extremity, 
 muscles of the shoulder. 
 
 Pectoralis Major. — Origin, from the sternal half of the 
 clavicle ( clavicular portion) and anterior surface of the sternum 
 and costal cartilages from the second to the sixth or seventh 
 rib (sterno-costal portion) ; insertion, into the anterior bicipital 
 ridge of the humerus ; action, draws the arm across the chest ; 
 nerves, external and internal anterior thoracic. 
 
 Pectokalis JUixoR. — Origin, upper and outer surface of the 
 third to the fifth rib, inclusive, and the aponeurosis of the inter- 
 costal muscles; insertion, into anterior border of the coracoid 
 ]3rocess of the scapula; action draws the scapula inward and 
 downward ; nerve, the anterior thoracic. 
 
150 HUMAN ANATOMY. 
 
 SuBCLAVius. — Origin, from cartilage of the first rib ; inser- 
 tion, under surface of the clavicle, about its middle third ; action, 
 depresses the shoulder, and draws clavicle forward and down- 
 ward; nerve, branch from the union of the fifth and sixth 
 cervical. 
 
 Sberatus Magnus. — Origin, by nine muscular portions, 
 from the outer surface of the eight upper ribs (two divisions 
 being from the second rib) and from the upper intercostal apo- 
 neurosis ; insertion, by three divisions — ^upper portion into supe- 
 rior angle of the scapula, middle portion into posterior portion 
 of the scapula between the inferior and superior angles, lower 
 portion into the inferior angle of the scapula; action, raises the 
 vertebral border and carries the scapula forward; nerve, the pos- 
 terior thoracic. 
 
 Deltoid. — Origin, from the outer third of the clavicle and 
 from the outer part of the acromion process and the lower bor- 
 der of the scapular spine; insertion, into the outer side of the 
 shaft of the humerus, about its middle into the deltoid tubercle ; 
 action, raises the arm; nerve, the circumflex. 
 
 SuBSOAPULARis. — Origin, from the internal two-thirds of 
 the subscapular fossa; insertion, into the lesser tuberosity of the 
 humerus; action, rotates the head of the humerus inward; 
 nerves, upper and lower subscapular. 
 
 SuPEASPiNATtrs. — Origin, from inner two-thirds of supra- 
 spinous fossa; insertion, into the uppermost facet of the great 
 tuberosity of the humerus; action, assists in raising the arm 
 and fixing the head of the humerus; nerve, the suprascapular. 
 
 Infeaspinatus. — Origin, from the inner two-thirds ojf the 
 infraspinous fossa; insertion, into the middle facet of the great 
 tuberosity; action, rotates the head of the humerus outward; 
 nerve, supra-scapular. 
 
 Teees Mince. — Origin, posterior surface of the upper two- 
 thirds of the axillary border of the scapula; insertion, into the 
 lowest facet of the great tuberosity; action, rotates the head of 
 the humerus outward; nerve, the circumflex. 
 
 Teees Major. — Origin, posterior surface of the inferior 
 angle of the scapula; insertion, into the posterior bicipital ridge 
 of the humerus ; action, draws the humerus backward and down- 
 ward, assisting the latissimus dorsi ; nerve, the lower subscapular. 
 
 HUMERAL REGION. 
 
 CoRAco-BRACHiALis. — Origin, from apex of the coracoid 
 process of the scapula; insertion, into the inner side of the 
 middle of the shaft of the humerus, between the origin of the 
 
THE MUSCU1.AR SYSTEM. 
 
 151 
 
 brachialis anticus and short humeral head of the triceps; action, 
 draws the huinerus inward and forward; nerves, the musculo- 
 cutaneous and a branch of the musculo-spiral. 
 
 Biceps (Flexor Cubiti). — Origin, by two heads; short 
 head from the apex of the coracoid process, along with the coraco- 
 brachialis; the long (glenoid) head from the upper margin of 
 the glenoid cavity of the scapula; insertion, into the posterior 
 
 Muscles of slioulder and arm; 4, 
 subscapularis; 5, teres major; 6, 
 coraco-bracliialis ; 7, biceps. 
 
 Triceps muscle; 1, external head; 
 2, scapular head; 3, internal head; 
 4, insertion. 
 
 part of the tuberosity of the radius ; action, flexes the forearm ; 
 nerve, the musculo-cutaneous. 
 
 Brachialis Anticus. — Origin, inner and outer surfaces of 
 the shaft of the humerus, embracing the insertion of the deltoid ; 
 insertion, into the anterior surface of the coronoid process of 
 the uhia; action, flexes the forearm; nerve, the musculo- 
 cutaneous. 
 
 Triceps (Extensor Cubiti). — Origin, by three heads — 
 middle, or scapular head, below the glenoid cavity of the scapula ; 
 external head, from the posterior aspect of the shaft of the 
 
152 HUMAN ANATOMY. 
 
 humerus, between the upper part of the musculo-spiral groove 
 and the insertion of the teres minor, and from the external 
 intermuscular septum; the internal head, from the posterior 
 aspect of the shaft of the humerus, below the insertion of the 
 teres major, and below the groove for the musculo-spiral nerve; 
 insertion, by a common head, into the posterior part of the under 
 surface of the olecranon process of the ulna; action, extends the 
 forearm; nerve, the musculo-spiral. 
 
 SuBANCONEUS. — Origin, from the posterior surface of the 
 humerus, above the olecranon fossa; insertion, into the posterior 
 ligament of the elbow-joint; action, draws up the posterior liga- 
 ment of the elbow-Joint during extension of the forearm; nerve, 
 the musculo-spiral. 
 
 MUSCLES OF THE FOEEAEM. 
 
 Anterior Superficial Layer. 
 
 Peonatoe Eadii Teees. — Origin, by two heads — ^the smaller 
 from the coronoid process of the ulna, the larger from the 
 humerus, above the internal condyle, and from the common 
 tendon of this group of muscles, and intermuscular septum; in- 
 sertion, into the outer aspect of the shaft of the radius; action, 
 pronates the hand ; nerve, the median. 
 
 Plexoe Caepi Eadialis. — Origin, by the common ten- 
 don from the inner condyle, and from the intermuscular septum 
 between it and the pronator teres ; insertion, into the base of the 
 metacarpal bone of the index finger; action, flexes the wrist; 
 nerve, the median. 
 
 Palmaeis Longus. — Origin, from the inner condyle of the 
 humerus by the common tendon and the intermuscular septum 
 and the deep fascia ; insertion, into the annular ligament, spread- 
 ing out in the palmar fascia; action, renders tense the palmar 
 fascia; nerve, the median. 
 
 Plexor Caepi Ulnaeis. — Origin, by two heads — one by 
 the common tendon from the inner condyle of the humerus, 
 the other from the inner margin of the olecranon, the inter- 
 muscular septum, between the ulna and the flexor sublimis digi- 
 torum, and from the upper two-thirds of the posterior aspect 
 of the ulna; insertion, pisiform bone; action, flexes the wrist; 
 nerve, the ulnar. 
 
 Flexor Sublimis Digitoeum (Perfoeatus). — Origin, by 
 three heads — one from the coronoid process of the ulna, above 
 the pronator radii teres, another from the common tendon from 
 the internal condyle of the humerus, and the third from the 
 
THE MXrSCULAE SYSTEM. 
 
 153 
 
 oblique line of the radius, from the insertion of the pronator 
 radii teres, to the tubercle ; each tendon divides at the base of 
 the first phalanges to allow the passage of the tendon of the 
 flexor profundus digitorum ; insertion, 
 into the lateral margins of the second 
 phalanges by four tendons ; action, 
 flexes the second phalanges ; nerve, 
 median. 
 
 Anterior Deep Layer. 
 
 Plexok Profundus Digitorum 
 (Peeforans). — Origin, from the inner 
 side of the coronoid process, and from 
 the upper two-thirds of the front and 
 inner aspect of the shaft of the ulna, 
 between the brachialis anticus above 
 and the pronator quadratus below ; 
 insertion, by four tendons into the 
 bases of the last phalanges, perforating 
 the tendons of the flexor sublimis ; 
 action, flexes the phalanges ; nerves, 
 the anterior interosseous and the ulnar. 
 
 Flexor Longus Pollicis. — Origin, 
 from the upper two-thirds of the shaft 
 of the radius and from the interosseous 
 membrane ; insertion, into the base of 
 the last phalanx of the thumb ; action, 
 flexes the phalanges ; nerve, the ante- 
 rior interosseous. 
 
 Pronator Quadratus. — Origin, 
 anterior border of the ulna and from 
 the oblique line of the lower fourth 
 of the anterior aspect of the ulna ; 
 insertion, into the lower fourth of the 
 front and outer border of the shaft of 
 the radius ; action, pronates the hand ; 
 nerve, anterior in erosseous. 
 
 Muscles of forearm: 
 1, biceps; 2, brachialis 
 anticus; 3, triceps; i, 
 supinator longus; 5, ex- 
 tensor carpi radialis lon- 
 gior; 6, extensor carpi 
 radialis brevier; 8, ex- 
 tensor communis digi- 
 torum; 12, extensor carpi 
 ulnaris; 13, U, extensors 
 of thumb. 
 
 Radial Region. 
 
 Supinator Longus. — Origin, irora 
 the upper two-thirds of the external condyloid ridge of the 
 humerus and the external intermuscular septum ; insertion, into 
 the base of the styloid process of the radius ; action, supinates 
 the hand ; nerve, musculo-spiraL 
 
164 HUMAN ANATOMY. 
 
 Extensor Carpi Radialis Longior. — Origin^ from the 
 lower third of the external condyloid ridge of the humerus, from 
 the common tendon of the extensor muscles of the forearm from 
 the external condyle, and the intermuscular septum; insertion, 
 into the radial side of the base of the metacarpal bone of the in- 
 dex finger; action, extends the wrist; nerve, musculo-spiral. 
 
 Extensor Carpi Eadialis Brevior. — Origin, from the 
 common tendon, from the external condyle of the humerus, the 
 external lateral ligament, and the intermuscular septum; inser- 
 tion, into the base of the metacarpal bone of the middle finger 
 on its radial side; action, extends the wrist; nerve, posterior 
 interosseous. 
 
 Posterior Superficial Layer. 
 
 Extensor Communis Digitorum. — Origin, from the ex- 
 ternal condyle of the humerus, the deep fascia, and the inter- 
 muscular septa; insertion, by four tendons into the second and 
 third phalanges of all the fingers (at the first phalanx they 
 receive the insertion of the lumbricales and interossei) ; action, 
 extends the fingers; nerve, posterior interosseous. 
 
 Extensor Minimi Digiti. — Origin, from the common ten- 
 don from the external condyle and the intermuscular septum; 
 insertion, into the second and third phalanges of the little finger ; 
 action, extends the little finger; nerve, posterior interosseous. 
 
 Extensor Carpi TJlnaris. — Origin, from the middle third 
 of the posterior border of the ulna, from the common tendon 
 from the external condyle of the humerus, and from the fascia 
 of the forearm; insertion, into the base of the metacarpal bone 
 of the little finger, on the ulnar side; action, extends the wrist; 
 nerve, posterior interosseous. 
 
 Anconeus. — Origin, from the outer condyle of- the hu- 
 merus ; insertion, into the upper fourth of the posterior aspect of 
 the shaft of the ulna and the side of the olecranon; action, 
 extends the forearm; nerve, musculo-spiral. 
 
 Posterior Deep Layer. 
 
 Supinator Brevis. — Origin, from the external lateral liga- 
 ment of the elbow-joint, from the external condyle of the hu- 
 merus, from the ulna below the lesser sigmoid cavity, and from 
 the orbicular ligament of the radius; insertion, into the neck, 
 bicipital tuberosity and oblique line of radius ; the posterior 
 interosseous nerve pierces this muscle; action, supinates the 
 hand; nerve, posterior interosseous. 
 
THE iirSCULAR SYSTEII. 155 
 
 ExTENTSOR Ossis Metacaepi Pollicis. — Origin, middle 
 third of posterior surface of radius, posterior surface of louver 
 three-fourths of shaft of ulna, and interosseous ligament; iiiser- 
 tian, into Ijase of metacarpal of thumb; action, extends meta- 
 carpal of thumb ; net ve, posterior interosseous. 
 
 ExTEXHOR LoxGUS PoLLicis. — Origin, from the interosseous 
 membrane and from the posterior aspect of the shaft of the 
 ulna; insertion, into the base of the last or terminal phalanx 
 of the thumb ; action, extends the thumb ; nerve, posterior inter- 
 usseous. 
 
 EXTEXSOR Bre\-is Polmcis. — Origin, from the posterior 
 aspect of the shaft of the radius and from the interosseous mem- 
 brane ; insertion, into the base of the first phalanx of the thumb ; 
 action, extends the thumb ; nerve, posterior interosseous. 
 
 ExTEXsoR IxDicis. — Origin, from the posterior aspect of 
 the ulna and from the interosseous membrane; insertion, into 
 the second and third phalanges of the index finger, along with 
 the tendon of the extensor communis; action, extends the index 
 finger; nerve, posterior interosseous. 
 
 MUSCLES or THE HAXD. 
 
 These are divided into three groups — the radial region, the 
 ulnar region, and the palmar region; 
 
 Radial Region. 
 
 Abductor Pollicis. — Oiigin, from the annular ligament 
 and ridge of the trapezium; insertion, into base of the first 
 phalanx of the thumb on its radial side; action, abducts the 
 thumb from the median line ; nerve, median. 
 
 OproxEXs Pollicis. — Origin, from annular ligament and 
 palmar surface of the trapezium ; insertion, into metacarpal bone 
 of the thumb throughout the whole length of its radial side; 
 action, flexes the first metacarpal bone; nerve, median. 
 
 Flexor Breyis Pollicis. — This muscle consists of two por- 
 tions, divided bj- tendon of fiexor longus pollicis; on-igin, super- 
 ficial portion from outer two-thirds of annular ligament and 
 trapezium, deeper portion (by some called adductor obliquus 
 pollicis) from sheath of flexor carpi radialis, the trapezoid, os 
 magnum, and base of first, second, and third metacarpal bones; 
 insertion, into either side of base of first phalanx of thumb, the 
 inner portion joining the adductor and the outer portion the 
 abductor; each tendon has a sesamoid bone developed in it; 
 action, adducts thumb toward median line; nerves, ulnar and 
 median. 
 
156 HUMAN ANATOMY. 
 
 Adductor Pollicis (Adductor Transversus Pollicis) . — 
 Origin, from lower two-thirds palmar surface of middle meta- 
 carpal bone; insertion, into ulnar side of base of first thumb 
 phalanx and internal sesamoid bone; action, adducts thumb; 
 nerve, ulnar. 
 
 Ulnar Region. 
 
 Palmaris Brevis. — Origin, from palmar fascia and annu- 
 lar ligament; insertion, into skin of palm of hand; action, 
 wrinkles skin of hand; nerve, ulnar. 
 
 Abductor Minimi Digiti. — Origin, from pisiform bone 
 and from tendon of flexor carpi ulnaris; insertion, into base of 
 first phalanx of little finger on its ulnar side; action, abducts 
 little finger from median line ; nerve, ulnar. 
 
 Flexor Brevis Minimi Digiti. — Origin, from annular 
 ligament and tip of unciform process of unciform bone; inser- 
 tion, into the first phalanx of little finger; action, flexes little 
 finger; nerve, ulnar. 
 
 Opponens Minimi Digiti. — Origin, from annular ligament 
 and from unciform process of unciform bone; insertion, into 
 ulnar border of whole length of metacarpal bone of little finger; 
 action, flexes little finger; nerve, ulnar. 
 
 Palmar Region. 
 
 LuMBRiCALES. — Origin, by four fleshy tendons from the 
 tendons of the deep flexors — the first and second from the palmar 
 surface and radial side of the tendons of the index and middle 
 fingers, the third from the adjoining sides of the tendons of the 
 middle and ring fingers, and the fourth from the adjoining sides 
 of the tendons of the ring and little fingers ; insertion, on dorsal 
 aspect of each finger into the expansion of the extensor communis 
 digitorum ; action, abduct the fingers to either side of the median 
 line; reereeSj ulnar and median. 
 
 Interossei muscles consist of two groups, the dorsal and 
 palmar. 
 
 Dorsal Interossei. — Origin, from two heads from the 
 adjacent sides of the metacarpal bones, four in number; inser- 
 tion, the first into the radial side of the base of the first phalanx 
 of the index finger, the second into the radial side of the middle 
 finger, the third into the ulnar side of the middle finger, and the 
 fourth into the ulnar side of the ring finger, the middle finger 
 having two, one on either side; action, abduct the fingers from 
 the median line; nerve, ulnar. 
 
THE MUSCtJIiAE SYSTEM. 157 
 
 Palmar Inteeossei. — Three in number. Origin, the first 
 from the entire length of the metacarpal bone of the index 
 finger on its ulnar side, the second from the ring finger on its 
 radial side, and the third from the little finger on its radial side; 
 insertion^ into the base of the first phalanx and into the ex- 
 pansion of the extensor communis tendon of the same finger 
 from which they arise; action, adduct the fingers toward the 
 median line; nerve, ulaar. 
 
 Muscles of the Lower Extremity, 
 iliac region. 
 
 Psoas Magnus. — Origin, from the sides and anterior sur- 
 faces of the transverse processes and bodies of the last dorsal and 
 all the lumbar vertebrae and the intervertebral substances between 
 them ; insertion, into the lesser trochanter of the femur, uniting 
 with the tendon of the iliacus ; this muscle is in relation behind 
 with the capsular ligament of the hip, being separated from it by 
 a synovial bursa; action, flexes and rotates the femur inward, 
 and also flexes the trunk and pelvis on the thigh; nerves, an- 
 terior branches of the lumbar nerves. 
 
 Psoas Parvus. — Origin, from the lateral surfaces of the 
 bodies of the last dorsal and first lumbar vertebrae and from the 
 intervertebral substances between them; insertion, into the ilio- 
 pectineal eminence, joining the iliac fascia; action, assists the 
 psoas magnus and renders tense the iliac fascia; nerves, anterior 
 branches of the lumbar. 
 
 Iliacus. — Origin, from the base of the sacrum and the ilio- 
 lumbar ligament behind, from the iliac fossa and inner margin 
 of the crest of the ilium and the anterior superior and anterior 
 inferior spinous processes of the ilium; insertion, into the 
 oblique or intertrochanteric line of the femur to the outer side of 
 the insertion of the psoas; action, flexes and rotates the femur 
 inward and flexes the trunk and pelvis on the thigh; nerves, 
 anterior crural and the anterior branches of the lumbar. 
 
 femoral and GLUTEAL REGION. 
 
 Tensor VAGiN-a; Femoris. — Origin, from the anterior supe- 
 rior spinous process between the sartorius and the gluteus medius, 
 and from the fore part of the outer lip of the crest of the ilium ; 
 insertion, into the fascia lata, about the upper fourth of the 
 outer side of the thigh; action, renders tense the fascia lata; 
 nerve, superior gluteal. 
 
158 HLTMAN ANATOMY. 
 
 Sartoeius. — Origin, from the anterior superior spinous 
 process of the ilium and the upper part of the notch below ; in- 
 sertion, into the inner and upper part of the shaft of the tibia; 
 action, flexes the leg upon the thigh and the thigh upon the 
 pelvis ; nerve, branches of the anterior crural. 
 
 Quadriceps Extensor. — This extensive muscle covers the 
 front and sides of the femur and consists of four portions — the 
 rectus femoris, the vastus extemus, the vastus internus, and the 
 crureus. 
 
 Rectus Femoeis. — Origin, by two heads — one, the long 
 head, from the groove above the brim of the acetabulum; the 
 other, the short head, from the anterior inferior spinous process 
 of the ilium ; insertion, by the common tendon into the patella ; 
 action, extends the leg upon the thigh; nerves, branches of the 
 anterior crural. 
 
 Vastus Bxtbenus. — Forms the greater part of the quadri- 
 ceps extensor. Origin, by an extensive aponeurosis extending 
 from the tubercle of the femur along the anterior border of the 
 great trochanter and the whole length of the outer lip of the 
 linea aspera; insertion, into the outer portion of the patella, 
 joining the common tendon; action, extends the leg on the 
 thigh ; nerves, branches of the anterior crural. 
 
 Vastus Inteenus and Ceueeus. — Origin, by a tendinous 
 aponeurosis extending from the neck of the femur throughout 
 the whole length of the inner lip of the linea aspera ; insertion, 
 into the common tendon, together with the rectus femoris and 
 the vastus externus ; action, extends the leg on the thigh ; nerves, 
 branches of the anterior crural. 
 
 SuBCEUEEUS. — Origin, from the anterior aspect of the lower 
 part of the shaft of the femur; insertion, into the synovial sac 
 behind the patella. 
 
 Gracilis. — Origin, from the inner margin of the ramus of 
 the ischium and the pubes; insertion, into the inner aspect of 
 tne shaft of the tibia, below the tuberosity; action, flexes the 
 leg and draws it inward, assisting the sartorius ; nerve, the obtu- 
 rator. 
 
 Pectineus. — Origin, from the tendinous prolongation of 
 Gimbernat's ligament and the linea ilio-pectinea ; insertion, into 
 the rough line leading to the linea aspera from the lesser tro- 
 chanter; action, adducts the thigh; nerves, obturator, the ac- 
 cessory obturator, and branches of the anterior crural. 
 
 Adductor Longus. — Origin, from the front of the os pubis 
 below the crest; insertion, into the middle third of the linea 
 aspera, between the adductor ma gnus and the vastus internus; 
 action, adducts the thigh; nerve, obturator. 
 
THE MUSCULAK SYSTEM. 
 
 169 
 
 Adductoe Beevis. — Origin, from the outer aspect of the 
 descending ramus of the pubes, between obturator extemus and 
 the gracilis; insertion, into the upper part of the linea aspera; 
 action, adducts the thigh ; nerves, branches of the obturator. 
 
 Adductor Magnus. — Origin, from 
 the luberosity of the ischium, the as- ■ — 
 
 cending ramus of the ischium, and 
 from the descending ramus of the 
 pubes ; insertion, into the rough line 
 leading to the linea aspera from the 
 great trochanter to the inner side of 
 the gluteus maximus and into the 
 adductor tubercle above the inner con- 
 dyle of the femur (z)tie page 64) ; action, 
 adducts the thigh ; nerves, the obtura- 
 tor and a branch from the great sciatic. 
 Gluteus Maximus. — Origin, from 
 the superior curved line of the ilium, 
 the posterior aspect of the last segment 
 of the sacrum, the border of the coccyx, 
 and the surface of the great sacro- 
 sciatic and posterior sacro-iliac liga- 
 ments ; insertion, into the rough line 
 leading to the linea aspera from the 
 great trochanter, between the adductor 
 magnus and the vastus externus, and 
 into the fascia lata ; action, it is a ten- 
 sor of the fascia lata, and an external 
 rotator and extensor of the thigh ; 
 nerves, the inferior gluteal and a branch 
 from the sacral plexus. 
 
 Gluteus Medius. — Origin, from 
 the outer lip of the crest and the outer 
 aspect of the ilium, between the middle 
 and superior curved lines, and from 
 the gluteal aponeurosis ; insertion, into 
 the oblique line on the outer surface of 
 the great trochanter ; action, rotates 
 the thigh outward ; nerve, from the 
 superior gluteal. 
 
 Gluteus Minimus. — Origin, from the border of the great 
 sacro-sciatic notch and between the inferior and middle curved 
 lines of the outer aspect of the ilium ; insertion, into a depression 
 on the front border of the great trochanter; action, rotates the 
 thigh inward ; nerve, superior gluteal. 
 
 FIG. 100. 
 
 Anterior femoral re- 
 gion: 4, tensor vaginas 
 femoris; 6, sartorius; 6, 
 rectus; 7, vastus exterr 
 nus; 8, vastus internus; 
 10, iliacus; 11, psoas; 12, 
 pectlneus; 13, adductor 
 longus; 14, adductor mag- 
 nus; 15, gracilis. 
 
160 
 
 HUMAN ANATOMY. 
 
 PTRiroKMis. — Origin, from the anterior surface of the sa- 
 crum, between the first to the fourth anterior sacral foramen, and 
 from the margin of the great sacro-sciatic foramen, and from 
 the anterior aspect of the great sacro-sciatic ligament ; insertion, 
 into the upper border of the great tro- 
 chanter, with the tendon of the obtu- 
 rator internus ; action, rotates, femur 
 outward ; nerve, obturator. 
 
 Obturator Internus. - — Origin, 
 from the inner side of the obturator 
 foramen and the internal surface of 
 obturator membrane and the anterior 
 and external wall of the pelvis it passes 
 out of the pelvis through the lesser 
 sacro-sciatic notch and receives the ten- 
 dons of the gemelli muscles ; insertion, 
 into the upper border of the great tro- 
 chanter in front of the pyriformis ; 
 action, rotates the thigh outward ; 
 nerves, branches from the sacral plexus. 
 Gemelli consist of two muscles 
 — gemellus superior and gemellus in- 
 ferior. 
 
 Gemellus Superior. — Origin, 
 from the outer aspect of the spine of 
 the ischium ; insertion, into the tendon 
 of the obturator internus. 
 
 Gemellus Inferior. — Origin, 
 from the outer border of tuberosity of 
 the ischium ; insertion, into the lower 
 portion of the tendon of the obturator 
 internus ; action, rotates the thigh out- 
 ward ; nerves, branches of the sacral 
 plexus. 
 
 QuADRATUS Femoris. — Origin, 
 from the external border of the tuber- 
 osity of the ischium ; insertion, into the 
 upper part of the linea quadrati, on 
 the posterior aspect of the trochanter 
 major; action, rotates the thigh outward; nerves, branches of 
 the sacral plexus. 
 
 Obturator Externus. — Origin, from the inner two-thirds 
 of the anterior aspect of the obturator membrane and the tendi- 
 nous arch covering the canal for the obturator vessels and nerves, 
 and the descending ramus of the pubis and the ascending ramus 
 
 Fig. 101. 
 
 Posterior femoral re- 
 gion: 1, gluteus medlus; 
 2, gluteus maximus; 3, 
 vastus externus; 4, bi- 
 ceps; 6, semi-tendinosls; 
 7, semi-membranosls; 8, 
 gracilis. 
 
THE MUSCULAR SYSTEM. 161 
 
 of the ischium; insertion, into the digital fossa of the femur; 
 action, rotates the thigh outward; nerve, the obturator. 
 
 BiGBTS.— Origin, arises by two heads — the long head, from 
 the lower and inner facet of the tuberosity of the ischium by a 
 common tendon to the long head of the semi-tendiaosus ; the 
 short head, from the outer lip of the liaea aspera, between the 
 vastus extemus and the adductor magnus; insertion, outer side 
 of head of fibula, by two portions, on either side of the external 
 lateral ligament of the knee-joint, sending a band forward to the 
 outer tuberosity of the tibia. This tendon forms the outer ham- 
 string; action, flexes the leg upon the thigh; nerve, the great 
 sciatic. 
 
 Semi-tendinosus. — Origin, from a common tendon, to- 
 gether with the long head of the biceps, from the tuberosity of 
 the ischium; insertion, into the inner and upper part of the 
 shaft of the tibia; action, rotates the leg inward; nerve, the 
 great sciatic. 
 
 Semi-membeanosus. — Origin, from the outer and upper 
 facet of the tuberosity of the ischium to the outer side and above 
 the origin of the semi-membranosus and the biceps; insertion, 
 into the posterior inner aspect of the inner tuberosity of the 
 tibia, under the internal lateral ligament by three portions — the 
 internal portion into the inner side of the internal tuberosity, 
 the posterior portion into the posterior part of the outer condyle 
 of the femur, forming the principal part~Tof the posterior liga- 
 ment of the knee-joint, and middle portion into the posterior 
 aspect of the inner tuberosity; action, flexes the leg upon the 
 thigh; nerve, the great sciatic. 
 
 These two tendons (semi-membranosus and semi-tendino- 
 sus), together with the gracilis and sartorius, form the inner 
 hamstring. 
 
 MUSCLES OP THE LEG. 
 
 Anterior Set. 
 
 Tibialis Anticus. — Origin, from the upper and outer two- 
 thirds of the shaft of the tibia, the interosseous membrane, and 
 the intermuscular septum between it and the extensor longus 
 digitorum; insertion, into the lower and inner aspect of the 
 internal cuneiform bone and base of the first metatarsal bone; 
 action, flexes the -foot; nerve, the anterior tibial. 
 
 Extensor Peoprius Pollicis. — Origin, from the anterior 
 aspect of the fibula and the interosseous membrane and the 
 intermuscular septum between it and the extensor longus digi- 
 torum; insertion, into the base of the last phalanx of the great 
 toe; action, extends the great toe; nerve, the anterior tibial. 
 
162 
 
 HUMAN ANATOMY. 
 
 Extensor Longus Digitorum. — Origin, from the upper 
 two-thirds of the anterior aspect of the shaft of the fibula and the 
 outer tuberosity of the tibia, from the deep fascia of the inter- 
 osseous membrane and the intermuscular septum, between it and 
 the perinei on the outer and the tibialis anticus on the inner 
 side; insertion, by three tendons into the bases of the first and 
 
 I 
 
 FlQ. 102. 
 
 Anterior muscles ol leg: 3, tibialis 
 Bntlcus; 4, extensor longus digitorum; 
 B, extensor proprius pollicis; 6, pe- 
 roneus tertius; 7, peroneus longus; 
 8, peroneus brevis. 
 
 Fig. 103. 
 
 Posterior muscles of leg: 4, pop- 
 liteus; 5, gastrocnemius: 6, tendo 
 Acliillis; 8, tendons of peroneus 
 longus and brevis; 9, tibialis posticus 
 and fiexors. 
 
 second phalanges of the four lesser toes, the innermost tendon 
 dividing into two; each tendon (except the fourth) is joined 
 opposite the metatarso-phalangeal joint by the tendon of the 
 extensor brevis digitorum, and receives an expansion from the 
 lumbricales and interossei; at the first interphalangeal articula- 
 tion the tendons divide into three slips — ^the middle one for inser- 
 
THE MUSCULAE SYSTEM. 163 
 
 tion into the second phalanges, and the other two tmiting to be 
 inserted into the bases of the third ; action, extends the phalanges 
 and, continuing, flexes the foot upon the leg; nervBj the anterior 
 tibial. 
 
 Peeoneus Teetius. — Origin, from the lower front part of 
 the fibula on its outer side, from the interosseous membrane, and 
 the intermuscular septum between it and the peroneus brevis; 
 insertion, into the metatarsal bone of the little toe ; action, flexes 
 the tarsus upon the leg; nerve, the anterior tibial. 
 
 Posterior Superficial Set. 
 
 Gasteocnemius. — Origin, from the upper and back part 
 of the external and internal condyles of the femur on either side, 
 above the origin of the popliteus, and from the supracondyloid 
 ridges; insertion, by joining with the tendon of the soleus to 
 form the tendo Achillis; action, extends the foot; nerve, from 
 the internal popliteal. 
 
 Soleus. — Origin, from the oblique line of the tibia, from 
 the middle third of the internal border, and from the posterior 
 surface of the head of the fibula; insertion, by joining with the 
 tendon of the gastrocnemius to form the tendo Achillis ; action, 
 extends the foot; nerve, the internal popliteal. 
 
 Tendo Achillis. — Origin, from the union of the gastroc- 
 nemius and soleus; is the largest and strongest tendon in the 
 body; it is inserted into the inferior surface of the posterior 
 tuberosity of the os calcis, having a synovial bursa between it 
 and the bone. 
 
 Plantakis. — Origin, from the posterior ligament of the 
 knee-joint and the lower portion of the outer division of the 
 linea aspera ; insertion, into the posterior part of the os calcis to 
 the inner side of the tendo Achillis; action, the rudiment of a 
 muscle intended to render tense the plantar fascia; nerve, the 
 internal popliteal. 
 
 Posterior Deep Set. 
 
 Popliteus. — Origin, from the outer side of the external con- 
 dyle, from the posterior ligament of the knee-joint; insertion, 
 above the oblique line on the posterior aspect of the shaft of the 
 tibia; action, assists in flexing the leg; nerve, the internal pop- 
 liteal. 
 
 Flexoe Longus Polliois. — Origin, from the lower two- 
 thirds of the internal surface of the fibula, from the lower part 
 of the interosseous membrane, fascia covering tibialis posticus. 
 
164 HUMAN ANATOMY. 
 
 and from the intermuscular septum; it passes behind the in- 
 ternal malleolus; insertion, into the base of the last phalanx of 
 the great toe; nerve, posterior tibial. 
 
 Flexor Longus Digitoeum (Peefobans). — Origin, from 
 the posterior aspect of the tibia, below the oblique line ; it passes 
 behind the internal malleolus; insertion, into the bases of the 
 last phalanges of the four lesser toes, passing through the division 
 in the tendons of the flexor brevis digitorum ; action, flexes the 
 phalanges and, continuing, extends the foot on the leg; nerve, 
 the posterior tibial. 
 
 Tibialis Posticus. — Origin, from the posterior aspect of 
 the shaft of the tibia, and from the upper two-thirds of the shaft 
 of the fibula, and from the whole length of the interosseous mem- 
 brane and the intermuscular septa on either side of it; it passes 
 behind the inner malleolus; insertion, into the internal cunei- 
 form bone and the tuberosity of the scaphoid; it contains a 
 sesamoid bone in its tendon ; action, extends the tarsus upon the 
 leg; nerve, the posterior tibial. 
 
 Fibular Region. 
 
 Pbeoneus Longus. — Origin, from the upper two-thirds of 
 the shaft of the fibula, the head of the fibula, the intermuscular 
 septa, and the deep fascia; it passes behind the outer malleolus 
 along with the peroneus brevis; insertion, into the base of the 
 metatarsal bone of the great toe; this tendon changes its course 
 twice, first at the external malleolus, second at the cuboid bone, 
 and usually has a sesamoid bone developed in its tendon ; action, 
 extends and everts the foot upon the leg; nerve, musculo-cutane- 
 ous branch of the external popliteal. 
 
 Peroneus Beevis. — Origin, from the outer and middle 
 third of the fibula and the intermuscular septa on eitier side; 
 insertion, into the upper surface of the base of the metatarsal 
 bone of the little toe; action, extends the foot upon the leg; 
 nerve, musculo-cutaneous branch of the external popliteal. 
 
 muscles of the foot. 
 Dorsal Region. 
 
 ExTENSOE Brevis Digitoeum. — Origin, from the external 
 calcaneo-astragaloid ligament, from the annular ligament, and 
 from the outer side of the os calcis ; insertion, by four tendons — 
 the first one into the first phalanx of the great toe, the other three 
 into the long extensor tendons of the second, third, and fourth 
 
THE MUSCULAR SYSTEM. 165 
 
 toes on their outer sides ; action, extends the phalanges of the four 
 inner toes and the first phalanx of the great toe; nerve, the an- 
 terior tibial. 
 
 Plantar Region. 
 The muscles of this region are divided into four sets. 
 
 First Set. 
 
 Abductor Hallucis. — Origin, from the internal annular 
 ligament, from the inner tubercle of the os calcis, from the inter- 
 muscular septum on its outer side ; plantar fascia ; insertion, into 
 the base of the first phalanx of the great toe on its inner side; 
 action, abducts the great toe; nerve, branch of the internal 
 plantar. 
 
 Flexor Brevis Digitorum (Perfgratus) . — Origin, from 
 the inner tubercle of the os calcis, from the plantar fascia and 
 the intermuscular septa between it and the muscles on either 
 side; insertion, into the second phalanges by a process on either 
 side, allowing the passage of the tendon of the flexor longus 
 digitorum; action, flexes first lesser toes; nerve, from the in- 
 ternal plantar. 
 
 Abductor Minimi Digiti. — Origin, from the plantar fascia, 
 from the os calcis in front of the tubercle, and from the inter- 
 muscular septum on its inner side; insertion, into the first 
 phalanx of the little toe on its outer side; action, abducts little 
 toe; nerve, external plantar. 
 
 Second Set. 
 
 Flexor Accessorius. — Origin, by two heads, one from the 
 OS calcis in front of the outer tubercle, the other from the inner 
 surface of the os calcis and the calcaneo-scaphoid ligament; in- 
 sertion, by a common tendon into the tendon of the flexor longus 
 digitorum; action, accessory to the long flexor; nerve, external 
 plantar. 
 
 LuMBRiCALES. — FouT Small muscles. Origin, from the ten- 
 dons of the flexor longus digitorum, after their division, each 
 one arising from two tendons; insertion, into the base of the 
 first phalanx of the same toe and the tendinous expansion of the 
 extensor longus digitorum; nerves, the external plantar nerve 
 supplies the two external, the internal plantar nerve the two in- 
 ternal, muscles. 
 
IQQ HUMAN ANATOMY. 
 
 Third Set. 
 
 Flexor Beevis Hallucis. — Origin, from the external cune- 
 iform bone, and the internal border of the cuboid bone, and 
 the tendinous expansion of the tibialis posticus ; insertion, into 
 the first phalanx of the great toe on either side; action, flexes 
 first phalanx of great toe ; nerves, the internal plantar and some- 
 times a branch from the external plantar. 
 
 Adduotoe Hallucis. — Origin, from the bases of the second, 
 third, and fourth metatarsal bones and from the sheath of the 
 tendon of the peroneus longus; insertion, into the base of the 
 first phalanx of the great toe on the outer side ; nerve, external 
 plantar. 
 
 Flexoe Brbvis Minimi Digiti. — Origin, from the sheath 
 of the peroneus longus and the base of the metatarsal bone of the 
 little toe J insertion, into the outer side of the base of the little 
 toe; nerve, external plantar. 
 
 Teansveesus Pedis. — Origin, from the inferior surface of 
 the head of the fifth metatarsal bone, from the transverse meta- 
 tarsal ligament ; insertion, into the first phalanx of the great toe, 
 on its outer side; action, adducts the great toe; nerve, the ex- 
 ternal plantar. 
 
 Fourth Set. 
 
 Dorsal Inteeossei. — Four in number. Origin, by two 
 heads from the adjoining bases of the metatarsal bones; inser- 
 tion, into the bases of the first phalanges of the second, third, 
 and fourth toes, the second having two, one on either side, and 
 the third and fourth on their outer side; action, abduct the toes 
 from the middle line of the second toe; nerve, external plantar. 
 
 Plantae Inteeossei. — Three in number. Origin, from 
 the bases of inner side of the third, fourth, and fifth metatarsal 
 bones ; insertion, into the bases of the first phalanges on the same 
 side ; action, adduct the toes toward the middle line of the sec- 
 ond toe; nerve, the external plantar. 
 
 The Fascias. 
 
 The fascias are strong, fibrous (fibro-areolar) investments 
 protecting and binding together the muscles, and in places form- 
 ing ligaments and intermuscular septa. They consist for the 
 most part of two layers, a superficial and a deep. 
 
 Fascias of the Head and Face. — The superficial fascia 
 of the head and face is everywhere intimately connected to the 
 skin, except over the temporal region, where it forms a distinct 
 lamina, inclosing the superficial temporal vessels and auricular 
 muscles. 
 
THE MUSCULAR SYSTEM. 167 
 
 The deep temporal fascia is a dense, fibrous membrane, at- 
 tached to the margins of the temporal fossa and zygoma, and 
 from which in part the temporal muscle arises. 
 
 Fascias of the Neck. — The superficial fascia is continuous 
 below with that covering the pectoral muscles and deltoid, and 
 blends above with the superficial facial muscles and fascia. 
 
 The deep fascia adheres below to the clavicle and sternum, 
 and is continuous with the thoracic fascia. As it ascends the 
 neck it ensheathes the great vessels of the neck, sends processes 
 to the larynx, trachea, pharynx, and oesophagus, and above en- 
 sheathes the submaxillary and parotid glands, and forms the 
 stylo-maxillary ligament. 
 
 Fascias of the Teunk. — The superficial fascia may con- 
 sist of two or more layers in places. It is continuous above 
 with the fascias of the neck and upper extremity, and below with 
 the thigh. Over the pectoral region the mammary glands are 
 inclosed between its layers; below the level of the umbilicus it 
 again divides into two layers, the superficial of which is con- 
 tinuous with the superficial layer of the superficial fascia in the 
 thigh, while the deep layer is attached to the crest of the ilium 
 and Poupart's ligament. 
 
 The deep fascia forms intermuscular septa and aponeuroses. 
 
 The lumbar fascia divides into three layers, inclosing the 
 quadratus lumborum, multifldus spinse, and erector spinas mus- 
 cles, and giving attachment to the internal oblique and trans- 
 versalis muscles. Its anterior and middle layers are attached 
 to the transverse processes, and its posterior layer to the spinous 
 processes. Above its anterior layer is attached to the lower bor- 
 der of the last rib, forming the ligamentum arcuatum externum. 
 (The ligamentum arcuatum internum extends from the body 
 of the first or second lumbar vertebra to the transverse process, 
 inclosing the psoas magnus muscle.) 
 
 Abdominal and Pelvic Fascia. — The transversalis fascia 
 is a thin aponeurosis between the peritoneum and transversalis 
 muscle. It is attached below to the pubes, pectineal line, Pou- 
 part's ligament, and the femoral vessels, and becomes continuous 
 with the iliac and pelvic fascia. The pelvic fascia lines the 
 pelvic cavity throughout, attached to the symphysis pubis, mar- 
 gin of obturator foramen, and the sacriun, and becomes con- 
 tinuous with the iliac and transversalis fascias. Below it forms 
 the arcus tendince, for the origin of muscles and the division 
 into the recto-vesical and obturator fascias (vide Perineum) . 
 
 The iliac fascia is a thin, fibrous membrane investing the 
 psoas and iliacus muscles. Above it is attached to the ligamen- 
 tum arcuatum internum, laterally with the bodies of the verte- 
 
168 HUMAN ANATOMY. 
 
 brae and sacrum, and below it is attached to Poupart's ligament, 
 the femoral vessels, pectineal eminence, and the capsule of the 
 hip-joint. 
 
 Upper Exteemity. — The superficial fascia is a thin mem- 
 brane, inclosing the parts throughout, and adherent to the deep 
 fascia beneath. 
 
 The deep fascia is very dense and strong. It gives oS 
 numerous intermuscular septa, and is attached to the olecranon 
 and back part of ulna, and becomes continuous below with the 
 anterior and posterior annular ligaments of the wrist-joint, both 
 of which it forms. 
 
 The anterior annular ligament is attached to the ridge of 
 the trapezium, the tuberosity of the scaphoid, the unciform proc- 
 ess of the unciform, and the pisiform bone, forming a strong, 
 fibrous arch, under which the flexor tendons of the fingers pass. 
 
 The posterior annular ligament is attached to the radius, 
 ulna, cuneiform, and pisiform bones, and the palmar fascia, 
 forming a fibrous arch for the passage of the extensors of the 
 fingers. 
 
 The palmar fascia is an exceedingly dense, triangular mass 
 of adipose and fibrous tissue, attached behind to the anterior 
 annular ligament, and in front divides into four fasciculi, each 
 of which subdivides into two, inserted into the lateral ligaments 
 of the metacarpo-phalangeal articulations. These digitations 
 allow the passage of the fiexor digitorum tendons, the digital 
 vessels, and nerves. It is attached above to the skin, and later- 
 ally gives off vertical septa, which separate the middle from the 
 lateral groups of palmar muscles. 
 
 FASOIAS OF THE LOWER EXTREMITY. 
 
 The superficial fascia resembles that in other localities, 
 except that, in the front of the thigh, it consists of two or more 
 layers between which are found the superficial vessels and nerves 
 and lymphatic glands. The under layer is attached to the mar- 
 gins of the saphenous opening, where it is perforated by numer- 
 ous lymphatic vessels and blood-vessels; hence its name, cribri- 
 form fascia. 
 
 The deep fascia of the thigh, or fascia lata, is a dense 
 fibrous aponeurosis attached to the pubes, Poupart's ligament, 
 crest of the ilium, sacrum, and coccyx, inclosing the gluteus 
 maximus and tensor vaginse femoris between its layers, attached 
 to the linea aspera, and below to all the bony points about the 
 knee-joint, being attached to the head of the fibula and tuber- 
 osities of the tibia by the ilio-tibial band. 
 
THE MUSCULAR SYSTEM. 169 
 
 The saphenovs opening is a large opening in the fascia 
 lata at its upper and inner part closed by the cribriform fascia. 
 Through it pass the internal or long saphenous vein, the super- 
 ficial epigastric and external pudic arteries, and lymphatics. It 
 is formed by the iliac and pubic portions of the fascia lata. The 
 iliac portion becomes continuous at the pectineal line with 
 Gimbemat's ligament, and its free border forms the falciform 
 harder {vide Femoral Hernia). 
 
 The pubic portion is continuous behind the femoral vessels 
 with the femoral sheath and the iliac and psoas fascia. At the 
 lower border of the saphenous opening it is continuous with the 
 iliac portion of the fascia lata. 
 
 The deep fascia of the leg is attached above to the bony 
 points about the knee, continuous with the fascia lata, investe 
 the leg completely, except the inner surface of the tibia, sends in 
 a deep transverse fascia between the superficial and deep muscles 
 on the posterior aspect of the leg, and below becomes continuous 
 with the annular ligament of the ankle-joint. 
 
 The annular ligament of the ankle-joint consists of three 
 portions — ^the internal, external, and anterior. It is attached 
 to the bony points about the ankle-joint, the external and in- 
 ternal malleoli, surfaces of the os calcis, and allows the passage 
 of the muscles to the foot. 
 
 The dorsal aponeurosis of the foot covers the back of the 
 foot, uniting with the plantar fascia at the sides, and terminat- 
 ing anteriorly at the heads of the metatarsal bones. 
 
 The plantar aponeurosis consists of three portions, a cen- 
 tral and two lateral portions. 
 
 The middle commences at the inner tubercle of the os calcis 
 and proceeds, gradually becoming broader, to the heads of the 
 metatarsal bones, where it divides into four branches, each of 
 which nearly surrounds the corresponding flexor tendon to 
 which it gives passage, and is inserted into the edges of the 
 dorsal expansion of the first phalanges. 
 
 The inner portion arises from the internal annular ligament, 
 covers the abductor pollicis muscle, and joins the dorsal aponeu- 
 rosis internally and the internal septum externally. 
 
 The outer portion, much stronger, arises from the os calcis, 
 covers the abductor minimi digiti muscle, and joins the external 
 plantar septum internally and dorsal aponeurosis externally, and 
 is firmly attached to the base of the fifth metatarsal bone. 
 
 Numerous septa pass from the upper surface of the plantar 
 fascia between the plantar muscles and tendons to be inserted 
 into the metatarsal and tarsal bones. 
 
THE HEART AND VASCULAR SYSTEM. 
 
 The pericardium is a conical, membranous, closed sac, 
 surrounding the heart and the roots of the great vessels. It 
 occupies the' greater part of the middle mediastinum, its apes 
 upward, its base downward and attached to the central tendon 
 of the diaphragm. It is a fibro-serous membrane, consisting of 
 an outer fibrous coat and an inner serous coat. The latter is 
 composed of a visceral layer reflected over the heart and vessels, 
 and a parietal layer lining the inner surface of the fibrous sac. 
 It secretes a thin, serous fluid. 
 
 The fibrous coat becomes continuous above with the deep 
 layer of the cervical fascia, being prolonged 'upward on the 
 outer surfaces of all the great vessels, except, the inferior vena 
 cava. 
 
 The Heart. 
 
 The heart is a hollow, muscular organ, placed obliquely 
 within the chest, and inclosed within the pericardium. Its 
 base is directed upward and backward, opposite the fifth to 
 eighth dorsal vertebrae ; its apex downward to the left, opposite 
 the interspace between the fifth and sixth costal cartilages. Its 
 weight is about ten to twelve ounces in male, eight to ten in 
 female; length five inches, breadth three and a half inches, 
 thickness two and a half inches. 
 
 It is divided into four parts : — 
 
 Eight auricle. Left auricle, 
 
 Right ventricle, Left ventricle, 
 
 an auricle and ventricle on each side. This division is indicated 
 on both surfaces of the organ by two grooves crossing each other 
 and named, from theii- position, the longitudinal the inter- 
 ventricular, the transverse the atericulo-ventricular grooves. 
 
 Eight Auricle. — The right auricle, consists of two por- 
 tions — a sinus or atrium and an appendix awriculcB, which pro- 
 jects to the right side of the origin of the aorta. The walls at the 
 fore and outer part and in the auricular appendage are thick- 
 ened by musculi pectinati. The muscular tissue of the auricles 
 is connected with that of the ventricles by a small band of fibres, 
 the auriculo-ventriaular fasciculus, or '^bundle of His." 
 
 This smooth ridge is known inside the auricle as the crista 
 terminaUs of His, and outside the groove is called' the sulcus 
 terminalis of His. Its interior presents the following parts : — 
 
 Openings of the superior and inferior venw cava; neither 
 of which are protected by valves ; 
 (170) 
 
THE HEART AND VASCULAR SYSTEM. 171 
 
 Opening of coronary sinus, protected by a valve of two un- 
 ■equal segments — ^the coronary valve ; 
 
 Foramina Thebesii, minute foramina returning the blood 
 from the heart-muscle; 
 
 Eustachian valve, the remains of a foetal structure, extend- 
 ing from the right of the orifice of the inferior vena cava to 
 the outer border of the oval foramen; 
 
 Fossa ovalis, the obliterated foramen ovale of foetal life; 
 
 Annulus ovalis, the oval margin of the preceding structure ; 
 
 Tubercle of Lower, a small rudimental projection on the 
 right wall, directing the blood toward the auriculo-ventricular 
 ■opening : 
 
 FIG. 104. 
 
 Right side of heart: a, apex; b, right ventricle; d, pulmonary 
 artery; e, t, chordae tendinae; p, aorta; 3, superior vena cava; 5, 
 Interior vena cava. 
 
 Musculi pectinati, elevated muscular columns before re- 
 ferred to; 
 
 Auriculo-ventricular opening, an oval aperture about one 
 inch in diameter, surrounded by a fibrous ring, and protected 
 by the tricuspid valve. 
 
 The Left Aueicle. — The left auricle is smaller, and its 
 walls somewhat thicker, than the right, and consists of a cuboidal 
 sinus and an elongated appendix auriculae. Its interior surface 
 is smooth, except the auricular appendage, which is provided 
 with musculi pectinati, and presents the following openings : — 
 
 Pulmonary veins, four in nupiber, two on either side; they 
 are without valves; 
 
172 HUMAN ANATOMY. 
 
 Auriculo-ventricular opening^ an oval aperture, rather 
 smaller than the right, and protected by the bicuspid or mitral 
 valve. 
 
 The Eight Venteicle. — The right ventricle is triangular, 
 with thick walls (one-quarter inch), and occupies the anterior 
 part of the organ. Its capacity is about three fluid ounces. It 
 presents the following: — 
 
 Infundibvlum, or conus arteriosus, a conical pouch, from 
 which the pulmonary artery arises; 
 
 GolumncB carnew, muscular columns projecting from the 
 inner surface, three or four of which (musculi papillares) give 
 attachment to the chordae tendinese; 
 
 ChordcB tendinem, delicate tendinous cords, connecting the 
 margins and central portions of the tricuspid valve with the 
 cojumnse carnese; 
 
 Tricuspid valve, consists of three triangular duplications of 
 endocardium, strengthened by fibrous tissue; they are attached 
 by their bases to the auriculo-ventricular orifice, and their free 
 margins give attachment to the chordae tendinese; 
 
 Semilunar valves, consist of three semicircular folds, guard- 
 ing the orifice of the pulmonary artery; their free margins are 
 thickened by nodules, the corpora Arantiij 
 
 Opening of the pulmonary artery, at the apex of the conus 
 arteriosus, is circular in outline and • protected by the semi- 
 lunar valves; 
 
 Sinuses of Valsalva, three pouches, situated one behind each 
 semilunar valve. 
 
 The Left Ventricle. — The left ventricle is longer, more 
 conical, and its walls three times as thick as the right. It 
 forms the apex and most of the posterior portion of the heart. 
 It presents the following parts in its interior : — 
 
 ColumncB carnece, and 
 
 ChordcB tendinew, much the same as the right; 
 
 Auriculo-ventricular opening, a little smaller than the corre- 
 sponding orifice on the right side, similarly formed, and pro- 
 tected by the mitral valve; 
 
 The mitral valve consists of two unequal segments, attached 
 the same as the tricuspid, and also affording attachment to 
 the chordae tendinese; 
 
 Aortic opening, a circular opening to the right of the 
 auriculo-ventricular opening ; 
 
 The semi-lunar valves, three in number, surround the aorta, 
 and are la:rger and stronger than those on the right side; 
 
 Sinus aortici (sinuses of Valsalva) are depressions situated 
 behind each valve. 
 
THE HEART AND VASCULAR SYSTEM. 173 
 
 Stedctdke of the Heart. — The heart is composed of finely 
 striated muscular walls, with external serous covering from the 
 pericardium and internal serous lining the endocardium^ the 
 latter continuous with that of blood-vessels. The endocardium 
 is a thin, translucent membrane, consisting of endothelium and 
 a fine basement membrane, beneath which is a fibro-elastic layer. 
 The doublings of these layers constitute the valves. The tricuspid 
 and mitral valves, as well as the aortic and pulmonary, are 
 surrounded by a fibro-elastic ring, which furnishes a "punctum 
 fixum" for the various muscles of the heart. 
 
 The muscular structure consists of an intricate interlace- 
 ment of fibrous bands. Of these there are two groups — ^those 
 of the auricles and those of the ventricles. 
 
 The former consist of a superficial transverse set and the 
 internal or deep set, of which there are the looped and the 
 circular. 
 
 The fibres of the ventricles consist of seven layers in a gen- 
 eral oblique and circular manner, and terminating in a whorl 
 or vortex at the apex, some of the fibres terminating in the 
 columnse earner, musculi pectinati, while others ascend, form- 
 ing in their course a twisted loop like 8. The arteries of the 
 heart are the right and left coronary. The veins are the an- 
 terior or great, middle or posterior cardiac, the left auricular, 
 the right auricular, and venae Thebesii. The lymphatics end in 
 thoracic and right lymphatic ducts. The nerves are derived 
 from the cardiac plexus of pneumogastric, spinal, and great 
 sympathetic. 
 
 The Vasculae System. 
 
 The vascular system consists of four sets of vessels — arteries, 
 capillaries, veins, and lymphatics. Anastomoses are common. 
 
 The vessels that convey blood to and from the tissues of the 
 body generally constitute the general system. 
 
 Those that carry blood to and from the lungs form the 
 pulmonary system. 
 
 The vessels passing to the liver form the portal system. 
 
 The aetekies, for the most part, are composed of three 
 coats : — 
 
 Tunica adventitial or external coat, consists of fibrous tissue, 
 thinnest on the largest trunks, and disappears in those which 
 merge into capillaries. 
 
 The tunica media, or middle coat, is thickest in the large 
 trunks, and consists mainly of elastic tissue, together with some 
 unstriated muscle and some connective tissue; in smallest ar- 
 teries it consists alone of muscular tissue. The elastic tissue 
 
174 HUMAN ANATOMY. 
 
 in layers forms nets, constituting so-called ■perforated or fenes- 
 trated membranes. 
 
 The tunica intima, or internal coat, thinnest, most trans- 
 parent, and elastic, is composed of lining endothelium, basement 
 membrane, and layers of elastic tissue. It becomes continuous 
 with capillaries. The -walls of larger arteries are supplied by 
 blood-vessels from neighboring arteries. Nutrient arteries form 
 a net-work of capillaries, and returning veins empty into con- 
 tiguous veins. The nerves are both medullated and non- 
 meduUated and chiefly pass to the muscle-fibres. 
 
 Arteries dilate and contract with the action of the heart, con- 
 stituting the pulse. 
 
 The Veins. — Larger, more numerous, and more capacious 
 than the arteries. With one exception (the portal vein) they 
 convey blood to the heart. The large veins emptying into the 
 heart are: — 
 
 Four pulmonary; 
 
 Superior and inferior venae cavae; 
 
 Coronary veins from walls of the heart through the coronary 
 sinus. 
 
 The larger arteries have each one companion vein, the 
 medium arteries two. In some positions they form venous plex- 
 uses, corresponding to arterial anastomoses. 
 
 Many large veins have valves, usually in pairs, attached by 
 convex border. 
 
 There are, however, no valves in the pulmonary, superior 
 and inferior cavae, azygos, portal vein and branches, hepatic, 
 renal, uterine, and spinal, and most of those of head or neck. 
 
 In certain membranes and organs channels exist, lined by 
 internal coat of blood-vessel, termed venous sinuses, as iu the 
 dura mater, bones, and uterus. 
 
 The coats of the veins are similar to those of the arteries, 
 and differ chiefly in the weakness of the middle or muscular coat, 
 which allows them to remain open. 
 
 The external fibrous coat has also longitudinal, unstriated 
 muscular tissue in veins of abdominal cavity : — 
 
 The middle J unstriated muscular and fibrous tissue; 
 
 The internal^ no fenestrated membrane. 
 
 The walls have nutritive vessels, and are well supplied with 
 non-medullated and medullated nerves, which pass to the muscu- 
 lar coat. 
 
 Both arteries and veins are insensitive in health. 
 
 The capillaries communicate with the terminations of the 
 arteries and veins, and do not communicate with tissue proper, 
 which is supplied by imbibition. They vary in size in different 
 
THE HfiART AXD VASCULAR SYSTEil. 175 
 
 organs from ^/gooo to ^Aooo inch in diameter, but all permit the 
 passage of blood-corpuscles. Their form is dependent on the 
 form of tissue supplied. 
 
 CoMPOSiTiox OF THE Blood. — Blood within the vessels is a 
 perfect fluid, of alkaline reaction, saline taste, average specific 
 gravity 1060, and feeble, peculiar odor. Within the arterial 
 vessels it is bright-red color, becoming in the veins (particularly 
 the venae portse and pulmonary arteries) a deep maroon or red- 
 dish-black color. 
 
 It consists about one-twelfth or one-fourteenth of the 
 body-weight, and consists of the liquor sanguinis and the cor- 
 puscles, red, white, etc. 
 
 The red corpuscles or erythrocytes are elastic, of specific 
 gravity 1088, nonnucleated, and average about one three- 
 thousandth line in diameter. A cubic millimetre of blood con- 
 tains, in the male, 5,000,000 red blood-cells, and, in the female, 
 4,500,000. On evaporation they become stellate, and swell up 
 with water. They vary much in size and shape in different 
 animals, and contain haemoglobin, which carries oxygen to the 
 tissues and COg to the lungs. 
 
 The colorless or leucocytes are free nucleated protoplasmic 
 masses, capable of amoeboid movement. They contain fat- 
 corpuscles, myosin, cholesterin, protagon, glycogen, and nuclein. 
 There is about 1 white corpuscle to every 600 red corpuscles, or 
 in 1 cubic millimetre of blood there are present about from 5,000 
 to 10,000 white corpuscles, average 7,500. According to Bhrlich 
 and others, by means of a "tri-acid stain," fine varieties of 
 colorless cells may be distinguished as follows : — 
 
 1. Small lymphocytes, 
 
 2. Large lymphocytes or mononuclear leucocytes, 
 
 3. Transitional leucocytes, 
 
 4. Polymorphonuclear leucocytes, and 
 
 5. Eosinophiles. 
 
 The liquor sanguinis is a pale, amber-colored fluid, holding 
 the corpuscles in suspension, and very prone to coagulate. The 
 coagulation of, the blood results in the formation of a clot, or 
 crassamentum, and the serum, in the following manner : — 
 
 Fluid blood . 
 
 Corpuscles. \ "'^""^ corpuscles. ■] 
 
 '^ ( Red corpuscles. mi 
 
 Plasma or 1 ,,., . \ *^''°*- 
 
 Liquor ^'^""^ J 
 
 Sanguinis J Serum. Serum. 
 
176 
 
 HUMAN ANATOMY. 
 
 Fig. 105. 
 
 Diagram of the (cetal circulation: 1, umbtUoal oorfl, with veins and arteries; 
 2, placenta; 3, divisions of umbilical vein; 4, hepatic branches; 6, ductus 
 venosus; 6, Inferior vena cava; 7, portal vein; 8, right auricle; 9, left auricle; 
 10, left ventricle; 11, arch of aorta; 14, superior vena cava; 15, right ventricle; 
 16, pulmonary artery; 17, ductus arteriosus; 18, descending aorta; 19, umbilical 
 arteries. 
 
THE HEART AND VASCULAR SYSTEM. I77 
 
 THE CIKCULATION OF THE BLOOD. 
 
 Fcetal Circulation. — The fresh arterial blood returning from 
 the placenta through the umbilical vein enters the foetus at the 
 umbilicus, passes along the suspensory ligament to the under 
 surface of the liver, where a portion passes directly into the 
 inferior vena cava by the junction of the ductus venosus with 
 the left hepatic vein, a portion enters the liver and reaches the 
 inferior vena cava through the hepatic veins, and the larger por- 
 tion mixes with the portal venous blood before reaching the vena 
 cava through the hepatic veins. It ascends in the inferior 
 vena cava along with the venous blood from the trunk and lower 
 extremities to enter the right auricle of the heart (Fig. 105). 
 Here it is directed by the Eustachian valve through the foramen 
 ovale into the left auricle, into the left ventricle, and so through 
 the aorta, chiefly to the head and upper extremities, a small por- 
 tion only entering the descending aorta. It is returned by the 
 superior vena cava to the right auricle, passes over the Eustachian 
 valve to the right ventricle, and so through the pulmonary artery 
 toward the lungs, but (the lungs being almost impervious) most 
 of it passes through the ductus arteriosus into the descending 
 aorta (mixing with the small quantity from the left ventricle 
 before mentioned) to supply the lower extremities, abdominal 
 and pelvic viscera, and as venous blood to return through the 
 umbilical arteries to the placenta. 
 
 Circulation After Birth and in Adult. — The dark venous 
 blood from the entire body is received through the superior and 
 inferior venffi cavje and coronary sinus into the right auricle, 
 from whence it passes into the right ventricle, to be sent through 
 the pulmonary artery into the lungs. Here it becomes oxy- 
 genated, and as bright arterial blood it returns to tlie left auricle 
 by the pulmonary veins, and passes into the left ventricle, from 
 whence it is distributed through the aorta and its branches to 
 the entire body. 
 
 AOKTA. 
 
 This is the main trunk of the systemic arteries. Commenc- 
 ing at the upper part of the left ventricle, it ascends for a short 
 distance, arches backward over the right pulmonary artery, the 
 root of the left lung, to the left side of the body of the fourth 
 dorsal vertebra, from where it passes downward through the dia- 
 phragm and becomes the abdominal aorta. It then descends to 
 the lower border of the fourth lumbar vertebra, where it termi- 
 nates by dividing into the left and right common iliac arteries. 
 
178 HUMAN ANATOMY. 
 
 In its course it is divided into the arch, the thoracic aorta, and 
 the abdominal aorta, the arch being subdivided into the ascend- 
 ing, transverse, and descending portion. 
 
 Relations. — The ascending portion of the arch is in relation on the 
 right side with the superior cava and right auricle; on the left side 
 with the pulmonary artery; in front, with the pulmonary artery, the 
 pericardium, the right appendix auriculae, and the thymus gland; and 
 liehind, with the root of the right lung and the right pulmonary vessels. 
 
 The transverse portion of the arch is in relation in front with the 
 left lung and pleura, the left pnemnogastric and phrenic nerves, the 
 superficial cardiac nerves, the left superior intercostal vein, and the 
 thymus gland; behind, with the trachea, the oesophagus, the thoracic 
 duct, the deep cardiac plexus, and the left recurrent nerve; above, with 
 the arteria innominata, the left innominate vein, the left subclavian, 
 and the left carotid; and below, with the left bronchus, the bifurcation 
 of the pulmonary artery, the left recurrent nerve, and the remains of 
 the ductus arteriosus. 
 
 The descending portion of the arch is in relation in front with the 
 root of the left lung and the pleura; behind, with the left side of the 
 body of the fifth dorsal vertebra; on the right side with the thoracic 
 duct and cesophagus; and on the left side with the pleura. 
 
 The branches of the aorta are, from the arch: — ■ 
 
 Two coronary, Left common carotid. 
 
 Innominate, Left subclavian. 
 
 The coeonaet aeteribs supply the heart and are two in 
 number — the right and the left. The right arises from the 
 aorta, above the right semi-lunar valve, and passes downward in a 
 groove between the right auricle and ventricle on its posterior 
 surface, dividing into two branches, one of which anastomoses 
 with the left coronary. The left coronary arises above the left 
 semi-lunar valve and descends in the anterior interventricular 
 groove, where it divides into two branches, one of which anas- 
 tomoses with the right coronary. 
 
 Arteeia Innominata. — This is the largest branch from the 
 arch of the aorta. It ascends to the upper border of the right 
 sterno-clavicular articulation, where it divides into the right 
 common carotid and the right subclavian arteries. It is a short 
 vessel, from one and a half to two inches long. 
 
 Relations. — It is in relation in front with the sternum, the sterno- 
 hyoid and sterno-thyroid muscles, the left innominate and right inferior 
 thyroid veins, the thymus gland, and the cardiac branch from the right 
 pneumogastrio ; behind, with the trachea; on the right side, with the 
 pleura and right vena innominata and right pneumogastrio nerve; on 
 the left side, with the left carotid and the thymus gland. 
 
 The Common Carotid Arteries. — The left common ca- 
 rotid, arising directly from the arch of the aorta, is longer and 
 ascends more obliquely and is more deeply placed than the right. 
 
THE HEART AXD VASCULAR SYSTEM. 179 
 
 From the stemo-clavicular articulation to their division at 
 the upper border of the thyroid cartilage the common carotid on 
 either side pursues the same course. At the lower part of the 
 neck the two vessels are separated by a very short interval, which 
 is occupied by the trachea, but at the upper part they diverge 
 widely, the larynx, pharynx, thyroid body, and several muscles 
 being interposed between them. It ascends the neck in a direc- 
 tion indicated by a line drawn from the stemo-clavicular articula- 
 tion to midway between the mastoid process and the angle of the 
 lower jaw. 
 
 Relations. — It is in relation in front with the sterno-mastoid, 
 sterno-thyroid, sterno-hyoid, and omo-hyoid muscles, the anterior 
 jugular and the superior and middle thyroid veins, the sterno-hyoid 
 artery, and the descendens and communicans noni nerves; behind it 
 rests upon the longua colli and rectus capitis anticus major muscles 
 and is in relation with the sympathetic nerve, the recurrent laryngeal 
 nerve, and the inferior thyroid artery; on the outer side, with the 
 pneumogastric and the internal jugular vein; to the inner side, the 
 larynx, trachea, pharynx, thyroid gland, inferior thyroid artery, and 
 the recurrent larygeal nerve. 
 
 THE EXTERNAL CAROTID AETEET. 
 
 From its commencement at the superior border of the thy- 
 roid cartilage it passes upward and forward and then backward, 
 beneath the anterior margin of the sterno-mastoid muscle, in a 
 direction indicated by an imaginary line drawn from the supe- 
 rior border of the thyroid cartilage to a point midway between 
 the meatus and the neck of the condyle of the lower Jaw. It 
 ascends through the space known as the superior triangle of the 
 necJc. 
 
 Relations. — It is in relation in front with the parotid gland and the 
 facial nerve and temporo-maxilJary passing through it, covered by the 
 skin, superficial fascia, platysma, and deep fascia, and Is crossed by the 
 digastric and stylo-hyoid muscles, hypoglossal nerve, lingual and facial 
 veins; behind it is separated from the internal carotid by the parotid 
 gland, stylo-glossus and stylo-pharyngeus muscles, and the glosso- 
 pharyngeal nerve, and at its lower part the superior laryngeal nerve 
 ascends behind it; to its inner side it is in relation with the pharynx, 
 hyoid bone, superior laryngeal nerve, and the ramus of the lower jaw, 
 from which it is separated by the parotid gland. 
 
 The branches of the external carotid are eight : — 
 
 1. Superior thyroid, 5. Posterior auricular, 
 
 2. Lingual, 6. Ascending pharyngeal, 
 
 3. Facial, 7. Temporal, 
 
 4. Occipital, 8. Internal maxillary. 
 
180 HUMAN ANATOMY. 
 
 1. Sdpeeior thyeoid arises below the great cornu of the 
 hyoid bone, passes beneath the sterno-hyoid, omo-hyoid, and 
 sterno-thyroid muscles to the upper part of the thyroid gland, 
 where its terminal branches anastomose with its fellow of the 
 opposite side. Its branches are : — 
 
 a. Hyoid, to the lower border of the hyoid bone; 
 
 6. Superficial descending branch, crosses the common carotid artery 
 to supply the skin and sterno-mastoid muscle; 
 
 c. Superior laryngeal, passes beneath the thyro-hyoid muscle with 
 the superior laryngeal nerve; 
 
 (2, Crico-thyroid, crosses the crico-thyroid membrane. 
 
 2. The LINGUAL ARTERY arises from the anterior part of the 
 external carotid, between the superior thyroid and the facial. It 
 passes inward and upward to the greater cornu of the hyoid 
 bone, and, descending, reaches the under surface of the tongue 
 and runs along its under surface as far as its tip, where it termi- 
 nates as the ranine. 
 
 In its course it passes through a triangle bounded on two 
 sides below by the two bellies of the digastric, and above by the 
 hypoglossal nerve, passing under the hyoglossus muscle. Its 
 branches are: — 
 
 Hyoid, to the hyoid bone; 
 
 Dorsalis linguae, supplies the epiglottis, soft palate, tonsil, and the 
 mucous membrane of tongue ; 
 
 Sublingual, supplies mylo-hyoid and genio-hyoglossus muscles and 
 sublingual gland; 
 
 Eanine, the terminal branch, ends at the tip of the tongue. 
 
 3. The FACIAL ARTERY arises from the anterior portion of 
 the external carotid artery above the lingual. It ascends for- 
 ward through the submaxillary gland, crosses the lower jaw at 
 the anterior border of the masseter muscle, and crosses the cheek 
 to the angle of the mouth and the side of the nose, where it 
 terminates as the angular artery. Its branches are in the 
 neck : — 
 
 Inferior or ascending palatine, supplies the soft palate, palatine 
 glands, tonsil, and Eustachian tube; 
 
 Tonsillar, supplies the root of the tongue and tonsil; 
 
 Submaxillary, supplies the submaxillary gland and neighboring 
 lymphatics, muscles, and skin; 
 
 Submental, supplies the chin, lower lip, and neighboring struc- 
 tures ; 
 
 Muscular, to the buccinator, masseter, and internal pterygoid mus- 
 cles. 
 
THE HEART AND VASCULAR SYSTEM. 
 In the face : — 
 
 181 
 
 Muscular, to the same muscles given above; 
 
 Inferior labial, to the skin of the lower lip; 
 
 Inferior coronary, to the mucous membrane, muscles, and glands 
 of the lower lip; 
 
 Superior coronary, to the structures of the upper lip and nasal 
 septum; 
 
 
 Fig. 106. 
 
 Arteries of face and head: 1, common carotid; 2, Internal carotid; 
 3, external carotid; 4, occipital; 6, superior tliyrold; 7, lingual; 9, 
 facial; 10, temporal: 11, submental; 12, transverse facial; 13, in- 
 ferior labial; 15, 17, inferior and superior coronary; 19, lateral nasal; 
 21, angular. 
 
 Lateralis naai, to the skin of the nostrils, anastomoses with the 
 nasal branch of ophthalmic; 
 
 Angular, supplies lachrymal sac and skin. All of these branches 
 anastomose freely with the neighboring arteries. 
 
182 HUMAN ANATOMY. 
 
 4. The OCCIPITAL artekt arises from the posterior portion 
 of the external carotid, about the lower border of the digastric 
 muscle. It passes beneath the stylo-hyoid muscle, the digastric 
 muscle, and part of the parotid gland, and, ascending, grooves 
 the internal surface of the mastoid portion of the temporal 
 bone and distributes itself over the occiput as high as the vertex. 
 Its branches are : — 
 
 Muscular, to splenius, digastric, stylo-hyoid, etc.; 
 
 Sterno-mastoid, crosses the hypoglossal to the sterno-mastoid 
 muscle ; 
 
 Auricular, is distributed to the back part of the concha; 
 
 Meningeal, passes through the foramen lacerum posterius to the 
 dura mater; 
 
 Arteria princeps cervicis. Its superficial branch anastomoses with 
 the superficial cervical, and its deep branch with the deep cervical 
 branch from the superior intercostal. 
 
 Cranial branches are distributed to the scalp over the 
 occiput. 
 
 5. The POSTERiOE auriculae artery arises from the pos- 
 terior portion of the external carotid, on a level with the apex 
 of the styloid process. It ascends beneath the parotid gland to 
 a point between the mastoid process and the cartilage of the 
 ear, where it divides into two branches, one going to the ear and 
 the other to the occiput. Its branches are: — 
 
 Stylo-mastoid, supplies the mastoid cells, tympanum, and semi- 
 circular canals, entering the cranium through the stylo-mastoid 
 foramen; 
 
 Auricular, supplies the cartilage of the ear; 
 
 Muscular, supply the sterno-mastoid, digastric, and stylo-hyoid 
 muscles ; 
 
 Glandular, to parotid gland. 
 
 6. The ASCENDING PHARYNGEAL artery arises about the com- 
 mencement of the external carotid artery and ascends to the base 
 of the skull upon the rectus capitis anticus major. Its branches 
 are: — 
 
 Pharyngeal, supplies the three constrictors of the pharynx and 
 the stylo-pharyngeus muscles; 
 
 External, to the neighboring muscles, glands, and hypoglossal and 
 pneumogastric nerves; 
 
 Meningeal, enter the skull through the posterior and middle lacer- 
 ated foramina and the anterior condyloid foramen. 
 
 7. The TEMPORAL artery is the smaller of the two terminal 
 branches. It arises in the parotid gland, crosses the root of the 
 zygoma, ascends forward a couple of inches, and divides into 
 
THE HEART AND VASCULAR SYSTEM. 
 
 183 
 
 the anterior temporal and the posterior temporal. Its branches 
 are: — 
 
 skin; 
 
 Transverse facial, supplies the masseter muscle, parotid gland, and 
 
 Middle temporal, crosses the face to supply the temporal muscle 
 and fascia; 
 
 Anterior auricular, supplies the lobule, external meatus, and front 
 part of pinna. 
 
 8. The INTERNAL MAXILLARY is the larger of the two termi- 
 nal branches of the external carotid. It arises in the parotid 
 gland about the level of the lower part of the lobe of the ear. 
 
 Fig. 107. 
 
 Internal maxillary artery; A, third portion; B, second portion; C, 
 first portion. 
 
 passing close to the inner side of the neck of the condyle of the 
 lower jaw to be distributed to the deep structures of the face. 
 Its course is divided into three portions : the maxillary portion, 
 passing inward and forward between the internal lateral liga- 
 ment and the ramus of the jaw; the pterygoid portion, passing 
 upward and forward upon the external pterygoid muscle; and 
 the third part, or spheno-maxillary , enters the spheno-maxillary 
 fossa. Its branches are, from the maxillary portion : — 
 
 Tympanic (anterior), supplies the tympanum through the Gla- 
 serian fissure, forming a capillary plexus on the tympanic membrane; 
 
 Middle meningeal, enters the cranium through the foramen 
 spinosum, supplies the dura mater, and gives oS a petrosal branch to 
 facial nerve in hiatus Fallopii; 
 
184 HU:\rA^' ANATOMY. 
 
 Small meningeal, or meningea parva, enters foramen oA'.nle to 
 supply dura mater and Gasserian ganglion; 
 
 Inferior dental, accompanies the dental nerve through the inferior 
 dental canal to the mental foramen, supplying the jawbone, teeth, chin, 
 and mouth. 
 
 The pterygoid portion : — 
 Deep temporal, supply the temporal muscle; 
 Pterygoid, to pterygoid muscles; 
 Masseteric, to the masseteric muscle; 
 Buccal, to the buccinator muscle. 
 
 Splieno-maxillary portion : — 
 
 Alveolar or posterior dental branch, supplies the upper molar and 
 bicuspid teeth, antrum, and gums; its principal branch is the superior 
 dental; 
 
 Infraorbital, passes through infraorbital canal to face; 
 
 Posterior or descending palatine, descends posterior palatine canal 
 and runs forward to foramen of Stenson; 
 
 Vidian, accompanies the Vidian nerve; 
 
 Pterygo-palatine, supplies Eustachian tube and pharynx; 
 
 Nasal, or spheno-palatine, descends through spheno-palatine fora- 
 men to antrum, sphenoidal, and ethmoidal cells. 
 
 THE UTTEENAL CAEOTID AETERT 
 
 arises about the upper border of the thyroid cartilage from the 
 bifurcation of the common carotid. It ascends in front of the 
 transverse processes of the cervical vertebrae to the carotid fora- 
 men in the petrous portion of the temporal bone to supply the 
 anterior part of the brain, the eye- with its appendages, and send 
 branches to the nose and forehead. It gives no branches until 
 it passes through the carotid canal, vs^here, after piercing the 
 dura mater at the anterior clinoid process, it divides into its 
 terminal branches — ^the anterior and middle cerebral. 
 
 Relations. — ^The internal carotid artery in the neck is in relation 
 in front with the parotid gland, the glosso-pharyngeal nerve, the stylo- 
 glossus and stylo-pharyngeal muscles, and is covered by the skin, super- 
 ficial and deep fascia; behind it rests upon the rectus capitis anticus 
 major and has resting upon it the superior laryngeal nerve and the 
 sympathetic; internally it is in relation with the pharynx, tonsil, 
 superior laryngeal nerve, and ascending pharyngeal artery; externally 
 it is in relation with the internal jugular vein and the pneumogastric 
 nerve. 
 
 Its branches are, from the petrous portion: — 
 
 Tympanic (internal or deep), supplies tympanum. 
 
 From the cavernous portion :— 
 
 Arteriw receptaculi, supply the Gasserian ganglion and pituitary 
 body; 
 
POSTEROMEDIAN fiANC.LION 
 FOSI-KHIOR TEMI-ORAI, 
 ANTEKIOR Tt:Mr'OR,^L- 
 SUPERFICrAL TEMWJRAI, 
 ANTERIOR AURICULAR 
 MIDDLE TEMITJRAL 
 
 ORBITAL 
 
 TRANSVERSE FACIAL 
 
 ANTERIOR CHOROID 
 TRANSVERSE 
 PUS.TERIOR AURICULAR 
 INTERNAL MAXILLARV 
 
 ARTERIA PKINCEPS CERVIC 
 
 OCCIPITAL 
 
 SUP OR. PRINCEPS CERVICIS- 
 
 DEEP BR, PBINCEPS rERVICIS' 
 
 ASCENDING CERVIf Al 
 
 DEEP CERVICAL 
 
 anterioh communicating 
 anterior 
 cerebral^ 
 
 .middle cerebral - 
 
 ophthalbiic . 
 
 temi'oral . 
 
 POST communicatinc; 
 
 ■POST CEREBRAL - 
 
 3UPERI0D CEREBELLAR, 
 
 SUP STERNO-MASTOID. 
 
 BASILAR- 
 A.NT. INFERIOR 
 CEREBELLAR - 
 
 L, INT. CAROTID . 
 FACIAL _ 
 
 R CORONARY 
 
 fNF VENA CAVA 
 
 THOE-ACJC AOKTA 
 
 Fro. 108. 
 The arteries of the head and neck. 
 
THE HEART AND VASCULAR SYSTEM. 185 
 
 Anterior meningeal, a branch from the preceding vessel to the 
 dura. 
 
 Ophthalmic arises about the position of the anterior elinoid 
 process and passes through the optic foramen to the outer side 
 of the optic nerve to reach the orbit. At the inner angle of the 
 eye it divides into its two termiQal branches — the frontal and 
 the nasal. It supplies the muscles and the globe of the eye, and 
 its branches may be divided into two groups — ^the orbital and 
 the ocular. 
 
 Orbital group: — 
 
 Lachrymal, supplies the lachrymal gland and gives off a malar 
 branch which passes through the malar bone to the temporal fossa; 
 
 Supraorbital, passes out through the supraorbital foramen to 
 supply the surrounding structures; 
 
 Posterior ethmoidal, descends through the posterior ethmoidal 
 foramen to the cells and adjacent parts; 
 
 Anterior ethmoidal, through the anterior ethmoidal foramen to 
 the nose; 
 
 Palpebral, supply the eyelids; 
 
 Frontal, supplies the skin and muscles of the forehead. 
 
 Nasal, supplies the lachrymal sac and bridge of the nose. 
 
 Ocular group: — 
 
 Muscular, supply the muscles of the eye; 
 
 Anterior ciliary, supply the iris, piercing the sclerotic near the 
 cornea ; 
 
 Short ciliary, supply the choroid and ciliary processes, piercing the 
 sclerotic near the optic nerve; 
 
 Long ciliary, enter with the short ciliary, but run forward to 
 the iris; 
 
 Arteria centralis retinae, supplies the optic nerve and the retina. 
 
 From the cerebral portion: — 
 
 Anterior cerebral, supplies the anterior part of the cerebrum, the 
 optic and olfactory nerves, and communicates with its fellow by the 
 anterior communicating; 
 
 Middle cerebral, or Sylvian artery, ascends in the Sylvian fissure, 
 and supplies the middle lobes of the cerebrum; 
 
 Posterior communicating, runs backward to join the posterior 
 cerebral ; 
 
 Anterior choroid, supplies the choroid plexus. 
 
 THE CIKCLE OF WILLIS 
 
 is an anastomotic circle formed at the base of the brain about 
 the pituitary body, between the branches of the internal carotid 
 and the vertebral arteries, for the purpose of equalizing the cere- 
 bral circulation. The anterior cerebrals, from the internal ca- 
 rotids, pass forward and are united in front by a short trunk, the 
 
186 HUMAN ANATOMY. 
 
 anterior comnmnicating. The posterior comnmnicating imites 
 the internal carotid with the posterior cerebral, the latter being 
 the terminal branches of the basilar, which in its turn is formed 
 by the union of the two vertebrals. 
 
 THE SUBCLAVIAN ARTEET 
 
 on the right side arises from the arteria innominata, behind 
 the right sterno-clavicular articulation, and on the left side 
 directly from the arch of the aorta. They pass outward to the 
 outer margin of the first rib, where they become the axillary, 
 being divided in their course by the scalenus anticus muscle into 
 three portions — the first portion to the inner side of the muscle, 
 second portion behind it, and the third portion between its outer 
 margin and the lower border of the first rib. The vessels differ 
 only in their first portions, the left ascending more vertically. 
 
 Relation. — ^The first portion of the right subclavian is in relation 
 in front to the internal jugular and vertebral veins, the sternohyoid 
 and sterno-thyroid and the clavicular portion of the sterno-mastoid 
 muscles, and the pneumogaatric, phrenic, and cardiac nerves; behind 
 it is in relation with the longus colli muscle, the transverse process 
 of the first dorsal or seventh cervical vertebrae, the sympathetic nerve, 
 and the recurrent laryngeal nerve beneath with the pleura. 
 
 The first portion of the left subclavian artery is in relation in 
 front with the left internal jugular and innominate veins, the left 
 carotid artery, the sterno-thyroid, sterno-hyoid, and sterno-mastoid 
 muscles, the pleura and left lung, and the pneumogastric, phrenic, and 
 cardiac nerves; behind, with the vertebral column and longus colli 
 muscle, the oesophagus, and thoracic duct, and the inferior cervical 
 ganglion of the sympathetic; on the inner side with the cesophagus, 
 thoracic duct, and trachea, and on the outer side with the pleura. The 
 second portion of the subclavian artery on either side is in relation with 
 the subclavian vein, the scalenus anticus muscle, and the phrenic nerve; 
 behind with the middle scalenus muscle and pleura; above by brachial 
 plexus, and below by the pleura. The third portion of the subclavian 
 artery on either side is in relation in front with the external jugular 
 vein and its branches, the clavicle, subclavius muscle and suprascapular 
 artery, the descending branches of the cervical plexus and the cervical 
 fascia; behind with the scalenus raedius, above with the omo-hyoid 
 muscle and the brachial plexus, and below with the first rib. 
 
 Its branches are: — 
 
 1. Vertebral, 5. Transverse cervical, or 
 
 2. Thyroid axis, transversalis colli, 
 
 3. Inferior thyroid, 6. Internal mammary, 
 
 4. Suprascapiilar, 7. Superior intercostsd. 
 
 These branches are all given off from the first portion, ex- 
 cept the superior intercostal, which arises on the right side, from 
 the second portion. 
 
mil. *tl, li.VLllAR PlOrTAUS 
 
 Fi(.i. 109. 
 The Jirtories a]' the uppi^r oxirciniiy. 
 
THE HEART AND VASCULAR SYSTEM. 187 
 
 1. The vertebral artery passes upward, enters the foramen 
 in the transverse process of the sixth cervical vertebra, and 
 ascends through the foramina until it reaches the atlas, when 
 it runs backward, pierces the posterior occipito-atloid ligament 
 and dura mater to enter the skull through the foramen magnum. 
 After entering the cranium it passes forward to the lower border 
 of the pons Varolii, where it unites with its fellow of the oppo- 
 site side to form the basilar artery. Its branches are — 
 
 Cervical branches : — 
 
 Lateral spinal, supply the spinal cord and its membranes, entering 
 the spinal canal through the intervertebral foramina; 
 Muscular, supply the deep muscles of the neck. 
 
 Cranial branches: — 
 
 Posterior meningeal, supply the falx cerebelli; 
 
 Anterior spinal, supplies the cord; uniting with branches from the 
 inferior thyroid, intercostals, and lateral sacral, descend to the cauda 
 equina ; 
 
 Posterior spinal, descends in the same manner as the anterior; 
 
 Posterior inferior cerebellar, supplies the inferior surface of the 
 cerebellum and the choroid plexus of the fourth ventricle. 
 
 The branches of the basilar artery are : — 
 
 Transverse, to the pons Varolii and inferior surface of the cere- 
 bellum ; 
 
 Anterior inferior cerebellar, a branch of the transverse; 
 
 Superior cerebellar, supplies pia mater, pineal gland, and velum 
 interpositum ; 
 
 Posterior cerebral, to posterior lobes of cerebrum and choroid 
 plexus. 
 
 2. The thyroid axis consists of three branches — ^the inferior 
 thyroid, the suprascapular, and the transversalis colli. 
 
 3. The inferior thyroid artery is distributed to the thyroid 
 gland, its branches being : — 
 
 Laryngeal, to muscles and mucous membrane of larynx; 
 
 Tracheal, to the trachea, anastomosing with the bronchial arteries; 
 
 OSsophageal, to oesophagus; 
 
 Ascending cervical, supplies the spinal cord and membranes, ver- 
 tebrae, and muscles of neighborhood; 
 
 Muscular, to inferior constrictor of pharynx, scalenus anticus, and 
 other muscles. 
 
 4. The suprascapular artery (transversalis humeri) passes 
 beneath the posterior belly of the omo-hyoid to the upper border 
 of the scapula, passing over the transverse ligament of the scapula 
 to the supraspinous fossa, where it is distributed to the supra- 
 spinatus, sterno-mastoid, and other muscles, and by means of the 
 
188 HUMAN ANATOMY. 
 
 supra-acroinial branch to the skin over the acromion, anastomos- 
 ing with the posterior circumflex and acromial thoracic arteries. 
 
 In about 50 per cent, of bodies this artery will be found to arise 
 from the third portion of the subclavian. 
 
 5. The transversalis colli passes outward to the trapezius 
 muscle, where it divides into 
 
 The (a) superficial cervical, an important branch passing beneath 
 the trapezius to anastomose with the superficial branch of the arteria 
 princeps cervicis; 
 
 And the (t) posterior scapular, the larger passing to and along 
 the upper and posterior border of the scapula, beneath the levator 
 anguli scapulae, rhomboidei, latissimus dorsi and trapezius, to anas- 
 tomose with the subscapular, suprascapular, and posterior branches of 
 the intercostals. 
 
 6. The internal mammary arises from the subclavian, oppo- 
 site the thyroid axis, and descends upon the internal surfaces 
 of the costal cartilages to between the sixth intercostal space, 
 where it divides into the musculo-phrenic and the superior epi- 
 gastric. Its branches are : — 
 
 Comes nervi phrenici (superior phrenic), supplies diaphragm, pass- 
 ing between the pleura and pericardium ; 
 
 Mediastinal, to the anterior mediastinum; 
 
 Pericardiac, to upper portion of pericardium; 
 
 Sternal, to posterior surface of sternum; 
 
 Anterior intercostal, to fifth or sixth upper intercostal spaces; 
 
 Perforating, perforate the intercostal spaces to supply the mam- 
 mary gland; 
 
 Musculo-phrenic, supplies lower part of pericardium, diaphragm, 
 and upper part of abdominal muscles; 
 
 Superior epigastric, supplies the rectus muscle, and anastomoses 
 with the deep epigastric from the external iliac. 
 
 7. The superior intercostal artery arises from the subclavian, 
 behind the anterior scalenus muscle, and descends behind the 
 pleura and anastomoses with the first aortic intercostal artery. 
 It gives off branches in the intercostal spaces to the spinal cord 
 and its membranes and the posterior spinal muscles. Its princi- 
 pal branch is the deep cervical (profunda cervicis). 
 
 THE AXILLARY ARTERY 
 
 is the continuation of the subclavian, extending outward from 
 the lower edge of the first rib to the lower margin of latissimus 
 dorsi and teres major muscles, where it becomes the brachial. It 
 is divided by the pcctoralis minor into three parts — the first 
 portion above, the second portion behind, and tlie third portion 
 
THE HEART AND VASCULAR- SYSTEil. 189 
 
 below that muscle. It passes throiigli the space known as the 
 axilla {vide Jiegions). 
 
 R( hit ions. — First portion: The first portion of the axillary is in 
 relation in front with the subclaviirs and pectoralis major muscles, 
 costo-coracoid membrane, and acromial thoracic and cephalic veins, and 
 the external anterior thoracic nerve; the axillary vein to its inner side, 
 the brachial plexus to its outer side, and the posterior thoracic nerve 
 and serratus magnua behind. Second portion: The relations of the 
 second portion are much the same as the first, with the addition of the 
 pectoralis minor in front and the division of the brachial plexus sur- 
 rounding the vessel. Third portion: The third portion is in relation in 
 front with the inner head of the median nerve and the pectoralis major 
 muscle ; to the inner side with the axillary vein, internal cutaneous and 
 ulnar nerves; to the outer side, the median and museulo-cutaneoua 
 nerves and coraco-brachialis muscle; and, behind, the circumflex and 
 musculo-spiral nerves and the subscapularis, latissimus dorsi, and teres 
 major muscles. 
 
 Its branches are: — 
 
 Superior thoracic, supplies the pectoralis major and minor 
 muscles ; 
 
 Acromial thoracic, gives ofE three branches — acromial, tho- 
 racic, and descending, supplying the pectoralis major, minor, 
 serratus, and deltoid ; 
 
 Long thoracic follows the lover border of the pectoralis 
 minor to supply the serratus, pectoralis major and minor, and 
 mammary glands ; 
 
 Alar thoracic supplies the axillary glands; 
 
 Subscapular, arises from the axillary artery about the level 
 of the lower border of the subscapularis muscle. It passes 
 backward and downward to the inferior dorsum of the scapula. 
 Its branches anastomose with the posterior scapular and the 
 suprascapular. They are: — 
 
 Subscapular, supplies the subscapularis muscle; 
 
 Dorsalis scapulae, is distributed to the infraspinous fossa, anasto- 
 mosing with the posterior scapular and suprascapular arteries; 
 
 Median branch, descends the axillary border of the scapula to 
 supply teres muscles. 
 
 Posterior circumflex, encircles the neck of the humerus to 
 supply the shoulder- joint and the deltoid muscle; 
 
 Anterior circumflex, descends beneath the short head of 
 biceps and coraco-brachialis muscles to supply the shoulder-joint. 
 
 THE BEAOHIAL ARTERY 
 
 commences at the lower border of the latissimus dorsi and teres 
 major muscles and descends on the front and inner aspect of the 
 arm to half an inch below the middle of a line drawn through 
 
190 HUMAN ANATOMY. 
 
 the condyles of the humerus, where it terminates by dividing into 
 the radial and ulnar artery. 
 
 Relations. — ^It is covered in front by the skin, superficial, and deep 
 fascia, and is crossed by the median nerve; behind it rests upon the 
 triceps, brachialis anticus, and coraco-brachialis muscles ; 
 
 And is in relation with the musculo-spiral nerve and the superior 
 profunda artery; to the outer side above it is in relation with the 
 biceps and coraco-brachialis muscles and the median nerve; and on 
 the inner side with the internal cutaneous and ulnar nerve, and the 
 basilic vein and median nerve below. 
 
 At the bend of the elbow it is crossed by the bicipital fascia. 
 Its branches are : — 
 
 Superior profunda, accompanies the musculo-spiral nerve to 
 supply the triceps, deltoid, and coraco-brachialis muscles; 
 
 Nutrient artery, supplies the shaft of the humerus ; 
 
 Inferior profunda, accompanies the ulnar nerve to supply 
 the triceps muscle and structures about the internal condyle ; 
 
 Anastomotica magna, forms an anastomosis on the lower 
 posterior aspect of the arm, with branches from the inferior 
 profunda and recurrent ulnar vessels. It supplies the triceps; 
 
 Muscular, supply the muscles on the anterior aspect of the 
 arm. 
 
 THE EADIAL AKTERT 
 
 descends from the bifurcation of the brachial below the bend 
 of the elbow to the wrist, where it winds around the carpus 
 beneath the extensor tendons of the thumb, passes between the 
 two heads of the first dorsal interosseous muscle and into the 
 palm of the hand, where it forms the deep palmar arch, anasto- 
 mosing with the deep branch of the ulnar artery. Its branches 
 are, in the forearm : — 
 
 Radial recurrent, supplies the brachialis anticus and supinator 
 longus and brevis; 
 
 Muscular, supply the radial muscles; 
 
 Superficialis volse, supplies the muscles of the thumb and anasto- 
 moses with the ulnar to form the superficial palmar arch; 
 
 Anterior carpal, supplies the wrist-joint. 
 
 In the wrist: — 
 
 Posterior carpal, supplies the wrist-joint, forms the posterioT 
 carpal arch, and gives off the dorsal interosseous arteries; 
 
 Metacarpal, is called the first dorsal interosseous; it supplies the 
 index and middle finger; 
 
 Dorsales pollicis, supply the back of the thumb; 
 
 Dorsalis indicis, supplies the outer and dorsal side of the index 
 finger. 
 
THE HEART AND VASCULAR SYSTEM. 191 
 
 In the hand : — 
 
 Princeps poUicis, supplies the sides of the palmar aspect of the 
 thumb; 
 
 Eadialis indicis, supplies the radial side of index finger; 
 
 Perforating, anastomose with dorsal interosseous arteries; 
 
 Interosseous, anastomose with digital branches of superficial 
 palmar arch. 
 
 THE ULNAE AETEEY 
 
 descends from the bifurcation of the brachial below the bend 
 of the elbow to the ulnar border of the wrist, passing beneath 
 all the superficial flexors excepting the flexor carpi ulnaris, 
 crosses over the annular ligament at the radial side of pisiform 
 bone, and enters the palm to form the superficial palmar arch, 
 anastomosing with the superficialis volaa from the radial. Its 
 branches are, in the forearm : — 
 
 Anterior ulnar recurrent, supplies the pronator radii teres and 
 brachialis anticus muscles; 
 
 Posterior ulnar recurrent, supplies the joint and neighboring 
 muscles, and anastomoses freely; 
 
 Interosseous, passes backward to the upper border of the inter- 
 osseous membrane, where it divides into 
 
 Anterior branch, descends on the front of the interosseous 
 
 membrane ; 
 Posterior, descends on the posterior aspect of the foramen and 
 gives off a recurrent interosseous branch; 
 Muscular, to muscles on ulnar side of forearm. 
 
 In the wrist: — 
 
 Anterior carpal, supplies the front of wrist and anastomoses with 
 the carpal branches of radial artery; 
 
 Posterior carpal, passes beneath the tendon of flexor carpi ulnaris 
 and forms posterior carpal branch. 
 
 In the hand: — 
 
 Deep, or communicating branch, passes between the flexor and 
 abductor minimi digiti to form part of deep palmar arch; 
 
 Digital, supply the ulnar side of the little finger and adjoining 
 sides of the little, ring, middle, and Index fingers. 
 
 THE DESCENDING AORTA. 
 
 The thoracic aorta extends from the lower border of the 
 fifth dorsal vertebra on the left side to about the last dorsal 
 vertebra, where by passing through the aortic opening in the 
 diaphragm it becomes the abdominal aorta. 
 
 Relations. — It is in relation in front with the left bronchus, oesoph- 
 agus, pericardium, and left pulmonary artery; behind it rests upon the 
 
192 HUMAN ANATOMY. 
 
 vertebral column and is in relation with the vena azygos minor ; on the 
 right side it is in relation with the thoracic duct, the oesophagus at 
 its upper part, and the vena azygos major; on the left side with the 
 left lung, the pleura, and the oesophagus below. 
 
 The branches of the thoracic aorta are : — • 
 
 Pericardiac, supply the pericardium; 
 
 Bronchial, two or three in number, supply the bronchi ; 
 
 CEsophageal, supply the oesophagus; 
 
 Posterior mediastinal, supply the neighboring pleura and 
 lymphatic glands; 
 
 Intercostal, ten on each side, supply the intercostal spaces. 
 They divide into — anterior branch, to intercostal and pectoral 
 muscles; posterior branch, to spinal column and dorsal muscles. 
 
 THE ABDOMINAL AORTA 
 
 descends from the last dorsal vertebra at the aortic opening of 
 the diaphragm, to opposite the fourth lumbar vertebra, a little to 
 the left of the median line, where it divides into the two common 
 iliac arteries. 
 
 Relations. — The abdominal aorta is in relation in front with the 
 pancreas, transverse duodenum, stomach, and lesser omentum, the mes- 
 entery, splenic vein, left renal vein, coeliae, solar, and aortic plexuses; 
 behind it is in relation with the vertebral column, the thoracic duct, 
 the left lumbar veins, and the receptaculum chyli; on the right side 
 with the inferior vena cava, vena azygos, thoracic duct, the right crus of 
 tne diaphragm above, and the right semilunar ganglion; on the left side 
 with the left semilunar ganglion and the sympathetic nerve. 
 
 The branches of the abdominal aorta are: — 
 Phrenic, two in number, supply the diaphragm; 
 Cceliac axis, divides into three large branches, the gastric, 
 hepatic, and splenic; 
 
 1. Oastric, or coronaria ventriculi, is the smallest, and sup- 
 plies the lesser curvature of the stomach ; 
 
 2. Hepatic, enters the transverse fissure of the liver, and 
 divides into two branches to supply the lobes of the liver. It 
 gives ofE : — 
 
 Pyloric, to lesser curvature of stomach; 
 
 Gastro-duodenalis, which descends behind the pylorus, and divides 
 into 
 
 Pancreatico-duodenalis superior branch to supply the pancreas 
 
 and duodenum; 
 Gastro-epiploica dextra, along the greater curvature of the 
 stomach from right to left. 
 Cystic, supplies the gall-bladder. 
 
THE HEART AND VASCULAR SYSTEM. 
 
 193 
 
 3. Splenic, the largest of the three, supplies the spleen and 
 gives off the 
 
 (a) Pancreatic — ^to the pancreas; 
 
 (h) Gastro-epiploica sinistra, runs from left to right, along the 
 greater curvature, to join the gastro-epiploica dextra; 
 
 (C) Gastric (vasa brevia), supply the fundus of the stomach. 
 
 Superior mesenteric, supplies the small intestine (except 
 first part of the duodenum) and the large intestine as far as the 
 splenic flexure, and part of the descending colon. It gives off : — 
 
 Fig, 110. 
 
 Abdominal aorta: 1, phrenic; 2, coelfac axis; 8, superior mesen- 
 teric; 4, suprarenal; 5, renal; 6, spermatic; 7, inferior meseuteric; 
 8, lumbar; 9, sacra media. - 
 
 (a) Inferior pancreatico-duodenal, supplies duodenum and pan- 
 creas ; 
 
 (h) Vasa intestini tenuis, supply nearly the whole length of the 
 small intestine (ileum and jejunum) ; 
 
 (c) Ileo-colic, descends to the right iliac fossa, between the layers 
 of the mesentery, and divides into two branches; 
 
 fdj Colica dextra, passes to the middle of the ascending colon, to 
 divide into two branches; 
 
 (ej Colica media, ascends in the layers of the transverse meso- 
 colon, to divide into two branches. 
 
 13 
 
iy4 ' HUMAN ANATOMY. 
 
 Suprarenal, supply the suprarenal bodies ; 
 
 Benal, supply the kidneys, a large trunk on each side spring- 
 ing directly from the aorta; 
 
 Spermatic, descend to supply the testicles, and in their pas- 
 sage form one of the constituents of the spermatic cord ; 
 
 Inferior mesenteric, gives off : — 
 
 (a) Coliea sinistra., supplies the descending colon; 
 
 (l>) Sigmoid, supplies the sigmoid flexure of the colon; 
 
 (g) Superior hsemorrhoidal, the continuation of the inferior mes- 
 enteric, supplies the mucous a,nd muscular coats of the rectum on its 
 posterior aspect. 
 
 Lumiar branches, four or five on each side, pass backward 
 and outward and divide into the 
 
 Dorsal branches, supply the spinal cord, muscles, and skin 
 of back; 
 
 Spinal branches, divide within the spinal canal, ascend and 
 descend, and form an arterial net-work throughout the whole 
 length of the spinal canal ; 
 
 Abdominal branches, supply the abdominal walls; 
 
 Middle sacral, is the continuation of the abdominal aorta, 
 descending in the middle of the sacrum to the upper part of the 
 coccyx. 
 
 THE COMMON ILIAC AKTEKIES 
 
 descend from the bifurcation of the abdominal aorta, opposite 
 the body of the fourth lumbar vertebra, to a point midway be- 
 tween the last lumbar vertebra and the sacrum, where they divide 
 into the external and internal iliac arteries. The righb common 
 iliac is a little larger than the left, and passes more obliquely 
 outward. 
 
 Relations. — The right common iliac is in relation in front with the 
 small intestine, the ureter, the peritoneum, and the sympathetic nerves; 
 behind, with the left and right common iliac veins, and to its outer side 
 it rests upon the psoas muscle, and is in relation with the vena cava 
 and the right common iliac vein. The left common iliac is in relation 
 in front with the ureter, the peritoneum, the superior hsemorrhoidal 
 artery, and the sympathetic nerves; behind with the left common iliac 
 vein, to its outer side the psoas muscle, and to its inner side the left 
 common iliac vein. 
 
 The common iliac arteries give off a few unimportant 
 branches to the ureters, peritoneum, etc. 
 
 THE INTERNAL ILIAC ARTERY 
 
 is about an inch and a half in length, extending from the bifurca- 
 tion of the common iliac, about the sacro-lumbar junction, to 
 
R. SUP. SUPRARENAL 
 
 CVSTIC, 
 
 IL MID, SUPRARKNAL, 
 
 INTERNAL PUDIC 
 BCLATIC 
 
 MIDDLE \ tSlCAL 
 
 DEEP EPIGASTRIC 
 
 Fig. 111. 
 The arteries of the trunk. 
 
THE HEART AOT) VASCULAR SYSTEM. 195 
 
 the upper border of the great sacro-sciatic foramen, where it 
 divides iato the anterior and posterior trunks. 
 
 The branches from the anterior trunk are : — 
 
 Superior vesical ^ is the pervious remains of the foetal hypo- 
 gastric artery. It supplies the apex and body of bladder, ureter, 
 and vas deferens; 
 
 Middle vesical, supplies the base of the bladder and part of 
 vesiculae seminalesj it may be given off from the superior 
 vesical ; 
 
 Inferior vesical, supplies the prostate gland, base of bladder, 
 and vesiculse seminales ; 
 
 Middle hwmorrhoidal, supplies part of the rectum; 
 
 OMurator, passes along the side of the pelvis to the obturator 
 foramen, through which it passes. It gives off within the pelvis 
 the iliac, vesical, and pubic branch ; 
 
 Internal pudic, supplies the external organs of generation. 
 It passes out of the pelvis through the great sacro-sciatic foramen, 
 winds aroimd the ischial spine, and re-enters the pelvis through 
 the lesser sacro-sciatic foramen. 
 
 It gives off the following branches in the perineum : — 
 
 (a) Inferior JiamorrTwidal, supplies the muscles and skin of the 
 anus; 
 
 (bj Siiperflcial perineal, supplies the erector penis and accelerator 
 urinse muscles and the scrotum; 
 
 (c) Transverse perineal, crosses the perineum on the transversus 
 muscle, which, together with the structures between the bulb and anus, 
 it supplies; 
 
 (d) Bulbo-urethral, supplies the bulb of the spongy body and Cow- 
 per's gland; 
 
 (e) Cavernous, supplies the corpus cavernosum, and is one of the 
 terminal branches; 
 
 (f) Dorsal artery of penis, or clitoris, runs forward on the dorsum 
 and supplies the glans and prepuce. 
 
 The distribution of the internal pudic artery is much the 
 same in the female as in the male, supplying analogous struc- 
 tures — ^the superficial artery to the labia, the artery of the bulb 
 to the bulb of the vagina, the artery of the corpus cavernosum 
 and dorsal artery to the clitoris. 
 
 Sciatic artery supplies the muscles at the back of the pelvis, 
 coccygeus, pyriformis, and levator ani, and passes out of the 
 great sacro-sciatic foramen to follow the course of the sciatic 
 nerve. Its branches external to the pelvis are : — 
 
 Coccygeal, supplies back part of coccyx; 
 Inferior gluteal, to the gluteus maximus muscle; 
 Comes nervi ischiadici, rims in the substance of the great sciatic 
 nerve j 
 
196 HUMAN ANATOMY. 
 
 Muscular, to the back part of the hip; 
 Articular, to supply the capsule of the hip-joint. 
 
 Uterine, is distributed to body of uterus, giving branches 
 to the ureter and bladder ; 
 
 Vaginal, supplies the mucous membrane of the vagina, giv- 
 ing branches to the rectum and neck of the bladder. It is analo- 
 gous to the male inferior vesical. 
 
 From the posterior trunk 
 
 Ilio-lumbar gives off two branches: — 
 
 Lumbar, supplies quadratus lumborum and psoas muscles; 
 
 Iliac, supplies iliacus, gluteal, and abdominal muscles. 
 
 Lateral sacral, are two in number — the superior and inferior 
 — supplying the contents of the sacral canal ; 
 
 Gluteal, gives off a superficial and deep branch to supply 
 the gluteus maximus, medius, and minimus muscles. 
 
 THE EXTERNAL ILIAO AETEEY 
 
 extends from the bifurcation of the common iliac to Poupart's 
 ligament, under which it passes to become the femoral. 
 
 Relations. — It is in relation in front with the peritoneum and 
 intestines, circumflex iliac vein, spermatic vessels, genito-crural nerve, 
 and the lymphatic vessels and nerves; behind it rests upon the psoas 
 muscle, and is in relation with the external Uiac vein, which, together 
 with the vas deferens, is also in relation to it on its inner side, beneath 
 Poupart's ligament. On its outer side it is in relation with the psoas 
 magnus and iliac fascia. 
 
 Its branches are : — 
 
 The deep epigastric, arises above Poupart's ligament and 
 ascends obliquely inward between the transversalis fascia and 
 peritoneum to the rectus muscle, in which it ascends to anasto- 
 mose with the termination of the internal mammary artery. It 
 gives off : — 
 
 Oremasterio branch, to supply the cremaster muscle; 
 PuMe, crossing Poupart's ligament to descend to the inner side of 
 the femoral ring, and 
 
 Muscular, to supply abdominal muscles and the peritoneum. 
 
 The deep circumflex iliac ascends outwardly behind Pou- 
 part's ligament to the crest of the ilium, where it gives off 
 
 Muscular branches, to supply the abdominal muscles. 
 
UJO-LL'MBAfl 
 
 K EXTERNAL [LUt 
 
 OUTER SIDE OF GREAT TOi; 
 
 Fig. 112. 
 The arteries of the lower txtremity. 
 
THE HEART AND VASCULAR SYSTEM. 197 
 
 THE FEMORAL AETEET 
 
 extends from Poupart's ligament down the inner side of the 
 thigh to the opening in the adductor magnus (Hunter's canal), 
 where it becomes the popliteal. Its course corresponds to a line 
 drawn from a point midway between the anterior superior spine 
 of the ilium and the symphysis pubis to the inner tuberosity of 
 the internal condyle. In the upper part of its course it is super- 
 ficial, where it passes through Scarpa's triangle, but in the lower 
 part it passes backward and becomes very deep. Where it passes 
 under Poupart's ligament the femoral vein is to the inner side, 
 and the anterior crural nerve to the outer side; thus, from within 
 outward, V. A. N. 
 
 Relations. — It is in relation in front with the Bartorius, the long 
 saphenous nerve, a branch of the anterior crural nerve, and is covered 
 by the fascia lata; behind it is in relation with the psoas magnus, 
 adductor longus, adductor magnus and pectineus, and the profunda 
 vein, and about the middle with the femoral vein; at its inner side it 
 is in relation with the sartorius and adductor longus muscles, and at 
 its upper part with femoral vein; on the outer side, with the vastus 
 internus, and at its lower part, the femoral vein. 
 
 The branches of the femoral artery are : — 
 
 Superficial epigastric, descends through the saphenous open- 
 ing in the fascia lata, and ascends in abdomen, supplying the 
 skin, inguinal glands, and superficial fascia; 
 
 Superficial circumfiex iliac, passes outward to the skin of the 
 groin and over crest of ilium; 
 
 Superficial external pudic, supplies the skin on the lower 
 part of the abdomen ; 
 
 Deep external pudic, supplies the scrotum in the male, the 
 labia pudendi in the female; 
 
 Profunda femoris, arises about two inches below Poupart's 
 ligament, and passes beneath the adductor longtis, giving off 
 the following: — 
 
 External circumflex, gives o£E ascending, transverse, and 
 descending branches, supplying the muscles on the front of the 
 thigh as low as the knee; 
 
 Internal circumflex, passes internally, supplying the adduc- 
 tor muscles and the hip- joint; 
 
 Three perforating, pierce the adductor magnus and brevis, 
 and supply the flexor muscles of the thigh, and give off the 
 medullary nutrient artery. The vessel terminates by a fourth 
 perforating. 
 
 Muscular, vary in number, and supply the sartorius and 
 vastus internus; 
 
198 HUMAN ANATOMY. 
 
 Anastomotica magna, gives off two branches — superficial, 
 accompanying the long saphenous nerve, and deep branch, to the 
 inner side of knee, and supplies knee-joint. 
 
 THE POPLITEAL ARTEET 
 
 descends from the opening in the adductor magnus to the lower 
 border of the popliteus muscle, passing behind the knee-joint, 
 where it divides into the anterior and posterior tibial arteries. 
 Its branches are : — 
 
 MtLscular, gives ofE two principal branches: — 
 
 Superior, to flexors of thigh and vastus externus muscles; 
 
 Inferior, or sural, to heads of -gastrocnemius and plantaris. 
 
 Cutaneous, supplies the skin of the calf; 
 
 Superior external articular, supplies knee-joint and vastus 
 externus ; 
 
 Superior internal articular, supplies knee-joint and vastus 
 internus ; 
 
 Azygos articular supplies the synovial membrane and liga- 
 ments of joints; 
 
 Inferior external articular, supplies knee-joint and fibular 
 head; 
 
 Inferior internal articular, supplies knee-joint and head of 
 tibia. 
 
 THE ANTEEIOH TIBIAL AETEET 
 
 descends from the bifurcation of the popliteal at the lower border 
 of the popliteus muscle; passes over the upper border of the 
 interosseous membrane, between the two heads of the tibialis 
 posticus, and descends on the anterior part of the interosseous 
 membrane and lower part of the tibia to the ankle-joint, where 
 it terminates as the dorsalis pedis. 
 
 In the upper third of its course it lies between the tibialis anticus 
 and extensor longus digitoruni, resting upon the interosseous membrane, 
 in the middle third, between the tibialis anticus and extensor proprius 
 pollicis, and at the lower third it becomes more superficial, and lies 
 between the extensor proprius and extensor longus digitorum tendons. 
 
 Its branches are: — 
 
 Recurrent tibial, ascends to supply the front and sides of 
 the knee-joint and anastomose with the anastomotica magna 
 and popliteal ; 
 
 Muscular, supplying the muscles and skin of the neighbor- 
 ing parts; 
 
 Internal malleolar, arises two inches above the ankle-joint, 
 and supplies it and the structures on its inner side; 
 
THE HEART AND VASCULAR SYSTEM. 199 
 
 External malleolar, supplies the outer side of the ankle. 
 
 The doesalis pedis artery extends from the bend of the 
 ankle, where it is continuous with the anterior tibial, to the 
 first interosseous space, where it divides into the dorsalis hal- 
 lucis and the communicating. Its branches are:— 
 
 Tarsal, supplies the tarsal articulations and the extensor 
 brevis digitorum muscle; 
 
 Metatarsal, passes to the outer side of the foot, and gives off 
 three interosseous branches to supply the adjacent sides of the 
 toes; 
 
 Dorsalis pollicis, or hallucis, passes along the outer border 
 of the great toe, supplying it; 
 
 Communicating, descends between the two heads of the 
 first dorsal interosseous to complete, with the external plantar, 
 the plantar arch; 
 
 Interosseous, branches of the tarsal branch, three in number. 
 
 THE POSTEHIOE TIBIAL AETEEY 
 
 begins at the lower border of the popliteus muscle and descends 
 along the posterior and tibial side of the leg to the space between 
 the heel and the inner ankle, where it passes beneath the abduc- 
 tor pollicis and divides into the internal and external plantar 
 arteries. 
 
 Relations.— In the upper part of its course it lies deeply, being 
 covered by the gastrocnemius and soleus muscle, but in the lower part 
 it becomes more superiieial, being covered only by the skin and the 
 fascia. 
 
 Its branches are: — 
 
 Peroneal, descends the inner border of the fibula, supplying 
 the muscles and skin of that region and the back of the ankle ; 
 
 Anterior peroneal, a branch of the peroneal, pierces the 
 lower part of the interosseous membrane to supply the dorsum 
 and outer side of the tarsus; 
 
 Muscular, supplies the posterior muscles; 
 
 Nutrient, supplies the tibia, being the largest nutrient artery 
 in the body; 
 
 Communicating, passes to the peroneal ; 
 
 Internal calcanean, supplies the inner side of the sole and 
 heel. 
 
 The inteenal plantae aeteet, the smaller of the two, 
 passes along the inner side of the foot between the abductor 
 pollicis and the flexor brevis digitorum to the inner border of 
 the great toe, anastomosing with its digital branch. 
 
200 
 
 HUMAN ANATOMY. 
 
 The- EXTERNAL PLANTAR ARTERY passes across the foot to 
 the base of the fifth metatarsal bone, where it turns inward and 
 crosses the foot to the first interosseous space, where it anasto- 
 moses with the communicating branch of the dorsalis pedis to 
 form the plantar arch. Its branches are : — 
 
 Posterior perforating, are three branches which pass between 
 the heads of the dorsal interossei muscles ; 
 
 Digital branches — these are four branches which supply the 
 adjacent sides of the three outer toes, and the outer sides of the 
 second and little toes. 
 
 TABLE OE THE ARTETIIAL SYSTEM. 
 
 Arch 
 
 of 
 
 aorta, 
 
 Right coronary, 
 Left coronary, 
 
 Innominate, 
 
 Aorta. 
 
 i < 
 LRig 
 
 ht common f External carotid, 
 carotid, \ Internal carotid, 
 
 gilt subclavian. 
 
 T ti i.j f External carotid. 
 
 Left common carotid, ■< t <. i i-j 
 
 ' (. Internal carotid. 
 
 _Left subclavian. 
 
 External 
 carotid. 
 
 Superior 
 thyroid, 
 
 Lingual, 
 
 Occipital, 
 
 Facial, ■ 
 
 Hyoid, 
 
 Superficial descending branch, 
 
 Superior laryngeal, 
 
 Crico-thyroid. 
 
 Hyoid, 
 
 Dorsalis lingute. 
 Sublingual, 
 Ranine. 
 
 In the 
 neck. 
 
 {Inferior or ascending palatine, 
 tonsillar, submaxillary, sub- 
 mental, muscular. 
 
 On the f Muscular, inferior labial, inferior 
 face I coronary, superior coronary, 
 ' L lateralis nasi, angular. 
 
 Muscular, 
 
 Sterno-mastoid, 
 
 Auricular, 
 
 Meningeal, 
 
 Arteria princeps cervieia, 
 
 Cranial brandies. 
 
THE HEART AXD ^'ASCULAR SYSTEJI. 
 
 201 
 
 External 
 
 carotid 
 
 coutinued, 
 
 Posterior 
 auricular, 
 
 Stj-lo-mastoid, 
 Auricular, 
 Muscular, 
 Glandular. 
 
 pliaryngefl, } ^'^aryngeal, external, meningeal. 
 
 Temporal, 
 
 Internal 
 maxillary. 
 
 Transverse facial. 
 Middle temporal. 
 Auricular, 
 Anterior temporal. 
 Posterior temporal. 
 
 Maxillary 
 portion. 
 
 Pterygoid 
 portion. 
 
 Spheno- 
 maxillary 
 portion, 
 
 Tympanic (anterior ) , 
 Deep auricular, 
 iliddle meningeal, 
 Small meningeal, 
 Inferior dental. 
 
 Deep temporal. 
 Pterygoid, 
 Masseteric, 
 Buccal. 
 
 Alveolar, 
 
 Infraorbital, 
 
 Post., or ascending palatine. 
 
 Vidian, 
 
 Pterygo-palatine, 
 
 Nasal or spheno-palatal. 
 
 portion! } Tympanic (internal, or deep). 
 
 Arterise receptaculi. 
 Anterior meningeal, 
 
 Cavern- 
 ous 
 portion. 
 
 Cerebral 
 portion. 
 
 . Ophthalmic, 
 
 Anterior cerebral, 
 Middle cerebral, 
 Anterior choroid, 
 
 Orbital 
 group. 
 
 Ocular 
 L group. 
 
 Lachrymal, 
 
 Supraorbital, 
 
 Post, ethmoidal. 
 
 Ant. ethmoidal. 
 
 Palpebral, 
 
 Frontal, 
 
 Nasal. 
 
 Muscular, 
 Ant. ciliary. 
 Short ciliary. 
 Long ciliary, 
 Arteria centralis 
 retinae. 
 
 Posterior communicating. 
 
202 
 
 HUMAN ANATOMY. 
 
 Verte- 
 bral, 
 
 Cervical Branches, 
 
 I * > 
 
 Lateral spinal. 
 Muscular. 
 
 Cranial Branches, 
 
 , * V 
 
 Posterior meningeal, 
 Anterior spinal, 
 . Posterior spinal. 
 
 Basilar, - 
 
 Transverse, 
 Anterior inferior 
 
 cerebellar, 
 Sup. cerebellar. 
 Post, cerebral. 
 
 
 Thyroid 
 axis. 
 
 Inferior thyroid. 
 
 Superior scapular, 
 (Transversalis humeri), 
 
 Transversalis colli. 
 
 Laryngeal, 
 Tracheal, 
 QSsophageal, 
 Ascend, cervical. 
 Muscular. 
 
 Muscular, 
 Supra-acromial. 
 
 Superfic. cervical, 
 Post, scapular. 
 
 Internal 
 mam- 
 mary. 
 
 Comes nervi phrenici (superior phrenic). 
 
 Mediastinal, 
 
 Pericardiac, 
 
 Sternal, 
 
 Anterior intercostal. 
 
 Perforating, 
 
 Musculo-pnrenie, 
 
 Superior epigastric. 
 
 Superior T 
 inter- ?■ Deep cervical branch (profunda cervicis), 
 costal, J 
 
 Axillary, 
 
 Superior thoracic, 
 Acromio-thoracic, 
 Thoraeica longa 
 Thoracica alaris, 
 
 Subscapular, 
 
 Anterior circumflex, 
 Posterior circumflex. 
 
 f Dorsal is scapuh-e, 
 \ iledlau branch. 
 
 Brachial, 
 
 Superior profunda. 
 
 Nutrient artery, 
 
 Inferior profunda, 
 
 Anastomotica magna. 
 
 Muscular, 
 
 Radialj 
 
 Ulnar. 
 
THE HEART AND VASCULAR SYSTEM. 
 
 203 
 
 Radial, 
 
 In forearm. 
 
 In the wrist. 
 
 In the hand, 
 
 Radial recurrent. 
 Muscular, 
 Superficialis volse. 
 Anterior carpal. 
 
 Posterior carpal. 
 Metacarpal, 
 Dorsalis poUicia, 
 Dorsalis indicis. 
 
 Princeps poUicis, 
 Radialis indicis. 
 Perforating, 
 Interosseons. 
 
 Ulnar, 
 
 Thoracic 
 aorta. 
 
 tn the forearm. 
 
 In the wrist, 
 , In the hand. 
 
 ' Anterior ulnar recurrent, 
 Posterior ulnar recurrent. 
 Interosseous, 
 Muscular. 
 
 f Anterior carpal, 
 I Posterior carpal. 
 
 f Deep, or communicating branch, 
 \ Digital. 
 
 Descending Aorta. 
 
 Pericardiac, 
 Bronchial, 
 
 Posterior mediastinal. 
 Intercostal. 
 
 Abdominal 
 aorta. 
 
 Two phrenic 
 
 Cceliac axis. 
 
 Gastric. 
 
 Hepatic, 
 
 - Splenic, 
 
 Pyloric, 
 
 Gastro- 
 duodenalis. 
 
 Cystic, 
 
 Pancreatico- 
 
 duodenalis 
 
 superior, 
 
 Gastro- 
 
 epiploica 
 
 dextra. 
 
 { 
 
 Pancreatic, 
 
 Gastro-epiploica sinistra. 
 Gastric (vasa brevia). 
 
 Superior 
 
 mesenteric, 
 Suprarenal, 
 Renal, 
 
 Panoreatico-duodenalis inferior, 
 Vasa intestinalis tenuis, 
 Ileo-colio, 
 Colica dextra, 
 . Colica media. 
 
204 
 
 HUMAN ANATOMY. 
 
 Abdominal 
 
 aorta, -<, 
 con tin ae i, 
 
 Spermatic, 
 
 Inferior 
 mesenteric. 
 
 Colica sinistra. 
 
 Sigmoid, 
 
 Superior haemorrhoidal. 
 
 Lumbar (four or five branches). 
 Dorsal branch, 
 Spinal branch. 
 Abdominal branches. 
 Middle sacral, 
 ^ Common ilii. 
 
 Branches to 
 ureter, peritoneum, etc. 
 
 (- Anterior 
 trunk, 
 
 o 
 
 Internal 
 iliac. 
 
 s 
 
 External 
 iliac, 
 
 Posterior 
 trunk. 
 
 Superior vesical, 
 Middle vesical, 
 Inferior vesical. 
 Middle hcemorrhoidal. 
 
 Deep 
 epigastric, 
 
 ie, I 
 
 Deep 
 
 circumflex 
 
 iliac. 
 
 
 Within 
 
 r Iliac, 
 Vesical, 
 
 
 pelvis. 
 
 Pubic. 
 
 Obturator, . 
 
 
 ■ External 
 
 
 Without 
 
 and 
 
 
 pelvis. 
 
 inteinal 
 
 
 
 branches. 
 
 
 ■ Inferior haer 
 
 noiThnidal, 
 
 
 Superficial f 
 
 evineal, 
 
 Internal 
 
 Transverse 
 
 lerineal. 
 
 pudic, 
 
 Bulbo-ureth 
 Cavernous, 
 
 ■al, 
 
 
 . Dorsal art'y 
 
 of the penis. 
 
 Sciatic, 
 
 In the 
 female. 
 
 Coccygeal, 
 
 Inferior gluteal. 
 
 Conies nervi ischiadicis. 
 
 Muscular, 
 
 Articular. 
 
 f Uterine, 
 
 \ Vagir 
 
 aginal. 
 
 Ilio-lurabar, 
 Lateral sacral. 
 Gluteal. 
 
 Cremasteric, 
 
 Pubic, 
 
 Muscular. 
 
 Muscular branches. 
 
THE HEART AND VASCULAK SYSTEM. 
 
 205 
 
 Femoral 
 (continuation). 
 
 Popliteal, 
 
 Anterior 
 tibial. 
 
 Posterior 
 tibial. 
 
 Plantar arch 
 
 (from external 
 
 plantar) , 
 
 Superficial epigastric, 
 Superficial circumflex iliac. 
 Superficial external pudie. 
 Deep external pudic. 
 
 Profunda, 
 
 External circumflex, 
 Internal circumflex. 
 Three perforating. 
 
 Muscular, 
 
 Anastomotica magna, 
 Popliteal (continuation). 
 
 f Superior, 
 \ Inferior, 
 
 Muscular, 
 
 Cutaneous, 
 Superior external articular, 
 Superior internal articular, 
 Azygos articular, 
 Inferior external articular. 
 Inferior internal articular, 
 Anterior tibial 1 BUurcation. 
 Posterior tibial, j 
 
 Recurrent tibial. 
 Muscular, 
 Internal malleolar. 
 External malleolar. 
 
 Dorsalis pedis 
 (continuation). 
 
 Tarsal, \ Three 
 
 Metatarsal, / interosseous. 
 Dorsalis poUicis or hallucia. 
 Communicating, 
 . Interosseous. 
 
 Anterior peroneal. 
 
 Peroneal, 
 Muscular, 
 Nutrient, 
 Communicating, 
 Internal caleanean, 
 
 LExtriltur, } Bifurcation. 
 
 (Three posterior perforating. 
 Four digital. 
 
 Pulmonary Artery. — The pulmonary artery carries venous 
 blood from the right ventricle to the lungs. It is about two 
 inches in length, passes upward and baclrward to the left side 
 to the under surface of the transverse portion of the arch of the 
 aorta, where it divides into the right and left pulmonary arteries. 
 It is attached to the under portion of the arch by a fibrous cord, 
 the remains of the ductus arteriosus of foetal life. The right 
 
206 HUMAN ANATOMY. 
 
 pulmonary artery is larger and longer than the left, and passes 
 behind the ascending aorta and superior vena cava to the root of 
 the right lung, where it divides into two branches. The left 
 pulmonary artery passes in front of the descending aorta and left 
 bronchus to the root of the left lung, where it divides into two 
 branches. 
 
 THE VENOUS SYSTEM. 
 
 The venous system, like the arterial, consists of two distinct 
 sets, the systemic and pulmonary. It is composed of seven (7) 
 main trunks and their branches: — 
 
 Systemic. Pulmonary. 
 
 1. Coronary vein; Four pulmonary veins. 
 
 2. Superior vena cava; 
 
 3. Inferior vena cava. 
 
 The systemic veins return the venous blood from the body, 
 head, and extremities to the right auricle.. 
 
 The portal vein, with its branches and capillaries, is an 
 appendage to the systemic set, collecting the venous blood from 
 the organs of digestion and carrying it to the liver, where it 
 breaks into capillaries, and finally reaches the inferior vena cava 
 by means of the hepatic veins. 
 
 The pulmonary veins are peculiar in carrying arterial 
 blood from the lungs to the left auricle. 
 
 Systemic Veins. — The coronary sinus returns all the blood 
 from the substance of the heart, except that returned directly 
 from the the walls of the right auricle by the vence Thebesii. It 
 is a dilatation of the great cardiac vein, about one inch in length, 
 situated in the posterior part of the left auriculo-ventricular 
 groove. It opens into the right auricle, its orifice being pro- 
 tected by the coronary valves, and receives the following : — 
 
 Great cardiac, or coronary vein; Posterior cardiac; 
 Anterior cardiac; Small cardiac; 
 
 Middle cardiac; Oblique vein. 
 
 The superior vena cava is a short trunk formed by the 
 union of the right and left innominate veins. It receives the 
 vena azygos major, has no valves, and is smaller in size than the 
 aorta. It ends in the right auricle, receiving the blood from the 
 whole upper half of the body and the right lymphatic and 
 thoracic ducts. The left innominate passes to join the superior 
 cava in front of the great arteries of the arch. The inferior 
 thyroid, the internal mammary, and vertebral veins follow 
 closely the courses of the corresponding arteries, and terminate 
 in the innominate vein. 
 
THE HEART AND VASCULAR SYSTEM. 207 
 
 The internal jugular vein is formed by the lateral and the 
 superior petrosal sinuses, descends at the outer side of the com- 
 mon carotid behind the anterior border of the stemo-mastoid 
 muscle, and joins the subclavian vein to form the innominate. 
 At its junction with the subclavian the left internal jugular vein 
 receives the thoracic duct and the right internal jugular vein the 
 right lymphatic duct. 
 
 The Sinuses of the Dura Mater. — These are venous 
 channels analogous to veins between the layers of the dura mater. 
 They are destitute of valves, follow no vessels, and their inner 
 coat is continuous with the lining membrane of the veins. They 
 are fifteen in number, divided into two sets, those at the back 
 and upper part of the skull five ia number : — 
 
 Superior longitudinal, Lateral sinuses (2), 
 
 Inferior longitudinal. Occipital sinus. 
 
 Straight sinus. 
 
 And those of the base five also : — 
 
 Cavernous (2), Superior petrosal (2), 
 
 Circular, Transverse (anterior occipital. 
 
 Inferior petrosal (2), Leidy). 
 
 The superior longitudinal sinus arises at the foramen csecum, 
 passes backward along the margin of the falx cerebri to the 
 crucial ridge of the occipital bone, where it terminates in the 
 torcular herophili (confluence of the sinuses). 
 
 The inferior longitudinal sinus passes in the free margin of 
 the falx cerebri. 
 
 The straight sinus passes backward from the junction of the 
 tentorium with the falx cerebri to enter the confluence of the 
 sinuses. 
 
 The lateral sinuses pass horizontally outward from the con- 
 fluence of the sinuses, torcular Herophili, along the temporal 
 bone to the jugular foramen, where they terminate in the internal 
 jugular vein. 
 
 The occipital sinus, the smallest of all the sinuses, com- 
 mences at the margin of the foramen magnum on either side and 
 passes backward to the confluence of the sinuses. 
 
 The cavernous sinuses pass from the sphenoidal fissure along 
 either side of the sella turcica to the apex of the petrous portion 
 of the temporal bone, where they join the petrosal sinuses. They 
 are crossed by fibrous bands or offsets of the dura mater, and 
 inclose the pathetic, motor oeuli, abducens, and ophthalmic 
 nerves, ' and the internal carotid artery, from which they are 
 separated by the lining membrane. 
 
208 HUMAN ANATOMY. 
 
 The circular sinus is. formed by two small vessels passing 
 in front of and behind the pituitary body, and connecting the 
 cavernous sinuses. 
 
 The inferior petrosal sinus on each side runs in a groove 
 between the petrous portion of the temporal bone and the basilar 
 portion of the occipital, connecting the cavernous sinuses with 
 the lateral sinuses. 
 
 The superior petrosal sinus on each side passes along the 
 upper border of the petrous portion of the temporal bone, con- 
 necting the cavernous with the lateral sinuses above. 
 
 The transverse sinus is a small, straight sinus, connecting 
 the inferior petrosal and cavernous sinuses. 
 
 Cehebral Veins. — The cerebral veins consist of two sets — 
 the superficial, on the surface, and the deep, within the substance. 
 They include: — 
 
 Superficial — 
 
 Superior cerebral veins. Inferior cerebral veins. 
 
 Deep — 
 
 Ventricular veins, or venae Veni corporis striati, 
 
 Galeni, Choroid vein. 
 
 The cerebellar veins consist of the superior, inferior, and 
 lateral. 
 
 DiPLOio AND Meningeal Veins. — The diploic veins, five 
 in number, — frontal, anterior temporal, posterior temporal, 
 occipital, — communicate with the sinuses of the brain and with 
 the veins of the dura mater, the scalp, and orbit. 
 
 The meningeal veins follow the course of the corresponding 
 arteries, two accompanying each vessel through its course, and 
 open into the sinuses of the dura mater. 
 
 The great meningeal veins terminate either in the cavernous 
 sinuses or by emptying into the internal maxillary vein. 
 
 The ophthalmic vein commences at the internal canthus of 
 the eye in an anastomosis with the facial, passes backward along 
 the inner part of the orbit, through the sphenoidal fissure, to 
 empty into the cavernous sinuses. 
 
 The external jugular vein, smaller than the internal jugular, 
 is formed by the union of the posterior auricular with the tem- 
 poro-maxillary veins; or it may be formed by union with the 
 facial. It descends beneath the platysma muscle from the angle 
 of the jaw to the middle of the clavicle, where it terminates by 
 emptying into the subclavian. It receives the following veins : — 
 
 Anterior jugular, Suprascapular, 
 
 Posterior jugular, Transverse cervical. 
 
THE HEART AND VASCULAR SYSTEM. 209 
 
 The facial vsin commences as the angular at the internal 
 canthus of the eye, where it anastomoses with the ophthalmic 
 vein, and receives the frontal vein. About the angle of the jaw 
 it usually ends in the internal jugular, but sometimes empties 
 into the external jugular or unites with the temporo-maxillary, 
 to enter the external jugular. It receives — • 
 
 Supraorbital and superior palpebral, Labial, 
 
 Nasal veins. Submental, 
 
 Inferior palpebral, Submaxillary, 
 
 Buccal and masseteric. Palatine. 
 
 The temporal vein is formed by the anterior temporal, which 
 anastomoses with the frontal, and the posterior temporal, which 
 anastomoses with the occipital. It penetrates the parotid gland 
 and forms the temporo-maxillary vein by uniting with the in- 
 ternal maxillary. It receives 
 
 Articular veins. Transverse facial. 
 
 Anterior auricular. Parotid. 
 
 Middle temporal. 
 
 The internal maxillary vein follows the course of the corre- 
 sponding artery, and receives veins corresponding to the branches 
 of that vessel. Some of these branches form the pterygoid 
 plexus. It passes backward and unites with the temporal vein 
 to form the temporo-maxillary. 
 
 The temporo-maxillary vein, formed by the junction of the 
 internal maxillary in part or whole with the temporal, passes 
 through the parotid gland and receives the posterior auricular, 
 to form the external jugular veia. 
 
 The occipital veins follow the course of the artery, and 
 terminate, usually, in the internal jugular; occasionally, in the 
 external jugular. The mastoid vein, passing through a foramen 
 in the mastoid portion, connects it with the lateral sinus. 
 
 Veins op the Tongue and Throat. — The dorsal lingual, 
 formed by branches from the tonsils, epiglottis, and tongue, fol- 
 low the course of the lingual nerve to empty into the facial, either 
 jugular, or the pharyngeal. 
 
 The ranine pursues the course of the hypoglossal nerve, and 
 terminates either in the facial or in one of the jugulars. 
 
 The pharyngeal, commencing in the pharyngeal plexus, re- 
 ceives branches from the brain, and terminates about on a level 
 with the hyoid bone in the internal jugular. 
 
 The superior thyroid conveys the blood from the larynx, 
 trachea, and thyroid gland to the internal jugular. 
 
 Veins of the Uppee Extremity. — Superficial and deep. 
 
210 HUMAN ANATOMY. 
 
 The subclavian vein, the continuation of the axillary, unites 
 with the internal jugular to form the innominate. In its pas- 
 sage over the first rib it is separated from the artery by the 
 scalenus anticus muscle. 
 
 Deep Set. — The deep veins accompany the corresponding 
 arteries and form the venae comites, one on either side, except the 
 axillary, which has a single vein. The valves are more numer- 
 ous in the deep set. About the middle of the arm one of the 
 brachial veins receives the basilic vein, one of the larger veins 
 of the superficial set. The two brachial veins unite with the 
 basilic to form the axillary vein, which in turn becomes the 
 subclavian vein, receiving in its course beneath the clavicle the 
 cephalic vein, a branch of the superficial set. 
 
 Superficial Set. — The anterior ulnar vein commences on the 
 inner surface of the hand and wrist, and terminates by uniting 
 with the posterior ulnar or the median vein. The posterior ulnar 
 vein commences on the inner back portion of the hand, anasto- 
 mosing with the radial cutaneous vein, and ascends to the bend 
 of the elbow, where it becomes the basilic vein ; 
 
 The basilic vein, from its formation at the bend of the elbow, 
 ascends the inner side of the biceps, pierces the fascia, to join 
 the brachial vein. 
 
 The radial cutaneous commences on the radial, dorsal aspect 
 of the hand, and at the bend of the elbow unites with the median 
 cephalic, to become the cephalic. 
 
 The cephalic vein ascends along the outer border of the 
 biceps, and above in the groove between the deltoid and pectoralis 
 major, and passes beneath the clavicle, to end in the axillary. 
 
 The median vein receives the blood from the palmar surface 
 of th.e hand and the front of the forearm, and usually divides 
 into two branches — the median cephalic, passing outward to 
 join the cephalic, and the median basilic, passing inward to join 
 the basilic. The median basilic vein, the larger, is the one 
 usually selected for plebotomy. 
 
 Veins of the Trunk. — The vena azygos major commences 
 in the abdomen, opposite the first or second lumbar vertebra, as 
 a continuation upward of the right ascending lumbar vein. It 
 communicates with the right renal and the inferior vena cava. 
 Through the lumbar veins it establishes communication with the 
 right common iliac vein. It passes through the aortic opening 
 of the diaphragm, or through an aperture in the right crus, 
 ascends on the dorsal vertebrse, arches over the root of the right 
 lung, and empties into the superior vena cava. It is in relation 
 on its left side with the aorta, thoracic duct, and oesophagus. It 
 receives 
 
THE HEART AND VASCULAR SYSTEM. 211 
 
 Vena azygos minor, Right superior intercostal 
 
 Vena hemi-azygos accessoria, vein, 
 
 Lower end of left superior Right subcostal vein, 
 
 intercostal vein. Oesophageal, 
 
 Lower 8 or 9 intercostal Right bronchial. 
 
 veins. 
 
 The hemi-azygos veins are two in number : — • 
 
 The vena azygos minor arises on the left side, similarly to 
 the azygos major, and passes through the left crus of the dia- 
 phragm and about the eighth dorsal vertebra crosses beneath the 
 aorta to join the vena azygos major; 
 
 The vena hemi-azygos accessoria communicates with the 
 upper left intercostal vein, and terminates either in the vena 
 azygos minor or the azygos major. 
 
 The inferior cava formed by the junction of the common 
 iliac veins, at the sides of the fourth lumbar vertebra, ascends on 
 the right of the aorta, grooves the posterior border of the liver, 
 and passes through the quadrate foramen in the central tendon 
 of the diaphragm, and ends in the right auricle. It receives 
 
 Middle sacral, Renal veins — the left, the 
 
 Lumbar, longer, crosses in front 
 
 Spermatic (from spermatic of the aorta, 
 
 plexus). Suprarenal, 
 
 Ovarian (from ovarian Phrenic, 
 
 plexus), Hepatic (2 or 3). 
 
 The portal vein, about three inches in length, is formed by 
 the inferior and superior mesenteric, the gastric, splenic, and 
 pancreatic veins. It ascends in the right border of the lesser 
 omentum to the transverse fissure of the liver, where it divides 
 into the right and left. Its blood is distributed through the liver, 
 mixing with the arterial blood from the hepatic artery, to be 
 returned to the inferior cava by the hepatic veins. It receives 
 
 The superior mesenteric. Cystic, 
 
 Splenic, Inferior mesentery, 
 
 Coronary, Right gastro-epiploie. 
 
 The portal vein and its branches are destitute of valves. 
 
 Veins of the Veetebeal Column. — 1. The dorsi-spinal 
 veins commence in an intricate net-work surrounding the verte- 
 bral arches and their processes. They communicate with the in- 
 tercostal, vertebral, intraspinal plexus, lumbar, sacral, and the 
 superficial veins of the back. 
 
 2. The intraspinal or meningo-rachidian veins form an in- 
 tricate plexus between the vertebra and dura mater within the 
 spinal canal. They consist of four longitudinal veins — two in 
 
212 HUMAN ANATOMY. 
 
 front and two behind. The anterior longitudinal spinal veins, 
 two in number, extend along the sides of the vertebral bodies 
 and opposite the bodies communicate by transverse trunlcs, which, 
 in their passage beneath the vertebral ligament, receive the di- 
 ploic veins, or vence basis vertebrce, from the interior of the body. 
 The posterior longitudinal veins, also two in number, smaller 
 than the anterior, extend down the vertebral arches and are con- 
 nected by transverse branches opposite the latter. 
 
 They receive the veins from the spinal cord and its mem- 
 branes. 
 
 3. The venoe basis vertebrce return the blood from the bodies 
 of the vertebrte into the anterior intraspinal plexuses. 
 
 The vence medulli spinalis are the essential veins of the cord, 
 situated between the arachnoid and pia mater. 
 
 Common Iliac Veins. 
 
 Formed by the internal and external iliac veins uniting 
 opposite the sacro-iliac articulation, pass beneath the right com- 
 mon iliac artery to a point a little to the left of the body of the 
 last lumbar vertebra, where they unite to form the inferior vena 
 cava. The right is shorter and more vertical in its course, and 
 both are without valves. 
 
 The internal iliac vein corresponds to the distribution 
 of the corresponding artery. 
 
 It receives the following venae comites : — 
 
 Gluteal, Internal pudic, 
 
 Sciatic, Lateral sacral, and 
 
 Obturator, Middle sacral; 
 
 and the following plexuses : — 
 
 Vesico-prostatio, 1 . „„,„. Uterine and 1 .„ , ,_ 
 
 HiEmorrhoidal, /"i«'^^«' Vaginal, ) 'n female. 
 
 The lateral and middle sacral form a small plexus — the 
 plexus sacralis. 
 
 The- veins of the rectum, bladder, and generative organs 
 anastomose freely and form three plexuses : — ; 
 
 1. Hcemorrhoidal plexus encircles the lower part of the rec- 
 tum, communicates with the sacral and prostatic plexuses, and 
 veins from it join the inferior mesenteric, internal iliac, and 
 pudic veins. 
 
 2. Vesica-prostatic plexus surrounds the membranous por- 
 tion of the urethra, neck of bladder, prostate body, and seminal 
 vesicles. It communicates behind with the hemorrhoidal. 
 
THE HEART AND VASCULAK SYSTEM. 213 
 
 3. Utero-vaginal plexuses. — These correspond in the female 
 with the prostatic, and communicate with the vesical and hsemor- 
 rhoidal plexuses, the ovarian, pudic, and through the uterine 
 veins join the internal iliac veins. 
 
 During pregnancy these veins or plexuses become greatly dis- 
 tended and enlarged, forming the uterine sinuses, but retain a 
 straight course. 
 
 The pudic vein follows the same course as the artery, com- 
 municates with the prostatic and hsemorrhoidal plexuses, and 
 terminates in the internal iliac vein. 
 
 In the female it originates from the clitoris and perineum, 
 and communicates with the vaginal plexus. 
 
 The dorsal vein of the penis returns the blood from the body 
 of that organ. It commences as two venje comites of the dorsal 
 artery, which unite on the dorsal surface of the root of the penis, 
 perforates the triangular ligament, and again divides to termi- 
 nate in the prostatic plexus. 
 
 The veins of the corpus cavernosum emerge at the lower 
 groove, and turn round their outer side to join the dorsal vein. 
 
 The dorsal vein of the clitoris has a corresponding origin and 
 course, and empties into the vaginal plexus. 
 
 The EXTERNAL ILIAC VEIN, the Continuation of the femoral, 
 lies internal to the artery beneath Poupart's ligament, and joins 
 the iaternal iliac opposite the sacro-iliac symphysis, to form the 
 common iliac vein. It runs along the brim of the pelvis. It 
 receives at its commencement the venae comites of the epigastric 
 artery and the circumflex iliac. 
 
 Lower Extremity. — The deep veins of the lower extremity 
 pursue the exact course of the corresponding arteries, anastomos- 
 ing across the vessels they accompany, except the femoral, which 
 has but one vein. 
 
 The popliteal vein, formed by the junction of the anterior 
 and posterior tibial veins, ascends to the lower margin of 
 Hunter's canal, where it becomes the femoral. It receives the 
 articular veins, sural veins, and the external saphenous. At its 
 commencement it lies internal and superficial, at the middle of 
 the space directly behind, and, in the upper part of its course, 
 external to the artery. 
 
 The femoral vein, at first behind the artery, inclines to the 
 inner side as it ascends, and at Poupart's ligament becomes the 
 external iliac. It receives the profunda femoris, the internal 
 saphenous vein, and numerous muscular veins. 
 
 The superficial veins of the lower extremity consist of two 
 principal trunks: the external short saphenous, or vein, com- 
 mences on the dorsum of the foot, passes behind the outer mal- 
 
214 HUMAN ANATOMY. 
 
 leolus, ascends the leg, and pierces the deep fascia in the popliteal 
 space, to terminate in the popliteal vein. The long saphenous 
 vein, and the larger, arises from the dorsTim and inner side of the 
 foot, ascends the front and inner side of the leg and thigh, 'and 
 passes through the saphenous opening to Join the femoral vein. 
 
 The Pulmonary Veins. — The pulmonary veins are four 
 short, venous trunks, two from the base of each lung passing 
 to the left auricle, returning arterial blood. 
 
 They differ from other veins in the following respects : — • 
 
 1. They are without valves; 
 
 2. They carry arterial blood; 
 
 3. They accompany the arteries singly; 
 
 4. They are a little larger only than their arteries. 
 
 The right are longer than the left, and pass from the root 
 of the lung, on a lower level than the artery, behind the aorta, 
 superior cava, and right auricle, to enter the left auricle. 
 
 The Lympliatic System. 
 
 The lymphatic system includes the lymphatic vessels and 
 glands and the lacteals, and forms an important accessory to the 
 blood-vascular system, collecting the transuded, unappropriated 
 fluids of the body and the nutritive material derived from the 
 food and conveying it into the venous system. 
 
 It consists of two main trunks : — 
 
 (a) Thoracic duct; (bj Eight lymphatic duct; 
 
 and five smaller trunks : — 
 
 1. Jugular lymphatic trunk; 
 
 2. Subclavian lymphatic trunk; 
 
 3. Broncho-mediaatinal lymphatic trunk; 
 
 4. Lumbar lymphatic trunk; 
 
 5. Intestinal lymphatic trunk. 
 
 Lymphatics have been found in nearly every organ and tex- 
 ture in the body except the brain, the spinal cord, cartilage, 
 tendon, eyeball, placenta, umbilical cord, membranes of the 
 ovum, hair, cutis, and the labyrinth of the ear. They appear to 
 originate as fine capillary nets interwoven among the blood- 
 vessels and proper elements of the tissues, or, more minutely, in 
 the lymph, perivascular, and perineural spaces. In the villi they 
 commence as closed, club-like tubes. 
 
 The lymphatic capillaries are somewhat larger than the vas- 
 cular capillaries and destitute of valves. Their main trunlcs pass 
 through lymphatic glands lying in their course, before doing 
 
THE HEART AND VASCULAR SYSTEM. 215 
 
 which, however, they divide into afferent vessels, which, on emerg- 
 ing, unite into a smaller number of larger vessels, the efferent. 
 
 In structure, they are composed of three coats — ^the external 
 fibro-areolar, middle muscular, and internal or endothelial and 
 elastic. 
 
 The lymphatic glands are generally situated in the course of 
 the blood-vessels, lymphatic vessels, or lacteal vessels, being ac- 
 cumulated together in certain localities, as the neck, abdomen, 
 axilla, etc. 
 
 The lymphatic glands and vessels are named from the 
 regions they occupy or the vessels they accompany, and consist 
 usually of a superficial and deep set. Thus, we have cervical, 
 axillary, mediastinal, lumbar, inguinal, etc., and the lymphatic 
 vessels corresponding. 
 
 The lacteals, or chyliferous vessels, are the lymphatic vessels 
 of the small intestine, and differ only from the others in carrying 
 chyle during digestion from the intestines to the thoracic duct. 
 
 The thoeacic duct is formed by the junction of the two 
 lumbar lymphatic trunks with the intestinal lymphatic trunk, in 
 front of the second lumbar vertebra, between the aorta and in- 
 ferior vena cava, as the receptaculum chyli, or cistern of Pecquet. 
 This receptacle is about one to two inches long and a quarter of 
 an inch wide. From its origin the thoracic duct ascends through 
 the abdomen, passes through the aortic orifice in the diaphragm, 
 and ascends behind the oesophagus between the aorta and azygos 
 vein to the fourth dorsal vertebra, where it passes to the left be- 
 neath the aorta, and ascends between the oesophagus and the left 
 subclavian artery to the last cervical vertebra, where it arches 
 forward, outward, and downward to enter the junction of the sub- 
 clavian and the left internal jugular vein at its posterior aspect. 
 Its orifice is protected by a pair of valves. It receives all the 
 lymphatic vessels below the diaphragm, those of the left side of 
 the head, neck, and left upper extremity. 
 
 The right lymphatic duct is about half an inch long and 
 one-twelfth inch wide. It empties in a corresponding manner on 
 the right side to the thoracic duct. It receives all the lym- 
 phatics of the right side of the thorax, neck, head, and right 
 upper extremity. 
 
 Lymphatics op the Head and Neck. — The substance of 
 the brain is probably destitute of lymphatics, but they are very 
 numerous in the pia mater and choroid plexuses of the lateral 
 ventricles, and pursue the same course as the principal veins, to 
 emerge at the base through the various foramina, to terminate in 
 the deep cervical glands. The occipital lymphatic vessels termi- 
 nate in the posterior auricular and occipital glands. The tem- 
 
216 HUMAN ANATOMY. 
 
 poral lymphatic vessels terminate in the anterior or auricular 
 glands. The lymphatics of the face are superficial and deep. 
 The superficial lymphatics are numerous, and terminate in the 
 submaxillary glands, six or more in number; the deep lym- 
 phatics accompany the branches of the internal maxillary artery, 
 and terminate in the deep cervical and deep parotid glands about 
 the ramus of the jaw. 
 
 Lymphatics of the Upper Extremity. — Lymphatics of 
 the upper extremity are composed of two sets, the superficial and 
 deep. The superficial lymphatic glands are few in number, one 
 or two only being situated at the internal condyle of the humerus. 
 The deep lymphatic glands lie along the course of the vessels, and 
 communicate with the axillary glands. All of these glands unite 
 in the deep axillary glands, about eight to ten in number, which 
 communicate with the deep cervical glands, and through them 
 empty into the subclavian lymphatic trunk, to end finally in the 
 thoracic or right lymphatic duct. The superficial and deep ves- 
 sels of the thorax, the former in the skin, the latter from the 
 mammary glands, pectoral and other muscles, for the most part, 
 pass to the axilla, a few only terminating in the glands below 
 the clavicle. 
 
 The Cavity op the Thorax. — The intercostal lymphatic 
 vessels, derived from the side of the abdomen and thorax, pleurte, 
 diaphragm, spinal canal, muscles of the back, etc., follow the 
 course of the veins, traverse fifteen to twenty intercostal glands 
 near the heads of the ribs, and terminate in the thoracic duct. 
 The posterior mediastinal glands are between the intercostal 
 glands, and communicate with them. They receive vessels from 
 the pericardium, oesophagus, and diaphragm. Some of the effer- 
 ent vessels end in the bronchial glands, others in the thoracic 
 duct. The anterior mediastinal lymphatic vessels are derived 
 from the anterior wall of the abdomen and thorax, the dia- 
 phragm, pericardium, upper surface of the liver, heart, and thy- 
 mus gland. They traverse about eighteen to twenty anterior 
 mediastinal glands, situated in the course of the internal mam- 
 mary vein, pericardium, and great vessels of the heart, and 
 terminate in thoracic and right lymphatic ducts. The pulmo- 
 nary lymphatic vessels consist of a superficial and deep set, trav- 
 ersing in the last part of their course the pulmonary glands. 
 The bronchial glands are twenty or more glands at the bifurcation 
 of the trachea and root of the lungs, and receive the lymphatic 
 vessels of the lungs and bronchi. They become pigmented, and 
 are often the seat of disease. Their efferent vessels terminate on 
 the right side in the right lymphatic duct, either directly or by 
 forming the broncho-mediastinal trunk, and on the left side into 
 the thoracic duct. 
 
THE HEART AND VASCULAR SYSTEM. 217 
 
 Lower Extremity and Pelvis. — The superficial lymphatic 
 vessels from the back of the foot follo-w the course of the long 
 saphenous vein, passing to the superficial inguinal glands; and 
 those from the sole of the foot follow the short saphenous vein, 
 joining the deep set in the popliteal space. The deep lymphatic 
 vessels follow the deep veins, traverse two to four popliteal glands, 
 and join the deep inguinal glands. The deep lymphatic glands 
 in the pelvis consist of three sets : the external iliac, around the 
 external iliac vessels ; the internal iliac, around the internal iliac 
 vessels ; and the sacral glands, on the anterior surface, and in the 
 mesorectal folds. 
 
 Lymphatics of the Abdomen. — The lymphatic vessels of 
 the external and internal iliac glands enter the lumbar glands, 
 twenty-five or more in number, situated upon the vertebrae, the 
 origin of the diaphragm, the psoas and quadratus lumborum mus- 
 cles, and the great blood-vessels. They receive vessels from the 
 kidneys, ureters, loins, suprarenal bodies, ovaries, and testicles, 
 and form lumbar lymphatic trunks, which ascend to join the tho- 
 racic duct or receptaculum chyli. The lymphatic vessels of the 
 stomacli follow the general course of the blood-vessels. They 
 consist of three groups : the first, along the lesser curvature, pass- 
 ing to the glands along the pylorus ; the second, at the great end 
 of the stomach, passing to the splenic lymphatic glands ; and the 
 third, at the greater curvature, passing to one of the principal 
 lacteal vessels. The lymphatics of the small intestine are called 
 also lacteals. They pass between the layers of the mesentery 
 ,and traverse a large number of mesenteric glands, arranged 
 irregularly into three rows. The lymphatic vessels of the large 
 intestine traverse the mesocolic glands, about thirty in number, 
 and pass into the superior mesenteric glands. The vessels from 
 the spleen and pancreas follow the course of the splenic vein, 
 traverse a number of the glands, to end in the coeliac glands. 
 The lymphatics of the liver consist of superficial and deep, and 
 are very extensive, both on the upper and lower surfaces. They 
 terminate in the right lymphatic duct, the glands of the gastro- 
 hepatic omentum, the anterior mediastinal glands, the oesopha- 
 geal glands, the glands of the lesser curvature, and of the thoracic 
 duct. The deep lymphatics follow the course of the portal vein 
 and hepatic artery and duct, and, emerging, join one of the 
 lacteal vessels before it enters into the thoracic duct. The cceliac 
 glands, fifteen or twenty in number, are situated behind the pan- 
 creas and duodenum, the aorta, portal vein, cceliac, and superior 
 mesenteric vessels. Their efferent vessels form the intestinal 
 lymphatic trunk and empty into receptaculum chyli. 
 
THE ALIMENTARY APPARATUS. 
 
 The alimentary apparatus consists of the alimentary canal 
 and of certain accessory organs. 
 
 The former is a mnscnlo-membranous canal about thirty feet 
 in length, extending from the mouth to the anus, and comprises : 
 first, the organs of deglutition, consisting of the mouth, pharynx, 
 and oesophagus ; and, second, the organs of digestion, consisting 
 of the stomach and small and large intestines. It is lined 
 throughout by mucous membrane. The accessory organs com- 
 prise the teeth, salivary glands, liver, and pancreas. 
 
 Alimentary 
 canal. 
 
 Alimentary Apparatus. 
 
 Mouth, 
 Organs of deglutition, ] Pharynx, 
 
 CEsophagus. 
 
 Accessory 
 organs, 
 
 Organs of digestion. 
 
 Teeth, 
 
 Salivary glands. 
 
 Liver, 
 . Pancreas. 
 
 Stomach, 
 
 Duodenum, 
 Small intestine, ■{ Jejunum, 
 eum. 
 
 f Dii 
 
 e, \ Je; 
 
 (. He 
 
 tine, \ 
 I 
 
 Coecura, 
 _ Large intestine, -j Colon, 
 Rectum. 
 
 Parotid, 
 
 Submaxillary, 
 
 Sublingual. 
 
 The mouth is an oval cavity in which mastication takes 
 place preparatory to deglutition. It is placed at the entrance 
 of the alimentary canal, is bounded laterally by the alveolar 
 processes of the upper and lower jaws and cheeks ; above by the 
 upper teeth and hard palate; below by the tongue, the lower 
 jaw, the mucous membrane between, and the lower teeth; in 
 front by the lips; and behind by fauces and soft palate. It 
 terminates posteriorly at the anterior pillars of the fauces, 
 through the fauces into the pharynx. 
 
 ('218') 
 
THE' ALIMENTARY APPARATUS. 219 
 
 It is invested throughout (except on the teeth) with highly 
 vascular mucous membrane covered with stratified squamous 
 epithelium containing conical papillae. 
 
 It presents for examination the following parts : — 
 
 The Teeth. — The teeth are firmly implanted within the 
 alveoli of the jaws and surrounded by the gums. 
 
 The gums are composed of dense fibrous tissue, covered by 
 smooth, vascular, mucous membrane of slight sensibility. This 
 fibrous tissue is continuous with the periosteum of the jaws, and 
 forms about the neck of the teeth a constricted ring — ^the dental 
 ligament. 
 
 " There are four kinds of teeth — incisors, canines or cuspids, 
 premolars or bicuspids, and molars. Man is provided with two 
 sets of teeth, the temporary, deciduous, or milk teeth, which 
 appear in childhood, and the permanent, which appear after the 
 shedding of the "milk teeth and last until old age. 
 
 The temporary or deciduous teeth are twenty in. number, 
 ten in each jaw, or five ia each side of each jaw : — 
 
 Two incisors, one canine, and two molars. 
 
 The permanent teeth are thirty-two in number, sixteen in 
 each jaw, or eight in each side of each jaw : — 
 
 Two incisors, one canine, two bicuspids, three molars. 
 
 Bach tooth consists of three parts: — 
 
 Crown, or body, the enameled portion above the gum ; necTc, 
 the constricted portion between the crown and root; root, or 
 fang, within the alveolus, and covered with cement. 
 
 Characteristics. — Incisors, or cutting, are so called from 
 their wedge-shaped, chisel-like crown, being adapted for biting 
 or cutting the food. The fang is long, single, conical, and com- 
 pressed at the sides. 
 
 Cuspids, or canines, have been so named from their con- 
 spicuous character in the canine or dog tribe. 
 
 The crown is large, conical, convex in front, and beveled 
 behind. The fang is single, longest, and thickest of all the 
 teeth. 
 
 Bicuspids, or premolars. The crown has a pair of project- 
 ing tubercles or cusps. Pang is conical, single, but deeply 
 grooved, indicating a disposition to bifurcate. 
 
 Molars, commonly known as grinders or jaw teeth. Crown, 
 broad, quadrilateral, with four cusps in upper, five in lower 
 molars. Lower molars have usually a pair of fangs placed lat- 
 erally; the upper, three fangs, two external and one internal. 
 
 The last or third molar has but one fang (with a tendency 
 to divide into the same number of roots as the other molars), and 
 is known as the dens sapientice, or "wisdom tooth/' from its 
 late appearance. 
 
220 HUMAN ANATOJIY. 
 
 Structure. — On section'a tooth consists of two portions, the 
 pulp cavity and the solid portion surrounding it. 
 
 The solid portion consists of three structures, dentine, or 
 ivory, which forms the principal mass of the tooth; enamel, 
 which covers the crown, and cement, which covers the surface 
 of the fang. 
 
 Dentine, or ivory, resembles bone, but differs from it in 
 composition and structure, consisting of twenty-eight parts ani- 
 mal and seventy-two parts mineral matter, and being made up 
 of minute tubuli held together by the intertubular substance. 
 
 The dental tubuli are minute cylindrical canals Visoo of an 
 inch in diameter. They pass in a spiral direction from the pulp 
 cavity to the periphery. 
 
 Enamel, the hardest and densest of all organized bodies, con- 
 tains but 3.5 per cent, animal matter, and is composed of minute 
 hexagonal rods ^/ggoo of an inch in diameter,' placed at right 
 angles to the surface of the dentine. The external surface of 
 unworn enamel can be separated as a thin, homogeneous mem- 
 brane, Nasmyth's mernbrane. 
 
 Cement, or cru^ta petrosa, is a thin layer of true bone with 
 eanaliculi and lacunse, disposed on the surface of the fang. 
 
 The pulp cavity is a cavity within the base of the crown, 
 continuous with a canal in the centre of the fang, and open at 
 the apex of the fang for the entrance of vessels and nerves. It 
 is filled with dental pulp. 
 
 Dental pulp consists of two kinds of cells, the fusiform and 
 the columnar, or odontoblasts ai Waldeyer, held together by 
 loose connective tissue. It is soft, vascular, and highly sensitive. 
 The nerves are both medullated and non-medullated, and form a 
 rich plexus beneath the odontoblastic layer. The terminal fibrils 
 probably unite with these cells, but the exact distribution is 
 still unsettled. 
 
 Development — Temporary. — They are formed very early, 
 seven to eleven weeks, in the primitive dental groove by an in- 
 volution of the epithelium of the oral cavity covering the maxil- 
 lary arches into the blastema or corium and connective tissue 
 below, the former forming the enamel, the latter the cement 
 and dentine. 
 
 The enamel is formed by the enamel germ (a mass of epi- 
 thelial cells) descending into the dental groove until it meets the 
 papilla, a vascular growth extending upward from the connective 
 tissue, upon which it forms a cap. A vascular membrane in- 
 closing the enamel germ then extends itself — as the dentinal 
 sac — ^upon the united papilla and enamel germ and cuts the latter 
 off from its former epithelial structure. The cells become dif- 
 ferentiated and finally calcify. 
 
THE ALIMENTARY APPARATUS. 
 
 221 
 
 The dentine is formed by tlie development of odontoblasts 
 in the periphery of the papilla in a similar manner to the develop- 
 ment of osteoblasts in bone. 
 
 The cement is developed from the wall of the dental sac by 
 the intramembranous process of ossification. 
 
 Permanent. — The successional permanent teeth, or those re- 
 placing the temporary, are formed in a different manner from 
 the superadded, or three molars in each side of each jaw. 
 
 The former are developed similarly to the temporary teeth, 
 but in a secondary dental groove, from which after their forma- 
 tion they recede behind the germs of the temporary teeth, in- 
 closed in sacs. The molars, or superadded teeth, however, are 
 formed by extensions backward of a portion of the enamel germ 
 of the tooth immediately in front. 
 
 e-8 
 
 C. la. 
 
 C.In. 
 
 L.In. 
 
 C. 
 
 M. 
 
 M. 
 
 6-8 
 
 7-9 
 
 17-18 
 
 14-16 
 
 18-24 
 
 Fig. 113,— Temporary Teeth. 
 
 Eruption, or "cutting of the teeth," takes place by the 
 growth of the fang, the gums being absorbed by the pressure 
 of the advancing crown. The development of the fangs of the 
 permanent causes the absorption of the fangs of the temporary 
 teeth through the agency of the odontoclasts, multinucleated cells 
 corresponding to the osteoclasts of bone. 
 
 The eruption of the temporary teeth takes place in months 
 in the order shown in Fig. 51, the lower preceding by a short 
 time the upper (according to Dr. C. N. Pierce, in "American 
 System of Dentistry") . The order of the eruptions is : first the 
 lower central incisors, the upper central incisors, lateral incisors, 
 upper and lower, first molars, followed by the canines or cuspids, 
 and ending with the second molars. 
 
222 
 
 HUMAN ANATOMY. 
 
 The eruption of permanent teeth takes place in years as in 
 Pig. 63, the order of the eruptions being, first the "first or 
 sixth year molar," followed by the first central incisors, four 
 lateral incisors, four first bicuspids, four second bicuspids, the 
 first canines or cuspids, the four second molars, and ending -with 
 the four third molars or "wisdom teeth." 
 
 About the sixth year the jaws contain the temporary teeth 
 fully erupted, and the crowns of all the permanent teeth except- 
 ing the four wisdom teeth, in all forty-eight. 
 
 It should be noted that the first permanent or "sixth -year" 
 molar is erupted before any of the permanent teeth, and that the 
 second bicuspid takes the place of the second temporary molar. 
 
 7-8 8-9 12-14 10-11 1W2 6-7 12-16 
 
 C. III. L. In. Co,. Bi. Bi. M. 31. 
 
 16-20 
 Wi. 
 
 C. In. 
 
 L. In. 
 
 Ca. 
 
 Bi. 
 
 Bi. 
 
 M. 
 
 M. 
 
 Wi. 
 
 7-8 
 
 8-9 
 
 12-14 
 
 lO-U 
 
 11-12 
 
 6-7 
 
 12-16 
 
 16-20 
 
 Fig. 114.— Permanent Teeth. 
 
 Vessels and Nerves of the Teeth. — The arteries of the upper 
 teeth are derived from the anterior dental branches of infra- 
 orbital and posterior or alveolar dental branches of the internal 
 maxillary; of the lower teeth, from the inferior dental branch 
 of the internal maxillary. 
 
 The nerves are distributed to the upper teeth from the an- 
 terior and posterior dental branches of the superior maxillary 
 (second division of fifth cranial nerve), and to the lower teeth 
 from the inferior maxillary (third division of fifth cranial 
 nerve) . 
 
 Soft palate is a movable fold of mucous membrane sus- 
 pended from the posterior border of the hard palate, and inclos- 
 ing an aponeurosis, vessels, nerves, glands, and the following 
 
THE ALIMENTAHY APPARATUS. 223 
 
 muscles on each side : tensor palati, levator palati, palatoglossus, 
 palato-pharyngeus, and azygos uvulse, the latter uniting with its 
 fellow to form the uvula. 
 
 Hard palate is formed by the palatal process of the superior 
 maxillary and the palate-bone, and covered by a thick, dense 
 structure composed of mucous membrane and periosteum com- 
 bined. It forms the roof of the mouth, and presents a median 
 raphe and corrugated surface. 
 
 Anterior pillars of the fauces are folds of mucous mem- 
 brane arching downward and forward from the base of the 
 uvula to the base of the tongue, and inclosing the palatoglossus 
 muscles. 
 
 Posterior pillars of the fauces are similar folds arching 
 downward and backward from the base of the uvula to the sides 
 of the pharynx, and inclosing the palato-pharyngeus muscles. 
 
 The tonsils, or amygdalse, are small, almond-shaped, glandu- 
 lar bodies situated on each side of the fauces between the an- 
 terior and posterior pillars. They rest upon the superior con- 
 strictor of the pharynx, which separates them from the ascending 
 pharyngeal and internal carotid arteries. They are composed of 
 numerous follicles (lined by closed capsules containing adenoid 
 tissue), which contain a thick, grayish secretion and open on 
 the surface of the gland by a dozen or more orifices. 
 
 The arteries to the tonsil are from the tonsillar and ascend- 
 ing palatine of the facial, dorsalis linguse from the lingual, 
 ascending pharyngeal from external carotid, branch from small 
 meningeal, and descending palatine branch of internal maxillary. 
 
 The nerves are from glossopharyngeal and Meckel's gan- 
 glion. 
 
 The Salivary Giands. — The salivary glands communicat- 
 ing with the mouth are three: the parotid, submaxillary, and 
 sublingual. 
 
 The parotid gland, so called from its location near the ear, 
 is the largest, weighing from a half to one ounce. It occupies 
 the space in front of the ear, bounded below by the angle of the 
 jaw, and a line extended from it to the mastoid process, above 
 by the zygoma, in front by the masseter muscle, and behind by the 
 mastoid process, the external meatus, and the digastric muscle. 
 The external carotid artery, the temporo-maxillary vein, the 
 facial nerve, and the great auricular nerve pass through it. 
 
 The duct of the parotid gland, Steno's or Stenson's duct, 
 empties its secretion into the mouth. It is about two and a 
 half inches in length, of the diameter of a crow's quill, and 
 crosses the face upon the masseter muscle, through the substance 
 of the buccinator muscle, in the direction of an imaginary line 
 
224 HUMAN ANATOMY. 
 
 drawn about a finger's breadth below the zygoma, from the lower 
 part of the ear to midway between the ala of the nose and the 
 margin of the upper lip, to open about the position of the second 
 molar tooth of the upper jaw. 
 
 Its arteries are branches of the external carotid. The veins 
 empty into the external jugular. The lymphatics empty into 
 the superficial and deep cervical glands, and the nerves are 
 derived from the facial, from the superficial temporal branches 
 of the great auricular, the auriculo-temporal, and sympathetic. 
 
 The submaxillary gland occupies the submaxillary fossa on 
 the inferior surface of the inferior maxilla, within the sub- 
 maxillary triangle of the neck. The facial artery grooves its 
 upper and posterior border, and it is separated behind from 
 the parotid gland by the stylo-maxillary ligament. The duct 
 of the submaxillary gland, or Wharton's duct, about two inches 
 in length, passes forward between the hyoglossus, geniohyoglos- 
 sus, and mylohyoid muscles, to open at the side of the frsnum 
 linguse. 
 
 Its arteries axe from the facial and lingual ; the veins follow 
 the course of the corresponding arteries; the nerves are from 
 the submaxillary ganglion, the sympathetic, and the mylohyoid 
 branch of the inferior dental. 
 
 The sublingual gland, the smallest, lies on the floor of the 
 mouth, at the side of the frsenum linguEe, beneath the mucous 
 membrane. Its ducts, called the ducts of Eivini, from eight to 
 twenty, open on the mucous membrane. One of them, the 
 longest, called the duct of Bartholin, joins Wharton's duct. Its 
 arteries are from the submental and sublingual. The nerves 
 are branches from the gustatory. 
 
 Besides these glands, the mucous membrane of the mouth is 
 plentifully supplied with mucous glands. 
 
 The pharyns is a masculo-membranous sac, extending 
 from the basilar process of the occipital bone above to the level 
 of the fifth cervical vertebra or the cricoid cartilage below. It 
 is about four and a half inches in length. It has communicating 
 with it seven openings : — - 
 
 Two posterior nares, Larynx, 
 
 Two Eustachian tubes, CEsophagua, 
 
 Mouth. 
 
 It is composed of three coats: — 
 
 1. Fibrous coat, or pharyngeal aponeurosis, attached above 
 to the pharyngeal spine of the basilar process of the occipital 
 bone ; it affords attachment in the median line to the constrictor 
 muscles of the pharynx. 
 
THE ALIMENTARY APPARATUS. 
 
 225 
 
 2. Mucous coat, continuous with that of the various open- 
 ings. It is covered in its upper part with columnar ciliated 
 epithelium, as low as the floor of the nares, below which it is 
 squamous. It contains numerous racemose glands, crypts, and 
 lymphoid structure similar to the tonsils, a mass of which, be- 
 tween the Eustachian tubes, has been called the "pharyngeal 
 tonsil." 
 
 FI&. 115. 
 
 Pharynx laid open from behind: 1, styloid process; 2, body of oc- 
 cipital; 3, sxptum nasi; 4, middle turbinated bone; B, posterior naria; 
 6, inferior turbinated bone; 7, soft palate; 9, uvula; 10, tonsil; 11, 
 back of tongue; 12, epiglottis; 13, arytasno-epiglottidean fold; 14, tip 
 of arytsenoid cartilage; IS, oesophagus; 16, back of cricoid cartilage. 
 
 3. Muscular coat, consists of the three pharyngeal con- 
 strictors, the palato-pharyngeus, and the stylo-pharyngeus. 
 {Vide Muscles.) 
 
 Arteries are from the inferior palatine, pharjmgeal, and 
 thyroid arteries. Nerves are branches of the pneumogastric, 
 glosso-pharyngeal, and sympathetic. 
 
 The cesophagus, or gullet, is a musculo-membranous tube 
 about nine inches long and less than one inch in diameter, flat- 
 tened from before backward, and extending from the pharynx to 
 the stomach or from the level of the fifth cervical to the ninth 
 dorsal vertebra. 
 
226 
 
 HUMAN ANATOMY. 
 
 Relations. — In the neek the trachea is in front, the common carotids 
 on either side, and in the chest the pericardium, the left carotid, left sub- 
 clavian, the aorta, and the left bronchus are in front; the longus colli 
 muscle and the intercostal vessels and the vertebral column are behind. 
 The pleura covers it laterally, the descending portion of the arch of the 
 aorta lying on the left and the vena azygos major on the right. 
 
 Its structure consists of three coats: — 
 Muscular coat, consisting of two layers, the longitudinal 
 and the circular, continuous with the inferior constrictor; 
 
 Fig. 116. 
 
 1, left hypochondriac region; 2, epigastric; 3, right hypochon- 
 driac; 4, left lumbar; B, umbilical; 6, right lumbar; 7, left iliac; 
 8, hypogastric; 9, right iliac. 
 
 Areolar or fibrous coat, connecting the two ; 
 
 Mucous coat, covered with stratified pavement epithelium, 
 and having beneath it some non-striated muscular fibres, the mus- 
 cularis mucosae. It also contains numerous compound racemose 
 glands, the oesophageal glands. 
 
 THE ABDOMEN. 
 
 The abdomen, the largest cavity in the body, is bounded 
 in front and laterally by the abdominal muscles, the lower ribs, 
 the ilii, and above by the diaphragm, below by the brim of the 
 

 Fig, 117. 
 The abdominal viscera. (Miklei/.) 
 
THE ALIMENTARY APPARATUS. 
 
 227 
 
 pelvis, and behind by the vertebral column, quadratns lumbomm, 
 and psoas muscles. It is lined throughout by peritoneum, inclos- 
 ing the greater portion of the alimentary canal. It has six 
 openings, as follows: — 
 
 Aortic opening, for the vena azygos, aorta, and thoracic duct; 
 CEsophageal opening, for the oesophagus and pneumogastric nerves; 
 Quadrate opening, for the vena cava inferior; 
 Umbilicus, in front, for the foetal umbilical vessels; 
 Femoral canal {vide femoral hernia) ; 
 
 Inguinal canal, for the round ligament in the female, and the sper- 
 matic cord in the male. 
 
 Eegions op the Abdomen. — Por convenience of study, the 
 cavity of the abdomen is divided into nine regions by four imag- 
 inary lines, two circular lines drawn around the body, one at the 
 lower margin of the thorax (Leidy) or on a level with the car- 
 tilages of the ninth ribs, the second at the highest point of the 
 crest of the ilium; and two vertical lines, drawn from the car- 
 tilage of the eighth rib on each side through the centre of Pou- 
 part's ligament, or from the anterior inferior spinous process 
 of the ilium, drawn upward (Leidy). These regions are named 
 as follows: — 
 
 Right hypochondriac, 
 
 Right lumbar, 
 
 Right inguinal (iliac). 
 
 Epigastric region, 
 Umbilical region. 
 Hypogastric region. 
 
 Left hypochondriac. 
 
 Left lumbar. 
 
 Left inguinal (iliac). 
 
 Right Hi/pocliondriao. 
 Hepatic flexure of 
 colon, right lobe of 
 liver, gall-bladder, and 
 upper part of right 
 kidney. 
 
 Right Lumbar. 
 Greater part of right 
 kidney, ascending co- 
 lon, and portions of 
 the small intestine. 
 
 Contents of Regions. 
 
 Epigastric. 
 Left lobe of liver, 
 lobulus Spigelii, 
 greater part of stom- 
 ach, duodenum, and 
 pancreas, portions of 
 the kidneys and su- 
 prarenal capsules, 
 vena cava, aorta, tho- 
 racic duct, semilunar 
 ganglia. 
 
 VnibiUcal. 
 Transverse portions 
 of colon and duode- 
 num, jejunum, and 
 ileum, part of mesen- 
 tery and great omen- 
 t u m , reeeptaculum 
 chyli, and portions of 
 both kidneys. 
 
 Left HypocJiondi-iac. 
 
 Splenic flexure of 
 colon, spleen, tail of 
 pancreas, splenic end 
 of stomach, and upper 
 part of left kidney. 
 
 Left Lumbar. 
 Part of left kidney, 
 descending colon, 
 some convolutions of 
 small intestine, and 
 part of the omentum. 
 
228 HUMAN ANATOMY. 
 
 BiffJit Inguinal (Iliac). Hypogastric. Left Inguinal (Iliac). 
 
 Eight ureter, CEecum, Portions of the small Left ureter, sigmoid 
 
 spermatic vessels, and intestine under certain flexure of colon, and 
 appendix cseci. circumstances, the spermatic vessels. 
 
 uterus (pregnant), 
 
 bladder (distended ) , 
 
 sometimes the caecum, 
 
 sigmoid flexure, and 
 
 appendix. 
 
 Peritoneum. — The peritoneum is a closed serous sac, its 
 parietal layer lining the cavity of the abdomen, its visceral layer 
 inclosing more or less completely all the abdominal and pelvic 
 viscera. It is not in all cases a closed sac, for in the female it 
 is continuous with the mucous membrane of the Fallopian tubes. 
 It consists essentially of tvfo sacs of unequal size, the greater and 
 lesser peritoneal sacs, united by a central constriction — ^the fora- 
 men of Winslow: — 
 
 The greater sac is located in front of the viscera, one layer 
 lining the internal abdominal wall, the other reflected upon the 
 viscera. Its cavity is known as the greater peritoneal cavity. 
 
 The lesser sac covers the upper part of the posterior abdom- 
 inal wall, and is reflected upon the posterior surface of the liver 
 and stomach. Its cavity is called the lesser peritoneal cavity. 
 It also gives off three processes, one of which is a broad, loose 
 fold, — the great omentum, — passes downward from the greater 
 curvature of the stomach between the two layers of the greater 
 sac, and is reflected upon itself back to the under surface of the 
 transverse colon. 
 
 The foramen of Winslow is a narrow canal, large enough 
 to admit one finger, between the greater and lesser peritoneal 
 cavities, located behind the right border of the lesser omentum, 
 and formed by the hepatic and gastric arteries, constricting the 
 sac at this point as they ascend from the cceliac axis. It is 
 bounded as follows: — 
 
 In front, by the lesser omentum, containing the hepatic artery, 
 portal vein, duodenum, and the ductus communis choledochus; 
 
 Behind, by the right crus of the diaphragm and the inferior vena 
 cava; 
 
 Above, by the lobus Spigelii; 
 
 Below, by the hepatic artery. 
 
 Reflections. — The reflections of the peritoneum viewed in 
 an antero-posterior section (the greater and lesser sacs together) 
 may be traced as follows : From the diaphragm it is reflected to 
 the upper surface of the liver. Enveloping this organ, it then 
 presents a doubling or fold — the gastro-hepatic omentum — ex- 
 tending downward from the transverse hepatic fissure to the 
 
THE ALIMENTARY APPARATUS. 
 
 229 
 
 lesser curvature of the stomach. Inclosing the stomach, it is 
 reflected upon itself in front of the intestines as a broad apron — 
 the great omentum — ^making a quadruple fold of peritoneum. 
 The two layers then embrace the transverse colon, unite, 
 and pass back to the vertebral column, forming the transverse 
 mesocolon. From here the layers separate, the upper one ascend- 
 
 FiG. 118. 
 
 D, diaphragm; L, llyer; S, stomach; P, pancreas; D, duodenum; 
 C, colon; I, small Intestine; B, bladder; R, rectum; 3, posterior 
 surface of liver; 4, foramen of Winslow; 5, great omentum; 6, 
 lesser omentum; 7, mesocolon; 8-9, lesser cavity of peritoneum; 10, 
 mesentery; 11, recto-vesical told. 
 
 ing in front of the pancreas to the starting point. The lower 
 layer descends in front of the duodenum aorta, incloses the small 
 intestine (forming the mesentery proper), is reflected upon the 
 rectum (forming the mesorectum) and the bladder, and ascends 
 upon the anterior abdominal wall to the starting point. 
 
 In the female, from the rectum it envelops the uterus and 
 upper part of the vagina before reaching the bladder. 
 
230 HUMAN ANATOMY. 
 
 In addition to the folds seen in the antero-posterior section, 
 the peritoneum passes between the various organs, and also lat- 
 erally to the sides of the abdominal and pelvic cavities. In this 
 manner are formed the right, left, and suspensory ligaments of 
 the liver, the suspensory ligament of the spleen, the broad liga- 
 ment of the uterus, and the three great ligaments or omenta of 
 the stomach — the gastro-hepatic, gastro-splenic, and gastro-colic 
 (already described) and the mesenteries. 
 
 The latter, the mesenteries, include the mesentery proper, 
 mesocaecum; ascending, transverse, and descending mesocolon; 
 sigmoid mesocolon, and mesorectum. 
 
 The mesentery proper is a broad fold, reflected from the 
 vertebra around the jejunum and ileum. Its base, attached ob- 
 liquely from the left side of the second lumbar vertebra to the 
 right iliac region, measures about six inches, while its expanded 
 extremity is quite considerable. 
 
 In the male the recto-vesical folds, one on each side, pass 
 from the rectum to the bladder, including between them the 
 recto-vesical pouch. In the female, however, this pouch is 
 divided into two— the recto-uterine and vesico-uterine pouches, 
 the recto-vesical folds being called recto-uterine and vesico- 
 uterine folds. Folds of peritoneum (superior false ligaments 
 of the bladder) ascend from the bladder to the umbilicus, in- 
 closing the remains of the f cetal urachus and hypogastric arteries, 
 and also a fold on each side follows the course of the epigastric 
 arteries toward the umbilicus, dividing the inguinal region into 
 the internal, middle, and external inguinal fossae. The peri- 
 toneum at the external inguinal fossa (corresponding to the 
 internal abdominal ring) is continuous in the male foetus with 
 the tunica vaginalis testis, and in the female forms a blind 
 sac about the round ligament — the canal of Nuch. 
 
 Viscera Partly Invested hy Peritoneum. 
 
 Vagina — upper part; 
 
 Bladder — posterior wall; 
 
 Duodenum — descending and transverse portions; 
 
 CtECum ; 
 
 Colon — ascending and descending; 
 
 Rectum — middle portion. 
 
 Viscera Entirely or Almost Entirely Covered. 
 
 Stomach, Sigmoid flexure, 
 
 Spleen, Rectum — upper part. 
 
 Ileum, Liver, 
 
 Jejunum, Uterus, 
 
 Colon — transverse, Ovaries. 
 
THE ALIMENTAKY APPARATUS. 231 
 
 Viscera Without Peritoneal Investment, 
 
 Bladder — except posterior wall; 
 
 Rectum — lower third; 
 
 Vagina — lower part of posterior wall; 
 
 Pancreas ; T 
 
 Suprarenal capsules ; > partly covered anteriorly. 
 
 Kidneys. J 
 
 THE STOMACH. 
 
 The stomach is a musculo-membranous sac, pyriform in 
 shape, situated below the diaphragm in an oblique position across 
 the upper abdomen, where it is held in position by the lesser 
 omentum and the gastro-splenic ligament. It measures about 
 nine to twelve inches long, four to five inches in its greatest 
 diameter, and has a capacity of from one to two quarts. It 
 occupies the epigastric, right and left hypochondriac regions, and 
 is ia relation above with the diaphragm and liver, below with 
 the transverse colon, in front with the abdominal walls, and 
 behind with the pancreas. When distended the stomach rotates 
 on its long axis and the greater curvature points somewhat for- 
 ward. It presents for examination a greater and lesser extrem- 
 ity, greater and lesser curvatures, anterior and posterior surfaces, 
 and cardiac and pyloric orifices. 
 
 The greater extremity, or fundus, occupies the left hypo- 
 chondriac region, in contact with the spleen, with which it is 
 attached by the gastro-splenic omentum, and behind the lower rib. 
 
 The lesser or pyloric end is smaller and lies in contact 
 with the under surface of the liver and the wall of the abdomen 
 ia the right hypogastric region. 
 
 The greater curvature extends between the pyloric and 
 oesophageal orifices, along the lower border of the stomach, and 
 to it is attached the great omentum. 
 
 The lesser curvature extends between the same two points 
 along the superior border of the organ. 
 
 The (esophageal or cardiac orifice occupies the highest part 
 of the stomach, behind the left seventh costal cartilage, and 
 receives the oesophagus. 
 
 The pyloric orifice occupies the right extremity, and opens 
 into the duodenum, being protected by a muscular valve, the 
 pylorus, or pyloric valve. 
 
 The anterior surface is in contact with the under surface 
 of the left lobe of the liver, the abdominal walls, and the dia- 
 phragm. 
 
 The posterior surface is in contact with the peritoneum of 
 the diaphragm, solar plexus, the pancreas, and the abdominal 
 vessels. 
 
232 HUMAN ANATOMY. 
 
 The structure of the stomach consists of four coats, a serous, 
 muscular, fibrous or areolar, and mucous. 
 
 The serous coat is derived from the peritoneum, which com- 
 pletely covers it, except along the lesser and greater curvature, 
 where the vessels and nerves enter. 
 
 The muscular coat consists of three sets of fibres : — 
 
 The longitudinal, the most superficial, are continuous below 
 with the longitudinal fibres of the small iatestine below, and the 
 oesophagus above; 
 
 The circular fibres, the second layer, are most abundant at 
 the pyloric extremity, where they form the pyloric valve; 
 
 The oblique fibres are distributed over -both surfaces, pass- 
 ing obliquely from right to left and left to right. 
 
 The areolar or submucous coat connects the muscular with 
 the mucous layer, and is sometimes named the vascular coat. 
 
 The mucous membrane is of a pale pinkish-ash color, thick- 
 ened toward the pylorus, where it presents numerous rugse, or 
 pleats, and at the pyloric end it helps to form the pyloric valve. 
 It is lined throughout with columnar epithelium, and is studded 
 with three kinds of minute tubes, the gastric follicles, and len- 
 ticular glands. The gastric follicles consist of two kinds, the 
 pyloric and the peptic glands, the former most abundant at the 
 pyloric end and the latter distributed all over the surface of the 
 stomach. 
 
 The pyloric or mucous glands consist each of from two to 
 four blind tubes opening into a common duct, and lined through- 
 out by columnar epithelium. 
 
 The peptic glands are similar in structure, but have a much 
 shorter duct, and contain in addition peculiar large, spheroidal, 
 granular peptic cells. 
 
 The lenticular or simple solitary glands are small masses 
 of lymphoid tissue scattered throughout the connective-tissue 
 framework of the stomach between the gastric follicles. 
 
 The arteries are derived from the gastric, pyloric, and right 
 gastro-epiploic branches of the hepatic artery, and the left gastro- 
 epiploic and vasa brevia branches of the splenic artery {vide 
 Arterial System). 
 
 The veins terminate in the portal, superior mesenteric, and 
 splenic veins. 
 
 The nerves are derived from the gastric plexuses (Auer- 
 bach's and Meissner's, in the muscular and submucous coats, 
 respectively), formed by the terminal branches of the right and 
 left pneumogastric, and the branches of the coeliac plexus, an 
 ofEshoot of the solar plexus of the sympathetic. 
 
THE ALIMENTARY APPARATUS. 233 
 
 THE SMALL INTESTINE. 
 
 The small intestine is a convoluted tube about twenty to 
 twenty-five feet in length, for the chylification of the food, occu- 
 pying the lower and central portions of the abdominal and pelvic 
 cavities, and held in position to the spinal column by the mesen- 
 tery. It is divided into three portions — ^the duodenum, jejunum, 
 and ileum. 
 
 The duodenum, so called from being about twelve fingers' 
 breadth in length, is about eight to tett inches in length. It 
 consists of four portions, from the position of its course — ascend- 
 ing, descending, transverse, and terminal ascending: — 
 
 The -first or ascending portion is about two inches in length, 
 and ascends to the neck of the gall-bladder. It is completely 
 invested by peritoneum for about an inch. 
 
 The second or descending portion, about three inches in 
 length, descends in front of the right kidney as far as the third 
 or fourth lumbar vertebra, and is overlapped in front by the 
 head of the pancreas, and into its posterior aspect the duct of 
 the pancreas and the common biliary duct open by a common 
 orifice. 
 
 The third or transverse portion is attached to the crura of 
 the diaphragm and the vessels in front of the vertebral column, 
 passes behind the transverse mesocolon, and has the pancreas 
 above it, and the superior mesenteric blood-vessels cross from 
 beneath the latter between the two or over the duodenum. 
 
 The fourth or terminal ascending portion runs upward and 
 forward to the duodeno-jejunal flexure. 
 
 The arteries are derived from the inferior pancreatico- 
 duodenal branch of the superior mesenteric and the superior 
 pancreatico-duodenal branch of the gastro-duodenal, a branch 
 of the hepatic. The veins terminate in the superior mesenteric 
 and splenic veins. The nerves are from the solar plexus. 
 
 The jejunum, named from jejunus, empty, includes the 
 upper two-fifths of the small intestine, is continuous above with 
 the duodenum and below with the ileum. It occupies chiefly 
 the left iliac and umbilical region. 
 
 The ileum, so called from its twisted condition, includes 
 the remaining three-fifths, is continuous above with the jejunum 
 and below with the caput caecum of the large intestine. It occu- 
 pies the right iliac, hypogastric, and umbilical regions. 
 
 The structure of the small intestine consists of four coats — 
 the serous, muscular, fibrous or areolar, and mucous : — 
 
 The serous coat is the peritoneal covering; 
 
 The muscular coat consists of two sets — a, longitudinal and 
 a circular; 
 
234 HUMAN ANATOMY. 
 
 The areolar or submucous coat connects the muscular with 
 the mucous coat; 
 
 The mucous coat is thinner and redder than that of the 
 stomach, ana is thrown into numerous transverse folds — the 
 valvulse conniventes— most numerous in the upper part; they 
 diminish as it descends and finally disappear in the ileum. They 
 increase the secreting and absorbing surface of the mucous mem- 
 brane and retard the passage of the food. 
 
 The mucous memlrane also contains the villi and four kinds 
 of glands: — 
 
 Simple follicles, or crypts of Lieberkiihn; 
 Duodenal glands, or Brunner's glands; 
 Solitary glands; 
 Agminate, or Peyer's glands. 
 
 The villi are minute vascular projections of the mucous 
 membrane scattered throughout the surface of the small intes- 
 tine. Their structure consists of a pouchlike termination of a 
 lacteal in the centre surrounded by a minute plexus of capillary 
 vessels inclosed in a basement membrane and covered with co- 
 lumnar epithelium. 
 
 The simple follicles^ or crypts of LieberTciihn, are scattered 
 throughout the mucous membrane of the entire small intestine. 
 They consist of, minute tubes of basement membrane, lined with 
 columnar epithelium and surrounded by a capillary net-work. 
 
 The duodenal or Brunner's glands are distributed to the 
 duodenum and jejunum only. They are largest and most numer- 
 ous in the vicinity of the pylorus. They are composed of tubular 
 alveoli, lined by epithelium, and having a small duct opening 
 on the mucous membrane. 
 
 The solitary glands are distributed throughout the small 
 intestine, being most numerous in the last portion of the ileum. 
 They consist of lymph follicles, and communicate with the lac- 
 teal system by means of lymph spaces. 
 
 Peyer's glands, or Peyer's patches, consist of an aggrega- 
 tion of the solitary glands into oval groups of twenty or thirty 
 along the small intestine at a point opposite the attachment 
 of the mesentery. The patches are about fifteen to thirty in 
 number, each measuring about one-half to two inches in length 
 and one-half inch in breadth. Their axes are parallel with the 
 length of the intestine. In the duodenum they are few and 
 small in size, and the mucous membrane of the valvulas conni- 
 ventes over them is reduced in size and much distorted. 
 
 The arteries are derived from the pyloric, pancreatico- 
 duodenal, and superior mesenteric. They reach the intestines 
 
THE AllMENTAKY APPAEATUS. 235 
 
 inclosed in and along the course of the mesenteries. In the in- 
 tervals of the coats they form three vascular nets, which supply 
 the serous, muscular, and mucous coats. The veins accompany 
 the arteries and join the portal vein. 
 
 The lymphatics follow the course of the superior mesenteric 
 vessels to enter the mesenteric glands. 
 
 The nerves are derived from the solar plexus of the sympa- 
 thetic, 
 
 THE LARGE INTESTINE. 
 
 The large intestine is about five feet long and extends from 
 the ileum to the anus. 
 
 It commences in the right iliac fossa, ascends through the 
 right lumbar and right hypochondriac regions, passes trans- 
 versely between the epigastric and umbilical regions to the left 
 hypochondriac region, where it descends through the left hypo- 
 chondriac, lumbar, and iliac regions, and through the pelvis on 
 its posterior wall to terminate at the anus. 
 
 It consists of three divisions: — 
 
 1. Csecum, 
 
 2. Colon, 
 
 3. Kectum. 
 
 ' Ascending, 
 Transverse, 
 Descending, 
 Sigmoid flexure. 
 
 The C^cum is a blind pouch measuring about two and one- 
 half inches in every diameter, lying free in the right iliac region. 
 
 It has opening into its lower back part the appendix vermi- 
 formis, and into its inner back part the ileum, guarded by the 
 ileo-csecal valve. 
 
 The appendix vermiformis is a long, narrow, twisted tube, 
 the rudiment of the prolonged csecum in all marmnalia. It ter- 
 minates in a blunt extremity. Its mueoiis membrane is contin- 
 uous with that of the csecum, and contains many solitary glands. 
 
 The ileo-cwcal valve, or valve of Bauhin, protects the opening 
 of the ileum into the csecum, and consists of two valve-like semi- 
 lunar folds of mucous membrane, strengthened by bands of cir- 
 cular fibres. The upper one is attached to the junction of the 
 ileum with the colon, the lower one to the junction of the ileum 
 with the csecum. On each side where the folds coalesce, a 
 ridge of mucous membrane continuous for a short distance 
 around the canal, forms the frcena or reiinaciild of the valve. 
 The mucous membrane on either side of the valves corresponds 
 
236 HUMAN ANATOMY. 
 
 to that of the large and small intestines respectively, being cov- 
 ered with villi on the side toward the ileum, and being destitute 
 of villi, and containing numerous tubular glands or crypts of 
 Lieberkiihn, on the side toward the cascum. This difference oc- 
 curs abruptly at the free margin of the valves. 
 
 The colox consists of four portions — ascending, transverse, 
 and descending colon, and sigmoid flexure: — 
 
 The ascendincj portion begins opposite the ileo-cseeal valve, 
 ascends through the right lumbar and hypochondriac regions, and 
 terminates beneath the under surface of the liver at the hepatic 
 flexure in the transverse portion. Its posterior surface is desti- 
 tute of peritoneum, and is attached to the quadratus lumborum 
 muscle by loose areolar tissue. 
 
 The transverse portion, or transverse arch of the colon, 
 passes from the hepatic flexure, through the adjoining portions 
 of the epigastric and umbilical regions, to terminate at the 
 splenic flexure in the descending portion. It is attached by 
 transverse mesocolon, and is most movable portion of the colon. 
 
 The descending portion begins at the splenic flexure, de- 
 scends through the left lumbar and iliac regions to terminate 
 in the sigmoid flexure. Like the ascending colon, its posterior 
 surface is destitute of peritoneum. 
 
 The sigmoid flexure (omega loop) is a narrow, twisted por- 
 tion of the colon, occupying the left iliac fossa, between the 
 descending portion of the colon and the rectum. It is held in 
 position by the sigmoid mesocolon. It terminates opposite the 
 third sacral vertebra. 
 
 The rectum — the terminal portion — extends from the sig- 
 moid flexure to the anus. It is four to six inches in length, not 
 sacculated, but club-shaped, with its large extremity downward, 
 and consists of two portions — superior and inferior: — 
 
 The lower four inches, formerly described as the upper por- 
 tion of the rectum, rest upon the sacral plexus of nerves and 
 the pyriformis muscle ; 
 
 The superior portion, about three and three-quarters inches, 
 is in relation in the male with the bladder, ]irostate gland, and 
 vesiculse seminalis; in the female with the uterus and vagina, 
 being adherent to the latter ; 
 
 The inferior portion, about one and one-quarter inches, turns 
 backward and terminates in the anus. It is supported by the 
 levator ani muscle, and is surrounded by the internal and external 
 sphincters of the anus. The slruciure of the larije intestine con- 
 sists of four coats — serous, muscular, cellular, and mucous: — 
 
 The serou.t coat, derived from the peritoneum, invests lom- 
 pk'toly the transverse portion and sigmoid portion of the colon. 
 
THE ALIMENTARY APPARATUS. 237 
 
 but only partially the others, being absent in the posterior sur- 
 faces of the ascending and descending portions, and on the 
 superior portion of the rectum. The inferior portion of the 
 rectum is without peritoneal covering. The appendices epiploicw 
 are folds of serous membrane filled with fat and attached chiefly 
 to the transverse colon, depending from it. 
 
 The muscular coat consists of longitudinal fibres arranged 
 into three flat bands, shorter by nearly one-half than the intes- 
 tine itself, and the circular, distributed more evenly, but accumu- 
 lated at points, producing with the former a sacculated condition. 
 
 The cellular coat connects the mucous with the muscular 
 coat beneath. 
 
 The mucous coat is smooth, destitute of villi and valvule 
 conniventes, and thrown into numerous folds, two to four of 
 which, situated in the rectum, have received the name of Hous- 
 ton's valves. 
 
 It contains crypts of Lieberkiihn, more numerous here than 
 in the small intestine, and solitary glands scattered throughout, 
 but most numerous in the appendix and csecum, where some of 
 them are accumulated into Peyer's patches. 
 
 The arteries of the csecum and colon are from the mesen- 
 teric. The lymphatics empty into the mesenteric glands, and 
 the nerves are derived from the mesenteric plexus of the sym- 
 pathetic system. 
 
 The arteries of the rectum are the hsemorrhoidal branches 
 of the inferior mesenteric, internal iliac, and internal pudie. 
 The veins form the hsemorrhoidal plexus, and empty into the 
 inferior mesenteric and internal iliac veins. 
 
 The lymphatics go to the sacral and lumbar glands, and the 
 nerves are from the hypogastric plexus of synipathetie and con- 
 tiguous spinal nerves. 
 
 THE PANCREAS. 
 
 The pancreas is an oblong compound racemose gland, about 
 six to eight inches in length, one and one-half inches in breadth, 
 and one-half to one inch in thickness, situated across the back 
 part of the epigastric and left hypochondriac regions. Its weight 
 varies from two to six ounces. 
 
 It consists of a head, body, and tail: — 
 
 The head, or right extremity, is received into the concavity 
 of the duodenum. The lesser pancreas, a detached portion of 
 the gland, lies behind it. 
 
 The tail, or lesser end, terminates above the left kidney and 
 suprarenal capsule, in contact with the spleen. 
 
238 HUMAN ANATOMY. 
 
 The lody is in relation in front with the stomach and trans- 
 verse mesocolon ; behind it rests upon the first lumbar vertebra, 
 having interposed the crura of the diaphragm, vena cava, left 
 renal vein, aorta, superior mesenteric artery and vein, the in- 
 ferior mesenteric vein, and commencement of portal vein. 
 
 The splenic artery and vein are lodged in a groove on its 
 upper border. 
 
 The pancreatic duct, or canal of Wirsung, runs throughout 
 the substance of the organ, to emerge at the head, and open into 
 the duodenum by an orifice in common with the ductus com- 
 munis choledochus. The lesser pancreas, when it exists, empties 
 by the ductus pancreaticus minor. 
 
 The structure resembles that of the salivary glands, but is 
 softer and looser. 
 
 Arteries are from the splenic and pancreatico-duodenal 
 branches of the hepatic and superior mesenteric. 
 
 The veins join the splenic or superior mesenteric. 
 
 The nerves are from splenic plexus of the sympathetic. 
 
 The lymphatics empty into the lumbar glands. 
 
 THE LIVER. 
 
 The liver is the largest gland in the body, measuring in 
 its transverse diameter from ten to twelve inches, and its antero- 
 posterior six to seven, and its thickest part about three inches, 
 and weighing about from three to four pounds. It occupies 
 the upper part of the abdominal cavity, and the right hypo- 
 chondriac, epigastric, and a portion of the left hypochondriac 
 regions. Its upper surface is convex and rests against the dia- 
 phragm and a small portion of the abdominal parietes in front. 
 Its lower surface is in contact with the duodenum and stomach, 
 the right kidney and suprarenal capsules, and the hepatic flexure 
 of the colon. It is divided by the longitudinal fissure into the 
 right and left lobes. The liver has five fissures, five lobes, five 
 ligaments, five sets of vessels, and is inclosed in a fibrous coat, 
 continuous at the transverse fissure with the capsule of Glisson. 
 It is also invested by the peritoneum, except at the attachment 
 of the coronary ligament. 
 
 Structure. — The liver is made up of lobules, which are 
 small, granular bodies about one-fifteenth of an inch in diameter, 
 held together by delicate connective tissue and the branches of 
 the five sets of vessels (to be described) and nerves, the whole 
 being inclosed in a serous and fibrous coat. 
 
 Each lobule is made up of a mass of polyhedral, nucleated 
 cells, inclosed in a capillary plexus derived from the hepatic 
 
THE ALIMENTARY APPARATUS. 
 
 239 
 
 artery and portal vein, and giving origin to the hepatic vein and 
 biliary duct. 
 
 The five fissures of the liver are all situated on its under 
 surface. They separate the five lobes from one another. They 
 are : — 
 
 1. Longitudinal fissure extends from before backward, from 
 the notch in front to the posterior border. It is sometimes 
 called the umbilical fissure, and lodges the round ligament, the 
 remains of the foetal umbilical vein. 
 
 2. Fissure for the ductus venosus is the posterior portion of 
 the longitudinal fissure, and lodges the remains of the ductus 
 venosus of foetal life. 
 
 Fig. 119. 
 
 1, left lobe ; 2, right lobe ; 8, quadrate lobe ; 4, caudate lobe ; 6, Spigelian 
 lobe ; 6, hepatic artery ; 7, portal rein ; 8, fissure of ductus venosus ; 9, gall- 
 bladder : 10, cysti..- duct; 11, hepatic duct ; 12, fissure for ^ ena cava ; IH, vena 
 cava ; 1^ right inferior phrenic Ttin ; 15, hepatic vein ; 16, right renal vein ; 
 17, left rend vein, 
 
 3. Transverse fissure, or portal fissure, crosses the inferior 
 surface of the liver transversely and joins the longitudinal. It 
 transmits the portal vein, hepatic artery and nerves, and the 
 hepatic duct and lymphatics. 
 
 4. Fissure for the gall-bladder is a shallow depression be- 
 neath the right lobe, running parallel with the longitudinal 
 fissure in front. 
 
 5. Fissure for the vena cava runs obliquely upward along 
 the inferior surface near its posterior margin to the left side, 
 joining the fissure for the ductus venosus behind, and separated 
 from the transverse fissure in front by the lobulus caudatus. It 
 lodges the inferior cava, which, withia this fissure, receives the 
 hepatic veins. 
 
Missing Page 
 
Missing Page 
 
242 HUMAN ANATOMY. 
 
 and the cystic, about one inch in length. It empties into the 
 descending portion of the duodenum in common with the pan- 
 creatic duct, about three and one-half inches below the pylorus. 
 
 THE DUCTLESS GLANDS. 
 
 The following group includes the glands without ducts, of 
 unknown function, which resemble each other in structure: — 
 
 Spleen, Thymus, 
 
 Thyroid, Suprarenal capsules. 
 
 Pituitary body, Glandula coeeygea, 
 
 Grlandula intercarotica. 
 
 The Spleen. — The spleen is a soft, very vascular, sponge- 
 like organ, situated deeply in the left hypochondriac region. It 
 varies much in size and weight, measuring about five inches in 
 length, three in width, one and one-half ia thickness, and weigh- 
 ing between seven and ten ounces. 
 
 Outer surface, smooth and convex, corresponds to the ninth, 
 tenth, and eleventh ribs, and is adapted to the inferior surface 
 of the diaphragm, to which it is connected by the suspensory 
 ligament. 
 
 Inner surface is concave and adapted to the cardiac end 
 of the stomach, to which it is attached by the gastro-splenic 
 omentum. 
 
 Hilus is a vertical fissure on the concave inner surface, ad- 
 mitting the passage of blood-vessels, lymphatics, and nerves. 
 The structure consists of two coats — a serous and fibro-elastic 
 coat, inclosing in its interior the spleen pulp. 
 
 Serous coat, derived from the peritoneum, covers the entire 
 organ, except at the hilus, where it forms the gastro-splenic 
 omentum. 
 
 Fibro-elastic coat, or tunica propria, surrounds the organ, 
 and from the hilus and periphery sends numerous fibrous bands, 
 or trabeculce, into the substance of the organ, dividing it into 
 small trabecular spaces, or areolce. 
 
 Splenic substance, or spleen pulp, is a soft, reddish-brown 
 mass, consisting of a fine reticulum of connective-tissue cor- 
 puscles, inclosing red and white blood-corpuscles, nucleated and 
 non-nucleated cells, granular matter, etc. 
 
 Malpighian corpuscles, or bodies, are spheroidal hyper- 
 plasise of lymphoid tissue from the outer coat of the arterioles. 
 They are not encapsuled, vary from one-sixtieth to one-twenty- 
 fifth of an inch, and are visible ia the fresh specimens to the 
 naked eye. 
 
THE ALIMENTARY APPARATUS. 243 
 
 Splenic artery, remarkable for its size and toriniosity, divides 
 in the hilns into four or five branches, each distributed to a 
 segment, terminating in a capillary plexus without anastomoses, 
 or opening directly into the areolae of the splenic pulp. 
 
 Splenic vein commences in the same manner as the arterioles 
 end, and empties into the portal vein. The smaller veins anas- 
 tomose freely. 
 
 Nerves are from the splenic plexus, formed from the right 
 pneumogastric nerve, and the left semilunar ganglion of the 
 solar plexus. 
 
 Thteoid Gland. — The thyroid is a vascular, glandlike body, 
 situated on the sides of the upper part of the trachea, and con- 
 sists of two lateral lobes connected by a transverse portion, the 
 isthmus. 
 
 A third lobe — ^the pyramid — sometimes arises from the left 
 lobe or upper margin of the isthmus. 
 
 Levator glandules thyroidecB are muscular bands sometimes 
 found passing from the isthmus to the body of the hyoid bone. 
 
 Structure. — ^This is similar to other glands, being made up 
 of a capsule and radiating septa inclosing alveoli — ^the closed 
 vesicles — each of which is lined with one layer of columnar 
 epithelium, and contains more or less viscid, transparent fluid — 
 the colloid substance. The closed vesicles are abundantly sup- 
 plied with blood by meshes of capillaries, while penetrating the 
 septa are lymphatic net-works, and lymph sinuses are found in 
 the tissue between the vesicles and septa. 
 
 Arteries are the superior thjrroid, a branch of external 
 carotid, and inferior thyroid, a branch of the thyroid axis, and 
 sometimes a branch from the arch of the aorta or innominate 
 artery, the middle thyroid, or arteria thyroidea ima. All the 
 vessels anastomose freely. 
 
 Veins form plexus about the gland and give off the superior 
 and middle thyroid to internal jugular, and inferior thyroid to 
 innominate vein. 
 
 Nerves, from middle and inferior cervical ganglia and from 
 pneumogastric. 
 
 Thymus Gland. — The thymus gland is a temporary organ 
 of unknown function which attains iis full size at the end of two 
 years and at puberty has almost disappeared. It occupies the 
 upper part of the anterior mediastinum, and is in relation in 
 front with the sternum, and below with the pericardium, aorta, 
 left innominate, and trachea. It is a flat, triangular body, com- 
 posed of a pair of lateral unequal lobes, about two inches in 
 length, one and one-half inches at the widest part, and one- 
 quarter inch thick, and weighing about one-half ounce. 
 
244 HUMAN ANATOMY. 
 
 Structure. — It is composed of a framework of fibro-connec- 
 tive tissue, consisting of a capsule and septa, and the gland sub- 
 stance, which is divided into lobes, these into lobules, and these 
 into units or follicles. 
 
 The follicles vary in shape, present for study a cortex and 
 medulla, and consist of adenoid tissue. 
 
 The cortical meshes of the reticulated adenoid tissue are 
 filled with lymph-corpuscles, while in the medulla the meshes are 
 less numerous and filled with large endothelioid plates and giant 
 cells. 
 
 The capillary blood-vessels surround the follicles. 
 
 Arteries are from superior and inferior thyroid and internal 
 mammary. 
 
 Veins join thyroid and left innominate veins. 
 
 Nerves are from sympathetic and pneumogastric. 
 
 SupEAEENAL CAPSULES. — The Suprarenal capsules are two 
 small, triangular bodies, situated upon the upper and front part 
 of either kidney. They measure from one and one-quarter to 
 two inches in length, and less in breadth, two to three lines in 
 thickness, and weigh about two drachms. 
 
 Structure. — Like the kidneys, they consist of a cortical and 
 medullary portion, inclosed in a capsule which sends septa into 
 the substance of the body. 
 
 The cortex is composed of three zones of epithelial cells — 
 outer, middle, and inner — the middle being the largest. 
 
 The medulla consists of streaks of small, transparent cells, 
 separated by connective tissue and capillaries. These streaks 
 are continuous with the inner zone of the cortex. The nerve 
 supply is rich, consisting of non-medullated fibres connected 
 with small ganglia. 
 
 Relations. — The inferior concave border rests upon the upper sur- 
 face of the kidney. The inner border rests against the inferior vena 
 cava on the right side, the aorta on the left, and is in relation with semi- 
 lunar ganglion and great splanchnic nerves. 
 
 The anterior surfaces touch on the right the under surface of the 
 liver and on the left side the pancreas and spleen. The posterior surface 
 lies upon the crus of the diaphragm, about opposite the tenth dorsal 
 vertebra;. 
 
 Arteries are suprarenal from the aorta, the renal, and 
 phrenic arteries. 
 
 Veins on the right join -^'ena cava, on left renal vein. 
 
 Nerves, from renal and solar plexus. 
 
 PiTUlTAET BODY (hi/pophysis cprebii) is a small, vascular 
 mass on the inferior surface of the cerebniui, but resembling iu 
 structure the ductless glands. 
 
THE ALIMENTARY APPARATUS. 245 
 
 Structure. — The upper lobe is part of the central nervous 
 system. The lower and larger lobe has a fibrous capsule which 
 sends processes into the interior, forming minute septa; these 
 divide and reunite around spaces called alveoli. The alveoli con- 
 tain epithelial cells of various shapes, between which are small 
 irregular cells having flattened nuclei. 
 
 The glandula cocctgba, lyiag near the tip of the coccyx 
 and the intekcaeotica, at the angle of bifurcation of the com- 
 mon carotid, have been recently included among the ductless 
 glands. They were both discovered by Luschka. The frame- 
 work of their bodies is identical with that of other glands, except 
 that the septa contain non-striped muscular tissue. The alveoli 
 are filled with gland substance, consisting of connected masses 
 of epithelial cells, having in. their centre a twisted capillary 
 blood-vessel. 
 
VOCAL AND RESPIRATORY APPARATUS. 
 
 The larynx is a musculo-cartilaginous box at the top of the 
 trachea, below the root of the tongue and the hyoid bone, and is 
 the organ of the voice. It is composed of cartilages connected 
 by ligaments, provided with muscles, blood-vessels, and nerves, 
 and lined with mucous membrane. The cartilages are nine in 
 number, three single and three pairs: — 
 
 Thyroid, 
 
 Cricoid, 
 
 Epiglottis, 
 
 Two arytenoid. 
 
 Two comieula laryngis. 
 
 Two cuneiform. 
 
 The thyroid, the largest cartilage, consists of two quadri- 
 lateral halves, united in front in the median line, or entering 
 angle of the thyroid, the upper part of which is the pomum 
 Adami. The outer surface is marked by an oblique ridge for the 
 attachment of muscles. The inner surface is smooth and cov- 
 ered by mucous membrane, and has in front attached the true 
 and false vocal cords. The posterior angles are prolonged into 
 superior and inferior horns, the superior giviag attachment to 
 the thyro-hyoid ligament, the inferior articulating with the 
 sides of the cricoid cartilage. 
 
 The cricoid cartilage resembles a seal ring, narrow in front, 
 the back part of the upper border articulates with the arytenoid 
 cartilage, and on each side externally are two facets for the 
 articulation of the inferior horns of the thyroid. 
 
 The epiglottis is a spoon-shaped, fibro-cartilaginous plate, 
 large above, its narrow inferior extremity is prolonged and 
 attached by a band of fibro-elastic tissue of thyro-epiglottic liga- 
 ment to the thyroid cartilage. It is also attached to the posterior 
 surface of the hyoid bone by the hyo-epiglottic ligament. The 
 anterior or lingual surface has three reflections of mucous mem- 
 brane between it and the tongue, called the glosso-epiglottidean 
 ligaments. 
 
 The arytenoid cartilages each resembles the mouth of a 
 pitcher, from which they are named. They are smaller than 
 the other two, and are situated on the summit of the cricoid 
 cartilage posteriorly. They are three-sided, the apex extends 
 backward, and is surmounted by the supra-arytenoid, comieula 
 laryngis, or cartilages of Santorini. 
 
 (246^ 
 
VOCAL AND RESPIRATORY APPARATUS. 247 
 
 The posterior surface has attached to it the arytenoid mus- 
 cle. The anterior surface has attached to it the thyro-arytenoid 
 muscle and the false vocal cord. The internal surfaces are op- 
 posed to each other and supplied with mucous membrane. Of 
 the three angles at the base, the outer gives attachment to the 
 crico-arytenoid muscle, lateral and posterior. The anterior is 
 prolonged for attachment of the true vocal cord. 
 
 The cuneiform cartilages, or cartilages of Wrisberg, are two 
 small rod-shaped bodies extending upward from the arytenoid 
 cartilages into the aryteno-epiglottidean fold. 
 
 Fig. 121. 
 
 Vertical section of larynx; 1, body of hyold bone; 2, epiglottis; 
 S, thyro-hyoid membrane; 4, great cornu of hyoid; B, false vocal 
 cord; 6, thyro-hyoid ligament; 7, ventricle of larynx; 8, thyro-Iiyoid 
 membrane; 9, true vocal cord; 10, aryteno-epiglottidean fold; 11, 
 thyroid cartilage; 12, superior cornu of thyroid; 14, arytenoid 
 muscle; 16, arytenoid cartilage; 18, cricoid cartilage. 
 
 The cartilages of the larynx, with the exception of the 
 epiglottis, are composed of true cartilage. 
 
 The LIGAMENTS of the LARYNX are divided into two sets — 
 the extrinsic, those connecting the epiglottis and thyroid car- 
 tilage with the hyoid bone, and the intrinsic, those which connect 
 the various cartilages together. The extrinsic consist of three : — 
 
 1. Thyro-hyoid membrane, connecting the upper border of the thy- 
 roid cartilage with the inner surface of the hyoid bone; 
 
 2 and 3. The two lateral thyro-hyoid ligaments, fibro-elastie cords 
 connecting the superior horns of the thyroid cartilage with the extrem- 
 ities of the great horns of the hyoid bone. They contain a small nodule, 
 tke cartilago-triticea. 
 
248 HUMAN ANATOMY. 
 
 The intrinsic ligaments are sixteen in number, as follows : — 
 
 Hyo -epiglottic ligament; 
 
 Crico- thyroid membrane ; 
 
 Two crioo-thyroid capsular ligaments; 
 
 Two crico-arytenoid ligaments ; 
 
 Two crico-arytenoid capsular ligaments; 
 
 Two superior thyro-arytenoid ligaments (in false cords) ; 
 
 Two inferior thyro-arytenoid ligaments (in true cords) ; 
 
 Thyro-epiglottio ligament; 
 
 Three glosso-epiglottic folds. 
 
 The hyo-epiglottic ligament is a fibro-elastic band, connect- 
 ing the anterior surface of the epiglottis with the upper border 
 of the hyoid bone. The ligaments connecting the cricoid to the 
 thyroid cartilage are three also — ^the crieo-thyroid ligament, cap- 
 sular ligaments, and synovial membranes. 
 
 The crico-thyroid membrane, a yellow, elastic band, connects 
 the adjacent margins of the cricoid and thyroid cartilages, and 
 extends from the upper border of the cricoid cartilage to the 
 lower margin of the true vocal cords. 
 
 The two crico-thyroid capsular ligaments surround the ar- 
 ticulations between the inferior horns of the thyroid and the 
 cricoid cartilage. 
 
 The snyovial membrane lines the capsular ligaments, form- 
 ing a true enarthrodial joint. 
 
 The ligaments of the epiglottis are the thyro-epiglottic, the 
 hyo-epiglottic, and the three glosso-epiglottic folds of mucous 
 membrane before described. 
 
 The superior aperture of the larynx is a triangular opening 
 with the apex in front. It is bounded behind by the apices of 
 the arytenoid cartilages and eomiculse laryngis, ia front by the 
 epiglottis, and laterally by the aryteno-epiglottidean folds. Prom 
 this, as its superior boundary, the cavity of the larynx extends 
 as low as to the lower border of the cricoid cartilage. The true 
 vocal cords and the thyro-arytenoid muscle divide it into two 
 parts, the narrow fissure between the two cords being called the 
 glottis, or rima glottidis. 
 
 The superior or false vocal cords are two folds of mucous 
 membrane inclosing the superior thyro-arytenoid ligaments. 
 
 The inferior or true vocal cords are two folds of mucous 
 membrane inclosing the inferior thyro-arytenoid ligaments, com- 
 posed of elastic tissue, from the sides of the upper border of the 
 cricoid cartilage, extending upward to the bases of the arytenoid 
 cartilages, and lower portion of the angle of the thyroid. Their 
 upper margins correspond to the lower edges of tie ventricles of 
 the larynx. 
 
VOCAL AND RESPIRATORY APPARATUS. 249 
 
 ♦ 
 
 The ventricle of the larynx is a deep fossa on either side 
 of the larynx, bounded above by the false vocal cords, below by 
 the inferior or true vocal cords, and externally by the thyro- 
 arytenoideus muscle. 
 
 The sacculus laryngis, or laryngeaV pouch, is a membranous 
 sac lined with mucous membrane, opening into the anterior 
 portion of the ventricle of the larynx. Its inner or laryngeal 
 surface is covered by the aryteno-epiglottideus inferior, and the 
 outer side by the thyro-epiglottideus and thyro-arytenoideus 
 muscles. It is compressed by these muscles, discharging its 
 mucous secretion upon the true vocal cords. 
 
 Muscles. — The intrinsic muscles of the larynx consist of 
 two sets, five connected with the vocal cords and rima glottidis, 
 and three with the epiglottis. The five muscles of the vocal 
 cords are: — 
 
 Crico-ihyroid. — Origin^ from the front and sides of the 
 cricoid cartilage; insertion j into anterior border of the inferior 
 comua, and lower margin of the thyroid cartilage; action, 
 elongates and renders tense the vocal cords; nerve, superior 
 laryngeal. 
 
 Crico-arytwnoidev^ Posticus. — Origin, from the sides and 
 posterior surface of the cricoid cartilage; insertion, into the 
 outer angle of the base of arytenoid cartilage; action, rotates the 
 arytenoid cartilages outward, opening the glottis, and rendering 
 tense the vocal cords ; nerve, recurrent laryngeal. 
 
 Crico-arytcenoideus Lateralis. — Origin, from upper and 
 outer side of the cricoid cartilage; insertion, in front of the 
 preceding into the outer angle of the base arytenoid; action, 
 rotates the arytenoids inward, closing the glottis; nerve, recur- 
 rent laryngeal. 
 
 Arytcenoideus. — Origin, from outer border and posterior sur- 
 face of one arytenoid cartilage ; insertion, into the same part of 
 the other — its fibres are oblique and transverse; action, by ap- 
 proximating the arytenoids closes the back part of the glottis; 
 nerves, superior and recurrent laryngeal. 
 
 Thyro-arytcenoideus. — Origin, from the crico-thyroid mem- 
 brane and lower half of the entering angle of the thyroid car- 
 tilage ; insertion, into anterior surface and base of the arytenoid 
 cartilage — it consists of inferior and superior portions, the for- 
 mer entering into the formation of the true vocal cords ; action, 
 mainly relaxes the true vocal cords by drawing the arytenoids 
 forward ; nerve, recurrent laryngeal. 
 
 The muscles of the epiglottis are : — 
 
 Thyro-epiglottideus. — Origin, from the inner surface of thy- 
 roid cartilage; insertion, into the margin of epiglottis and 
 
250 HUMAN ANATOMY. 
 
 aryteno-epiglottidean fold ; action^ compress the sacculus laryngis 
 and depress the epiglottis; nerve, recurrent laryngeal. 
 
 Arytceno-epiglottideus superior. — Origin, from apex _ of 
 arytenoid; insertion, into aryteno-epiglottidean folds; action, 
 constricts the superior laryngeal aperture; nerve, recurrent 
 laryngeal. 
 
 Arytceno-epiglottideus inferior. — Origin, from middle of in- 
 ternal portion of the arytenoid ; insertion, into upper and inner 
 part of epiglottis; action, compresses the sacculus laryngis; 
 nerve, recurrent laryngeal, muscle of Hilton. 
 
 The lining mucous membrane of the larynx is continuous 
 with that of the pharynx and trachea. It forms the glosso- 
 epiglottic and arytseno-epiglottic folds, adheres tightly to the 
 epiglottis, vocal cords, and the interior of the cricoid cartilage, 
 but is more loosely attached to other parts. It contains numer- 
 ous racemose glands, particularly along the posterior margin of 
 the arytseno-epiglottidean fold, and in front of the arytenoid car- 
 tilages, where they are called the arytenoid glands. Its epithe- 
 lium is of the ciliated, columnar variety below the true vocal 
 cords, and above this point in front as high as the middle of 
 the epiglottis. The other portions are covered by squamous 
 epithelium. 
 
 The arteries a;re the laryngeal branches from the superior 
 and inferior thyroid, and the crico-thyroid branches of the supe- 
 rior thyroid. 
 
 The veins join the inferior, middle, and superior thyroid 
 veins. 
 
 The lymphatics enter the deep cervical glands. 
 
 The nerves are the inferior or recurrent laryngeal, the supe- 
 rior laryngeal branches of the pneumogastric, and branches from 
 the sympathetic nerve. 
 
 The superior laryngeal supplies sensation to the larynx. It 
 descends from the inferior ganglion of the pneumogastric, behind 
 the internal carotid at the side of the pharynx, and divides into 
 two branches — ^the internal laryngeal pierces the thyro-hyoid 
 membrane to supply the mucous membrane and arytenoid muscle, 
 the exterrial laryngeal supplies the crico-thyroid muscle. 
 
 The inferior or recurrent laryngeal, from its origin, winds 
 around the subclavian on the right side and around the arch of 
 the aorta on the left side, and ascends by the side of the trachea 
 to the larynx, of which it is the motor nerve, supplying all the 
 muscles of the larynx except the crico-thyroid, giving off in its 
 course' cardiac, oesophageal, tracheal, and pharyngeal branches, 
 and anastomosing with the superior laryngeal nerve. 
 
VOCAL AND RESPIRATORY APPARATUS. 251 
 
 TRACHEA AND BRONCHI. 
 
 The trachea, or windpipe, is a membrano-cartilaginous tube, 
 about four and a half inches in length, three-quarters to one inch 
 in width, extending from the fifth cervical to the upper border 
 of the fifth dorsal vertebra. It divides into two bronchi, the 
 right, about an inch long and nearly at right angles, passing 
 behind the right pulmonary artery on a level with the fifth dorsal 
 vertebra; the left, narrower, about twice as long, passes beneath 
 the arch of the aorta on a level with the fifth or sixth dorsal 
 vertebra, behind the left pulmonary artery. The trachea and 
 bronchi are formed of a series of cartilaginous rings, incomplete 
 at their posterior third, connected by fibro-elastic membrane, 
 and lined by columnar ciliated epithelium. The last ring is 
 triangular, so as to fit the rings of the two bronchi. The mucous 
 membrane contains numerous racemose glands, the largest on the 
 posterior surface, called the tracheal glands. The muscular fibres 
 consist of two layers, longitudinal, the most external and trans- 
 verse internal, both unstriated. 
 
 Relations. — The trachea has the following relations in the 
 neck :— 
 
 Laterally. 
 
 Lobes of the thyroid body; 
 Carotid arteries; 
 Inferior thyroid arteries. 
 
 Anteriorly. 
 
 Skin, superficial and deep fascia; 
 
 Anterior jugular veins; 
 
 Left innominate vein; 
 
 Inferior thyroid plexus of veins; 
 
 Isthmus of thyroid body; 
 
 Arteria thyroidea ima (sometimes). 
 
 Posteriorly, 
 
 Qj^sophagus ; 
 
 Vertebral column; 
 
 Recurrent and inferior laryngeal nerves. 
 
 The following in the thorax: — 
 
 Laterally, 
 
 Pleura; 
 Pneumogastrie nerves. 
 
252 HUMAN ANATOMY. 
 
 Anteriorly. 
 Sternum ; 
 
 Remains of thymus; 
 Arch of aorta; 
 
 Eight and left innominate veins; 
 Left carotid artery; 
 Deep cardiac plexus. 
 
 Posteriorly. 
 (Esophagus. 
 
 The arteries are derived from the inferior thyroid and bron- 
 chial. 
 
 The veins empty into the thyroid and bronchial plexuses. 
 
 The nerves Are from the pneumogastrie and sympathetic. 
 
 The lymphatics empty into the mediastinal glands. 
 
 The bronchi are the continuation of the trachea from its 
 bifurcation to the hilus of the lung. 
 
 Bight hronchus is shorter, about one inch in length, placed 
 more horizontally, and wider. It divides at the hilus into three 
 short branches, corresponding to the divisions of the right lung. 
 
 Left hronchus is longer, nearly two inches in length, placed 
 more obliquely, and narrower than the right. It divides iato 
 two long branches corresponding to the number of lobes : — 
 
 Relations. — ^The right bronchus has the right auricle and the supe- 
 rior vena cava in front of it, the right pulmonary artery at first below, 
 then passing also in front, and the vena azygos arching over it from 
 behind ; 
 
 The left bronchus has the arch of aorta above, the left pulmonary 
 artery at first above, then in front, and the oesophagus, thoracic duct 
 and descending aorta behind. 
 
 The arteries, veins, nerves, and lymphatics are the same as 
 for the trachea. 
 
 The two bronchi subdivide into the bronchial tubes, or bron- 
 chioles, which ramify throughout the lungs, dividing and sub- 
 dividing, to end finally in the primary lobules, where they 
 communicate with the intercellular air-passages. Their carti- 
 lages consist of thin plates, distributed irregularly along the 
 tubes, and in the finer tubes disappearing entirely. The mucous 
 membrane of the bronchi and bronchial tubes is lined throughout 
 with columnar ciliated epithelium. 
 
 THE LUNGS. 
 
 The lungs, the organs of respiration, are two in number, 
 occupying the lateral cavities of the chest, separated from each 
 other by the heart and structures within the mediastinum. They 
 
VOCAL AND RESPIRATORY APPARATUS. 253 
 
 accurately fill the cavity of the chest at all times, and are covered 
 by the pleura. They are conical in shape, presenting each a base, 
 apex, two borders, and two surfaces. The apex extends upward 
 above the level of the first rib; the base occupies the convex 
 surface of the diaphragm; the external^ or thoracic surface is 
 accurately applied to the wall of the thorax ; the inner surface is 
 in contact with the pericardium, and is marked by a depression, 
 the hilum pulmonis, at the root of the lungs. The posterior bor- 
 der rests on either side of the spiaal column, and the anterior 
 border is thin and overlaps the pericardium. 
 
 The root of each lung, situated near its middle, is composed 
 of the following structures, surrounded by a reflection of 
 pleura : — 
 
 Bronchus ; 
 
 Pulmonary artery; 
 
 Pulmonary veins; 
 
 Bronchial glands; 
 
 Bronchial vessels; 
 
 Posterior and anterior pulmonary plexuses of nerves; 
 
 Connective tissue. 
 
 The root of the right lung is behiud the right superior 
 cava and the vena azygos arches over it. The root of the left 
 lung lies below and in front of the arch and descending aorta. 
 The relative positions of the pulmonary veins, pulmonary artery, 
 and bronchus on either side are: — 
 
 Both sides, from before backward — 
 
 V. Pulmonary veins, 
 
 A. Pulmonary artery, 
 
 B. Bronchos. 
 
 Eight side, from above downward — 
 
 B. Bronchus, 
 
 A. Pulmonary artery, 
 
 V. Pulmonary veins. 
 
 Left side, from above downward — 
 
 A. Pulmonary artery, 
 
 B. Bronchus, 
 
 V. Pulmonary veins. 
 
 The weight of the lungs varies according to many conditions. 
 In the adult the approximate weight is about forty-two ounces, 
 the right being two ounces heavier than the left, and their total 
 capacity about three hundred cubic inches. The right lung has 
 three lobes, the left but two, of which the lower is the larger. 
 
254 
 
 HUMAN ANATOMY. 
 
 The lungs in infancy are of a pale-rose color, but later become of 
 a leaden hue, variegated with dark slate and bluish-black. They 
 are highly elastic, crackle on pressure, and float in water, having 
 a specific gravity of 0.345 to 0.746. In the foetus before birth, 
 and also in certain diseases, they sink in water. The structure 
 of the lung consists of an external serous coat, the visceral layer of 
 the pleura, a subserous areolar tissue, highly elastic, and the 
 parenchyma, or proper substance of the lungs. The latter is 
 made up of small polyhedral primary lobules, which imite to 
 
 FlO. 122. 
 
 Heart and lUBgs: 1, right Tentricle; 3, right auricle; 5, pulmonary 
 artery; 9, aorta; 10, superior cava; 20, root of lung; 21, 22, 23, 
 upper, middle, and lower lobes ot right lung; 24, 25, upper and lower 
 lobes ot left lung. 
 
 form secondary lobules, the latter giving rise to the markings on 
 the surface. Both the primary and secondary lobules are held 
 together by connective tissue. A primary lobule represents the 
 structure of the entire organ, consisting of a hronchiole and in- 
 fundibula, or air-passage, communicating with numerous air- 
 cells. 
 
 The air-cells are minute polyhedral cavities, from one two- 
 hundredths to one-seventieth of an inch in diameter, separated 
 from each other by a thin lamina, and communicating freely with 
 the infundibula. They vary much in size, being largest on the 
 surface, the thin borders, and the apices. Each air-cell is com- 
 posed of the basement membrane, lined with squamous epi- 
 
VOCAL AND RESPIRATORY APPARATUS. 255 
 
 thelium, and surrounded by a minute capillary net-work of 
 blood-vessels, which intervene between the terminal branches of 
 the pulmonary artery and the commencement of the pulmonary 
 veins. Between the cells the capillary net-work forms a single 
 layer. 
 
 The pulmonary artery conveys the venous blood to the lungs 
 and terminates in the capillary net-work about the air-cells, from 
 which proceeds the pulmonary vein, which proceeds along the 
 bronchial tubes to the left auricle of the heart. The bronchial 
 arteries supply the structure of the lungs. They are derived 
 from the aorta, and follow the course of the bronchial tubes, 
 the ironchial veins returning the blood to terminate in the hemi- 
 azygos or superior intercostal vein on the left. 
 
 The lymphatics are numerous and consist of a superficial 
 set converging to the root and a deep set along the course of 
 the tubes, and both enter the bronchial glands. 
 
 The nerves are derived from the anterior and posterior pul- 
 monary plexuses of the pneumogastric and sympathetic, the lat- 
 ter the larger. Ganglia are found upon these nerves. 
 
 THE PLEUE^. 
 
 Bach lung is invested by a delicate serous membrane, the 
 pleura, which lines the internal wall of the thorax and is reflected 
 at the root of the lung over that organ. It consists essentially 
 of two layers, a parietal, or pleura costalis, and visceral, or pleura 
 pulmonalis. It adheres accurately to the subjacent structures, 
 and is called, from its position, costal, diaphramatie, mediastinal, 
 and pulmonary. The space between the two layers of each 
 pleura, known as the cavity of the pleura, contains a thin, serous 
 secretion. 
 
 A fold extending downward from the root of the lung to 
 the diaphragm forms the so-called pulmonary ligament, or liga- 
 mentum latum pulmonis. 
 
 Each pleura is a closed sac ; the right is wider, shorter, and 
 extends higher in the neck than the left. They do not meet in 
 the median line, except opposite the upper part of the gladiolus, 
 but have a space between them known as the mediastinum. 
 
 The arteries are from the intercostal, bronchial, pericardiac, 
 internal mammary, musculo-phrenie, and thymic. 
 
 The veins accompany the arteries. 
 
 The lymphatics are numerous, and empty into the intercostal 
 and posterior mediastinal glands. 
 
 The nerves are from the phrenic and sympathetic. 
 
256 HUMAN ANATOMY. 
 
 MEDIASTINUM. 
 
 The mediastimim is the space left between the two pleurse 
 in the median line between the stenmm and vertebral column, 
 and contains the heart within its pericardium and all the thoracic 
 viscera except the limgs. The intervals in the mediastinum from 
 their position are named anterior, middle, posterior, and superior 
 mediastinal cavities. The boundaries and contents of the four 
 mediastinal cavities are as follow: — 
 
 Anterior mediastinum, bounded in front by the sternum; 
 laterally, pleura; behind, the pericardium. It contains: — 
 
 Triangularis sterni muscle; 
 
 Remains of thymus gland ; 
 
 Left internal mammary artery and vense comites ; 
 
 Lymphatic vessels from convex surface of the liver; 
 
 Areolar connective tissue. 
 
 Middle mediastinum, bounded in front by the anterior 
 mediastinum; laterally, by the pleura; behind, posterior media- 
 stinum. It contains : — 
 
 Ascending portion of aorta; 
 
 Superior vena cava; 
 
 Heart, inclosed in the pericardium; 
 
 Bifurcation of trachea; 
 
 Pulmonary artery and veins; 
 
 Phrenic nerves; 
 
 Arteriae comites nervl phrenici, from the internal mammary. 
 
 Posterior mediastinum, bounded in front by the pericardium 
 and root of the lungs; behind, vertebral column; laterally 
 pleura. It contains: — 
 
 (Esophagus; Vena azygos major; 
 
 Thoracic duct; Vena azygos minor; 
 
 Descending aorta; Superior intercostal veins; 
 
 Lymphatic glands and vessels; Pneumogastrio nerves; 
 
 Great splanchnic nerves. 
 
 The superior mediastinum is that portion of the mediastinal 
 space above the upper border of the fifth thoracic vertebra. It is 
 bounded in front by the manubrium sterni ; behind, by the upper 
 dorsal vertebra ; laterally, by the pleura. It contains : — 
 
 Origin of stemo-thyroid muscle; Left superior intercostal vein; 
 
 Origin of stemo-hyoid muscle; Left recurrent laryngeal nerves; 
 
 Lower end of the longus colli muscle; Cardiac nerves; 
 
 Innominate artery; Pneumogastrio nerves; 
 
 Left carotid artery; Phrenic nerves; 
 
 Subclavian artery; CEsophagus; 
 
 Transverse portion of the aorta; Trachea; 
 
 Innominate veins; Thoracic duct; 
 
 Superior vena cava; Remains of the thymus gland; 
 
 Lymphatics. 
 
THE GENITO-URINARY APPARATUS. 
 
 The genito -urinary apparatus consists of the urinary organs 
 and the male and female generative organs. 
 
 THE DEINAET 0K6ANS. 
 
 The urinary organs consist of the kidneys, ureters, bladder, 
 and urethra. 
 
 The kidneys are two glandular organs, situated deeply 
 in the lumbar region, opposite the second or third lumbar verte- 
 bra and last dorsal, the right a little lower than the left. They 
 are surrounded by fat and held in position by the blood-vessels 
 and loose connective tissue. The right kidney is ia relation in. 
 front with the liver, descending portion of the duodenum and 
 ascending colon. The left is in relation with cardiac end of 
 stomach, lower end of spleen, tail of pancreas, and descending 
 colon. Bach kidney measures about four inches in length, two in 
 width, and one in thickness, and weighs from four and one-half 
 to six ounces in male, four to five and one-half in female. Their 
 shape is characteristic. The notch at the inner side is called 
 the hilus, and communicates with the interior cavity, the sinus, 
 at which the blood-vessels, nerves, and ureter have their passage. 
 The kidneys have a special fibrous coat, slightly adherent, which 
 extends into the hilus and becomes continuous with the fibrous 
 coat of the blood-vessels and ureters. The relative position of the 
 arteries, veins, and ureter at the hilus are, from above down- 
 ward : — 
 
 A. Artery, 
 
 V. Vein, 
 
 U. Ureter; 
 
 from before backward : — 
 
 V. Vein, 
 A. Artery, 
 U. Ureter. 
 
 The general structure of the kidney consists of a cortical 
 substance and a medullary substance, the latter arranged into 
 conical masses called renal pyramids, with their bases in the 
 cortical substance, and their apices, the renal papillse, projecting 
 
 (257) 
 
258 
 
 HUMAN ANATOMY. 
 
 into the calices of the pelvis within the sinus of the kidney. 
 The renal pyramids of Malpighi, about ten to fifteen in number, 
 corresponding to the foetal lobules, are arranged into three irregu- 
 lar rows. The substance, or parenchyma of the kidney, is com- 
 posed of urinif erous tubules, held together by comparatively little 
 
 
 —A. 
 
 Pia. 123. 
 
 Longitudinal section o£ kidney: 1, cortex; 2, medulla; S, section 
 of tubules In boundary layer; 4, fat of renal sinus; B, renal ar- 
 teriole; A, branch of renal artery; C, renal calyx; U, ureter. 
 
 connective tissue. The terminal orifices of these, several hundred 
 to each papilla, open on its summit. 
 
 Course of the Tuhuli Urinif eri. — ^Beginning at the Mal- 
 pighian capsule within the cortex, each tubule pursues a very 
 tortuous and complicated course before it terminates in the renal 
 papillaa, the outline of which is as follows (after Gray) : — 
 
THE GENITO-URINAEY APPARATUS. 259 
 
 fa) Neck — the constricted portion below the capsule, before it ter- 
 minates in t}ie renal papillae. 
 
 (b) Proximal convoluted tube, i Within the cortical struc- 
 
 (cj Spiral tubule of Schachowa, f ture. 
 
 (d) Descending limb of Henle's loop, -i Within the medullary 
 
 (ej Henle's loop, | structure. 
 
 (f) Ascending limb of Henle's loop, i Partly in medullary and 
 
 partly in cortical. 
 (g) Irregular tubule, \ 
 
 (h) Distal convoluted tubule, I Cortical structure. 
 
 { i) Curved tubule, J 
 
 (}) Straight collecting tubule — descends through the medullary 
 structure to open by an orifice in a renal papilla. 
 
 The straight, collecting or receiving tubes converge as they 
 descend, and unite and reunite until there are about one dozen, 
 but they vary from eight to twenty, one opening on the summit of 
 each papilla. In the cortical portion they form groups, or medul- 
 lary rays, giving the appearance of conical masses in the cortical 
 substance with their apices toward the periphery — the so-called 
 pyramids of Ferrein. The tubules are composed of a basement 
 membrane, lined with pavement epithelium. In the neck the 
 epithelium becomes continuous with that of the Malpighian 
 capsule, and at the glomerule the wall is reflected upon the in- 
 closed tuft, or Malpighian corpuscle. In other situations the 
 epithelium varies much in shape and size. The renal arteries 
 subdivide at the hilum, cross the sinus, and enter the renal sub- 
 stance between the renal papillfe. They terminate in the renal 
 glomerules, or Malpighian corpuscles. Each one of these re- 
 markable convolutions of capillaries is about one one-hundredth 
 of an inch in diameter and inclosed in a pouch-like dilatation 
 of the uriniferous tubules or Malpighian capsule, or capsule of 
 Bowman. The efferent vessels form, together with others, a 
 capillary net-work between and around the uriniferous tubules. 
 They are made up of three sets: (a) the plexuses around the 
 tubuli contorti ; (b) the veins beneath the capsule ; and (c) the 
 plexuses about the apices of the pyramids of Malpighi. These 
 form the venw interlobulares, ivhich join the venw rectce, and 
 together form the renal veins, vencB propria renales. Those in 
 the sinus unite together to form the renal vein, and open iato 
 the inferior vena cava, the left crossing in front of the abdominal 
 aorta. 
 
 The ureter commences as a compressed pouch, the pelvis. 
 Within the sinus the pelvis divides, and subdivides into several 
 small funnels, or calices, each one of which receives one or two 
 projecting renal papillse. The calices, pelvis, and ureter are all 
 of the same structure, consisting of a fibrous and unstriated mus- 
 cular and a mucous coat. The fibrous coat becomes continuous 
 Avitli the capsule above and below in the fibrous structure of the 
 
260 
 
 HUMAN ANATOMY. 
 
 bladder. The muscular coat ceases at the base of the renal 
 papillae, but the mucous membrane becomes continuous with that 
 of the uriniferous tubules. Its epithelium is of the "transi- 
 
 T and 8. Ascending 
 limb of Henle'B 
 loop tube. 
 
 15. Tabnle of Bellini. |b 
 
 Sulieapsiilnr layer with- 
 out Malpighian cor- 
 puscles. 
 
 12. First part of col- 
 lecting tube. 
 
 11. Distal convoluted 
 tubule. 
 
 A. Cortex. 
 
 10. Irregular tubule. 
 
 3. Proximal convo- 
 luted tubule. 
 
 9. Wavy part of as- 
 cending limb. 
 
 2. CoDstnction or 
 neck. 
 
 4. Spiral tnbnia. 
 1. Malpighian 
 
 surrounded 
 
 tuft 
 Bovrmana capsule. 
 
 8. Spiral part of as- 
 cending limb of 
 Henle's loop. 
 
 B. BouiroABT Zone. 
 6. Pescending limb of 
 Henle's loop tube. 
 
 0. Benis B loop. 
 
 C Fafillart Zonb. 
 
 Diagram of uriniferous tubules: 1, Malpighian capsule; 2, proxi- 
 mal convoluted tubule; 2 b, distal convoluted tubule; 3, descending 
 limb of Henle's loop; 4, ascending limb of Henle's loop; B, irregular 
 tubule; 6, collecting tube; a, apex of pyramid; b, base of pyramid; 
 o. cortical portion. 
 
THE GENITO-URINARY APPARATUS. 261 
 
 tional" variety, consisting of several layers of cells of varying 
 shapes, resting upon a basement membrane. 
 
 The nerves are derived from the renal plexus of the sympa- 
 thetic, formed by branches in the semilunar ganglion, the solar 
 plexus, and the lesser and smallest splanchnic nerve. 
 
 The lymphatics communicate with the lumbar glands. 
 
 The ureter proper is a musculo-membranous tube, sixteen to 
 eighteen inches in length, about the diameter of a goose-quill, 
 extending from its origin in the pelvis of the kidney to the 
 basal or posterior angle of the vesical trigone, which it enters by 
 passiag obliquely through the muscular and mucous walls of 
 the bladder. 
 
 Course. — It descends upon the psoas magnus muscle, be- 
 neath the peritoneum, being crossed by the spermatic vessels. 
 About the first division of the sacrum it crosses the external or 
 common iliac artery, passing behind the sigmoid flexure on the 
 left and the ileum on the right side, to enter the pelvis, where it 
 reaches the bladder withia its posterior false ligament. 
 
 In the male it passes behind the vas deferens. 
 
 In the female it crosses the uterine artery ^/g to V^ i^^h 
 from the cervix uteri and passes along the side and upper part of 
 the vagiaa to the bladder {vide Vagina). 
 
 Muscles of the Ureters. — Two oblique muscles. Origin, be- 
 hind the orifices of the ureters ; insertion, into the middle lobe of 
 the prostate gland ; action, they guard the orifices of the ureters, 
 and prevent the reflux of uriae. 
 
 Suprarenal capsules {vide Ductless Glands). 
 
 THE BLADDEH, 
 
 The bladder is a musculo-membranous sac, the reservoir for 
 the urine, situated in the anterior part of the pelvis, behind the 
 pubes, in front of the uterus and vagina ia the female, and the 
 rectum in the male. 
 
 It measures, moderately distended, five inches in length, 
 three in width, and holds about one pint. It consists of a body, 
 summit, base, and neck. 
 
 The body is partially invested with peritoneum behind, but 
 in front it is wanting, the body being in relation with the sym- 
 physis pubis, triangular ligament, and internal obturator muscles. 
 
 The summit, or apex, is rounded, and directed upward and 
 forward, being connected to the umbilicus by the urachus, the 
 remains of the foetal allantois, and also by the obliterated hypo- 
 gastric arteries, one on either side. 
 
262 HUMAN ANATOMY. 
 
 The space bounded by the pubic surface and the sides of 
 the bladder uncovered by peritoneum, filled by the recto-vesical 
 fascia, is known as the space of Eetzius. 
 
 The base, or fundus, in the male is situated upon a triangular 
 space upon the second portion of the rectum, its base formed 
 behind by the recto-vesical fold, its apex by the prostate gland, 
 and its sides by the vas deferens and vesiculee seminales. 
 
 In the female it is situated in contact with the cervix uteri 
 and anterior wall of the vagina, adhering closely to the latter. 
 Its upper portion has a peritoneal covering. 
 
 The nech, or cervix, is the contracted portion, continuous 
 with the urethra. It is encircled in the male by the prostate 
 gland, and is directed in both obliquely forward and downward. 
 
 The ligaments of the bladder consist of five true ligaments 
 derived from the pelvic fascia and the urachus; and five false 
 ligaments derived from the peritoneum. 
 
 The true ligaments are: — 
 
 Two anterior (pubo-prostatic), two folds of recto-vesical 
 fascia passing from the pubic symphysis to the cervix and upper 
 surface of prostate gland; 
 
 Two lateral folds of recto-vesical fascia connecting the lat- 
 eral surfaces of prostate gland with sides of base of bladder; 
 
 The urachus, an obliterated fcetal structure, passing as a 
 fibro-muscular cord from the apex of the bladder to the um- 
 bilicus. 
 
 The false ligaments are : — 
 
 Two posterior ligaments are peritoneal folds passing be- 
 tween sides of rectum in male, sides of uterus iu female, to 
 postero-lateral surface of bladder, inclosing obliterated hypogas- 
 tric arteries, ureters, vessels, and nerves ; 
 
 Two laterals are folds of peritoneum passing from iliac fossae 
 to sides of bladder ; 
 
 The superior is a single peritoneal fold inclosing the oblit- 
 erated hypogastric arteries from apex of bladder to umbilicus. 
 
 The structure consists of four coats, a serous, muscular, sub- 
 mucous, and mucous. 
 
 The serous coat is derived from the peritoneum. It covers 
 the posterior surface from the ureters to the summit, and is re- 
 flected from the sides to the walls of the pelvis and abdomen. 
 
 The muscular coat is made up of unstriated fibres arranged 
 in three layers: — ■ 
 
 (a) Longitudinal external layer, named the detrusor urinm 
 muscle; 
 
 (b) Circular middle layer, forming at the neck the sphincter 
 vesica; 
 
THE GENITO-TJRINAEY APPARATUS. 263 
 
 (c) Longitudinal internal layer. 
 
 The submucous or cellular coat, made up of fibrous and 
 elastic tissue, supports the mucous coat and unites it with the 
 muscular. 
 
 The mucous membrane is smooth and of a pale-rose color. 
 Its epithelium is continuous with that of the ureters and pelvis 
 of kidneys; its superficial layer, large, tessellated, polyhedral 
 cells, its deep layer of club-shaped and spindle-shaped cells. 
 
 The inner surface of the base presents a triangular space, 
 the vesical trigone, or trigonum vesicce, apex in front, formed 
 by the orifice of the urethra, its basal angles behind about two 
 inches apart, and each about one and one-half inches behind the 
 urethral orifice, formed by the orifices of the ureters : — 
 
 U 
 
 I'A IV," 
 
 U U 
 
 2" 
 
 The uvula vesicce is an elevation of mucous membrane pro- 
 jecting from the floor near the apex of the trigone into the 
 orifice of the urethra. 
 
 The arteries are the superior, middle, and inferior vesical, 
 with branches from the obturator and sciatic in the male, and 
 branches from the vaginal and uterine in the female. 
 
 The veins from the vesico-prostatic empty into the internal 
 iliac vein. 
 
 Lymphatics follow the course of the vessels and enter the 
 lumbar glands. 
 
 The nerves to the base and neck are from the third and 
 fourth sacral, and to the summit from the hypogastric plexus 
 of the sympathetic. 
 
 GENERATIVE APPAEATU8. 
 
 Male Organs. 
 
 The male organs of generation consist of the testes, vasa 
 deferentia, vesiculse seminales, and penis. 
 
 The testicles (testes) are two glandular bodies which 
 secrete the spermatic fluid, and are suspended by the spermatic 
 cords within the scrotum, the left a little larger and lower than 
 the right. They are oval, compressed laterally, measure one and 
 a half to two inches in length, one inch in breadth, one and one- 
 fourth inches in their antero-posterior diameter, and weigh from 
 six to eight drachms. 
 
264 HUMAN ANATOMY. 
 
 They each consist of a body, or testicle proper, and an 
 epididymis. The latter consists of a head, body, and tail. 
 
 The scrotum consists of the skin marked in the median line 
 by the raphe, formed by the union of the genital folds, and the 
 dartos, a reddish, contractile tissue which surrounds the tester 
 and extends from the raphe to the under surface of the penis, 
 forming the septum scroU, which divides it into two cavities for 
 the testes. 
 
 The spermatic cord is made up of the following struc- 
 tures : — 
 
 External spermatic, or intercolumnar fascia; 
 
 Cremaster muscle; 
 
 Internal spermatic fascia, or fascia propria; 
 
 Vaa deferens; 
 
 Spermatic artery; 
 
 Deferential artery from superior vesicle; 
 
 Cremasteric artery, from epigastric; 
 
 Vasa spermatica; 
 
 Lymphatic vessels; 
 
 Spermatic plexus of nerves [from renal and aortic plexuses] ; 
 
 Genital branch of genito-crural ; 
 
 Scrotal branch of the ilio-inguinal. 
 
 It commences at the internal abdominal ring, passes ob- 
 liquely through the inguinal canal, emerges at the external ab- 
 dominal ring, descends into the scrotum, and terminates at the 
 posterior border of the testes. 
 
 The external spermatic or intercolumnar fascia is derived 
 from the aponeurosis of the external oblique muscle. This mus- 
 cle arises within the inguinal canal from Poupart's ligament and 
 pubic spine, and descends along the cord in loops. Its fibres are 
 striated. 
 
 The cremaster muscle, or cremasteric fascia or middle sper- 
 matic fascia, is derived from the lower border of the internal 
 oblique and transversalis muscle. 
 
 The internal spermatic fascia, or fascia propria, is the in- 
 fundibuliform process of the transversalis fascia. 
 
 The proper coverings or tunics of the testicle are three — 
 tunica vaginalis, tunica albuginea, and tunica vasculosa : — 
 
 The tunica vaginalis is a serous membrane surrounding the 
 testes, and at the posterior portion is reflected on itself to form 
 a sac. The outer portion of the latter is loosely attached, except 
 at the lower part of the testicle, where the gubernaculum testis 
 binds it down. 
 
 The tunica albuginea is a dense, white, fibrous structure, 
 continuous at the upper part with a similar structure on the 
 epididymis. At the back part it projects into the glandular sub- 
 
THE GENITO-UKINARY APPARATUS. 
 
 265 
 
 stance of the testicle to form the mediastinum testis (or corpus 
 Highmorianum), from which numerous septula (trabeculae) 
 
 Fig. 125. 
 
 Male organs of generation: A, interior of blaflder; B, sympliysia 
 pubis; C, integument: D, vas deferens; E, vesiculse seminales; F, 
 prostate gland; G, corpus cavernosum; H, scrotum; I, verumontanum; 
 J, Cowper's gland; K, orifice of ejaoulatory duct; L, bulb of corpus 
 spongiosum; M, corpus spongiosum; N, urethra; O, prepuce; P, glans 
 penis; Q, suspensory ligament; K, space of Retzlus; S, peritoneal told. 
 
266 HUMAN ANATOMY. 
 
 diverge, and with similar cords from the tunica albnginea serve 
 to maintain the shape of the gland and divide it into lobules. 
 
 The tunica vasculosa (pia mater testis) lies within the 
 tunica albuginea, and is the source and termination of the blood- 
 vessels to the secretory substance of the gland, resembling the 
 pia mater of the brain. 
 
 The glandular structure of the testis is divided into several 
 hundred (two hundred and fifty to four hundred) pyramidal 
 lolules (lobuli testis), each one of which consists of from one 
 to three tubuli seminiferi. 
 
 At the conical extremity of the lobules the tubules end in 
 straight tubes, vasa recta, which enter the mediastinum to form 
 the plexus retiformis. Prom the upper part of this the vessels 
 unite into from twelve to twenty vasa efferentia, which pass out 
 of the testicle to the epididymis. Within the epididymis these 
 efferent canals form a series of spermatic cones, the coni vasculosi. 
 These end in a coarse, convoluted tube, about twenty feet in 
 length, forming the body and tail of the epididymis, and ending 
 in the spermatic duct, or vas deferens. These tubes are lined 
 with columnar ciliated epithelium. 
 
 The vas aberrans of Haller is a spermatic cone joining the 
 epididymis, but unconnected with the testicle. 
 
 The hydatids of Morgagni are one or two pediculated bodies 
 attached to upper part of testis or head of epididymis, and sup- 
 posed to be the remains of Miiller's duet. 
 
 Structure of the Tubules. — The tubuli seminiferi are minute 
 convoluted tubules, closed at one extremity, consisting of a hya- 
 line membrana propria lined with several layers of epithelial 
 polyhedral cells, the seminal cells, from which the seminal or 
 spermatic fluid is directly elaborated. 
 
 These cells undergo a process of indirect division to form 
 the spermatoblasts, which are arranged into bundles, and are con- 
 verted into spermatozoids, the nuclei becoming the head, and 
 the tail, or ciliary appendages, being afterward developed. These 
 cells are constantly cast off and replaced. 
 
 Descent of the Testes. — In early foetal life the testes are 
 placed at the back part of the abdomen, below and in front of 
 the kidneys, and behind the peritoneum. 
 
 About the third month a peculiar structure, the gubcmacu- 
 lum testis, appears, attached to the lower end of the epididymis, 
 and extending as a cord to the bottom of the scrotum. It is 
 supposed to cause the descent of the testicle. It reaches its full 
 development between the fifth and sixth month, at which time 
 the testicle reaches the iliac fossa. It enters the internal abdom- 
 inal ring by seventh month, and the scrotum by the eighth 
 
THE GENITO-UEINAEY APPARATUS. 
 
 267 
 
 month, carrying before it a fold of peritoneum, which is after- 
 ward shut, off, forming the tunica vaginalis testis. Other cover- 
 ings of the testicles are also derived in this manner. In the 
 female a structure similar to the gubernaculum forms the round 
 ligament. 
 
 The vas deferens has three coats — (1) an external fibrous 
 coat, (2) an unstriated muscular coat, and (3) a lining mem- 
 
 mu scle: 
 
 FlO. ]2«. 
 
 The testicle and eplflldymis: A, testis; B, epididymis; C, tunica 
 vaginalis: D, vas deferens; E, spermatic artery and veins; P, artery 
 of cord, 
 
 brane of columnar epithelium. It is about one and one-half feet 
 long and one line in diameter. From the tail of the epididymis 
 it ascends in the cord, forming an important part, and lying 
 behind the blood-vessels. It ascends through the inguinal canal, 
 and at the internal ring descends on the bladder, crosses the 
 ureter and obliterated hypogastric artery, and runs forward to 
 form with the duct of the seminal vesicle the ejaculatory duct. 
 
268 HUMAN ANATOMY. 
 
 The walls of the vas are very thick and the canal very small. 
 Its course for the most part is straight, but beneath the bladder 
 it becomes enlarged, tortuous, and more capacious, but again 
 contracts near its termination. 
 
 The arteries of the cord are: — 
 
 The spermatic, to the testicle from the aorta; 
 
 The vas deferens, or deferent artery, from the superior vesical ; 
 
 The cremasteric, from the deep epigastric. 
 
 The veins from the testis — spermatic veins — ^unite with 
 branches from the epididymis to form the pampiniform plexus, 
 which terminates on the left side, passing beneath the sigmoid 
 flexure in the left renal vein, on the right side in the inferior 
 vena cava. 
 
 The lymphatics are numerous, and terminate in the lumbar 
 glands. 
 
 The nerves are from the sympathetic system, and form the 
 spermatic plexus. 
 
 The arteries of the scrotum are derived from the 
 
 Cremasteric branch of epigastric; 
 
 Superficial external pudic, from the femoral; 
 
 Deep external pudic, from the femoral ; 
 
 Superficial perineal, branch of internal pudic, from internal iliac. 
 
 The seminal vesicles are two membranous pouches, closely 
 adhering to the under surface of the bladder. 
 
 Their size varies, but they usually measure two and one-half 
 inches in length, one-half inch in breadth, and two to three 
 lines in thickness. 
 
 Each consists of a tube closed at one end, about four to sis 
 inches long, the diameter of a quill, convoluted into a mass. Its 
 structure is analogous to that of the ducts, but thinner. 
 
 The ejaculatory ducts, two in number, are formed by the 
 union of the vasa deferentia with the duct of the vesiculse semi- 
 nales. Each duct is three-fourths to one inch in length, and 
 passes through the prostate gland to terminate at the margin 
 of the sinus pocularis by a slit-like orifice. 
 
 The arteries are derived from the inferior vesical and middle 
 hsemorrhoidal. The veins and lymphatics correspond, and the 
 nerves are from the hypogastric plexus of the sympathetic. 
 
 The sepiinal vesicles are not only reservoirs, but secrete a 
 fluid to dilute the spermatic liquid. 
 
 The semen is a viscid, whitish liquid, composed of a color- 
 less liquid, the liquor seminis, and the spermatozoa and seminal 
 granules. 
 
THE GENITO-URINAKY APPARATUS. 
 
 269 
 
 The seminal granules are about one four-thousandth of an 
 inch in diameter. 
 
 The spermatozoa are the essential elements, and consist of an 
 oval head, a body or middle piece, and a tail. 
 
 The penis is composed of three columnar bodies, two cor- 
 pora cavernosa and one corpus spongiosum, invested with skin, 
 and filled with a peculiar, vascular, sponge-like structure. 
 
 It is attached to the pubic arch and symphysis by its root, 
 has a free expanded extremity, the glans penis, or head, and 
 an intermediary portion, the body. 
 
 
 Fig. 127. 
 Vertical section ol testicle. (After Ora]/.) 
 
 The upper surface is the dorsum, or back. The glans is a 
 olunt, cone-like body, expanded at its base, the corona, and 
 attached by its cervix, or neck. 
 
 The summit has a slit-like aperture, the meatus^ or orifice 
 of the urethra. 
 
 The ?kin adheres loosely to the organ, and has a loose, cup- 
 like fold over the glans, called the prepuce, after which it is 
 reflected into the cervix and glans, becoming continuous with 
 
270 HUMAN ANATOMY. 
 
 the mucous membrane of the urethra at the meatus, to which 
 it is attached below by a band or bridle — frenum or frenulum 
 
 The skin covering the glans resembles mucous membrane, 
 is very vascular and sensitive, but about the cervix and corona 
 has numerous preputial glands — glandulw Tysoni odoriferi, 
 which secrete the smegma. 
 
 The superficial fascia is thin, free from adipose tissue, and 
 continuous with that of the abdomen and scrotum. 
 
 From the front of the pubis a fibro-elastic fasciculus de- 
 scends to the root of the penis, called the suspensory ligament. 
 
 The corpora cavernosa, or cavernous bodies, constitute more 
 than two-thirds of the bulk of the organ. They spring as crura 
 from the rami of the ischium and pubis, swell out into the hulb 
 of the cavernous hody, or corpus cavernosum, join each other in 
 the median line, to terminate in a conical extremity, which re- 
 ceives the glans. 
 
 They are grooved above for the dorsal vein, and below for 
 the corpus spongiosum. 
 
 They each have a strong outer fibrous membrane, which, 
 on uniting, forms a thick partition, complete behind, but incom- 
 plete and comb-like in front — septum pectiniforme. 
 
 From this septum fibro-elastic bands diverge in all directions 
 and form trdbeculce, which with the blood-vessels occupying their 
 intervals, form the erectile tissue of the corpora cavernosa. 
 
 The corpus spongiosum commences as a bulb below the crura 
 and in front of the triangular ligament. It expands anteriorly 
 into the glans penis, which fits upon the conical termination 
 of the corpora cavernosa. 
 
 The urethra enters above and anteriorly to the bulb, and 
 traverses its entire length to the summit of the glans, opening 
 at the meatus. 
 
 The corpus spongiosum consists of an external fibrous coat, 
 thinner and more elastic than that of the corpora cavernosa, and 
 an interior erectile tissue. A thin, muscular layer lines the ex- 
 ternal fibrous coat, and another is found beneath the mucous 
 membrane of the urethra. 
 
 The corpora cavernosa get their blood from the arteries of 
 the corpora cavernosa, and branches from the dorsal artery of 
 the penis, from the internal pudic. 
 
 The corpus spongiosum is supplied by the artery of the bulb. 
 
 The arteries of all three bodies terminate finally in the 
 erectile tissue. Many arterial branches, especially at the root 
 of the penis, form short convolutions — the helecine arteries, 
 which terminate in finer vessels, and subsequently open into the 
 spaces of the erectile tissue. Others open directly. 
 
THE GENITO-URINARY APPARATUS. 271 
 
 From these spaces the veins begin; some wind around the 
 side of the organ to the dorsal vein, while others pass under 
 the pubis to join the prostatic plexus. 
 
 The lymphatics are numerous; the superficial join the 
 inguinal glands, the deep Join the lymphatic plexus about the 
 prostate and other deep lymphatics of the pelvis. 
 
 The male ueethea is the common canal for the emission 
 of semen and urine, extending from the neck of the bladder to 
 the meatus urinarius. It is from eight to nine inches in length, 
 and consists of three portions — the prostatic, membranous, and 
 spongy. 
 
 The prostatic portion extends from the neck of the bladder 
 to the anterior border (apex) of the prostate gland. It is one 
 and one-quarter inches in length, and is the widest and most 
 dilatable part. 
 
 Its floor is raised, and presents : — 
 
 Veru montanum, or caput gallinaginis, an elevated ridge; 
 
 Prostatic sinus, on each side of the veru montanum ; 
 
 Orifices of the prostatic ducts, in the floor of the prostatic 
 sinuses ; 
 
 Sinus pocularis, a depression in the median line in front of 
 the veru montanum, presenting the slit-like openings of the 
 ejaculatory ducts. This cul-de-sac is one-quarter of an inch in 
 length. It is homologous with the uterus, and has received the 
 name of utricle, or uterus masculinus. 
 
 The membranous portion is about three-quarters of an inch 
 in length, extending from the apex of the prostate gland to the 
 corpus spongiosum above and in advance of the bulb. It passes 
 out of the pelvis beneath the symphysis pubis, traversing the 
 triangular ligament. It is the least dilatable portion and has 
 four <!oats : — 
 
 Fibrous, continuous with both layers of the triangular liga- 
 ment; erectile, continuous with that of the spongy body; an un- 
 striated muscular layer, and a mucous coat. 
 
 The spongy portion extends from the membranous portion 
 through the corpus spongiosum to the meatus urinarius on the 
 summit of the glans. 
 
 The portion within the bulb has received the name of 
 hulbous portion of the urethra. The spongy portion diminishes 
 gradually in size to near the orifice, where it suddenly dilates 
 into the fossa navicularis, contracting again at the meatus, the 
 narrowest part of the urethra. 
 
 The mucous membrane is provided with colunmar epithe- 
 lium, except near the meatus, where it is tessellated, a fibro-elastic 
 submucous layer with unstriated muscular fibres, and numerous 
 
272 HUMAN ANATOMY. 
 
 minute racemose glands, the glands of Littre. These latter open 
 forward into the urethra by good-sized orifices, especially one in 
 the upper part of the fossa navicularis, called the lacuna magna. 
 Into the bulbous portion of the urethra the ducts of Cowper's 
 glands open. 
 
 The prostate gland is a glandular body which resembles 
 in size and form a chestnut, and surrounds the first portion of 
 the urethra between the neck of the bladder and the triangular 
 ligament. It measures one and one-half inches in length and 
 breadth and three-quarters in depth. Its weight, about six 
 drachms. Its flat, under surface rests on the rectum. 
 
 It has two lateral lobes, and one middle lobe which corre- 
 sponds in position to the vesicle uvula, and is held in position 
 by the anterior ligaments of the bladder, by a portion of the deep 
 perineal fascia, and of the levator ani muscle. 
 
 It is perforated by the urethra and the common seminal 
 ducts. 
 
 Its structure consists of a mass of fibro-muscular (unstri- 
 ated) tissue with imbedded follicular pouches, the whole inclosed 
 in a firm fibrous capsule, continuous in front with the triangular 
 ligament, behind with the posterior layer of the deep perineal 
 fascia. 
 
 The muscular fibres are longitudinal and circular, the latter 
 surrounding the urethra, continuous behind with the bladder, in 
 front with the fibres about the membranous portion. 
 
 The glands open into the floor of the prostatic sinuses by 
 twelve to twenty ducts. 
 
 The arteries are from the vesical, hsemorrhoidal, and internal 
 pudic. 
 
 The veins enter into the formation of the prostatic plexus, 
 receive the dorsal vein of the penis, and empty into the internal 
 iliac vein. 
 
 The nerves are from the hypogastric plexus. 
 
 Cowper's glands, or suburethral glands, are two small lobu- 
 lar bodies, about one-quarter of an inch in diameter, inclosed 
 between the two layers of the deep fascia, situated behind the 
 bulb of the corpus spongiosum, below the membranous portion 
 of the urethra. They are racemose glands and empty their 
 secretion by a long duct into the bulbous portion of the urethra. 
 
 Female Organs. 
 
 The female organs of generation are divided into the ex- 
 ternal, termed the vulva, or pudendum, consisting of the mons 
 veneris, labia majora and minora, clitoris, meatus urinarius, and 
 
THE GENITO-URINARY APPARATUS. 273 
 
 orifice of the vagina; and the internal, consisting of the uterus, 
 ovaries, Fallopian tubes, and vagina, with certain accessories. 
 
 The uterus is a hollow, muscular organ for the reception 
 of the fecundated ovum and the development and expulsion of 
 the fcetus. 
 
 The virgin uterus holds an oblique anterior position in the 
 pelvis, being supported by attachments to the vagina, rectum, 
 bladder, and sides of the pelvis. 
 
 It is in contact with the bladder in front, the rectum behind, 
 and above the small intestine. 
 
 Its shape is pyriform, compressed from before backward, 
 and measures three inches in length, two in breadth, one in thick- 
 ness, and weighs from one to one and a half ounces. 
 
 Fio. 128. 
 
 Internal female genitals. 
 
 It consists of a neck, fundus, and body. 
 
 The mouth, os uteri, or os tincce, opens into the vagina, 
 being protected by two lips, an anterior thick lip, and a posterior, 
 long and narrow. 
 
 The cavity of the uterus is triangular A from side to side, 
 but a mere slit from before backward, and measures two and 
 one-half inches in its longitudinal diameter. 
 
 The two upper angles are prolonged to communicate with 
 the Fallopian tubes ; the lower angle forms the ostium internum 
 uteri, communicating with the cavity of the cervix. 
 
 Its structure consists of three coats: — 
 
 Serous coat, derived from the peritoneum and investing all 
 but the lower anterior quarter; 
 
274 HUMAN ANATOMY. 
 
 Muscular coat, about one-half inch thick, composed of nn- 
 striated muscular fibres arranged into three layers; 
 
 Mucous coat, has numerous tubular follicles, is lined with 
 ciliated columnar epithelium, and has no submucous coat to con- 
 nect it with the muscular coat. 
 
 The mucous membrane of the cervix is thrown into folds, or 
 rugce, which assume on the anterior and posterior walls a 
 branched arrangement, or arbor vitce uterina. It is lined by 
 squamous epithelium, and presents numerous follicular glands — 
 the ovula of Nahoth, or glandulw Nahothi. 
 
 The arteries are branches of the ovarian from the aorta, 
 and. the uterine from the internal iliac, remarkable for their 
 tortuosity and anastomoses. 
 
 The veins form plexuses or uterine sinuses, the branches of 
 which correspond to the uterine arteries and terminate in the 
 uterine plexuses. 
 
 The lymphatics are very numerous and terminate in the 
 lumbar and pelvic glands. 
 
 The nerves are from the ovarian and hypogastric plexus 
 of the sympathetic. 
 
 The ligaments of the uterus are folds of peritoneum ar- 
 ranged into four pairs ; — 
 
 Two anterior, or vesico-uterine, passing one on either side from the 
 posterior surface to the cervix uteri; 
 
 Two posterior or recto-uterine, passing between tlie sides of the 
 rectum and uterus, and inclosing a cul-de-sac, the recto-vaginal pouch, 
 or Douglas' pouch; 
 
 A prolongation of this ligament upward to the second sacral verte- 
 bra, with some unstriated muscular fibres derived from the uterus and 
 vagina, forms the so-called utero-sacral ligaments ; 
 
 Two lateral, or broad, extending from the uterus to the sides of 
 the pelvis, dividing it into two portions, and inclosing the Fallopian 
 tubes, ovary, ovarian ligament, uterine blood-vessels, lymphatics, and 
 nerves, and some unstriated muscular fibres; 
 
 Two round ligaments, are cords of unstriated muscular and fibrous 
 tissue, extending from the side of the fundus uteri to the inguinal canal, 
 where it is lost in the subcutaneous tissue of the pubes and labia 
 majora. 
 
 The canal of Nurk, u. pouch of peritonevim, incloses the ligament in 
 the young subject, but is usually obliterated later. 
 
 The ovaries correspond to the male testicles, and 'are sus- 
 pended behind the broad ligament inclosed in its posterior layer. 
 
 They are largest from puberty to adult age, and measure 
 one and one-half inches in length, three-quarters of an inch in 
 width, and one-third of an inch in thickness, and weigh from 
 one to two drachms. The inner border is attached to the fundus 
 uteri by the ovarian ligament, and its outer border to the fim- 
 
THE GENITO-UKINAKY APPARATUS. 
 
 275 
 
 briated extremity of the Fallopian tube by a cord (tubo^ovarian 
 ligament) . 
 
 The structure of the ovary is made up of a reddish, spongy 
 stroma, well supplied with blood-vessels, containing numerous 
 ovisacs, or Graafian vesicles inclosed in a serous covering derived 
 from the peritoneum. 
 
 BIcKJdef 
 
 Ul•c^h^•c^ 
 
 Fig. 329. 
 Female organs of generation. 
 
 The serous coat differs from the peritoneum in having a 
 single layer of columnar cells, the germinal epithelium of 
 Waldeyer. 
 
 The tunica albuginea is a dense, white, fibrous layer inclos- 
 ing the ovary, and consisting of a condensation of the stroma. It 
 is perforated at its upper border, hilus ovarii, to admit the pas- 
 sage of blood-vessels. 
 
 The Graaffian vesicles, or ovisacs, containing the human ova, 
 vary in size from microscopic bodies to one-quarter of an inch ia 
 diameter, and are most abundant in the periphery. 
 
276 
 
 HUMAN ANATOMY. 
 
 In structure they consist of a fibrous coat — the ovicapsuU — 
 lined by a basement membrane — memhrana propria — and a layer 
 of cells, the membrana granulosa. The interior is filled with a 
 transparent albuminous fluid, liquor folliculi. 
 
 The epithelial lining nearest the ovary presents an accumu- 
 lation of cells — the germinal eminence, or discus proligerus, 
 within which is the ovum or egg. 
 
 Discharge. — The Graaffian vesicles approach the surface of 
 the ovary and burst, their contents passing into the opened apcr- 
 
 FlQ. 130. 
 
 Section of an ovary: e, germ epithelium; 1, large-sized follicles; 
 2, 2, smaller-sized follicles: o, ovum within a Graafian follicle: v, v, 
 blood-vessels of the stroma; g, cells of the membrana granulosa. 
 
 ture of the tube, the fimbriated extremity apparently applying it 
 to the region of the bursting ovisac* 
 
 The rupture occurs periodically and corresponds to the 
 menstrual flow. 
 
 The ovum is surrounded by the tunica vasculosa and some 
 additional epithelial structures (retinacula). It is one-tenth 
 line in diameter, and represents all the elements of an organized 
 cell, being composed of a 
 
 * The fimbriated extremity contains no erectile tissue, and the 
 ovum probably falls into the peritoneal cavity and is swept into the 
 tube by the action of the cilia- (Spigelberg.) 
 
THE GENiTO-tJRINARY APPARATUS. 277 
 
 Cell-wall, or vitelline membrane, or zona pellucida; 
 Cell-contents, or vitellus; 
 Nucleus, or germinal vesicle; 
 Nucleolus, or germinal spot. 
 
 At the seat of the rupture the walls collapse, and the vesicle 
 immediately becomes filled with a blood-tinged fluid, which, 
 together with the hypertrophy of the walls, forms the false corpus 
 IvAeum, which remains and develops for two to three months and 
 gradually disappears. 
 
 Under the influence of pregnancy it enlarges for some time, 
 forms the trua corpus luteum of pregnancy, and disappears two 
 to three months after parturition. 
 
 The arteries are the ovarian from the aorta. 
 
 The veins form an intricate plexus from which emerge ves- 
 sels corresponding to the arteries; they form a plexus near the 
 ovary — the pampiniform plexus — which communicates with the 
 uterine and terminates as in the male. 
 
 The lymphatics are numerous and of large size in the im- 
 pregnated uterus, and terminate in the lumbar and pelvic glands. 
 
 The nerves are from the ovarian and hypogastric plexuses 
 of the sympathetic. 
 
 The Parovarium consists of a series of tortuous tubes ex- 
 tending from the ovary to a main transverse trunk (the epoopho- 
 ron), near the Fallopian tubes. It is also called the organ of 
 Bosenmuller, and is the remains of the Wolffian body of embryo 
 life, and corresponds to the origin of the epididymis in the male. 
 
 The Fallopian tubes, or oviducts, are the passageways for the 
 ovum from the ovaries to the uterus. They are trumpet-shaped 
 tubes about four inches long, with the largest extremity outward. 
 
 Its ovarian extremity is fimbriated; hence its name, fim- 
 iriated extremity. It is also called morsus diaholi, from its sup- 
 posed erectile action. 
 
 One of these fimbrias extends along the border of the broad 
 ligament to the outer extremity of the ovary, forming the tuho- 
 ovarian ligament. ■ 
 
 The ovarian orifice — ostium abdominale, or pavillion — is 
 much larger than the uterine, or ostium internum. 
 
 The tube has three coats: — 
 
 Serous, derived from the peritoneum ; 
 
 Fihro-muscular, from the uterine walls; 
 
 Mucous coat, with ciliated columnar epithelium, continuous 
 with the uterine. 
 
 The remains of the duct of Miiller form the hydatid of 
 Morgagnij a small vesicle, attached by a long pedicle near the 
 fimbriated extremity. 
 
278 
 
 HUMAN ANATOMY. 
 
 The arteries are from the ovarian, the veins follow the same 
 course, and the lymphatics and nerves are the same as the ovarian 
 and uterine. 
 
 The vagina is a cylindrical membranous canal extending 
 from the vulva to the uterus. It is formed by the coalescence of 
 two symmetrical tubes in foetal life. 
 
 MONS VENERIS 
 
 ^\ 
 
 1 CLITORIS 
 
 MEATUS 
 URINARIUS 
 
 ■^^ 
 
 FlO. 181. 
 External female genitals. {Ecktey,) 
 
 Relations. — It is in relation in front with the base of the bladder 
 and urethra, behind its upper fourth with Douglas' pouch, its lower 
 three-fourths connected loosely with the rectum, and laterally with the 
 broad ligaments, pelvic fascia, and levator ani muscles. 
 
 On the posterior wall just below the cervix uteri the ureters 
 approach each other, leaving a space of only three-quarters of an 
 inch between them, — important in lithotomy. 
 
THE GENITO-TJRINAEY APPARATUS. 279 
 
 In the virgin adult it measures about four inches in length, 
 one inch in width, somewhat larger in its middle. Its anterior 
 and posterior walls are in contact. 
 
 Its lower orifice or entrance, is constricted by a crescentie 
 or circular fold of mucous membrane, the hymen. 
 
 ■The upper extremity, or fundus, receives the cervix uteri, 
 extending higher up posteriorly (five to six inches), making the 
 anterior lip apparently the longest. 
 
 The mucous membrane has numerous transverse folds, or 
 rugce, passing to either side of a median ridge, both anterior 
 and posterior, the columnce vaginm, formed by the coalescence of 
 the two tubes in foetal life. Some of these rugse present wart- 
 like eminences, most numerous about the entrance of the vagina, 
 where they form the carunculce myrtiformes, the remains of the 
 hymen after intercouse (or after parturition — Budin) . 
 
 The walls of the vagina are about one line thick and con- 
 sist of three coats :— 
 
 Fibro-elastic coat; 
 
 Muscular coat, of unstriated fibres, elastic tissue and blood- 
 vessels, consisting of two layers, external longitudinal and in- 
 ternal circular, and about the entrance the internal circular 
 fibres form the sphincter vagince {vide Perineum) ; 
 
 Mucous or internal coat, containing numerous conical 
 papillffi, and covered by squamous epithelium. 
 
 The arteries are from the vaginal, uterine, vesical, and 
 internal pudie. 
 
 The veins form an intricate plexus on each side with the 
 returning vessels, corresponding to the prostatic plexus, and join 
 the internal iliac veins. 
 
 The nerves are from the hypogastric plexus of the sympa- 
 thetic, also the fourth and fifth sacral and internal pudic nerves. 
 
 The vulva, or pudendum, consists of the mons veneris, labia 
 majora and minora, clitoris, and meatus urinarius. 
 
 The mons veneris is the prominence of skin over the sym- 
 physis pubis, supported upon a mass of adipose tissue, and cov- 
 ered with hair. 
 
 The labia majora are two folds of skin bounding the vertical 
 fissure of the labia, the junctions of which in front and behind 
 form the anterior and posterior commissures. The labia corre- 
 spond to the scrotum in the male. 
 
 Within the posterior commissure is a depression, fossa navic- 
 ularis., which separates it from a fold of mucous membrane — 
 the fourchette. 
 
 The triangular space between the anus and the posterior 
 commissure is termed the perineum. 
 
280 HUMAN ANATOMY. 
 
 The clitoris corresponds to the penis in the male, resem- 
 bling it also in form, structure, and connections. 
 
 It is about one and one-half to two inches in length, and 
 consists of a pair of corpora cavernosa, and a double, spongy 
 body, surmounted by a glans clitoridis. 
 
 The corpora cavernosa arise by two crura attached to the 
 rami of the pubes and ischium like the penis, and united in front 
 by the septum pectiniforme. They curve abruptly down, being 
 attached to the pubic symphysis by a suspensory ligament. The 
 body and crura represent a tripod. 
 
 The glans corresponds to that of the male penis, but is not 
 perforated by the urethra. It is covered by the prceputium 
 clitoridis^ a hood-like fold of skin continuous with the nymphse. 
 
 The corpus spongiosum consists of an intermediate portion 
 and semibulbs. The former consist of a plexus of veins, inclosed 
 in a fibrous membrane. 
 
 The semibulbs, or hulbi vestibuli, are about the size of large 
 almonds, and are situated beneath the vestibule, embracing the 
 orifices of the urethra and vagina. In front of the bulbs, between 
 them and the clitoris, is a smaller plexus called the pars inter- 
 media. 
 
 The arteries, nerves, and veins are the same as those of the 
 
 The nymphcBj or labia minora, are two folds of mucous 
 membrane diverging from the prseputium clitoridis to the labia, 
 where they are lost. At their superior extremity they divide 
 into two folds, the upper forming the prceputium clitoridis, the 
 lower one the frcenum. ' 
 
 These diverging labia inclose a triangular space, the vesti- 
 bule, at the middle of the base of which is situated the orifice 
 of the urethra, or meatus urinarius. 
 
 The bladder in the female is larger and broader than in 
 the male. It is situated behind the pubes, in front of the 
 uterus, from which it is separated by the small intestine, and 
 rests upon the anterior wall of the vagina and cervix uteri. 
 
 The urethra is a short but capacious canal, one and one-half 
 inches in length, one-quarter inch in diameter, extending beneath 
 the pubic symphysis from the neck of the bladder to the meatus. 
 It lies in the anterior wall of the vagina, and perforates the 
 triangular ligament precisely as does the male urethra {vide 
 Urethra) . 
 
 Below the vestibule is the entrance or orifice of the vagina. 
 The mucous membrane of the labia is reflected continuously to 
 the clitoris, nymphse, prepuce, and vestibule, and becomes con- 
 tinuous with the vagina and urethra. 
 
THE GENITO-UEINARY APPARATUS. 281 
 
 Its epitheliuni is squamous, and its glands racemose, mucous, 
 and sebaceous glands or glanduloe odoriferi Tysoni. 
 
 The Bartholine or suburethral glands are two racemose 
 glands about one-third inch in diameter, situated just behind the 
 semibulbs of the spongy body. The ducts, about three-fourths 
 inch long, open between the nymphse and the vaginal orifice, or 
 the hymen, if present. They secrete mucous. 
 
 The blood-vessels and nerves of the vulva correspond to those 
 of the penis and scrotum {vide Internal Pudic Artery). 
 
 MAMMAET GLAND. 
 
 The mammae, or breasts, are the milk-secreting organs of 
 the female (being rudimentary in the male). They consist 
 of two large, hemispherical bodies, in the antero-lateral region of 
 the thorax, resting upon the pectoralis major muscle, between 
 the third and seventh ribs, inclosed between the two layers of 
 the superficial fascia. 
 
 The nipple (mammilla) is roseate or brownish, and sur- 
 rounded by an areola of the same color, the skin of which con- 
 tains numerous sebaceous glands, the tubercles of the areola, 
 or the glands of Montgomery. The skin of the nipple is thin, 
 vascular, and erectile. On its summit are the orifices of the 
 fifteen to twenty milk-duets, or lactiferous ducts. 
 
 Its structure is firm and pinkish-white, consisting of fifteen 
 or twenty lobes forming a racemose gland, held together and 
 invested with fibrous tissue. 
 
 Bach lobe ends in one of the tubuli lactiferi, or galactophori, 
 which beneath the areola dilates into a lactiferous sinus, or 
 galactophorous sinus, or ampulla, and terminates on the summit 
 of nipple in an orifice. 
 
 The arteries are, the long thoracic, with other branches of 
 the axillary, the internal mammary, and intercostals. 
 
 The veins follow the corresponding arteries to end in the 
 internal mammary and axillary veias. They form about the 
 base of the nipple a venous circular anastomosis, the circulus 
 venosu£. 
 
 The lymphatics terminate in the axillary glands, a few also 
 entering the anterior mediastinal glands. 
 
 The nerves are from the anterior and lateral cutaneous 
 branches of the intercostals. 
 
 Milh, the secretion of the mammary gland, is an emulsion, 
 consisting of a colorless fluid, the milk-plasma, holding in sus- 
 pension the milk-globules. It has a specific gravity of 1.028 to 
 1.034, and slightly alkaline reaction. 
 
THE NERVOUS SYSTEM. 
 
 The nervous system, for description, is divided into two 
 parts : central and peripheral. 
 
 The central nervous system, cerebro-spinal axis, or encephalo- 
 spinal axis, or neuraxis, consists of the brain and spinal cord, 
 and also comprises certain exterior ganglia. 
 
 The peripheral nervous system consists of the cranial and 
 spinal nerves and ganglia, and the sympathetic nerves and 
 ganglia. 
 
 The nervous system may also be divided into the cerehro- 
 spinal system, that supplying muscles, skin, and mucous mem- 
 branes; and the sympathetic system, presiding over organs and 
 blood-vessels. 
 
 Structure. — Nervous tissue consists of three distinct sub- 
 stances, combined in variable proportions in the different parts 
 of the nervous system (white, or fibrous substance : gray, or 
 vesicular substance, and neuroglia) . 
 
 (a) White substance is found in the cortex of the cord, the 
 interior of cerebrum, in nerves, etc., and is made up of medullated 
 nerve-fibres. These are smooth, round fibres, measuring one two- 
 thousandth to one twelve-thousandth of an inch in diameter, and 
 have each three parts : — 
 
 1. Axis cylinder of Purkinje is a round or band-like striated 
 structure consisting of fibrillar, called the primitive fibrillfe of 
 Schultze. There is said to be an envelope of tissue around this 
 composed of a substance called neurokatin ; 
 
 3. The medullary sheath, or wliite substance of Scliwann, 
 whicli is made up of fatty matter in a fluid condition and prob- 
 ably insulates the axis cylinder ; and 
 
 3. The neurilemma, or sheath of Schwann, a delicate, struc- 
 tureless men;brane, closely surrounding the medullary sheath, and 
 forming the surface of the nerve-fibres. 
 (2S2) 
 
THE NERVOUS SYSTEM. 283 
 
 Near their termination the nerve-fibres lose their medullary 
 sheath and become non-medullated (Kemak's) fibres. Such are 
 the olfactory and most of the sympathetic nerves. 
 
 (b) Qray substance, found in the middle of the spinal cord, 
 in the cortex of the brain, in ganglia, etc., consists of three ele- 
 ments: (1) nerve-fibres; (2) nerve-cells; and (3) blood-vessels 
 and connective tissue. 
 
 Nerve-fibres. — The nerve-fibres are the prolongation of the 
 nerve-cells. If there be but one process it is termed the axone, 
 axis cylinder, or Dietrich's process. If there be more than one 
 there is one which is the axone and the rest are called dendrites, 
 or protoplasmic processes. There are two kinds of fibres, 
 medullated and non-medullated. 
 
 Nerve-cells are of three kinds, according to the number of 
 their processes : unipolar, bipolar and multipolar cells. 
 
 A neuron is the term given to a nerve-cell with its axone, or 
 axis-cylinder process, and its dendritic processes, Each neuron 
 is a distinct and separate unit. According to the neuron theory 
 the neurons mass together to form cell groups and fibre systems. 
 Each neuron is not joined to the other neurons but is in contact 
 with them. Process touches process or process touches cell. The 
 neuron theory is as yet not firmly established and a new theory, 
 that of Apathy and others, claims that the chief constituents of 
 the nervous system are neurofibrils which go from cell to cell. 
 
 (c) Neuroglia, the supporting framework of nerve-tissue, 
 is made up of a matrix of delicate, fibrillar net-work and small 
 neuroglia cells, and forms an imbedding substance for the other 
 elements. 
 
 Nerves are round, or flattened white, shining cords, belong- 
 ing either to the eerebro-spinal or the sympathetic systems. They 
 are made up of bundles of nerve-fibres held together by fibio- 
 connective tissue, the epineurium . The individual fibres are held 
 together within the bundles by connective tissue, the endonewium. 
 
 The nerve-fibres have a twofold function — sensory and 
 motor. 
 
 Sensory, or afferent, transmit impressions from the periph- 
 ery to the centres. 
 
 Motor, or efferent, transmit impressions from the centres to 
 the periphery. 
 
284 HUMAN ANATOMY. 
 
 Ganglia form independent nerve-centres, similar to but less 
 complex than the brain. They are connected with some of the 
 cranial nerves, all of the spinal nerves, and form an important 
 part of the sympathetic system. 
 
 Terminations. — The motor nerves end in the voluntary and 
 involuntary muscles, the former having special endings called 
 the motorial end plates. 
 
 The sensory nerves terminate in the peripheral organs to 
 which they are distributed by first becoming non-medullated, 
 and then dividing and Joining one another to form a minute 
 plexus or by means of one of the five special endings, called 
 "peripheral end organs" : (1) tactile corpuscles of Wagner; (2) 
 end bulbs of Krause; (3) the Pacinian corpuscles; (4) neuro- 
 tendinous spindles; or (5) neuro-museular spindles. 
 
 CEEEBEO-SPINAL AXIS. 
 
 The cerebro-spinal axis is divided into two grand divi- 
 sions : — 
 
 The encephalon, or brain, and spinal cord. 
 
 Membranes of the Brain. — The membranes of the brain are 
 three — dura mater, arachnoid, and pia mater. 
 
 Dura mater is a dense, white, fibrous membrane lining the 
 interior of the skull, and forming its internal periosteum, to 
 which it is adherent at the sutures. 
 
 It contains the sinuses or venous channels (already de- 
 scribed), and forms four partitions for the support of the 
 brain — the falx cerebri, falx cerebelli, tentorium eerebelli, and 
 diaphragma sellae. 
 
 Falx cerebri is an arched or sickle-shaped process received 
 into the longitudinal fissure. It contains in its upper and lower 
 margins the superior and inferior longitudinal sinuses and 
 forms by its attachment to the tentorium the straight sinus. 
 
 Tentorium cerebelli is a lamina, arched across, between the 
 superior borders of the petrous portion of temporal on either side, 
 the anterior and posterior clinoid processes in front, and the 
 transverse ridge of the occipital behind, for the support of the 
 posterior lobes of the cerebrum. It incloses the superior petrosal 
 and lateral sinuses. 
 
THE NERVOUS SYSTEM 285 
 
 Falx cerebelli is a small median, triangular partition de- 
 scending from the tentorium to the foramen magnum, and 
 separating the lateral lobes of the cerebellum. 
 
 Diaphragma sella is a horizontal process formed by a doub- 
 ling of the meningeal layer of the dura mater. It forms a small 
 circular fold which roofs the sella turcica and covers the pituitary 
 body. 
 
 The arachnoid is a thin, transparent, delicate membrane con- 
 sisting of fibrous and elastic tissue, and situated between the 
 dura and pia mater. From the former it is separated by the 
 subdural space; from the latter, by the subarachnoid space. 
 
 Unlike the pia mater, it does not dip into the sulci on the 
 brain surface, except the sylvian and great longitudinal fissures. 
 
 The subarachnoid space contains cerebro-spinal fluid, and 
 communicates through certain foramina with the cavities of the 
 brain. The space is much broken up by loose connective tissue, 
 which connects it to the pia mater. 
 
 The three expanded portions of the subarachnoid space are 
 the cisterna magna, cistema pontis, and cisterna basalis. 
 
 The cisterna magna, or posterior subarachnoid space, is placed 
 over the roof of the lower portion of the fourth ventricle, and 
 communicates with the fourth ventricle by the foramen of 
 Majendie and two smaller foramina : those of Keyes and Eetzius. 
 
 The cisterna pontis is placed in front of the pons Varolii. 
 
 The cisterna basalis incloses the circle of Willis. 
 
 The Pacchionian bodies, or granulationes arachnoides, are 
 projections of the arachnoid into, but not through, the dura 
 mater, and are most numerous along the great longitudinal sinus. 
 They make impressions on the under surface of the calvarium, 
 from which, however, they are separated by a thin layer of dura 
 mater. Their function is to allow the passing of fluid from the 
 subarachnoid space into the brain-sinuses when the blood-pressure 
 in the sinuses is lower than in the subarachnoid space. 
 
 Pia mater, the investing membrane of the brain, is composed 
 of a net-work of blood-vessels derived from the vertebral and 
 internal carotid arteries, held together by delicate connective 
 tissue. It dips into the sulci, and is prolonged into the ven- 
 tricles, forming the velum interpositum, or tela choroidea supe- 
 rior, and the tela choroidea inferior. The former covers the 
 third ventricle and extends into the lateral ventricles, carrying 
 
286 
 
 HUMAN ANATOMY. 
 
 in its margins the choroid plexus of the lateral and third ven- 
 tricles. It is perforated by two slit-like foramina, one com- 
 municating with each lateral ventricle. 
 
 The tela choroidea inferior forms the roof of the lower 
 part of the fourth ventricle. It contains nerves and lymphatics. 
 
 The Encephalon, or The Brain. 
 
 The encephalon, or brain, consists of four distinct portions — 
 the cerebrum, cerebellum, pons Varolii, and medulla oblongata. 
 The average weight of the brain in the male adult is. forty-nine 
 and a half ounces, in the female forty-four ounces, of which the 
 cerebrum is about seven-eighths. The maximum male brain 
 weighs sixty-five ounces; minimum, thirty-four ounces. The 
 maximum female brain weighs fifty-six ounces; minimum, 
 thirty-one ounces. The brains of idiots seldom weigh more than 
 twenty-three ounces. Excepting the whale and elephant, the 
 human brain is heavier than that of all the lower animals. 
 
 The brain is developed from the anterior portion of the 
 primitive neural tube. This expands and later becomes con- 
 stricted into three primary brain-vesicles, which are called the 
 forebrain (prosencephalon), midbrain (mesencephalon), and 
 hind-brain (rhombencephalon). The forebrain becomes differ- 
 entiated later into the telencephalon and diencephalon ; and the 
 hind-brain likewise is differentiated into two parts: the meten- 
 cephalon and the myelencephalon. 
 
 From these brain-vesicles are developed the following : — 
 
 Encephalon,^ 
 or Brain, 
 
 Rhombencephalon, _ 
 or hind-brain, 
 
 Myelenceph- 
 alon, 
 
 Metenceph- 
 alon, 
 
 f Medulla oblongata, 
 ■j Lower part of fourth 
 L ventricle. 
 
 Cerebellum, 
 Pons Varolii, 
 Upper part of fourth 
 ventricle. 
 
 Isthmus rboni-" 
 bencepbali 
 (narrow part 
 connecting 
 with mesen- 
 cephalon), 
 
 Superior cerebellar pe- 
 duncles, 
 Valve of Vieussens. 
 
 Mesencephalon, or f *^^,''®"°^P^ fS"'^""^* quadrigemina, 
 midbrain, 1 f^^""' ~ '"^'^-1 9"'"™/«'?l'f ' , . 
 
 ' I brain, (.Aqueduct of Sylvius. 
 
THE NERVOUS SYSTEM. 
 
 287 
 
 ' Thalamanoeph- 
 alon, or dien- 
 cephalou, 
 
 Encephalon, f prosencephalon, or 
 
 Telencephalon, 
 
 Optic thalami, 
 Subthalamic regions, 
 Pituitary and pineal 
 
 bodies, 
 Structures in interpe- 
 duncular space. 
 Optic nerve and retina, 
 Hinder part of third 
 ventricle. 
 
 Cerebral hemispheres, 
 Olfactory lobes, 
 Lateral ventricles. 
 Foramina of Monro, 
 Anterior portion of third 
 ventricle. 
 
 The medulla oblongata is the upper expanded portion 
 of the spinal cord, extending between the lower border of the 
 pons and the upper border of .the atlas. It is divided by two 
 fissures — the anterior and posterior median fissures — into two 
 halves, each one of which is subdivided into four columns, from 
 before backward, the following : — 
 
 (a) Anterior pyramids, or corpora pyramidalia, are two 
 pyramidal masses of white nervous matter, placed between the 
 anterior median fissure and the olivary body, and continuous with 
 the anterior columns of the cord below ; 
 
 (b) Lateral tract and olivary body, are continuous with 
 the lateral columns of the cord below; 
 
 (c) Bestiform bodies are continuous below with the poste- 
 rior columns of the cord. They are composed of the fibres of tlie 
 columns of Goll and Burdach and the direct cerebellar tract. 
 They diverge, the interval between them being the lower portion 
 of the fourth ventricle. 
 
 The structure of the medulla oblongata consists of both 
 white and gray matter, the former arranged into four columns, 
 the latter contained in the interior. 
 
 The gray matter of the medulla is partly arranged into 
 masses and partly continuous with the gray matter of the cord. 
 The posterior horns are called here "the tubercles of Eolando." 
 On the floor of the fourth ventricle the ganglion-cells are ar- 
 ranged into nuclei, from which several of the cranial nerves 
 have their origin. 
 
 The Pons Vaeolii connects the cerebrum above with the 
 cerebellum behind and the medulla oblongata below. On its 
 under surface it presents a groove for the passage of the basilar 
 artery. The upper surface forms a portion of the floor of the 
 
288 
 
 HUMAN xlNATOMY. 
 
 Oj>.n 
 
 C.fnam 
 
 / 
 
 . y^m^tu .. 
 
 Dp tr 
 
 IS- -t 
 
 W 
 
 ^h-s.u 
 
 V.m.fffr 
 
 Pig. 132. 
 
 Surface anatomy of the myelencephalon. (Roman numerals refer 
 to cranial nerves.) C. 1, first cervical spinal nerve; C. mam., corpus 
 naammlllare; Op. n., optic nerve; Inf., infundibulum; Op. ch., optic 
 chiasm; Subs, int., substantia interpeduncu-geniculate body s Sub. b., 
 basilar sulcus; M. p. c, middle peduncle of cerebellum; P., flocculus; 
 P. h., horizontal fissure; C, olive; V. 1. s., ventrolateral sulcus; Pyr., 
 pyramid; V. m. t., ventral median fissure. (Aflcr Tan Gehuchteti.) 
 (Whitclieacl.) 
 
 fourth ventricle, and on either side, under the name of the crus 
 cerebelli, it passes to the cerebelhim, forming its middle peduncle. 
 
 OEREBELLFir. 
 
 The cerchelJiim. or little brain, occupies the inferior occipital 
 fossse beneath the great cerebral lobes, from which it is separated 
 by the tentorium. Its average weight is a little over five ounces 
 in the male, and is proportioned to the greater brain about one 
 to twenty. It is oblong, flattened from abova downward, and 
 
THE NERVOUS SYSTEM. 
 
 289 
 
 divided into two lateral hemispheres connected by a central por- 
 tion, the vermiform process. 
 
 It is composed of gray and white matter — the former upon 
 the surface. It is not convoluted, like the cerebrum, but con- 
 sists of a number of thin plates, folia, arranged in a series of 
 crescentric curves, with the concavity forward. 
 
 The cerebellum consists of a central lobe, or vermis, and two 
 lateral hemispheres. The latter are separated on the inferior 
 surface of the cerebellum by a deep hollow, the vallecula, which 
 lodges the medulla oblongata. The floor of the vallecula is 
 formed by the inferior portion of the vermis. 
 
 The incisura cerebelli anterior, anterior cerebellar notch, 
 separates the hemispheres in front, and rests against the corpora 
 quadrigemina ; 
 
 The incisura cerebelli posterior, posterior cerebellar notch, 
 or incisura marsupialis, separates the hemispheres behind, and 
 receives the upper portion of the f alx cerebelli ; 
 
 The great horizontal fissure separates the cerebellum into 
 a superior and an inferior surface. 
 
 The upper surface of the cerebullum shows the superior 
 vermis, with its corresponding lobes in the hemispheres. These 
 latter are separated from each other by fissures. The following 
 table gives the arrangement of the lobules : — 
 
 Great horizontal fissure. 
 
 Pre- 
 
 Post- 
 
 Pre- 
 
 Post- 
 
 Frenui.um. 
 
 Ala. 
 
 Great 
 
 Anterior 
 
 crescentic 
 
 lobule. 
 
 Posterior 
 
 crescentic 
 
 lobule. 
 
 LlJfGUI.A. 
 
 Lobus centralis. 
 
 Lobus eulminis. 
 
 Lobus clivi. 
 
 Folium cacuminis. 
 
 FnEJSfULUM. 
 
 Ala. 
 
 Anterior 
 
 crescentic 
 
 lobule. 
 
 Posterior 
 
 crescentic 
 
 lobule. 
 
 Posterior 
 superior 
 lobule. 
 
 -central fissure, 
 -central fissure. 
 
 -clival fissure. 
 
 -clival fissure. 
 
 horizontal 
 ~ fissure. 
 
 The inferior surface of the cerebellum presents the deep 
 depression, the vallecula, which renders the connection between 
 
290 
 
 HUMAN ANATOMY. 
 
 the vermis and the hemisiDheres less intimate. The divisions 
 of the vermis and their corresponding lobules in the* hemispheres 
 are as follows : — 
 
 Great 
 
 Post- 
 
 Pre- 
 
 Post- 
 
 Great 
 
 Slender lobe, 
 post gracile pos- 
 terior inferior 
 lobule. 
 
 Lobulus 
 biventer. 
 
 Amygdala. 
 
 Flocculus. 
 
 Tuber valvulse. 
 
 Pyramis. 
 
 Uvula. 
 
 Nodule. 
 
 Posterior 
 Inferior 
 lobule. 
 
 Lobulus 
 biventer. 
 
 Amygdala. 
 
 Flocculus. 
 
 horizontal 
 fissure. 
 
 pyramidal 
 
 fissure. 
 
 pyramidal 
 fissure. 
 
 nodular 
 fissure. 
 
 horizontal 
 fissure. 
 
 The cerebellum is connected with the encephalon by the 
 peduncles of the cerebellum^ three in number, from above down- 
 ward, as follows : — 
 
 Crura ad cerebrum, superior, or processus e cerebello ad 
 testes, pass to the cerebrum; 
 
 Crura ad posterior, middle, or processus ad pontem, the 
 transverse fibres of the pons Varolii, connect the hemispheres ; 
 
 Crura ad medullam, inferior, or processus a cerebello ad 
 medullam, the restiform bodies of the medulla oblongata, connect 
 with medulla oblongata. 
 
 The internal structure of the cerebellum consists of an arbor 
 vitse arrangement of gray matter, inclosing a white mass. In 
 centre of the latter is found a grayish, dentated mass, the corpus 
 dentatum, an irregular capsule of gray matter opening anteriorly. 
 
 THE CEREBRUM 
 
 consists of a large, ovoidal mass, divided into two lateral halves, 
 or hemispheres, by the great longitudinal fissure, connected by 
 a white, transverse coinniissure — the corpus callosum. The sur- 
 face is irregularly marked by convolutions, or gyri, separated 
 from each other by irregiilar depressions, fissures, or sulci. The 
 outer surface is composed of gray matter, which, from its loca- 
 tion, is called the cortical substance. The interior surface, for 
 the most part, is white. 
 
THE NERVOUS SYSTEM. 
 
 291 
 
 The principal fissures of the brain are five, as follows : — 
 
 1. The great longitudinal fissure, separating the two hemispheres 
 from one another. 
 
 2. The great transverse fissure of Bichat, between the cerebellum 
 and the cerebrum, admitting the pia mater to form the velum inter- 
 positum. 
 
 3. The fissure of Bylvius, beginning at the anterior perforated 
 space and ascending obliquely. 
 
 4. The fissure of Rolando, descends from near the middle of the 
 great longitudinal fissure to join the fissure of Sylvius. 
 
 ^.f.ns. 
 
 -^^^p. S..postei 
 
 Ji.ant:cisc.5. 
 
 S.temp.. 
 
 ■(S.'fefnp.Tn^ 
 
 Pig. 133. 
 
 Left Bide of human cerebrum. S. fr. B., superior frontal sulcus; 
 S. praec, precentral sulcus; S. R., central sulcus of Rolando; S. poste., 
 Post-central sulcus; S. interp., Interparietal sulcus; S. p. o., parieto- 
 occipital fissure; Ram. post. S., posterior ramus of fissure of Sylvius; 
 S. temp, m., middle temporal sulcus; S. temp, s., superior temporal 
 sulcus: F. S., fissure of Sylvius; R. ant. asc. S., ascending anterior 
 ramus of fissure of Sylvius; R. a. h. S., horizontal anterior ramus of 
 fissure of Sylvius; S. fr. inf., inferior frontal sulcus. (After Tan 
 Oehuchten.) (Whitehead.) 
 
 5. The parieto-occipital fissure, on the postero-lateral aspect of the 
 cerebrum. 
 
 6. The calloso-marginal fissure. 
 
 7. The collateral fissure. 
 
 8. The limiting sulcus of ReiL 
 
292 
 
 HUMAN ANATOMY. 
 
 The principal lobes of the brain are six, as follows : — 
 
 1. Frontal lobe, on the outer surface of the brain; it is bounded 
 below by the fissure of Sylvius, and behind by the fissure of Rolando. 
 On the mesial surface it is bounded by the callaso-marginal fissure, and 
 on the inferior surface it is bounded behind by the stem of the Sylvian 
 fissure. 
 
 On the outer surface it is divided into the 
 (a) Gyrus frontalis ascendens; 
 Cb) Gyrus frontalis superior; 
 
 (c) Gyrus frontalis medius; 
 
 (d) Gyrus frontalis inferior. 
 
 suice. 
 
 
 Sulsiibf' 
 
 .,,Sulcalmgiy. 
 
 Fi!s.csk. 
 
 Convolutions and fissures of the median and tentorial surfaces of 
 the right cerebral hemisphere. Fis. S., fissure of Sylvius; Sul. cal. 
 marg., calloso-marginal sulcus; Sul. subt., subf rental sulcus; Sul. 
 C. C, sulcus of corpus callosum; Sul. marg., marginal sulcus; Sul. 
 Bubp., subparietal sulcus; Fis. p. o., parieto-occipital fissure; Fis. 
 calc, calcarine fissure; Fis. den., dentate fissure; Fis. col., collateral 
 Assure. (A^er Tan Oehuchten.) iTVMtehead.) 
 
 On the mesial surface it is divided into 
 
 (a) Gyrus marginalis; 
 
 (b) Paracentral lobule. 
 
 On the orbital surface it is divided into 
 (aj Gyrus orbitalis internus; 
 
 (b) Gyrus orbitalis anterior; 
 
 (c) Gyrus orbitalis posterior. 
 
 2. Parietal lobe, lies between the fissure of Rolando, the parieto- 
 occipital, and the fissure of Sylvius, and consists of five gyri: — 
 
 (a) Ascending parietal; "j Supramarginal, 
 
 (b) Superior parietal; V Angular, 
 
 (cj Inferior parietal, J Post parietal; 
 
THE NERVOUS SYSTEM. 
 
 293 
 
 3. Occipital lobe, lies at the posterior aspect of the cerebrum and 
 is divided into first, second, and third occipital convolutions. 
 
 4. Temporo-sphenoidal lobe, occupies the middle fossa of the skull. 
 
 Sul.pl/. 
 
 -'^^ul.temp.inj' 
 '- -Fis.co2. 
 
 FlO. 135. 
 
 Inferior aspect of cerebral hemisphere. Sul. olf . 
 Sul. temp, inf., inferior temporal sulcus; Pis. col., 
 (Aiter Fon Oehuchten.) (WMteliead.) 
 
 olfactory sulcus; 
 Collateral fissure. 
 
 5. Island of Reil, or central lobe, lies within the fissure of Sylvius. 
 It consists of six convolutions — the gyri operti. 
 
 6. The limbic lobe surrounds the corpus callosum. Its extremities 
 are united hj the roots of the olfactory tract. 
 
294 HUMAN ANATOMY. 
 
 The inner of median surface of the hemispheres presents five 
 fissures, as follows : — 
 
 1. Calloso-marginal. 
 
 2. Parieto-occipital. 
 
 3. Calcarine. 
 
 4. Oocipito-temporal or collateral. 
 
 5. Dentate fissure, or sulcus hippocampi. 
 
 The lobes on the iaternal surface are six in number, as 
 follows : — 
 
 1. Gyrus fornicatus, or convolution of the corpus callosura, de- 
 scends as the gyrus hippocampi and terminates as the uncinate gyrus. 
 
 2. Marginal, or first frontal convolutions. 
 
 3. Quadrate, or prseeuneus. 
 
 4. Cuneus, or occipital lobule. 
 
 5. Uncinate gyrus. 
 
 6. Temporo-sphenoidal lobe. 
 
 The inferior surface of each hemisphere is divided into three 
 lobes — the anterior, middle, and posterior. The two former 
 occupy the anterior and middle fossa of the sloill and the poste- 
 rior rests upon the cerebellum, separated from it by the tento- 
 rium. This surface presents for study from before backward 
 the following points: — 
 
 The longitudinal fissure, separates the two hemispheres ; 
 
 Corpus callosum, the great transverse commissure of the cerebrum, 
 extending by means of its peduncles to near the Sylvian fissure ; 
 
 Lamina cinerea, is a thin, gray layer, forming the anterior part of 
 the inferior boundary of the third ventricle; 
 
 Olfactory nerve, with its bulb; 
 
 Fissure of Sylvius, between the anterior and middle lobes of the 
 cerebrum, and lodges the middle cerebral artery; 
 
 Anterior perforated space, transmits vessels to the corpus striatum; 
 
 Optic commissure, is formed by the junction of the optic tracts; 
 
 Tuber cinereum, is a gray eminence between the corpora albicantia 
 and optic tracts, and forms part of the floor of the third ventricle; 
 
 Infundibulum, is a tube of gray matter connecting the pituitary 
 body with the third ventricle; 
 
 Pituitary body, is a small, vascular, bilobed body, connected by 
 the infundibulum and occupying the sella Turcica (for histologv vide 
 "Ductless Glands"); °^ 
 
 Corpora albicantia, or mammillaria, are two white, rounded 
 masses, formed by the folding of the anterior crura of the fornix, and 
 are sometimes called the bulbs of the fornix; 
 
 Posterior perforated space, allows the passage of blood-vessels to 
 the optic thalami; 
 
 Crura cerebri, or cerebral peduncles, connect the cerebrum with the 
 medulla, cerebellum, and spinal cord; it consists of the anterior portion, 
 
THE NERVOUS SYSTEM. 295 
 
 or crusta, and the posterior portion, or tegmentum, between which is a 
 mass of gray matter — the locus niger; 
 
 Pons Tarolii, covers up the posterior portion of the cerebral lobes. 
 
 Interior of the Cekebkum. — The interior of the cerebrum, 
 viewed above the level of the corpus callosum, presents a white 
 surface — the centrum ovale mintis, the margins of which are con- 
 voluted gray matter, and are called lahia cerebri. It is studded 
 throughout with minute blood-vessels — puncta vasculosa. 
 
 The hemispheres, viewed on a level with the corpus callosum, 
 present a large white mass — the centrum ovale majus — in the 
 centre of which is the connecting band, the corpus callosum. 
 
 Corpus Callosum. — This connecting band forms the roof of 
 the lateral ventricles. It is about four inches in length and 
 varies from an inch and a half to two inches in width, presenting 
 in front a bend, or genu, below which it terminates in the tuber 
 cinereum through the lamina cinerea. 
 
 Posteriorly it forms a thick, rounded fold — ^the splenium, 
 or pad — which is continuous with the fornix. 
 
 The peduncles of the corpus callosum are two reflected bun- 
 dles of white matter given off near the anterior termination of 
 the corpus, and each passing backward across the anterior per- 
 forated space of its own side to the fissure of Sylvius. 
 
 The superior surface of the corpus callosum shows a depres- 
 sion — the raphe — ^bounded on each side by elevated bands, the 
 strice longitudinales, or nerves of Lancisi. External to these 
 are the strice longitudinales laterales. On either side of the raphe 
 are many transverse lines — ^the lineje transversse, which indicate 
 the direction of the fibres of the corpus. 
 
 The cerebral commissures are connecting bands of gray 
 and white matter, pursuing either a transverse or antero-posterior 
 course. 
 
 Transverse: — 
 
 Anterior, middle, and posterior commissures; 
 
 Corpus callosum; 
 
 Optic chiasm; 
 
 Fornix; 
 
 Pons Varolii; 
 
 Posterior medullary velum. 
 
 Antero-posterior: — 
 
 Corpus callosum (nerves of Lancisi) ; 
 
 Fornix ; 
 
 Fasciculus uncinatus; 
 
 Tsenia semicircularis; 
 
 Gyrus fornicatus; 
 
296 HUMAN ANATOMY. 
 
 Fasciculus longitudinales inferior; 
 
 Olfactory tracts; 
 
 Crura cerebri; 
 
 Peduncles of pineal gland; 
 
 Processus e cerebello ad testes. 
 
 VENTRICLES OF THE BRAIN. 
 
 The interior of the brain contains five distinct cavities, 
 named the ventricles of the brain, situated as follows : Two lat- 
 eral ventricles in the upper part, within the substance of the 
 hemispheres, the third ventricle between the optic thalami at the 
 base of the brain, the fourth ventricle between the medulla 
 oblongata and the cerebellum, and the fifth ventricle within the 
 septum lucidum between the two lateral ventricles. 
 
 The ventricles intercommunicate- — the two lateral ventricles 
 with the third by means of the foramen of Monro, the third 
 with the fourth ventricle by means of the iter a tertio ad quartum 
 ventriculum, and, in the foetus, with the fifth, and through the 
 infundibulum with the cavity of the pituitary body. 
 
 The lateral ventricles are bounded as follows: — 
 
 The roof, the corpus callosum; the floor is formed by the follow- 
 ing parts from before backward: corpus striatum, taenia semicircu- 
 laris, optic thalamus, choroid plexus, corpus fimbrlatum and fornix; 
 internally, by the septum lucidum; externally, in front and behind by 
 the brain-substance. Each lateral ventriole presents three cornua — the 
 anterior cornu, posterior cornu, or digital cavity, and the middle cornu. 
 
 The anterior cornu curves outward and forward over the 
 corpus striatum and into the anterior lobe. 
 
 The middle cornu passes into the middle lobe, ascending to 
 the transverse fissure at the base of the brain. Its course is back- 
 ward, outward, downward, forward, and inward (B., 0., D., 
 F.,L). 
 
 The posterior cornu runs backward into the posterior lobe, 
 its course being backward, outward, and inward (B., 0., I.). 
 
 Parts of Lateral Ventricle — Corpus Callosum. — Described 
 above. 
 
 Septum Lucidum. — Forms the internal boundary of the 
 lateral ventricle. It consists of two layers of white and gray 
 matter, and is attached above to the under surface of the corpus 
 callosum, below to the fornix, and anteriorly to the prolongation 
 of the corpus callosum. 
 
 B.etween the laminse forming the septum is a narrow interval 
 — the fifth ventricle. 
 
 The Corpus Striatum. — Situated in the lateral ventricle, its 
 broad end directed forward into the fore part of the body and 
 
THE NERVOUS SYSTEM. 
 
 297 
 
 anterior cornu of the ventricle, its narrow end directed outward 
 and backward, and separated from its fellow by the thalami 
 optici. 
 
 The intraventricular portion is called the caudate nucleus, 
 the extraventricular the lenticular nucleus, the two separated 
 by the internal capsule. 
 
 —Antcaif 
 ^JfuclcauJ 
 
 JVelint 
 Chp} 
 
 ' Post.cor. 
 
 Fio. 136. 
 
 The lateral ventricles and choroid plexus. St. term., stria termln- 
 alis; Thai., thalamus; Hipp., hippo-campus; Fimb., fimbria; Ant. cor., 
 anterior cornu Of lateral ventricle; Nucl. caud., nucleus caudatus; Col. 
 for., columns of- thfe fornix; Vel. int.. Velum interpositum; Ch. pi., 
 choroid plexus; Cal. av., calcar avis; Post, cor., posterior cornu of 
 lateral ventricle. (After Gray.) (.Whitehead.) 
 
 The internal capsule is a large layer of white fibres, derived 
 from the medulla and crura cerebri, separating the lenticular 
 nucleus from the caudate nucleus anteriorly, and the lenticular 
 nucleus from the optic thalamus posteriorly. 
 
298 HUMAN ANATOMY. 
 
 The external capsule is a small layer of white fibres on 
 the outer surface of the corpus striatum, between the lenticular 
 nucleus and the elaustrum. 
 
 The elaustrum is a convoluted layer of gray fibres between 
 the external capsule and the island of Eeil. 
 
 The Tcenia Semicircularis, or Horny Band of Tarinus. — A 
 band of medullary substance in the furrow between the corpus 
 striatum and the optic thalamus. Its anterior portion descends 
 with the anterior pillar of the fornix, its posterior portion passes 
 into the descending horn. Beneath it is the vena corporis striati. 
 
 The choroid plexus, a vascular membrane, occupying the 
 margin of a fold of pia mater, known as the velam interpositum. 
 It runs across the floor of the lateral ventricle, and communicates 
 with its fellow of the opposite side through the foramen of 
 Monro. Posteriorly it descends into the middle horn of the 
 lateral ventricle. 
 
 The corpus fimbriatum (tfenia hippocampi), a narrow white 
 band behind the choroid plexus. It is the lateral edge of the 
 posterior pillar of the fornix. 
 
 The fornix, a lamella of white fibrous matter, beneath the 
 corpus callosum, continuous with it posteriorly, but separated 
 from it anteriorly by the septum lucidum. It consists of two 
 symmetrical halves which join to form the iody, each half having 
 an anterior and posterior crus where they do not join. 
 
 The anterior crura curve down to the base of the brain, 
 where each crus spreads out and curves upon itself to form 
 the corpus albicans of that side. Prom this point it passes to 
 the corresponding optic thalamus. 
 
 The posterior crura, at their commencement, are joined to 
 the under surface of the corpus callosum. They pass downward 
 into the descending horns of the lateral ventricles, being con- 
 tinuous with the concave borders of the hippocampi majores. 
 
 The lateral edge of the posterior crus is called the corpus 
 fimbriatum. 
 
 The lyra is a series of lines, some transverse, others longi- 
 tudinal and oblique, on the under surface of the fornix, between 
 the diverging posterior crura. 
 
 Optic Thalamus. — The thalami optici are two large gan- 
 glionic masses, situated between the diverging portions of the 
 corpora striata. Each thalamus rests upon the corresponding 
 crus cerebri. 
 
 The thalamus is bounded externally by the corpus striatum 
 and taenia semicircularis, and internally forms the lateral bound- 
 ary of the third ventricle. 
 
THE NERVOUS SYSTEM. 299 
 
 Its upper surface is partly covered by the fornix. Its 
 under surface forms the roof of the descending horn of the lateral 
 ventricle. 
 
 Its posterior and inferior part exhibits two rounded emi- 
 nences, the external and internal geniculate bodies. Its anterior 
 extremity forms the posterior boundary of the foramen of Monro, 
 which foramen connects the two lateral ventricles with the third. 
 
 Velum interpositum, a vascular membrane, reflected from 
 the pia mater into the interior of the brain through the trans- 
 verse fissure. It passes beneath the posterior border of the corpus 
 callosum and fornix, and above the corpora quadrigemina, the 
 pineal gland, and the optic thalami. It forms the roof of the 
 third ventricle. Its anterior extremity passes on each side into 
 the corresponding lateral ventricle, forming the anterior extrem- 
 ity of the choroid plexus. The vascular fringes of the velum 
 interpositum projecting into the third ventricle are called the 
 choroid plexuses of the third ventricle. 
 
 It has two veins, the venee Galeni, which run along its under 
 surface and are formed by the veins of the choroid plexuses and 
 the venae corporis striata. The vense Galeni unite to form a 
 single trunk and empty into the straight sinus. 
 
 The posterior cornu of the lateral ventricle runs into the 
 substance of the posterior lobe. On the floor of this horn is an 
 eminence corresponding to a sulcus between two convolutions, 
 and called the hippocampus minor. 
 
 Between the posterior and middle horns is another emi- 
 nence — ^the eminentia collateralis, or pes accessorius. 
 
 The hippocampus major, or cornu ammonis, a white emi- 
 nence running the entire length of the floor of the middle horn. 
 This eminence is the doubled-in surface of the gyrus fornicatus. 
 
 The lower extremity of the hippocampus major is called 
 the pes hippocampus. 
 
 The fascia dentata, the gray and serrated edge of the middle 
 lobe. It is really external to the cavity of the middle cornu. 
 
 The third ventricle is a mere flssure in the median line 
 of the cerebrum, situated between the optic thalami. It com- 
 municates with the lateral ventricle by the foramen of Monro 
 and with the fourth ventricle by the iter a tertio ad quartum 
 ventriculum. The cavity is crossed by three commissures — the 
 anterior commissure, a white, rounded cord; the middle or soft 
 commissure, composed of gray matter; and the posterior com- 
 missure, a white band connecting the two optic thalami. It is 
 bounded by the following structures: — 
 
300 HUMAN ANATOMY. 
 
 The roof, by the vlum interpositum, suspending tTiQ choroid plex- 
 uses of the third ventricle, and laterally the peduncles of the pineal 
 gland; floor, by the parts inclosing the interpeduncular spax:e at the 
 base of the brain, viz. : the lamina, cinerea, tuber cinereum and infundibu- 
 lum, corpora albicantia and the posterior perforated space ; laterally, by 
 the optic thalami; in front, by the anterior commissure and anterior 
 crura of the fornix; behind, the posterior commissure and the iter a 
 tertlo ad quartam ventriculum. 
 
 The fourth ventricle is a diamond-shaped cavity between 
 the cerebellnm behind and the posterior surface of the medulla 
 oblongata and pons in front. It is inclosed behind by the pia 
 mater, which contains an opening for the exit and entrance of 
 
 ■C.hp|l»oi,d > 
 
 
 /P.'^eal Stria 
 ^^-^.^^^^ /P'lea) Kece*& 
 
 of fir ^nt. 
 
 
 
 .^/^^^ Pineal Body 
 
 ^mf^^ jL^S'H.p. Corp. O.M.aJ, 
 W^^>^::^^r^^-^r^;^'^^^i ^f Sylvia ^ 
 
 1 
 
 )KSii^""^' 
 
 
 \ 
 
 
 
 ■fe 
 
 
 FlO. 137. 
 
 Mesial section of brain and brain stem. 1, anterior commissure; 
 2, middle commissure; 3, posterior commissure: 4, pituitary body; 
 IV, fourth ventricle. 
 
 the subarachnoid fluid from the subarachnoidean space of the 
 brain and spinal cord, and a vascular fold of pia matfer — the 
 choroid plexus. It communicates in front with the third ven- 
 tricle by the iter a tertio ad quartum ventriculum. It is bounded 
 as follows : — 
 
 The roof, valve of Vieussens and the cerebellum, containing in front 
 the foramen of Magendie, by which it communicates with 'the subarach- 
 noidean space; the floor, the posterior median fissure of the medulla 
 and pons, the fovea posterior, the orifice [ventricle of the central canal 
 of the cord] of Aurantius, the locus caeruleus, and the taenia violacea. 
 
THE NERVOUS SYSTEM 801 
 
 the calamus scriptorius and the fasciculi teretes; anteriorly, the pons 
 Varolii and medulla oblongata; posteriorli') the cerebellum j laterally, 
 the processus a cerebello ad testes, the restiform bodies, and posterior 
 pyramids of the medulla. 
 
 Its lining membrane is continuous with that of the third 
 ventricle. The gray matter of the floor of the fourth Yentricle 
 presents masses for the origin of certain cranial nerves. 
 
 The fifth ventricle is a narrow fissure, formed within 
 the two lamina of the septum lucidum, being origiaally a part 
 of the great longitudinal fissure. It is bounded : — 
 
 Above, by the under surface of the corpus callosum; 
 Below, by the anterior part of the fornix; 
 
 Laterally, by the lateral ventricles, from which it is separated by 
 the septum lucidum. 
 
 It is not lined with epithelium. 
 
 The mesencephalon includes those portions of the brain 
 SAibstance which connect the cerebrum, cerebellum, and medulla 
 oblongata together, and comprises the following structures : — 
 
 Crura cerebri, before described {ante, p. 294). 
 
 The valve of Vieussens, or anterior medullary velum, is a 
 thin layer of white matter stretched between the processes e 
 cerebello ad testes, and forming the roof of the iter a i-ertio ad 
 quartum ventriculum. It presents an elevated ridge descending 
 on its upper part from the corpora quadrigemina — the frcenulum. 
 
 Corpora or tubercula quadrigemina, or optic lobes, are four 
 spherical eminences, placed in pairs above the valve of Vieussens, 
 ind behind the third ventricle, beneath the posterior border of 
 the corpus callosum. 
 
 The two anterior are called the nates, the two posterior the 
 testes. The brachia (anterior and posterior) are two white 
 cords connecting them with the optic thalamus and beginning 
 of the optic tracts. 
 
 The processus a cerebello ad testes connect them with the 
 cerebellum. 
 
 To the outer side of the optic lobes are two small masses 
 called the corpus geniculatum externum and internum. 
 
 The pineal gland, or epiphysis cerebri, is a small, reddish, 
 conical body resting upon and between the nates. It represents 
 the rudiment of a median eye of certain extinct lizards and am- 
 phibia (Spencer), well marked in Hatteria. It is attached to 
 the cerebrum ]jy its two peduncles, and is held in position by a 
 fold of the pia mater. It contains a cavity, filled with a viscid 
 fluid and secretory matter composed of phosphate and carbonate 
 of lime, phosphate of magnesia, ammonia, and a little animal 
 matter — the acervuliis cerebri. 
 
302 HUMAN ANATOMY. 
 
 THE INTERNAL STRUCTURE OP THE MEDULLA OBLONGATA. 
 
 The anterior and lateral pyramidal tracts of the cord are 
 continued into the medulla oblongata as the pyramids. The 
 lateral pyramidal tracts decussate in the lower part of the me- 
 dulla. 
 
 The anterior ground bundle is continued upward • into the 
 medulla as the posterior longitudinal bundle. It lies behind the 
 pyramids in the medulla. 
 
 The sensory columns of the cord (Goll and Burdach) are 
 continued into the medulla oblongata and terminate in the 
 funiculus gracilis and cuneatis. They increase in size and each 
 develops a uncleus : the clava and cuneate nucleus, respectively. 
 These fibres partly form the restiform bodies. 
 
 The decussation of the sensory fibres takes place at a higher 
 plane than that of the motor fibres. It is also called the decus- 
 sation of the fillet and it consists of the decussating fibres derived 
 from the clava and the cuneate nucleus. These fibres are called 
 deep arcuate fibres. After decussating the fibres are continued 
 upward behind the pyramids, displacing backwards the posterior 
 longitudinal bundle. 
 
 In the medulla on cross-section are seen the olivary bodies, 
 which contain the dentate nuclei. 
 
 The restiform bodies, or inferior cerebellar peduncles are 
 formed by the direct cerebellar tract, the posterior superficial 
 arcuate fibres, the anterior superficial arcuate fibres, and the 
 cerebello-olivary fibres. 
 
 The formatio reticularis is seen behind the pyramids and 
 the olivary bodies in the medulla oblongata. It is composed of 
 the deep arcuate fibres, fibres of Gower's tract, and the antero 
 lateral ground bundle. 
 
 The gray matter of the cord is continued into the medulla. 
 The anterior horns are cut off and displaced by the decussation of 
 the lateral pyramidal tract and the posterior horns are displaced 
 outward by the increase in size of the posterior sensory tracts. 
 The latter are known as the nucleus of Eolando and are capped 
 by the substantia gelatinosa Eolandi. 
 
 The central canal is expanded into the fourth ventricle. 
 The gray matter forms nuclei for the cranial nerves in the floor 
 of the fourth ventricle. 
 
THE NERVOUS SYSTEM. 303 „ 
 
 THE IXTEKXAL STRUCTURE OF THE POXS YAEOLII. 
 
 On cross-section the pons is seen to consist of a dorsal 
 tegmental part, and a ventral part, or crusta. 
 
 The crusta is composed of transverse fibres (fibres from the 
 cerebellum to the pons and from the nucleus pontis to the cere- 
 bellum), which go to form the middle cerebellar peduncles; lon- 
 gitudinal fibres, which belong to the pyramidal tracts, much scat- 
 tered; and gray matter, which here forms a nucleus called the 
 nucleus pontis. 
 
 The tegmentum of the pons contains a thick layer of gray 
 matter, which forms the floor of the fourth ventricle, and from 
 which cranial nerves take their origin; formatio reticularis, 
 which is the continuation upward of the same from the medulla ; 
 the superior olivary nucleus; the posterior longitudinal bundle; 
 the fillet; the superior cerebellar peduncle; and the corpus 
 trapezoides. 
 
 The fillet occupies a position between the crusta and tegmen- 
 tum, and to differentiate it from a tract that makes its appear- 
 ance above the nucleus of the third nerve is called the me- 
 sial fillet. 
 
 The other tract is named the lateral fillet. 
 
 The lateral fillet is composed of longitudinal fibres which 
 take origin from the nucleus of the eighth cranial nerve (coch- 
 learis) of the same side, from that of the opposite side, and 
 from the superior olive. They end in the inferior quadri- 
 geminal body, the internal geniculate body, and a few in the 
 superior quadrigeminal body. 
 
 The mesial fillet has been described. It takes its origin in 
 the medulla from the cuneate and gracile nuclei of the opposite 
 side. Some of its fibres end in the superior quadrigeminal body, 
 but the remainder pass through the subthalamic tegmental 
 region into the posterior part of the lateral nucleus of the optic 
 thalamus. Some end here, while some are continued through 
 the thalamus, enter the corona radiata, and pass to the posterior 
 central gyrus of the Eolandic region. 
 
 THE STRUCTURE OF THE CEREBELLUM. 
 
 On section the gray matter of the cerebellum is found to 
 occupy the cortex; to its arborescent appearance the term arbor 
 ritce has been applied. 
 
 The white matter, medullary body, of each hemisphere con- 
 tains a nucleus of gray matter : the corpus dentatum. 
 
 The middle peduncles connect the cerebellum with the pons. 
 
304 HUMAN ANATOMY. 
 
 The inferior peduncles, or restiform bodies, connect the 
 medulla and cord with the cerebellum. 
 
 The superior peduncles connect the cerebellum with the 
 cerebral cortex. After decussating below the corpora quadri- 
 gemina some of the fibres pass to the opposite red nucleus in 
 the tegmentum of the crura cerebri passing through the optic 
 thalamus to end in the Eolandic region, and others end in the 
 optic thalamus. Each superior peduncle contains both aflEerent 
 and efferent fibres. 
 
 The cerebellar cortex consists of two layers : an outer, 
 molecular layer, and an inner, granular layer. Between these 
 two layers is a single layer of large cells, the cells of Purkinje. 
 
 THE STEUCTUEE OF THE illDBEAIN. 
 
 The midbrain consists of a dorsal part, the corpora quad- 
 rigemina, and a ventral part, the crura cerebri. 
 
 It is tunneled by the aqueduct of Sylvius, which connects 
 the fourth ventricle with the third ventricle. 
 
 The upper end of the crura cerebri is encircled by the optic 
 tract. 
 
 On section the crura cerebri show a ventral and lateral 
 portion, — the tegmentum, — and a dorsal portion, the lamina 
 quadrigemina. The ventral portion contains the substantia 
 nigra. The fissure of Sylvius is surrounded by gray matter, 
 from which the third and fourth cranial nerves take origin. 
 
 The inferior or posterior quadrigeminal bodies contain the 
 fibres of the lateral fillet posteriorly and the brachium laterally. 
 
 The superior or anterior quadrigeminal bodies consist of four 
 strata : stratum zonale, stratum cinereum, stratum opticum, and 
 stratum lemnisci. The mesial and upper fillet in part ends in 
 the latter, which also contains large nerve-cells. 
 
 Some fibres from the occipital lobe and fibres from the 
 retina, conveyed by the superior brachium, end in the superior 
 quadrigeminal bodies. 
 
 The superior cerebellar peduncles have been described ; they 
 connect the cerebellum with the cerebral cortex. 
 
 The red nucleus is found in the tegmentum. Some of the 
 fibres of the superior cerebellar peduncles end there. 
 
 The posterior longitudinal bundle lies in tlie tegmentum and 
 is the continuation upward of the tract of the same name in 
 the medulla and pons. It is connected with the nuclei of the 
 motor nerves of the muscles of the eyeball. 
 
 The lateral fillet is continued upward from the pons in the 
 tegmentum. Its connections with the superior olivary nuclei 
 and the nuclei of the eighth nerve have been described. 
 
THE NERVOUS SYSTEM. 
 
 305 
 
 The mesial fillet likewise is eontinued upward from the pons 
 in the tegmentum of the crura. The course of the fibres has 
 been described. 
 
 The crusta of the crura contains the pyramidal fibres and 
 the cortico-pontine fibres. 
 
 H.nuci.caiid-. 
 
 Ant con. 
 
 Tnuc/. caud: . 
 
 ■St term 
 Paly. : 
 
 /^ntcol .. 
 Post Col 
 
 ^n}:cdH 
 
 ..-Hnuclcaui/. 
 
 -J-ilnt.cap. 
 
 £xt.cap. 
 Is/. 
 MecL ?ent 
 
 ■ Claus. 
 -■-fi Lint cap. 
 
 Thai. 
 
 ■ C.jf.m. 
 -• T.nud.caudl 
 
 Tinih 
 -Hipp. 
 
 Post, con 
 
 Fig. 138. 
 
 Interior of mesencephalon. For., -fornix; Sep. pel., septum pellu- 
 cidum; Col. for., column of fornix; H. nucl. caud., head of nucleus 
 caudatus; Ant. com., anterior commissure: T. nucl. caud., tail of 
 nucleus caudatus; Mas. int. massa intermedia; Thai., thalamus; St. 
 term., stria terminalis; Pulv., pulvinar; Ant. col., anterior colliculus; 
 Post, col., posterior colliculus; IV, Trochlear nerve; Ant. cor., anterior, 
 cornu of lateral ventricle; A. 1. int. cap., anterior limb of internal 
 capsule; Ext. cap., external capsule; Isl., island of Reil; Nucl. lent., 
 nucleus lentiformis; Claus., claustrum; P. 1. int. cap., posterior limb 
 of internal capsule; Hipp., hippocampus; Post, cor., posterior cornu of 
 lateral ventric' 'After Landois.) Whitehead.) 
 
306 
 
 HUMAN ANATOMY. 
 
 SENSORV MOTOR AREA > 
 
 INTERNAL CATSVtB 
 
 FIRST TEMF ORAl. 
 OYBUS ' 
 
 SENSORY DECUSSATION 
 <D1SCUSSATI0N OF FILLET 
 
 NUCLEUS CUNEATIS. 
 
 QOWERS'S TRACT 
 
 <!!}>!?■ 
 
 OF CEREBELLUS 
 
 , •'•'^'■^ J\ CERE BELLAR 
 
 :- ^ CORTEX 
 
 ''•'... y DENTATE 
 
 NUCLEUS 
 
 FIFTH NERVE 
 
 EIGUTH NERVE 
 NINTH NERVE 
 TENTH NERVE 
 
 NUCLEUS GRACILIS 
 
 , POSTEROMEDIAN COLUMN 
 POSTEROLATERAL COLUMN 
 
 -DIRECT CEREBEUJ\R TRACT 
 
 POSTERIOR NERVE ROOT 
 
 FlQ. 139. 
 
 Diagram of sensory tracts from spinal cord to brain (original). 
 
THE NERVOUS SYSTEM. 
 
 307 
 
 CORTSX OF THE 
 BBNSORY MOTOR AREA 
 
 CORONA BADIATA 
 
 INTERNAL CAPSULE 
 
 >7V.'v''/'' ■-,■■■.■. t- '^•*'™-*TE NUCLEUS 
 ^^imi I \''\ ' ' •] °™C THALAMUS 
 
 LENTICULAR NUCLEUS 
 
 roURTH NERVE 
 
 •PINAL COED 
 
 DECUSSATION OF PYRAMIDS 
 
 ANTERIOR PYRAMIDAL TRACT 
 
 ANTERIOR COMMISSURE 
 
 THIRD NERVK 
 
 FIFTH NERVE 
 
 SIXTH NERVE 
 SEVENTH NERVE 
 
 NINTd NERVE 
 
 TENTH NERVE 
 
 ELEVENTH NERVE 
 
 TWELFTH NERVB 
 
 UTERAL PYRAMIDAL TRACT 
 
 ANTERIOR-NERVE ROOT 
 
 Fig. 140. 
 Diagram of motor tracts from brain to spinal cord (original). 
 
308 
 
 HUMAN ANATOMY. 
 
 THE STRUCTURE OF THE CEREBRUM. 
 
 On cross-section the cut brain surface shows an outer gray 
 cortex and the inner white matter and cavities, one to each 
 hemisphere: the lateral ventricles. The white matter contains 
 
 "iF 
 
 
 CZ-— • 
 
 cj[—Wi 
 
 CM— 
 
 Fia. 141. 
 
 Scheme of the nuclei and root-fibres of the cranial nerves. 
 {After Edinger.) {Whitehead.) 
 
 certain masses of gray matter : the optic thalami and the corpora 
 striata, which latter are on each side of the brain divided into 
 the caudate and lenticular nuclei by the internal capsule. Be- 
 tween the optic thalamus and caudate nucleus on the inside and 
 the lenticular nucleus on the outside passes the broad band of 
 
THE NERVOUS SYSTEJI. 309 
 
 white fibres known as the internal capsule. As it nears the cortex 
 the fibres spread out. To this is given the name corona radiata. 
 Between the external capsule and the cortex of the island of 
 Eeil is seen a thin sheet of gray matter : the claustrum. 
 
 The white matter between the claustrum and the lenticular 
 nucleus is known as the external capsule. On horizontal section 
 of the brain the internal capsule is seen to be bent upon itself, 
 the interval between the optic thalamus and the caudate nucleus. 
 This bend is called the genu. One-third of the capsule lies in 
 front of this bend, and is called the anterior limb; the portion 
 behind the genu is called the posterior limb. 
 
 The anterior limb, contains (1) fibres that pass from the 
 optic thalamus to the lenticular and caudate nucleus, (2) fibres 
 that pass from the optic thalamus to the cortex of the frontal 
 lobe, and (3) fibres that pass from the cortex of the frontal 
 lobe to pass to the nucleus pontis. 
 
 The posterior limb contains (1) a continuation upward 
 of a portion of the mesial fillet and the superior cerebellar 
 peduncles, (2) the pyramidal tracts or motor fibres from the 
 Eolandic area, (3) the fibres of the optic radiation, (4) the 
 fibres of the auditory radiation, and (5) the temppro-pontine 
 tract. 
 
 The opposite sides of the brain are connected by the com- 
 missural fibres. Convolutions on the same stde are connected by 
 association fibres. Projection fibres are those which unite the 
 cerebral cortex with nuclei in lower levels. They pass princi- 
 pally through the corona radiata. 
 
 The cerebral cortex consists of four layers: the stratum 
 zonale, the layer of small pyramidal cells, the layer of large 
 pyramidal cells, and the layer of polymorphic cells. 
 
 CRANIAL NERVES. 
 
 The cranial nerves consist of twelve pairs, as follows: — 
 
 1. Olfactory, 8. Auditory (portio mollis), 
 
 2. Optic, 9. Glosso-pharyngeal, 
 
 3. Motores oculorum, 10. Pneumogaatric (vagus, or 
 
 4. Pathetici, par vagum), 
 
 5. Trifacial, 11. Spinal accessory, 
 
 6. Abducentes, 12. Hypoglossal. 
 
 7. Facial (portio dura), 
 
 1. Olfactory nerve, special nerve of smell. A number of 
 nerves (20) arise from the olfactory bulb or lobe of the brain. 
 Superficial origin of the tract by roots: internal from frontal 
 lobe, middle or gray root from the olfactory tubercle between 
 
310 
 
 HUMAN ANATOMY. 
 
 the other roots of the tract, and external from the middle lobe; 
 deep origin, from gyrus fomicatus, uncinate gyrus of limbic 
 lobe; course, roots unite, pass forward, and form bulbus olfac- 
 torius (from this the olfactory nerves are given off) ; exit, fora- 
 mina of cribriform plate of ethmoid; distriiution, by three 
 
 Fig. 142. 
 
 Base of brain and cranial nerves: 1, olfactory bulb; J, opOc 
 nerves; 4, tractus opticus; 5, crus cerebri; 6, third pair ot nerves; 
 7, fourth pair of nerves; 8, fifth pair of nerves; 9, sixth pair of 
 nerves; XO, pyramid; 11, olivary body; 22, pons Varolii; 24, seventh 
 and eighth pairs ot nerves; 25, ninth, tenth, and eleventh pairs of 
 nerves; 26, twelfth pair of nerves; 27, cerebellum. 
 
 groups to mucous (Schneiderian) membrane of nares, inner 
 to septum nasi, middle to roof of nasal fossa, outer to superior 
 turbinated bone. 
 
H,l\„-h,uJ ,",^ S,^/p 
 
 Fiii. u:i. 
 Intii; Ofiiloinot.ir, tr.)clilc;iv, unci liiliuial iirivcs. 
 
THE NERVOUS SYSTEM. 311 
 
 2. Optic nerve, special nerve of sight; superficial origin, 
 optic chiasma or commissure formed by union of the optic tracts. 
 The commissure and tracts contain intereerebral fibres, the cere- 
 bro-retinal fibres of the same side, and the cerebro-retinal fibres of 
 opposite sides. Deep origin, the optic tracts arise from optic 
 thalamus, the upper corpora quadrigemina, and corpora genicu- 
 lati; course, riiverge and pass forward; exit, optic foramen; 
 distribution, to ganglion cells in the retina. 
 
 3. Motor oculi, motor nerve; superficial origin, inner sur- 
 face of crus cerebri ; deep origin, from the oculo-motor nucleus 
 in floor of aqueduct of Sylvius; course, from inner side of crus 
 cerebri passes forward, descends along external wall of cavernous 
 sinus ; exit, sphenoidal fissure between two heads of external rec- 
 tus muscle; distribution, by superior and inferior divisions, to 
 all the ocular muscles (including the iris) except the external 
 rectus and superior oblique. 
 
 4. Teochleae (pathetic), motor nerve; superficial origin, 
 from valve of Vieussens, on outer side of crus cerebri; deep 
 origin, from floor of aqueduct of Sylvius; course, outer side of 
 crus cerebri, through outer wall of cavernous sinus; exit, sphe- 
 noidal fissure ; distribution, to superior oblique muscle. 
 
 5. Trifacial, or Trigeminus^ common sensation, taste and 
 motion ; superficial origin, by two roots, like a spinal nerve, from 
 the side of the pons Varolii; deep origin, the motor root, from 
 (1) a nucleus in the fioor of the aqueduct of Sylvius (descending 
 motor r&ot), and (3) from a nucleus in the pons (these join to 
 form the motor root) ; the sensory root ends in two terminal 
 nuclei — (1) the sensory nucleus of the fifth nerve in the pons 
 and (3) the substantia gelatinosa Eolandi in the pons, medulla, 
 and the spinal cord as far down as the second cervical nerve; 
 course, passes forward to apex of petrous portion of temporal 
 bone, where the sensory root enters Gasserian ganglion, the 
 motor passing beneath, and later joins a branch of the ganglion. 
 It divides into three branches — ophthalmic, superior maxillary, 
 and inferior maxillary; exit, ophthalmic by sphenoidal fissure, 
 superior maxillary by foramen rotundum, inferior maxillary by 
 foramen ovale. 
 
 Ophthalmic nerve, entirely sensory, supplies lachrymal 
 gland, upper eyelid, skin and muscles of forehead, eyebrow, nose, 
 eyeball (ciliary muscle, iris, etc.), mucous membrane of eyelids 
 and nose, and the ciliary ganglion. 
 
 Its branches are : — 
 
 Lachrymal, Frontal, Kasal. 
 
312 HUMAN ANATOMY. 
 
 Superior maxillary nerve, entirely sensory also; supplies 
 sensation to upper jaw, teeth, hard and soft palates, tonsils, 
 gums, antrum of Highmore, muscles, skin and mucous membrane 
 of lower eyelid, muscles and skin of cheeks and upper lip, and 
 mucous membrane of floor of nares. 
 
 Its branches are : — 
 
 Orbital, 
 
 Middle dental. 
 
 Palpebral, 
 
 Spheno-palatine, 
 
 Anterior dental. 
 
 Nasal, 
 
 Posterior dental, 
 
 
 Labial. 
 
 Inferior maxillary nerve consists of two portions : anterior, 
 or motor, and posterior, or sensory, having a threefold function, 
 because one of its branches, the lingual, is joined by the chorda 
 tympani nerve (given off from the facial nerve), which conveys 
 gustatory fibres to the anterior two-thirds of the tongue. It 
 supplies motion to all the muscles of mastication (except to 
 buccinator) , anterior belly of digastric, and mylo-hyoideus ; sen- 
 sation to skin of ear, lower part of face, lower lip, and tongue. 
 Its branches are: — 
 
 Anterior Portion. Posterior Portion. 
 
 Masseteric, Auricujo-temporal, 
 
 Deep temporal (2), Inferior dental. 
 
 Buccal, Lingual. 
 Pterygoid (2). 
 
 The fifth nerve has four ganglia connected with it : — 
 
 (a) Ophthalmic, or lenticular; 
 (bj Spheno-palatine, or Meckel's; 
 
 (c) Otic, or Arnold's; 
 
 (d) Submaxillary {vide Sympathetic System). 
 
 6. Abddcens, motor ; superficial origin, pyramidal body and 
 pons Varolii; deep origin, floor of fourth ventricle; course, 
 passes forward in cavernous sinus; exit, sphenoidal flssure; dis- 
 tribution, to external rectus muscle. 
 
 7. Facial, motor nerve; superficial origin, lateral tract of 
 medulla and pons Varolii; deep origin, from a nucleus in the 
 pons, deeply placed, from which the fibres ascend close to the 
 floor of the fourth ventricle, where they form the eminentia teres 
 arch over the nucleus of the sixth nerve, and then emerge (this 
 nerve carries some sensory fibres, probably gustatory fibres from 
 the tongue, through the chorda tympani nerve to the pass inter- 
 media, near the nucleus of the ninth nerve) ; course, forward and 
 outward, through internal auditory meatus, aqusductus Fallopii, 
 
THE NERVOUS SYSTEM. 313 
 
 and inner wall of tympanum; exit, stylo-mastoid foramen; dis- 
 tribution, to muscles of expression, buccinator, and platysma, 
 posterior belly of digastric, stylo-hyoid, attrahens and retrahens 
 aurem muscles, to laxator tympani and stapedius through tym- 
 panic branch, dorsal surface of tongue through chorda tympani, 
 and levator palati, and azygos uvulae muscles through Vidian. In 
 its course through the temporal bone it communicates with many 
 important nerves; in the internal auditory meatus, with audi- 
 tory; in aquseductus Fallopii, with otic ganglion, by the small 
 petrosal; Meckel's ganglion, by the large petrosal nerve; the 
 sympathetic of the great meningeal, by the external petrosal 
 nerve; and at its exit from the stylo-mastoid foramen, with the 
 glosso-pharyngeal, pneumogastric, auriculo-temporal, auricularis 
 magnus, and the carotid plexus. Its branches are : — 
 
 On the Face. 
 
 In Aquwductus FallopU. "Cb^ 
 
 Tympanic, ^ ^ 
 
 Chorda tympani. Kl « 
 
 Temporal, 
 Temporo-facial, -j Molar, 
 
 { 
 
 InfraorbitaL 
 
 Buccal, 
 Cervico-facial, -j Supramaxillary, 
 Inframaxillary. 
 
 Posterior auricular, 
 
 Stylo-hyoid, 
 
 Digastric. 
 
 8. Auditory, special nerve of hearing, consists of two por- 
 tions — (1) cochlear, or auditory portion, and (2) vestibular, or 
 fibres whose function is to localize position. 
 
 The former pass from the cochlea to the (1) accessory 
 auditory nucleus in the medulla, and (2) to the lateral acoustic 
 tubercle in the medulla. These fibres, by means of the lateral 
 fillet, communicate with the inferior corpora quadrigemina. 
 
 The vestibular fibres pass from the vestibule to the external 
 and internal dorsal nuclei in the floor of the fourth ventricle, 
 and by the sensory decussation to the nucleus euneatus. 
 
 Superficial origin, from groove between olivary and restif orm 
 bodies ; course, winds around restiform body, and passes forward 
 to internal auditory meatus, with the facial; distribution, to in- 
 ternal ear by two branches : — 
 
 Vestibular, and Cochlear {vide Ear, p. 370). 
 
 9. Glosso-pharyngeal, or ninth, nerve of motion, common 
 sensation, and taste; superficial origin, from medulla oblongata, 
 between olivary and restiform bodies; deep origin, from motor 
 
314 
 
 HUJIAN ANATOMY. 
 
 FlO, U4. 
 
THE NERVOUS SYSTEM. 
 
 315 
 
 Fig. 145. 
 
316 HUMAN ANATOMY. 
 
 and sensory gray nuclei in floor of fourth ventricle; course, 
 passes outward across flocculus; exit, jugular foramen, in sepa- 
 rate sheath, in front of pneumogastric and spinal accessory, hav- 
 ing two gangliform enlargements upon it — Jugular and petrosal, 
 petrous, or ganglion of Andersch ; distribution, to mucous mem- 
 brane of fauces, tonsil, pharynx, and middle ear, muscles of the 
 pharynx, and special sense of taste to the base and sides of the 
 tongue. Its branches are: — 
 
 Tympanic (Jacobson), Pharyngeal branches. 
 
 Carotid branches. Tonsillar branches. 
 
 Muscular branches. Lingual branches. 
 
 10. Pneomogastkio (vagus, or par vagum), tenth nerve, 
 motor and sensory; superficial origin, from groove between 
 olivary and restiform bodies by a dozen filaments; deep origin, 
 from nuclei in floor of fourth ventricle; course, passes outward 
 across the flocculus; exit, jugular foramen in a common sheath 
 with the spinal accessory nerves; distribution (not definitely 
 known), motor nerve to the organs of respiration and voice, and 
 a motor and sensory nerve to heart, oesophagus, pharynx, and 
 stomach. Its branches are : — 
 
 Auricular (Arnold's), Thoracic cardiac. 
 
 Pharyngeal, Anterior pulmonary, 
 
 Superior laryngeal, Posterior pulmonary. 
 
 Recurrent laryngeal, (Esophageal, 
 
 Cervical cardiac, Gastric. 
 
 It also communicates with the left hepatic sympathetic 
 plexus. 
 
 11. Spinal accessory, eleventh, motor nerve; superficial 
 origin, from lateral tract of medulla and spinal cord as low as 
 sixth cervical nerve; deep origin, spinal portion from anterior 
 horn of gray matter, accessory portion from gray nucleus in 
 floor of fourth ventricle; course, the spinal portion enters the 
 skull through the foramen magnum, and joins the accessory por- 
 tion in the jugular foramen; exit, jugular foramen in sheath 
 with the pneumogastric; distiibution, to sterno-cleido-mastoid 
 and trapezius muscles, communicating with the cervical plexus 
 and pharyngeal and laryngeal branches of pneumogastric. 
 
 13. Hypoglossal, or twelfth nerve, motor nerve of tongue; 
 superficial origin, from groove between olivary and pyramidal 
 bodies by about a dozen filaments ; deep origin, from gray nucleus 
 at lowest part of floor of fourth ventricle; exit, anterior condy- 
 loid foramen; distribrition, to the omo-hyoid (both bellies), 
 Bterno-hyoid, sterno-thyroid, thyro-hyoid, and muscles of the 
 
THE NERVOUS SYSTEM. 317 
 
 tongue — styloglossus, hyoglossus, genio-hyoid, genio-hyoglossus, 
 communicating with the pneumogastric, sympathetic, first and 
 second cervical, and gustatory nerves. Its branches are : — 
 
 bescendens hypoglossi. Muscular, 
 
 Thyro-hyoid, Meningeaj. 
 
 Membranes of the Coed. — The membranes of the spinal 
 cord are three — the dura mater, arachnoid, and pia mater. 
 
 Dura mater is a loose fibrous sheath, continuous with the 
 dura of the brain, and from which it differs in not inclosing the 
 venous sinuses, not dipping into the fissures of the cord, and 
 not being adherent to the bony canal. From the latter it is 
 separated by the venous plexuses and some connective tissue. 
 
 It extends the whole length of the canal, from the foramen 
 magnum (to which it is attached) to the top of the sacrum. 
 
 Arachnoid is a delicate serous sac, continuous above with the 
 cerebral arachnoid, inclosing the pia mater, from which it is 
 separated by an interval — the suharachnoidean space. It is filled 
 with the cerebrospinal fluid. The outer surface of the arachnoid 
 is in contact with the dura, the space between them being called 
 the subdural space. 
 
 Pia mater is a fibrous membrane, closely adhering to the 
 cord and forming its neurilemma. Over the anterior median 
 fissure it is strengthened by a fibrous band — the linea splendens — • 
 and laterally has the ligamentum denticulatum. It terminates 
 below the cord as the.filum terminale — a slender filament. 
 
 THE SPINAL COED. 
 
 The spinal cord (medulla spinalis) is the elongated portion 
 of the cerebro-spinal axis contained in the spinal canal. Its 
 length is about sixteen to eighteen inches, extending from the 
 medulla above to the lower border of the first lumbar vertebra 
 below, where it terminates in the cauda equina by a slender pro- 
 longation of gray substance, called the conus medullaris. 
 
 It presents two enlargements, the upper or cervical, extend- 
 ing from the third cervical to the second dorsal vertebra, and 
 the lower or lumbar, about the position of the second or third 
 dorsal vertebra. It is divided into two lateral halves by the 
 anterior and posterior median fissures, united in centre Ijy the 
 commissure. The lateral portions are subdivided by antero-Iateral 
 and postero-lateral fissures into anterior lateral and posterior 
 lateral columns, and posteriorly a narrow fissure separates the 
 
318 
 
 HUMAN ANATOMY. 
 
 posterior median column from the posterior median fissure. The 
 gray substance occupies the centre of the cord, and is arranged 
 into two crescentie masses connected together by the gray com- 
 missure. The posterior horn forms the apex cornu, from which 
 arises the posterior root of the spinal nerves. The anterior horn 
 is thick and short, and affords origin to the anterior root of the 
 nerve. The gray commissure contains throughout its whole 
 length a minute canal — the central canal, or ventricle of the 
 cord, continuous above with the fourth ventricle. 
 
 SPINAL NERVES. 
 
 The spinal nerves consist of thirty-one pairs, arranged in 
 the following order : cervical, eight pairs ; dorsal, twelve pairs ; 
 lumbar, five pairs ; sacral, five pairs ; coccygeal, one pair. 
 
 Pig. 146. 
 
 Section of spinal cord and membranes; 1, dura mater; 2, aracb- 
 noid membrane; 3, ganglion on posterior root; 4, anterior root of 
 spinal nerve; 6, 5, subarachnoid space; 6, posterior branch of spinal 
 nerve; 7, anterior branch of spinal nerve. 
 
 Each of the spinal nerves arises by two roots, an anterior or 
 motor and a posterior or sensory. The fibres of the anterior 
 root arise from the antero-lateral columns, originating deeply 
 in the gray matter of the cord. The posterior roots arise at the 
 postero-lateral fissure, also originating deeply in the gray matter 
 of the cord. The posterior roots have each a ganglion developed 
 upon it — except sometimes the first cervical. These roots unite 
 and the nerve then subdivides into two branches, both having 
 motor and sensory fibres. The posterior branches are smaller 
 and unimportant ; they supply the skin and muscles of the back. 
 
 The anterior branches supply the neck, front and sides of 
 the trunk, and the extremities. 
 
 Cervical Plexus. — The cervical plexus is formed by the 
 anterior divisions of the first to the fourth cervical nerves. It 
 is covered by the sterno-mastoid muscle, and rests upon the 
 
THE NEPvVOUS SYSTEM 
 
 319 
 
 ^11 
 
 
 II 
 
 
 
 
 'si 
 
 
 
 II 
 
 1 
 
 
 Ji:i 
 
 
 III 
 
 il;^ V 
 
 iH iliS 
 
 :§\\.A ^ 
 
 .1 
 
 
 «5..-" 
 
 Fio. 147. 
 
320 HUMAN ANATOMY. 
 
 scalenus medius and levator anguli scapulae muscle. It gives 
 ofi:— 
 
 Superficial. 
 
 Superficialis colli. Occipitalis minor, 
 
 Auricularis magnus. Supraclavicular. 
 
 Deep. 
 
 Communicating, Communicantes hypoglossi. 
 
 Muscular, Communicating, 
 
 Phrenic, Muscular. 
 
 The phrenic nerve, or internal respiratory of Bell, is derived 
 from the third and fourth cervical nerves, with a branch from 
 the fifth. It descends into the chest between the subclavian 
 artery and vein, between the pericardium and the pleura, to the 
 diaphragm, to which it is distributed. The course of the two 
 nerves differs in the thorax {vide Mediastinum). 
 
 The bkachial plexus is formed by the anterior branches 
 of the four lower cervical and the first upper dorsal nerves — the 
 fifth, sixth, and seventh forming one cord, and the eighth cervical 
 and first dorsal another cord. Below the line of the clavicle, 
 both these trunks divide, the adjacent cords of the two upper 
 uniting to form the posterior, and the remaining cords forming 
 the outer and inner cords respectively, receiving their names 
 from their relative position to the subclavian artery. Each of 
 these cords again bifurcates, the adjacent divisions at the outer 
 ending of the cords uniting over the artery to form the median 
 nerve, the other divisions forming the musculo-cutaneous, ulnar, 
 circumflex, and musculo-spiral, the two latter being the divisions 
 of the posterior cord. Its branches are: — 
 
 Above the clavicle : — 
 
 Comrriunicating, arises from the fifth cervical, and passes 
 to the phrenic ; 
 
 Muscular, supply the scaleni, rhomboidii, longus colli, and 
 Bubclavius ; 
 
 Posterior thoracic, long thoracic, or external respiratory of 
 Bell, arises by five roots from the fifth to seventh cervical nerves, 
 which unite within the scalenus medius muscle and descend to 
 supply the serratus magnus ; 
 
 Suprascapular, passes beneath the trapezius, through the 
 suprascapular notch, to supply the shoulder-joint and supra- 
 spinatus muscle. 
 
 Below the clavicle : — 
 
 The anterior thoracic nerves are two in number : an external 
 branch from the outer cord and an internal from the inner cord. 
 
THE NERVOUS SYSTEM. 
 
 821 
 
322 HUMAN ANATOMY. 
 
 The former supplies the pectoralis major and the latter the pec- 
 toralis minor, and sending branches to the pectoralis major. 
 
 The subscapular nerves are three in number. The upper 
 subscapular supplies the subscapular muscle, the lower sub- 
 scapular nerve supplies the teres major and subscapularis, the 
 middle or long subscapular supplies the latissimus dorsi. 
 
 The circumflex nerve accompanies the posterior circumilex 
 artery, passing through the space formed between the teres major, 
 teres minor, and long head of the triceps to supply the shoulder- 
 joint and skin over the shoulder and the neighboring muscles. 
 It gives off two branches, an upper and a lower branch. 
 
 The musculo-cutaneous nerve pierces the coraco-brachialis 
 muscle and descends the arm to supply the brachialis anticus, 
 biceps, coraco-brachialis, and the skin of the forearm. At the 
 outer border of the tendon of the biceps, above the elbow, it be- 
 comes superficial and divides into two branches — ^the anterior 
 descending the radial side of the forearm to the wrist and supply- 
 ing the skin of that part, the posterior branch descending the 
 back part of the radial side of the forearm to the wrist to supply 
 that part. 
 
 The internal cutaneous nerve descends the inner side of the 
 arm together with the basilic vein to about its middle, where 
 it becomes cutaneous, supplying the skin of this region. It has 
 an anterior and a posterior branch. 
 
 The lesser internal cutaneous nerve of Wrisberg is derived 
 from the inner cord, and receives filaments from the eighth cer- 
 vical, first dorsal, and the intercosto-humeral nerve, and is dis- 
 tributed to the skin on the inner side of the arm. 
 
 The median nerve, formed by a root from the outer and 
 inner cord of the brachial plexus, descends the arm, crossing the 
 brachial artery from its outer to its inner side at the bend of the 
 elbow. Its branches are: — 
 
 Muscular branches, supply all the superficial anterior muscles ex- 
 cept the flexor carpi ulnaris ; 
 
 Anterior interosseous, supplies all the deep anterior muscles except 
 the inner half of the flexor profundis digitorum; 
 
 Palmar cutaneous, crosses above the annular ligament, divides into 
 two branches to supply the ball of the thumb and the palmar surface 
 of the hand; 
 
 Branches to the muscles of the thumh, supplies the opponens, outer 
 head of the small flexor, and the abductor; 
 
 Digital hi-ancJies, supply both sides of the thumb, index and middle 
 and the radial side of the ring finger. 
 
 The ulnar nerve descends the inner side of the axillary 
 artery to the middle of the arm, where it crosses the internal head 
 of the triceps, and accompanies the inferior profunda artery to 
 
THE NERVOUS SYSTEM. 323 
 
 the elbow, where it passes between the heads of the flexor -carpi 
 ulnaris. Its branches are, in the forearm: — 
 
 Articular (elbow), supplies the elbow-joint; 
 
 Muscular, to inner half of the deep flexors and flexor carpi ulnaris; 
 Cutaneous, supplies the skin of the palm; 
 
 Dorsal cutaneous, supplies both sides of the little finger and the 
 ulnar side of the ring flnger; 
 
 Articular (wrist), supply the wrist-joint. 
 
 In the hand : — 
 
 Superficial palmar, supplies the skin of both sides of the little and 
 the ulnar side of the ring finger and palmaris brevis muscle ; 
 
 Deep palmar, supplies the interossei, lumbrieales, adductor poUicis, 
 and inner head of flexor brevis poUicis. 
 
 The musculo-spiral nerve, derived from the posterior cord 
 of the brachial plexus, descends the arm in front of the teres 
 major and latissimus dorsi muscle, accompanies the superior 
 profunda artery through the musculo-spiral groove to the outer 
 side of the elbow, between the supinator longus and the brachialis 
 anticus, where it divides into the radial and posterior interosseous 
 nerves. Its branches are : — 
 
 Muscular, supply the supinator longus, external carpi radialis 
 longior, triceps, anconeus, and brachialis anticus; 
 
 Radial, descends in the course of the radial artery to three inches 
 above the wrist, where it becomes superficial, and supplies the adjoining 
 sides of the thumb and index, index and middle, middle and ring fingers. 
 
 Cutaneous, supply the outer side of the arm, elbow, and radial side 
 of forearm and wrist ; 
 
 Posterior interosseous, passes through the supinator brevis muscle, 
 and supplies, as it descends, all the posterior brachial and radial muscles, 
 except those supplied by the muscular branches of the ulnar. It has a 
 ganglion upon it. 
 
 Dorsal Nerves. — The posterior divisions of the dorsal 
 nerves subdivide into the external and internal branches to supply 
 the muscles of the skin of the back. The anterior divisions of 
 the dorsal nerves (intercostal nerves), twelve in number, supply 
 the walls of the abdomen and thorax. They are divided into two 
 sets — ^the six upper, distributed for the most part to the walls 
 of the chest, and the six lower, to the walls of the chest and 
 abdomen. The upper six dorsal nerves run between the two sets 
 of the intercostal muscles, accompanied by the intercostal vessels, 
 to supply the skin over the front of the chest and the mammae. 
 Their branches are : — 
 
 Lateral cutaneous, divide into two branches, anterior and posterior; 
 Anterior branches, to the skin of the chest and mammse principally; 
 Posterior branches, to the skin over the scapular and lower dorsal 
 regions. 
 
324 HUMAN ANATOMY. 
 
 The jirst intercostal nerve is not distributed to the skin, hut 
 crosses the axilla under the name of the intercosto-humeral 
 nerve; it joins the brachial plexus. The six lower dorsal nerves 
 have received the name of lower, or abdominal intercostal nerves, 
 from their distribution. The last dorsal one is of large size, and 
 gives off a branch, the dorsi lumbar nerve, to join the lumbar 
 plexus. 
 
 Lumbar Nerves. — The posterior divisions of the lumbar 
 nerves have the same distribution as the other spinal nerves. The 
 anterior divisions of the upper four lumbar nerves unite to form 
 the lumbar plexus. The fifth, with a branch from the fourth, 
 joins the sacral nerves to form the lumbo-sacral cord. 
 
 The lumbar plexus is formed by the communicating loops 
 from the anterior branches of the first four liunbar nerves and a 
 branch from the last dorsal. 
 
 Its branches are: — 
 
 1. Ilio-hypogastric, divides into two branches : — 
 
 (a) Iliac branch, supplies the skin of the gluteal region and the 
 oblique muscles of the abdomen ; 
 
 (h) Hypogastric branch, supplies the skin of the hypogastric region 
 and the oblique muscles. 
 
 2. Ilio-inguinal, supplies the skin of the inner and upper 
 part of the thigh, the scrotum, and labium (in female). 
 
 3. Genito-crural, passes through the psoas muscle and di- 
 vides into two branches: — 
 
 (a) Genital branch, follows the spermatic cord to supply the cre- 
 master muscle ; in female, supplies round ligament ; 
 
 (h) Crural branch, descends in the sheath of the femoral vessels to 
 supply the skin in front of the thigh. 
 
 4. External cutaneous emerges below the anterior superior 
 spine of ilium and divides into : — 
 
 (a) Anterior branch, to skin of outer and front aspect of thigh; 
 Cb) Posterior branch, to skin of outer and back aspect of thigh. 
 
 5. Obturator, follows the brim and outer wall of pelvis to 
 foramen (obturator), which it pierces to enter thigh, 
 
 (a) Anterior branch, supplies the femoral artery; 
 
 (i) Posterior branch, supplies the adductor muscles ; 
 
 (c) Articular branch, supplies the synovial membrane of knee-joint. 
 
 6. Accessory obturator, sends a branch to the hip-joint and 
 one to join the anterior branch of the obturator nerve. 
 
 7. Anterior crural, the largest branch of the lumbar plexus, 
 descends through the psoas muscle, beneath Pouparfs ligament. 
 
Trom Las/ D.irjf.i/ 
 
 
 ^-_Toffidvpa7i^offpojitorT/uij7i 
 
 
 7'o sk I iL oTvr uumrAnhU • 
 
 Fig. Utf. 
 Lunihiir plexus ii'id liranches. 
 
THE NERVOUS SYSTEM. 325 
 
 into the thigh, where it divides into an anterior or cutaneous 
 branch, and a posterior or muscular branch. It supplies all the 
 muscles and the front of the thigh, excepting the tensor vaginae 
 femoris, gives branches to the knee, and supplies the skin of the 
 inner side in front of the thigh, and to the leg and foot. Its 
 branches are, from the anterior division : — 
 
 (a) Middle cutaneous, to sartorius muscle and skin of fiont of 
 thigh; 
 
 Cb) Internal cutaneous, supplies the skin in the inner aspect of 
 the leg; 
 
 (c) Long saphenous, or internal saphenous, passes through 
 Hunter's canal, accompanies the internal saphenous vein, to supply the 
 skin of the inner side of the foot. 
 
 From the posterior division: — 
 
 (a) Muscular, to the muscles of the anterior and lateral aspects 
 of the thigh; 
 
 Cb) Articular, to the knee-joint. 
 
 The saceal nerves, five in number, divide into anterior 
 and posterior nerves. The four upper sacral nerves, with the 
 fifth lumbar, and a filament from the fourth, the two latter 
 forming the lumbo-sacral cord, together form the sacral plexus. 
 It lies upon the anterior surface of the pyriformis muscle, and is 
 separated from the viscera, the sciatic and pudic branches of the 
 internal iliac artery, by the pelvic fascia. Its branches are : — 
 
 1. Muscular, supply the obturators, gemelli, quadratus 
 femoris, and pyriformis. 
 
 3. Superior gluteal, supplies the glutei muscles and tensor 
 vagina femoris. 
 
 3. Pudic, accompanies the internal pudic artery, passing 
 out of the great saero-sciatic foramen, around the spine of the 
 ischium to re-enter the lesser sacro-sciatic foramen. It gives 
 off:— 
 
 (a) Inferior hsemorrhoidal, supplies the skin of the anus; 
 
 (b) Perineal, follows the course of the superficial perineal artery 
 to supply the perineal structures generally; 
 
 (o) Dorsal nerve of the penis, follows the course of the correspond- 
 ing artery to supply the skin of the glans, prepuce, and penis generally. 
 
 4. Small sciatic, supplies the skin of the thigh, leg, perin- 
 eum, and the gluteus maximus muscle. Its branches are : — 
 
 (a) Inferior gluteal, to the gluteus maximus; 
 
 (i) Internal cutaneous branches, to the skin of the inner and upper 
 part of the thigh, and one branch, the inferior pudendal, supplies tha 
 skin of the scrotum in the male and labium in the female; 
 
326 HtJMAN ANATOMY. 
 
 (e) Ascending, cutaneous branches supply the skin over the gluteus 
 maximus. 
 
 5. The great sciatic nerve, the largest in the body, passes out 
 of the great saero-seiatic foramen, and descends between the 
 tuberosity of the ischium and the great trochanter to the lower 
 third of the thigh, where it divides into the internal and external 
 popliteal. It gives off: — 
 
 (a) Muscular branches, to the muscles on the inner and posterior 
 aspect of the thigh; 
 
 (i) Articular branches, to the hip-joint. 
 
 The internal popliteal, descends through the popliteal space 
 to the arch of the soleus muscle, where it becomes the posterior 
 tibial. It gives off : — 
 
 (a) Articular branches, to knee-joint; 
 
 (h) Muscular branches, to the muscles on the posterior aspect of 
 the leg; 
 
 (c) External, or short saphenous nerve, passes between the two 
 heads of the gastrocnemius muscle, and descends the leg, receiving the 
 eommunicans peronei branch from the external popliteal, around the 
 outer malleolus to supply the skin of the outer side of the foot. 
 
 The posterior tibial nerve descends the leg in company with 
 the posterior tibial vessels to below the inner ankle, where it 
 divides into the external and internal plantar nerves. It gives 
 off:— 
 
 1. Muscular branches, to the deep muscles of the calf ; 
 
 2. Plantar, cutaneous branch, supplies the skin on the 'inner side 
 of the sole and heel; 
 
 3. Articular brauch, to ankle-joint. 
 
 The internal plantar accompanies the corresponding artery 
 to the inner side of the foot and gives off: — 
 
 1. Cutaneous branches; 
 
 2. Muscular branches; 
 
 3. Articular branches ; 
 
 4. Four digital branches, supplying both sides of the first three toes 
 and the inner side of the fourth. 
 
 The external plantar supplies by a superficial branch the 
 outer side of the fourth and both sides of the fifth toes, and gives 
 off a deep, or muscular branch. 
 
 The external popliteal or peroneal nerve descends to the 
 inner side of the biceps tendon, pierces the peroneus longus about 
 
offYt'atattxLa4canAToe, 
 
 FJi.i. 150. 
 Harral plexus ; ijcl hirariches 
 
THE NERVOUS SYSTEM. 327 
 
 one inch below the head, and divides into the anterior tibial and 
 musculo-cutaneons. It gives off : — 
 
 1. Articular branches to knee-joint; 
 
 2. Cutaneous branches, one of which is the eommunieans peronei, 
 which joins the short saphenous. 
 
 The anterior tibial accompanies the corresponding artery on 
 its outer side to the ankle, where, after giving off an articular 
 branch, it divides into : — 
 
 1. External or tarsal branch, to the tarsal and metatarsal joints, 
 and 
 
 2. Internal, to the dorsal adjoining sides of the great and second 
 toes. 
 
 The musculo-cutaneous gives off : — 
 
 Internal branches, supply skin of inner side of foot and ankle, and 
 inner side of great toe; 
 
 2. External branch, to the dorsum of the adjacent sides of the 
 second, third, fourth, and fifth toes. 
 
328 
 
 HUMAN ANATOMY. 
 Table of the Spinal Nerves. 
 
 First 
 
 cervical 
 
 nerve, 
 
 Second 
 cervical 
 nerve, 
 
 Posterior 
 
 division 
 
 (suboccipital). 
 
 Anterior 
 
 division 
 
 (occipital). 
 
 Posterior 
 division. 
 
 Anterior 
 division. 
 
 h 
 
 Complexns, recti, and obliqui muscles. 
 
 } Unites with the second cervical nerve, 
 and supplies the anterior recti and 
 
 rectus lateralis muscles. 
 
 } 
 
 External 
 brajich. 
 
 Spleniua, complexus, 
 trachelo-mastoid muscles. 
 
 Internal 
 
 branch 
 
 (great 
 
 . oEcipital), 
 
 With branch from third 
 cervical, supplies the 
 skin of the scalp. 
 
 Small occipital, 
 Branch to great auricular. 
 Branch to superficial cervical. 
 Branch to communicans nom. 
 
 Third 
 cervical 
 nerve. 
 
 Fourth 
 
 to 
 eighth 
 cervical ' 
 nerves. 
 
 Posterior 
 division. 
 
 Anterior 
 division. 
 
 Posterior 
 divisions, 
 
 Anterior division 
 of fourth. 
 
 External 
 
 and 
 internal 
 branches. 
 
 Splenius, semispinalis, 
 complexus, trachelo-mas- 
 toid muscles. 
 
 Branches to form the great auricular, 
 superficial cervical, and communicantes 
 minor. 
 
 External 
 branches 
 
 ', } 
 
 Internal \ 
 branches, J 
 
 Muscles of the side of the 
 neck. 
 
 Skin and larger muscles 
 of the neck. 
 
 Anterior 1 
 
 iivisiona, [■ 
 
 i to eighth, J 
 
 Branch to phrenic. 
 
 Branches to the trapezius, scalenus 
 medius, levator anguli scapulae mus- 
 cles. 
 
 Unite with the first dorsal nerve to form 
 the brachial plexus. 
 
 Cervical plexu8.«{^,,'JP"gh"g^ < 
 
 {Superficialis colli, 
 Auriculasis magnus, 
 Occipitalis minor. 
 
 Descending, ■< Supraclavicular. 
 
 ' Formed by the anterior divisinna of the first to the fourth cervical 
 nerves. 
 
THE NERVOUS SYSTEM. 
 
 329 
 
 Table of the Spinal Neeves. — (Continued.) 
 Internal set. 
 
 Cervical plexus f Deep 
 [continued), \ branches. 
 
 " Above 
 the 
 clavicle. 
 
 Brachial plexus,i< 
 
 Below 
 
 the 
 
 clavicle. 
 
 Communicating, 
 
 Muscular, { ^u^^jes. 
 Phrenic, 
 Communicans nonL 
 
 „_ , T i f Muscular, 
 External set. | Communicating. 
 
 \ Tovphrenio. 
 
 (• Communi- 
 cating, 
 
 Muscular, 
 
 Posterior 
 thoracic. 
 
 Supra- 
 scapular, 
 
 "1 Scaleni., rhomboidei. Ion- 
 J gus colli, subclavius. 
 
 > Serratus magnus. 
 ' (External respiratory 
 nerve of Bell.) 
 
 1 Shoulder-joint and supra- 
 / spinatus muscle. 
 
 
 External f Pectoralis 
 branch, \ major. 
 
 "lor 
 cic. 
 
 Internal 
 branch. 
 
 Pectoralis 
 minor, 
 
 Pectoralis 
 major. 
 
 Three sub- 
 scapular. 
 
 Circum- 
 flex, 
 
 Musculo- 
 cutaneous, 
 
 Subscapular 
 muscle. 
 
 Upper, I 
 
 Lower, < Teres major. 
 
 L Middle, 
 
 Upper, 
 Lower, 
 
 Anterior 
 branch. 
 
 Posterior 
 . branch. 
 
 { 
 
 Latissimus 
 dorsi. 
 
 Shoulder- 
 joint, and 
 muscles and 
 skin about it. 
 
 Integument 
 of palmar sur- 
 face of the 
 wrist. 
 
 Integument 
 of dorsal sur- 
 face of the 
 wrist. 
 
 > Formed by the anterior branches of four lower cervical and first 
 dorsal nerves. 
 
330 
 
 HUMAN ANATOMY. 
 
 Table of the Spinal Nerves. — (Continued.) 
 
 Brachial 
 
 plexus, 
 
 below the 
 
 clavicle, 
 
 contin'd, 
 
 Internal 
 cutaneous. 
 
 Anterior 
 
 and 
 posterior 
 branches, 
 
 Integument 
 
 of inner side of 
 
 the arm. 
 
 Lesser internal 
 
 cutaneous 
 
 (Wrisberg's) 
 
 :i 
 
 Integument of the inner 
 side of the arm. 
 
 Median, 
 
 Ulnar, 
 in forearm. 
 
 {Superficial anterior mus- 
 cles, except flexor carpi 
 ulnaris. 
 
 I Deep anterior muscles, ex- 
 cept the inner half of 
 flexor profundus digi- 
 torum. 
 
 Palmar f Ball of thumb and palmar 
 
 cutaneous, \ surface of the hand. 
 
 Branch to f Opponens, outer head of 
 the muscles of -j small flexor and ab- 
 the thumb, I ductor. 
 
 r Both sides of thumb, in- 
 Digital dex and middle fingers, 
 branches, and radial side of ring 
 finger. 
 
 Articular, i (Elbow). 
 
 TiT,.„„„i„- / Inner half of deep flexors. 
 Muscular. | ^^^ ^^^^^ ^^^ ^j^^^j^; 
 
 Ulnar, 
 in hand. 
 
 Cutaneous, < Skin of the palm 
 
 { 
 
 ■[ (Wrist) 
 
 Dorsal 
 cutaneous. 
 
 Both sides of little finger, 
 and ulnar side of ring 
 finger. 
 
 Articular, 
 
 Superficial 
 palmar. 
 
 Deep 
 palmar. 
 
 Skin of both sides of little 
 finger, and ulnar side of 
 ring finger, and palmaris 
 brevis muscle. 
 
 Interossei lumbricales, ad- 
 ductor pollicis, inner 
 head of flexor brevis 
 pollicis. 
 
THE NERVOUS SYSTEM. 
 
 331 
 
 Table of the Spinal Nerves. — (Continued.) 
 
 Brachial 
 plexus, 
 
 below the 
 clavicle, 
 cont'd. 
 
 Miisculo- 
 spiral. 
 
 Dorsal 
 nerves. 
 
 Posterior 
 divisions. 
 
 Anterior 
 divisions' 
 
 Muscular 
 branches. 
 
 Radial, 
 
 Lumbar 
 
 Posterior 
 divisions. 
 
 Anterior 
 divisions. 
 
 '■{ 
 
 Cutaneous, 
 
 Posterior 
 interosseous. 
 
 External 
 branches. 
 
 Internal 
 branches. 
 
 Upper six 
 
 (thoracic 
 
 intercostals). 
 
 Supinator longus, extensor 
 carpi radialis longior, tri- 
 ceps, anconeus, brachialis 
 anticus. 
 
 Supplies adjoining sides of 
 thumb and index finger, 
 index and middle, middle 
 and ring fingers. 
 
 Inner side of arm, elbow, 
 radial side of forearm, and 
 wrist. 
 
 Posterior brachial and radial 
 muscles, except those sup- 
 plied by ulnar (muscular 
 branches). 
 
 Muscles and skin of the back. 
 
 First intercostal crosses the 
 axilla to join the lesser in- 
 ternal cutaneous (Wris- 
 
 berg's). 
 
 Lower six 
 
 (thoraeico- 
 
 abdominal 
 
 intercostals). 
 
 External 
 branches. 
 
 Internal 
 branches. 
 
 Skin of 
 chest and 
 mammae. 
 
 Skin over 
 scapula 
 
 and lower 
 dorsal 
 region. 
 
 The last dorsal gives off the 
 dorsi lumbar to the quad- 
 ratus lumborum muscle. 
 
 
 Ante- 
 
 
 rior, 
 
 Lateral 
 
 >- 
 
 cutane- - 
 
 f 
 
 ous. 
 
 
 
 Poste- 
 
 
 L rior. 
 
 
 . 
 
 Muscles of 
 back. 
 
 the skin of the 
 
 The four upper unite to form the liunbar 
 plexus. The fifth, with a branch from the 
 fourth, joins the sacral nerves to form the 
 lumbo-sacral cord. 
 
 ' To the walls of chest and abdomen. 
 
332 
 
 Luinbar 
 plexus. 
 
 HUMAN ANATOMY. 
 
 Table of the Spinal Nerves. — (Continued.) 
 Iliac, 
 
 nio- 
 hypogastrie, ' 
 
 Anterior 
 crural, 
 
 f Skin of gluteal region, ob- 
 \ lique muscles of abdomen. 
 
 Hypo- / Skin of hypogastric region 
 rie, I 
 
 gastric 
 
 and oblique muscles. 
 
 Ilio- 
 inguinal, 
 
 Genito- 
 crural. 
 
 External 
 cutaneous. 
 
 Obturator, 
 
 Accessory 
 obturator, 
 
 f Skin of inner and upper part of thigh, scro- 
 \ turn, labium (in female). 
 
 Genital i Cremaster muscle, round liga- 
 ' \ ment (in female). 
 
 Crural, i Skin of front of thigh. 
 
 Anterior, ( S"^™. °^ ""^^"^ ^'■°"* ^^P^''* °* 
 ' \ thigh. 
 
 Posterior, ( ^^J". °t ""^^'^ ^^"^ ^^P^<=* °* 
 ' I, thigh. 
 
 Anterior, < Femoral artery. 
 Posterior, < Adductor muscles. 
 
 { 
 
 Articular, { ^^^°^X^ membrane of knee- 
 Branch to hip-joint, branch to anterior 
 branch of obturator nerve. 
 
 Anterior 
 division. 
 
 Posterior 
 division, 
 
 Middle 
 cutaneous. 
 
 Internal 
 cutaneous, 
 
 Long 
 saphenous. 
 
 Muscular, 
 
 Sartorius 
 
 muscle, 
 
 skin of 
 
 thigh (ant.). 
 
 Skin of 
 
 inner 
 
 aspect of 
 
 leg. 
 
 Skin of 
 
 inner side of 
 
 foot. 
 
 Muscles 
 of the an- 
 terior and 
 
 lateral 
 
 aspect of 
 
 thigh. 
 
 Articular, < Knee-joint. 
 
Sacral 
 nerves. 
 
 " Posterior 
 divisions, 
 
 Muscles and skin of the 
 back. 
 
 Sacral 
 plexus, 
 
 THE NERVOUS SYSTEM. 333 
 
 Table of the Spinal Nerves. — (Continued.) 
 
 f External ■» 
 
 -j and internal > 
 
 '' (. branches, J 
 
 r / The four upper j< 
 divisions, \ cord form the sacral plexus. 
 
 Muscular / Obturators, gemelli, quadratus femoris, and 
 muscular, ^ pyriformis. 
 
 f^ufpa?' f Crlutei muscles, and tensor vaginse femoris. 
 
 hemorrhoidal, } ^'^^^ °^ *'^« *""«• 
 
 Perineal, \ Perineal structures. 
 
 Dorsal nerve of 1 oi • r ii. 
 
 > Skin of the penis. 
 
 Pudic, 
 
 the penis. 
 Articular, | To hip- joint. 
 
 Small 
 sciatic. 
 
 Inferior 
 gluteal. 
 
 Internal 
 cutaneous, 
 
 > Gluteus maximus. 
 
 Branch to skin of inner and 
 upper part of thigh. 
 
 Inferior pudendal, skin of 
 scrotum, labium in fe- 
 male. 
 
 Ascending 
 cutaneous, 
 
 Great 
 sciatic. 
 
 > Skin over gluteus maximus. 
 Articular, < Hip-joint. 
 
 Muscular, -f Muscles of inner and pos 
 ' \ tenor part of thigh. 
 
 Bifurcation, { ^^^^^^^ } PopliteaL 
 
 Internal 
 popliteal. 
 
 brSet } TO knee-joint. 
 
 Muscular \ To muscles of the posterior aspect of 
 branches, / the leg. 
 
334 
 
 HUMAN ANATOMY. 
 
 Internal 
 
 popliteal 
 
 {contintied), 
 
 Table of the Spinal Nerves. — (Continued.) 
 
 '^"^litlt''* } S'^'" °^ ""t^' ^^^^ °f *^« ^°°*- 
 
 Muscular. { De^P^ muscles of the 
 
 Plantar f Skin of inner side of 
 
 cutaneous, \ sole and heel. 
 
 Articular, < To ankle-joint. 
 
 Posterior tibial 
 (continuation) , 
 
 Bifurca- f Internal plantar, 
 tion, \ ~ 
 
 Internal 
 plantar. 
 
 External 
 plantar. 
 
 External plantar. 
 
 Cutaneous, 
 
 Muscular, 
 
 Articular, 
 
 . Four digitaL 
 
 Supplies the outer 
 side of the fourth 
 and both sides of 
 the fifth toes. Mus- 
 cular branch. 
 
 External 
 
 popliteal 
 
 (peroneal), 
 
 Articular, < To knee-joint. 
 
 < Communicans peroneL 
 
 ] 
 
 Two 
 cutaneous. 
 
 Anterior 
 tibial. 
 
 Musculo- 
 cutaneous, 
 
 External 
 
 or tarsal 
 
 branch, 
 
 Tarsal and metatar- 
 sal joints. 
 
 (Inner and dorsal, ad- 
 joining sides of 
 great and second 
 toes. 
 
 Internal f To skin of inner side 
 branches, \ of foot and ankle. 
 
 C To dorsum of adja- 
 
 External cent sides of third, 
 
 branch, fourth, and fifth 
 toes. 
 
Ir,/>T,iiT! Ctjralid^irtery 
 
 y,, .'£«>-„' "■— ..^-^^ ridiatt^tiTe(u SfihfniJ Pai^rtinj 6analiOit 
 
 _ _ , . . . ., ^ \ ^ ~ XarvfSuB/^A.^i.aLPwtfBsai^m^iaJXjm' 
 
 To iiaiff^i'i/i it/"^./! a/'J'tit h mafOAtr 
 
 aniiitt bra./rchfs 
 
 J'iV.-.'i.f'f' S,tr/u/.V, , I , 
 /hnn (V..V,.,,v./.r. 
 
 
THE NERVOUS SYSTEM. 335 
 
 THE SYMPATHETIC NERVOUS SYSTEM. 
 
 The sympathetic system, like the cerebro-spinal axis, is 
 double, consisting of a gangliated cord on each side, extending 
 the entire length of the vertebral column, and numerous nerve- 
 fibres, both communicating, by which it anastomoses with the 
 cerebro-spinal axis, and distributory, by which the blood-vessels 
 and viscera are supplied. 
 
 Branches of the ganglionated cords ascend through the 
 carotid canal to communicate with the ganglia of the fifth cranial 
 nerve, and also with each other through the ganglion of Eihes, 
 situated upon the anterior communicating artery. They also 
 communicate below in the ganglion impar, located in front of 
 the coccyx. 
 
 The ganglia of each cord correspond very nearly in position 
 and number to the vertebrse, except in the cervical region, where 
 there are but three: cervical three, dorsal twelve, lumbar four, 
 sacral five. 
 
 From the ganglionated cords three important plexuses are 
 given off — the cardiac, solar, and hypogastric — situated in the 
 thoracic, abdominal, and pelvic cavities respectively. 
 
 Cranial Ganglia — Ganglia Connected with the Fifth Cranial 
 Nerve. — Besides the Gasserian ganglion upon the root there are 
 four — ophthalmic, spheno-palatine, otic, and submaxillary — each 
 of which have three branches of communication or roots — ^motor, 
 sensory, and sympathetic — ^besides several branches of distribu- 
 tion. 
 
 The ophthalmic, or ciliary, ganglion is situated in the orbit 
 between the external rectus muscle and optic nerve upon the first 
 division of the fifth cranial nerve. 
 
 Its sensory root is from the nasal branch of ophthalmic, 
 motor root from the motor oculi or third and sympathetic from 
 the cavernous plexus. 
 
 Its branches are the short ciliary nerves (^vide Bye). 
 
 Spheno-palatine, or Meclcel's, the largest, is situated in the 
 spheno-maxillary fossa upon the superior maxillary, or second 
 division of the fifth. 
 
 Its sensory root is derived from the superior maxillary, its 
 motor root, from the facial, through means of the Vidian, and its 
 sympathetic from the carotid plexus. Its branches are : — 
 
 1. Ascending; 
 
 „ T-, ,. (■ Anterior, or large palatine, 
 
 2. Descending, or I j^j^jj^^ ^^ external palatine, 
 
 paianne, ^ Posterior, or small palatine; 
 
336 HUMAN ANATOMY, 
 
 3. Internal, 5 Superior nasal, 
 
 ' I Naso-palatine; 
 
 4. Posterior, 
 
 Vidian, 
 
 Large superficial petrosal. 
 Deep petrosal, 
 Pharyngeal branch. 
 
 The Vidian nerve passes from the back part of Meckel's 
 ganglion through the foramen lacerum medium, where it divides 
 into the large superficial and deep petrosal nerves. It gives 
 off the upper posterior nasal branches to the mucous membrane 
 of septum, orifice of Eustachian tube, and roof of the nose. Or, 
 more correctly, the Vidian is formed by the union of the great 
 petrosal (large superficial petrosal) from the facial and the large 
 deep petrosal from the carotid sympathetic, runs forward through 
 the Vidian canal, and joins the spheno-palatine ganglion (Meck- 
 el's). In this description, the nerves given off to the nasal 
 mucous membrane must be considered branches from the gan- 
 glion inclosed in the same sheath. 
 
 The large superficial petrosal branch enters the cranium 
 through the foramen lacerum medium, passes beneath the dura 
 mater and Gasserian ganglion, enters the hiatus Fallopii, re- 
 ceives a branch from the tympanic branch of the glosso-pharyn- 
 geal (Jacobson's), and through the aquseductus Fallopii to termi- 
 nate in the geniculate ganglion of the facial nerve. 
 
 The large deep petrosal branch crosses the foramen lacerum 
 medium to the carotid canal, where it joins the carotid plexus 
 of the sympathetic. 
 
 The pharyngeal or ptery go-palatine nerve desends from the 
 back part of the ganglion through the pterygo-palatine canal, 
 to supply the upper part of the pharynx. 
 
 Besides the Vidian and its branches there are two other 
 petrosal nerves {vide Facial Nerve), the small and external 
 petrosal. 
 
 The small petrosal connects the geniculate ganglion of the 
 facial, within the aquaeductus Fallopii, with the otic ganglion. 
 
 The external petrosal connects the geniculate ganglion of 
 the facial, within the same canal, with the sympathetic plexus 
 of the middle meningeal plexus. 
 
 The otic ganglion (Arnold's) is placed below the foramen 
 ovale upon the inferior maxillary nerve, or third division of the 
 fifth. 
 
 Its sensory root is derived from the auriculo-temporal branch 
 of the inferior maxillary; the motor root, from the internal 
 pterygoid branch of the same, the sympathetic root, from the 
 plexus on the middle meningeal artery. Branches are distributed 
 to the tensor palati and tensor tympani muscles. 
 
THE NERVOUS SYSTEM. 337 
 
 The submaxillary ganglion is placed above the deep portion 
 of the submaxillary gland. 
 
 Its sensory root is derived from lingual branch of inferior 
 maxillary ; its motor root, from the facial nerve through a branch 
 of the chorda tympani; and its sympathetic, from the plexus of 
 the facial artery. 
 
 Beside these ganglia, situated upon branches of the trifacial 
 nerve, the following are found within the cavity of the cra- 
 nium : — 
 
 Ganglion of Ribes, on the anterior communicating artery; 
 Ganglion of Bidder, on the middle meningeal artery ; 
 Ganglion of Laumonier, on the internal carotid artery; 
 Ganglion of Cloquet, on the naso-palatine nerve in the incisor fossa; 
 Ganglion of Bochdaleck, near the spheno-palatine ganglion. 
 
 Cervical Ganglia. — The cervical ganglia consist of three, — 
 superior, middle, inferior, — of which the superior is the largest 
 and the middle the smallest. These are connected above with 
 the cranial ganglia, below with the thoracic ganglia, and com- 
 municate with each other. 
 
 The superior cervical ganglion lies opposite the second or 
 third cervical vertebra, behind the internal carotid artery. It is 
 connected with the middle ganglion, the upper four cervical, and 
 tenth and twelfth cranial nerves, distributes branches to the 
 carotid (internal), cavernous, and pharyngeal plexuses, and gives 
 off the superior cardiac nerve to the cardiac plexus. 
 
 The middle cervical ganglion lies upon inferior thyroid ar- 
 tery, opposite fifth cervical vertebra. It is connected with the 
 upper and lower ganglia and spinal nerves, and gives off the 
 middle cardiac nerve to cardiac plexus. 
 
 The inferior cervical ganglion lies internal to the superior 
 intercostal artery, below the last cervical vertebra. It is con- 
 nected to the middle ganglion, first thoracic, lower cervical 
 nerves, forms the vertebral plexus, and gives off the inferior car- 
 diac nerve to cardiac plexus. 
 
 Thoracic ganglia lie upon the heads of the ribs on each side 
 of the vertebral column. They are connected with the inferior 
 cervical ganglion above, the lumbar ganglion below, the dorsal 
 spinal nerves behind, and give off internal branches divided into 
 two sets of six each — upper and lower. 
 
 Internal branches from upper set are distributed to the 
 pulmonary and aortic plexuses, and internal branches from lower 
 set unite to form the three splanchnic nerves, — great splanchnic, 
 lesser splanchnic, renal splanchnic, — distributed respectively to 
 the semilunar ganglion, renal and suprarenal plexiises, and to 
 renal and cceliac plexuses. 
 
338 HUMAN ANATOMY. 
 
 The lunibar ganglia lie along inner margin of the psoas 
 muscle. They communicate above and below with the other 
 ganglia and with the lumbar spinal nerves, and give ofE internal 
 branches which form the hypogastric plexus. 
 
 The sacral ganglia are situated internal to the anterior 
 sacral foramina. They unite below in front of the coccyx in the 
 coccygeal ganglion, or ganglion inipar. They communicate with 
 the sacral nerves, join the pelvic plexus, and send branches on the 
 middle sacral artery. 
 
 Cakdiac Plexus. — The cardiac plexus, formed from the 
 superior, middle, and inferior cardiac nerves from the cervical 
 ganglia, and the cardiac branches from the pneumogastric and 
 recurrent laryngeal, consists of two portions — ^the superficial and 
 deep. 
 
 The superficial cardiac plexus, situated beneath the arch of 
 the aorta, is formed by the left superior cardiac nerve and the left 
 inferior cervical cardiac nerve, and contains the cardiac ganglion 
 of Wrisberg. It forms part of the anterior coronary plexus, and 
 sends branches to the left anterior pulmonary plexus. 
 
 The deep cardiac plexus lies between the arch of the aorta 
 and trachea, and receives all the cardiac nerves except the two 
 mentioned above. It forms part of the anterior coronary and 
 posterior coronary plexuses. 
 
 The SOLAR PLEXUS^ or "abdominal brain," consists of ganglia 
 and a net-work of nerve branches, formed chiefly from the 
 branches of the two great splanchnic nerves and branches from 
 the right pneumogastric. It is situated between the aorta and 
 the crura of the diaphragm and the stomach, and surrounds the 
 superior mesenteric artery and cceliac axis. 
 
 Its ganglia are two crescentic ganglionic masses — ^the semi- 
 lunar ganglia (the largest in the body) — situated in front of the 
 crura of the diaphragm. They are composed of smaller ganglia 
 aggregated together. From the solar plexus and semilunar gan- 
 glion are derived numerous branches which are distributed as 
 plexuses over all the abdominal arteries, as follows : — 
 
 Coeliao, 
 
 Phrenic, 
 
 Aortic, 
 
 Gastric, 
 
 Suprarenal, 
 
 Superior mesenteric. 
 
 Hepatic, 
 
 Renal, 
 
 Inferior mesenteric. 
 
 Splenic, 
 
 Spermatic, 
 
 Ovarian. 
 
 The HYPOGASTRIC PLEXUS is situated below the bifurcation 
 of the aorta, in front of the sacrum, and is formed by branches 
 from the lumbar ganglia and aortic plexus. It divides into two 
 parts which, with branches from the sacral ganglia and nerves, 
 become the pelvic plexuses. 
 
THE NERVOUS SYSTEM. 339 
 
 The inferior htpogastkic or pelvic plexus on each side 
 gives ofE the following branches : — 
 
 Vesical plexus, Inferior hsemorrhoidal, 
 
 T)_„„i„4.;^ i„„ ( Small cavernous nerves, "I 4.„ ^„- 
 
 Prostatic plexus, ■( t ' > to penis, 
 
 ^ ' I. Large cavernous nerves, I *^ ' 
 
 Vaginal plexus, Uterine plexus. 
 
ORGANS OF SPECIAL SENSE. 
 
 THE NOSE. 
 
 The nose, the special organ of smell, consists of two parts, — 
 the external prominence, or nose proper, and the internal cavities, 
 or nasal fossse. 
 
 BEPTA 
 OF S 
 
 AL branch) 
 SUPERIOR r 
 NASAL i 
 
 Fig. 152. 
 
 The olfactory nerves and nerves of common sensation to the nose, 
 (Eclcleu.) 
 
 The nose proper is made up of a cartilago-osseous frame work 
 covered with muscles {vide Muscles) and skin, and lined with 
 mucous membrane. The osseous portion is formed by the mar- 
 gins of the anterior meatus {vide Osteology). 
 
 The cartilaginous portion consists of an upper and lower 
 lateral cartilage on either side, and the nasal septum dividing 
 the nasal cavity into two nasal fossfe. 
 
 Arteries are from nasal branch of ophthalmic and infra- 
 orbital, nasal artery from superior coronary, and branches of the 
 lateralis nasi. 
 
 Veins empty into the ophthalmic and facial veins. 
 
 Nerves from iufratrochlear, infraorbital, and facial. 
 (340) 
 
ORGANS OF SPECIAL SENSE. 
 
 841 
 
 Fig. 153. 
 
 Nasal meatuses and accessory cavities. 1, right termination of the 
 left frontal sinus; 2, right frontal sinus; 3, probe extending from the 
 right frontal sinus through the infundibulum into the right nasal 
 fossa; 4, ethmoid cells; 5, large opening into the maxillary sinus; 6, 
 anterior antrum of the sphenoid bone; 7, posterior sphenoid antrum; 
 8, middle nasal meatus ; 9, inferior meatus ; 10, inferior turbinated 
 bone; 11. probe extending through the nasal duct. {Bishop.) 
 
342 
 
 HUMAN ANATOMY. 
 
 The nasal fossce are the two bony cavities already described 
 (vide page 3C). They are lined throughout with mucous mem- 
 brane called Schneiderian membrane, which is continuous with 
 the antrum of Highmore, frontal, ethmoidal, and sphenoidal 
 sinuses, with the conjunctiva through the lachrymo-nasal duet, 
 with the pharynx through the posterior nares, and with cavity 
 of the tympanum through the Eustachian tube. Its epithelium 
 is columnar, ciliated in the lower part and the sinuses, and is 
 
 Sis as front. 
 Ximmlna pspyr. OBa. ethmoid. 
 
 Foramfna ethToofcI. 
 Froo. ortit. oaa. palat. 
 Corpus osa. sphenoid. 
 
 For. optic, 
 Flamra orbit. Bnp. 
 Sella turcica V 
 
 Spina trooWear. 
 PAra orbit, oss. front. 
 
 Fosea boccI lacrito. 
 Oa nosald 
 
 'acies orbit. 
 
 xOl. 
 
 00. nncia. ose. 
 ethmoid. 
 Froo. ethmoid, conohao 
 
 naeal. inf. 
 
 Froo. maxill. conchaa 
 
 naeal. inf. 
 
 For epbenopalat. 
 Fossa pterygopalat. 
 
 lamina lat. proo. pteryg. 
 
 Froo. pyramid, osb. palat. 
 
 maxilla rls 
 Farfl perpendio. oas. palat. 
 
 Sonde in canal, palat. 
 
 Fig. 1B4. 
 Inner wall of orbit and adjacent parts. (His.) (Ball.) 
 
 columnar but not ciliated in the membrane to which the olfactory 
 nerve is distributed. 
 
 Arteries are anterior and posterior ethmoidal from the 
 ophthalmic to the roof, frontal and ethmoidal sinuses, spheno- 
 palatine from the internal maxillary to the mucous membrane of 
 the spongy bones, septum, and meatuses, and alveolar from the 
 internal maxillary to the antrum. 
 
 Veins empty into facial, ophthalmic, and beginning of great 
 longitudinal sinus. 
 
ORGANS OF SPECIAL SENSE. 
 
 343 
 
 Nerves are : — 
 
 Olfactory, or first cranial, the special nerve of smell, is dis- 
 tributed over the upper third of the septum, and superior turbin- 
 ated bones. 
 
 Anterior dental branch of superior maxillary to the inferior 
 turbinated bone and inferior meatus. 
 
 Nasal branch of ophthalmic, to the outer walls and septum. 
 Besides these, the spheno-palatine ganglion, the vidian, the supe- 
 rior nasal branch, naso-palatine, and anterior palatine also send 
 branches to the parts. 
 
 Horizontal section of right orbit. 1, Horner's muscle; 2, septum or- 
 bitale; 3, fibres of the orbicularis palpebrarum muscle; 4, tarsal plate; 
 6, conjunctival sac; 6, outer palpebral ligament; 7, temporal muscle; 
 8, wall of the orbit; 9, external rectus muscle; 10, orbital fat; 11. optic 
 nerve; 12, internal rectus muscle; 13, Inner check ligament; 14, inner 
 wall of the orbit; 16, attachment of the capsule of Tenon (16) to the 
 conjunctiva; 17, Tenon's space; 18, outer check ligament; 19, lachrymal 
 gland; 20, ciliary process; 21, iris. (After Gerlach.) {Ball.) 
 
 THE EYE. 
 
 The ORGAN'S of sight comprise the eyeballs and their ap- 
 pendages and the optic nerves. 
 
 The eye is a spherical organ, situated in the anterior part 
 of the skull, protected in front by several appendages, acted upon 
 by muscles, and supplied by blood-vessels and nerves. 
 
 Within the orbit it rests upon a bed of fat, from which it is 
 separated by a membranous sac — ^the capsule of Tenon. 
 
344 HUMAN ANATOMY. 
 
 It presents the following: — 
 
 Diameters. — Antero-posterior, in the adult, .950 inch; 
 transverse, .925; vertical, .915; oblique, .943. 
 
 Anterior and posterior poles are the geometric centres of the 
 cornea and fundus respectively. 
 
 Optic axis is a straight line passing through the cornea and 
 posterior pole of the eye. 
 
 Line of vision, or visual axis, is an imaginary line which 
 connects the point of fixation with the fovea centralis, through 
 the nodal point, usually to the outer side of the centre of the 
 pupil. It forms with the optic axis as it cuts the cornea, the 
 visual angle — an angle of from 3° to 7°. 
 
 Antero-posterior section of EyebaU, 1, optic nerve; 2, sclera; 3, 
 cornea; 4, spaces of Fontana; B, choroid; 6, ciliary muscle; 7, ciliary 
 processes; 8, iris; 9, retina; 10, Jacob's membrane; 11, anterior cham- 
 ber; 12, posterior chamber; 13, pupillary area; 14, aqueous humor; 
 IB, hyaloid membrane; 16, canal of Stilling; 17, canal of Petit; 18, 
 vitreous humor; 19, capsule of the lens; 20, fluid of Morgagni; 21, 
 lens. (Liveilli.) {.Ball.) 
 
 Nodal point is an imaginary point — the centre of curvature 
 of the refracting media — where all the luminous rays pass with- 
 out deviation. 
 
 Equatorial plane, an imaginary plane passing through the 
 centre of the eyeball at right angles to the optic axis, dividing 
 the globe into two hemispheres — -the anterior and posterior. 
 
 Equator is the line upon the surface of the globe where the 
 equatorial plane cuts it. 
 
 Meridional planes are imaginary antero-posterior planes co- 
 inciding with the axis. 
 
ORGANS OF SPECIAL SENSE. 345 
 
 Meridians are the lines upon the surface where these merid- 
 ional planes cut it. 
 
 The capsule of tenon, tunica vaginalis oculi, is a fascia 
 between the eyeball and the walls of the orbit, isolating the eye- 
 ball and allowing free movement. It is continuous in front with 
 the subconjunctival connective tissue, and behind with the dura 
 mater, through the sphenoidal fissure and optic foramen, and 
 consists of two layers — a visceral layer investing the posterior 
 portion of the eyeball, and a parietal layer lining the cushion of 
 fat on which the eye rests. 
 
 The inner aspect is lined with flattened endothelial cells, and 
 incloses a lymph space communicating with subdural and sub- 
 arachnoidean lymph spaces of the optic nerve-sheath. It sup- 
 ports the lachrymal gland, is strengthened by numerous fibrous 
 bands, and is pierced by the ocular muscles, inclosing them in 
 imperfect sheaths. 
 
 The capsule of Bonnet is the name given to the portion 
 posterior to the passage of the tendons, and 
 
 The capsule of Tenon is then applied to the anterior socket- 
 like half. 
 
 The eyeball is composed of a large, opaque segment of a 
 sphere, forming about five-sixths of the globe, for the protection 
 of its contents, and a smaller transparent segment of a sphere, 
 implanted upon and continuous with it in front. The optic 
 nerves enter the eyeballs to their nasal side, in the direction of 
 the axes of the orbit. 
 
 It is composed of three tunics or coats: — 
 
 1. Sclerotic and cornea, 
 
 2. Choroid, iris, and ciliary processes, 
 
 3. Retina; 
 
 And three humors, or refracting media :— 
 
 1. Aqueous humor, 
 
 2. Crystalline lens (and capsule), 
 
 3. Vitreous humor, or body. 
 
 The sclerotic coat, so called from its extreme hardness, 
 is thicker behind (one twenty-fifth of an inch) than in front 
 (one-sixtieth of an inch), and presents two surfaces for study — 
 the external and internal. 
 
 The external surface is smooth and white, and has attached 
 to it the various muscles of the eye. 
 
 The internal surface is grooved for the passage of the ciliary 
 nerves, and connected to the choroid by a fine areolar layer — the 
 lamina fusca. 
 
346 HUMAN ANATOMY. 
 
 Behind, and a little to the nasal side, where the optic nerve 
 enters, it presents a perforated appearance — ^the lamina cribrosa 
 — the larger opening of which — ^the porus opticus— transmits the 
 arteria centralis retinae; the others transmit the ciliary vessels 
 and nerves. It is continuous in front with the cornea, over- 
 lapping it a little on its outer margin. 
 
 In structure it is made up of white, iibrous tissue, with a 
 small quantity of elastic fibres, and connective-tissue corpuscles. 
 It probably contains no nerves. 
 
 The cornea is the convex, transparent, nearly circular 
 tissue forming the 8,nterior one-sixth of the globe. It is from 
 one twenty-second to one thirty-second of an inch in thickness. 
 Its thickness at the periphery is 1.13 millimetres, hence its pos- 
 terior surface is more curved than the anterior. Its transverse 
 diameter is a little greater than the vertical, owing to the over- 
 lapping of the sclerotic above and below. It is composed of four 
 layers : — 
 
 1. Conjupctival epithelium; 
 
 2. Cornea proper, { ^^^^^^ '^^^^' 
 
 I: ^^ t^, '^"^"^ } ^-^-- °^ ^— *• 
 
 The conjunctival epithelium consists of several layers of 
 cells (columnar, polyhedral, and squamous) covering the ante- 
 rior surface of the cornea, continuous with the conjunctiva. 
 
 The anterior elastic lamina is the name given to the outer 
 epithelial layer of the cornea proper. 
 
 The cornea proper is made up of a transparent fibrous struc- 
 ture, identical with the sclerotic, and consisting of about sixty 
 layers or lamina, connected by a cement substance inclosing cor- 
 neal spaces, each of which contains a corneal corpuscle. 
 
 The posterior elastic lamina consists of an elastic homo- 
 geneous membrane, internal to the proper structure of the cornea, 
 and constituting, with the epithelial lining, the membrane of Des- 
 cemet, or Demours. 
 
 The structure of the cornea is non-vascular, being nourished 
 by channels representing lymphatic vessels, and continuous with 
 the corneal spaces. The nerves derived from the ciliary nerves 
 are numerous, and form between the outer surface of the cornea 
 proper and the epithelial covering the subepithelial plexus, from 
 which is given off the intraepithelial plexus. 
 
 The second tunic consists of the choroid, lining the sclerotic 
 coat throughout; the iris, the circular curtain suspended in the 
 
ORGANS OF SPECIAL SENSE. 
 
 347 
 
 aqueous humor and perforated by the pupil ; and the ciliary liga- 
 ment and muscle at the junction of the two. 
 
 The choroid is a dark, reddish-brown, highly vascular 
 membrane, lining the sclerotic coat from the optic nerve to the 
 ciliary ligament, where it projects backward in a number of 
 processes, the ciliary processes. It is in contact externally with 
 the sclerotic, to which it is attached by the membrana fusca, and 
 internally with the retina. 
 
 Pig. 157. 
 
 Vessels of the eye. A, conjunctival vessels; B, anterior ciliary 
 vessels; C, vena vorticosa; D, posterior ciliary arteries; E, central 
 retinal vessels. iBall.) 
 
 The structure consists chiefly of a dense capillary net-work. 
 
 The choroid proper consists of an external and an internal 
 layer, and is separated from the sclerotic by the lamina supra 
 choroidea, continuous with the lamina fusca of the sclerotic, and 
 from the pigmentary layer of the retina by the lamina vitrea. 
 
 The external layer consists of a capillary net-work, derived 
 from the larger branches of the short ciliary arteries, inclosing 
 between the meshes large, star-shaped pigment cells, which are 
 connected together by a delicate stroma. They terminate in the 
 
348 HUMAN ANATOMY. 
 
 venm verUcosw, which emerge through the sclerotic midway be- 
 tween the optic nerve and the margin of the cornea. 
 
 The internal layer is also composed of a iine capillary net- 
 work, derived from the short ciliary arteries, and continuous 
 in front with the vessels of the ciliary processes. It is called 
 the tunica Ruyschiana. 
 
 The vitreous membrane lamina vitrea is a thin, structure- 
 less layer, separating the pigmentary layer of the retina from the 
 membrana Euysehiana. 
 
 The arteries are from posterior ciliary, short ciliary (prin- 
 cipally in the external layer), and recurrent branches of long 
 and anterior ciliary. 
 
 The veins converge from the venfe verticosse to form four or 
 five trunks, which pierce the sclerotic midway between the optic 
 nerve and corneal margin to join the cavernous sinus. 
 
 The nerves are the long and short ciliary. 
 
 The ciliary processes are a series of sixty to eighty pig- 
 mented vascular processes arranged circularly around the lens 
 behind the iris, and composed of the two internal layers of the 
 choroid folded inward. They are continuous in front with the 
 iris, and are connected behind with the suspensory ligament of 
 the lens. 
 
 The structure is similar to that of the choroid. 
 
 The iris is a thin, circular curtain, suspended in the 
 aqueous humor, between the lens and cornea, and perforated by a 
 circular aperture — the pupil. 
 
 Its circumference is connected with the choroid, and also 
 by means of the ciliary ligament with the sclerotic and cornea. 
 The sclerotic contains in this position, near its Junction with the 
 cornea, a circular canal (lymph canal, or venous sinus), the 
 sinus circularis iridis, or canal of Schlemm. 
 
 The circumference of the iris is also connected in front with 
 the cornea by ligamentuni pectinatum iridis, derived from the 
 membrane of Descemet. 
 
 The structure is composed of four elements : — 
 
 1. A basement membrane and polyhedral cells, continuous with the 
 membrane of Descemet ; 
 
 2. Stroma, consisting of bundles of fibrous tissue and cells; 
 
 Circular fibres, forming the sphincter of the 
 
 pupil; 
 Radiating fibres, forming the dilator of the 
 
 pupil; 
 
 4. Pigment, consisting of polyhedral or round pigment cells, dis- 
 tributed for the most part to the posterior surface, which, from its 
 deep-purple tint, has been called the uvea. 
 
 3. Muscular fibres, 
 
ORGANS OF SPECIAL SENSE. 349 
 
 The arteries are from the long and anterior ciliary and from 
 the ciliary processes (from the short ciliary). 
 
 The veins join those of the ciliary processes and anterior 
 ciliary veins. 
 
 The nerves are the long ciliary from the nasal branch of the 
 ophthalmic (first division of fifth), and ciliary branches from 
 the lenticular or ophthalmic ganglion. 
 
 The circular fibres are supplied by the fibres from the third 
 or motor oculi, ihe radiating fibres are supplied by the sympa- 
 thetic. 
 
 The menibrana pupillaris is a delicate, vascular membrane, 
 closing the pupil in the foetus, continuous at its margin with the 
 iris. It usually disappears about the eighth month, but occa- 
 sionally, persists. 
 
 'Hhe. ciliary muscle is a grayish, circular band of unstriated 
 fibres, attached to the fore part of the choroid. It consists of 
 two sets of fibres — ^the external radiating fibres, dilator pupillce — 
 arising from the junction of the sclerotica and cornea, and is 
 inserted into the choroid opposite the ciliary processes; the in- 
 ternal circular fibres, sphincter pupillcB, pursue a circular course 
 around the insertion of the iris. 
 
 It is the muscle of accommodation, its contraction drawing 
 on the ciliary processes, relaxing the circular fibres described as 
 the ligament of the lens, and allowing the anterior surface of the 
 lens to become more convex by its inherent elasticity. 
 
 The retina is a delicate, white, nervous membrane, the ex- 
 pansion of the optic nerve. It lines the eyeball, being in con- 
 tact externally with the choroid and internally with the vitreous 
 body. It terminates in front near the ciliary ligament in an 
 irregular margin, the ora serrata, but is prolonged forward as the 
 pars ciliaris to the iris. Its internal posterior surface presents at 
 a point corresponding to the axis of the eyeball a small, round, 
 elevated spot of yellowish color, the macula lutea, or yellow spot 
 of Sommering, in the centre of which is the fovea centralis, a 
 central depression, the region of most acute vision, and about one- 
 tenth of an inch to its nasal side, at a point corresponding to the 
 axis of the orbit, the entrance of the optic nerve, an oval, bluish- 
 white depression, with distinct, often pigmented margins, a re- 
 gion destitute of vision and called the optic dish. Its centre 
 presents the arteria centralis retinae, giving branches to the nasal 
 upper and lower side of the macular region. 
 
 The structure of the retina is exceedingly complex, con- 
 sisting microscopically of ten distinct layers from within out- 
 ward, as follows: — 
 
350 
 
 HUMAN ANATOMY. 
 
 1. Membrana limitans interna, the most internal layer of the retina, 
 forms the base of the connective-tissue frame-work of the retina, from 
 which it is derived. 
 
 2. The fibrous layer consists of nerve-fibres, the termination of the 
 optic nerve-fibres. 
 
 FiQ. 158. 
 
 The structure of the human retina. I, pigment epithelium layer; 
 II, rods and cones; III, granules ot the visual cells; IV, outer plexl- 
 torm layer; V, layer of horizontal cells; VI, layer of bipolar cells; 
 VII, layer of amaUrine cells; VIII, Inner plexiform layer; IX, gan- 
 glion-cell layer; X, layer of nerve-flbres; 1, diffuse amakrine cell; 
 2, diffuse ganglion cell; 3, centrifugal nerve-fibre; 4, amakrine asso- 
 ciation fibres; 5, neuroglia-cells; 6, Miiller'a radial fibres. (A.tter 
 ereeff.) IBall.) 
 
ORGANS OP SPECIAL SENSE. 
 
 351 
 
 3. The vesicular layer, composed of a layer of large, flask-shaped 
 ganglionic cells. It is wanting in the muscular region. 
 
 4. The inner molecular layer is composed of a layer of glandular- 
 like structure, forming a reticulum inclosing minute granules. 
 
 5. The inner nuclear layer is composed of three sets of nuclear 
 bodies, the first resembling bipolar nerve-cells, the second without 
 branches, and the third continuous with the radiating fibres, or fibres of 
 Miiller. 
 
 6. The outer molecular layer resembles closely the inner molecular 
 layer, from which it differs only by containing branched stellate cells. 
 
 FIG. 169. 
 
 Diagram of the retinal vessels. 1, superior temporal artery: 2, 
 superior temporal vein; 3, superior nasal vein; 4, superior nasal ar- 
 tery; 5, inferior nasal vein; 6, inferior nasal artery; 7, inferior tem- 
 poral vein; 8, interior temporal artery; 9, macula lutea; 10, macular 
 veins. (Ball.) 
 
 7. The outer nuclear layer is composed of several layers of nuclear 
 cells, separable into two kinds, the rod granules and cone granules, both 
 continuous with the rods and cones of Jacob's membrane. 
 
 8. The memhrana Umitans externa is, like the internal limiting 
 membrajie, derived from the radiating fibres, or fibres of MuUer. 
 
 9. Jacob's membrane, or the layer of rods and cones, consists of 
 two distinct kinds of cells — the rods and cones, distributed alternately 
 throughout this layer, the rods being much more numerous. 
 
 The rods are solid, stand perpendicularly to the surface, and con- 
 sist of two portions — an outer striated and an inner granular. 
 
 23 
 
352 HUMAN ANATOMY. 
 
 The cones are flfisk-shaped, with their pointed extremities toward 
 the choroid. They also consist of two portions — an outer striated and 
 an inner granular. 
 
 10. The pigmentary layer was formerly described as a layer of the 
 choroid. It has received the name of tapetum nigrum, consisting of a 
 layer of pigmented hexagonal epithelial cells. 
 
 In many of the lower animals, this layer on the posterior surface 
 is destitute of pigment, and is called from its iridescent lustre the 
 tapetum lucidum. 
 
 The radiating fibres, or fibres of Muller, consist of connective-tissue 
 fibres, connecting all the layers together, and forming the membrana 
 limitans interna and the membrana limitans externa. 
 
 The structure of the retina at the macula lutea differs in the 
 following manner: the cones only of Jacob's membrane are 
 present ; the vesicular layer consists of several layers, and in the 
 outer nuclear layer only the cone-fibres are present. 
 
 At the fovea centralis only the cones of Jacob's membrane, 
 the outer nuclear layer, and the internal granular layer are 
 present. 
 
 The arteria centralis retina supplies only as far as the inner 
 nuclear layer. 
 
 THE HUMOKS OF THE EYE. 
 
 The aqueous humok is a transparent, alkaline, serous fluid, 
 small in quantity, weighing four to five grains, and filling the 
 anterior and posterior chambers of the eye. It is composed of 
 water, 96.7; extractive matters, principally chloride of sodium 
 and albumen, 0.1. 
 
 The anterior chamber is the space (about 2.7 millimetres in 
 depth) between the iris and the cornea. 
 
 The posterior chamber is the space between the anterior sur- 
 face of the lens and the iris. It amounts to a space only at the 
 circumference, the two being in contact at the posterior surface. 
 
 The crystalline lens is a biconvex, transparent, elastic 
 body, suspended within its capsule, surrounded by the ciliary 
 processes. It is more convex on its posterior surface (anterior 
 surface has an average radius of ten millimetres, the posterior 
 six millimetres), and is received into a hollow depression in the 
 hyaloid membrane. 
 
 It measures about one-third inch in diameter, one-fourth 
 inch in axis, and weighs from four to four and one-half grains. 
 
 Its index of refraction increases from the periphery to the 
 centre, with an average of 1.4371. 
 
 Its composition consists of about 60 per cent, water ; soluble 
 albuminous matter, 35 per cent. ; insoluble albuminous matter, 
 S.5 per cent.; cholesterine and fat, 2 per cent 
 
ORGANS OF SPECIAL SENSE. 353 
 
 The structure of the lens consists of concentric lariiinse, made 
 up of hexagonal prisms, about one five-thousandth inch in 
 breadth, united laterally by dentated margins, and curving round 
 the borders of the lens. The laminae are arranged into three 
 triangular segments. 
 
 The central portion, or nucleus. Is unstratified, while the 
 outer layers, or cortex, each contain a nucleus, forming a nuclear 
 layer. 
 
 The capsule of the lens is a clear, elastic, brittle membrane, 
 inclosing the lens, and held in position by the suspensory liga- 
 ment. Its anterior layer is thicker, and is attached to the lens by 
 a layer of polygonal nucleated cells, which break down post- 
 mortem to form the liquor MorgAgni. 
 
 The canal of Petit is about one-tenth of an inch in diam- 
 eter, encircliiig the capsule of lens. Its base is formed by the 
 capsule, and it is bounded in front by suspensory ligament, be- 
 hind by the hyaloid membrane of the vitreous humor. 
 
 The suspensory ligament, or zonula of Zinn, is a thin, trans- 
 parent structure, extending from the margins of the hyaloid 
 fossa, where it is continuous with hyaloid membrane, to the an- 
 terior margin of the lens. 
 
 The vitebous humor, or body, is a clear, albuminous fluid, 
 filling the cavity of the retina, hollowed out in front — hyaloid 
 fossa — for the lens, and inclosed in the hyaloid membrane. It 
 is composed of water, with a few salts, and a little albumen. 
 
 Its structure is finely reticular, particularly in the fcetus. 
 
 The canal of Stilling, canal of Cloquet, or hyaloid canal, 
 is a canal extending in the fcetus from the entrance of the optic 
 nerve to the lens, containing fluid, and lined by a fold of hyaloid 
 membrane. 
 
 In the fcetus a canal extends parallel but independent of this, 
 and transmits a minute artery to the capsule of the lens. 
 
 The hyaloid mejribrane is a delicate capsular membrane, 
 investing the vitreous body, excepting its anterior surface, sends 
 fibrous septa into the structure of the vitreous, and is continuous 
 in front with the posterior capsule, and with the anterior capsule 
 through the suspensory ligament. 
 
 MUSCLES OF THE EYEBALL. 
 
 Rectus Superior. — Origin, sheath of the optic nerve and 
 upper margin of optic foramen; insertion, into upper surface of 
 sclerotic coat, three or four lines from corneal margin; action, 
 rotates the eyeball upward; nerve, third cranial. 
 
354 
 
 HUMAN ANATOMY. 
 
 Eeotus Infeeioe. — Origin, from lower and inferior part 
 of optic foramen (ligament of Zinn) ; insertion, into lower sur- 
 face of sclerotic; action, rotates the eyeball downward; nerve, 
 third cranial. 
 
 Eeotus Inteenus. — Origin, same as inferior rectus; inser- 
 tion, into inner surface of sclerotic; action, rotates the eyeball 
 inward ; nerve, third cranial. 
 
 fP 
 
 Q,. 
 
 ■! ' 
 
 i?S. 
 
 m — 
 
 ''Rm. 
 
 JXi 
 
 ^•^^^ 
 
 Fig. 160. 
 
 The orbital muscles. Lp., levator palpebrse superlorls; Os, supe- 
 rior oblique; Rs, superior rectus; Rl, external rectus; Oi, inferior 
 oblique; Ri, interior rectus; Rm, internal rectus; Tr, trochlea. (Ball.) 
 
 Eeotus Exteenus. — Origin, by two heads — lower, from 
 ligament of Zinn and lower margin of sphenoidal fissure ; upper, 
 from outer margin of optic foramen; insertion, into outer sur- 
 face of sclerotic; nerve, abducens, or sixth cranial. Passing 
 between the two heads are the ophthalmic vein, the tliird, nasal 
 branch of fifth, and sixth nerves. 
 
ORGANS OF SPECIAL SENSE. 
 
 855 
 
 Sdpeeioe Oblique. — Origin, from inner margin of optic 
 foramen. Its tendon passes through a pulley near the internal 
 angular process of the frontal bone; insertion, into sclerotic 
 between external and superior recti, midway between entrance of 
 optic nerve and the cornea; action, rotates the eyeball on its 
 axis; nerve, fourth, or patheticus. 
 
 Infeeiob Oblique. — Origin, orbital plate of superior 
 maxilla; insertion, near that of superior oblique, between ex- 
 ternal and superior recti ; action, rotates the eyeball on its axis ; 
 nerve, third cranial. 
 
 Bupra-orbital 
 
 tAorimal 
 
 MuBcuInr and oiliary 
 
 Anterior meningeal 
 Ophthalmic 
 
 ^ " Nasal 
 
 SnpeTlor reotas 
 Iievator palpebrie Bupeiieria 
 
 Anterior ethmoidal 
 Mnecular trunk 
 
 Ciliary 
 
 Arteria centralis 
 Foatericr ethmoidal 
 
 Optic nerve 
 Internal carotid 
 
 Fig. 161. 
 Opthalmlc artery and branches. (After MerTcel and KalUus.) (Ball.) 
 
 The AKTERiES of the globe of the eye are : — 
 
 1. The short ciliary, enter through the sclerotic around the 
 optic nerve, to supply the choroid and ciliary processes. 
 
 2. The long ciliary arteries, two in number, pierce the 
 sclerotic, run forward between the choroid and sclerotic to the 
 ciliary muscle, which they supply, and where they form an anas- 
 tomotic circle about the iris. 
 
 3. The anterior ciliary arieries, five or six in number, enter 
 the sclerotic in front, supply the ciliary processes, and anasto- 
 mose about the iris. 
 
 4. The arteria centralis retina, supplies the retina, dividing 
 into four or five branches, which enter as deeply as the inner 
 nuclear layer. 
 
356 HUMAN ANATOMY. 
 
 The other arteries supplying the eye and its appendages are 
 derived from the ophthalmic branch of the internal carotid (the 
 same source as the ciliary arteries), the anterior cerehral branch 
 of the internal carotid, and the infraorbital branch of the in- 
 ternal maxillary. 
 
 The branches of the ophthalmic are the 
 
 Lachrymal ; 
 
 Supraorbital ; 
 
 Anterior and posterior ethmoidal; 
 
 Palpebral; 
 
 Frontal; 
 
 Nasal. (For description see Arterial System.) 
 
 The veins of the eyeball emerge as the vence vorticosce, unite 
 with the other veins to form two main trunks — ^the ophthalmic 
 and inferior ophthalmic veins — ^to terminate in the cavernous 
 sinus. The ophthalmic vein anastomoses freely with the angular 
 vein, the commencement of the facial at the inner angle of the 
 orbit. 
 
 The nerves of the eye and its appendages are nerve of special 
 sense, the optic or second cranial; motor nerves, the third and 
 fourth; branches of the fifth and sixth, and filaments from the 
 sympathetic. 
 
 Sensory nerve, ophthalmic division of the trifacial, or fifth 
 cranial {vide Cranial Nerves). 
 
 Sympathetic branches, derived chiefly from the ciliary gan- 
 glion, Meckel's ganglion, and the cavernous and carotid plexuses 
 {vide Cranial Sympathetic Ganglion). 
 
 APPENDAGES OF THE EYE. 
 
 The appendages of the ej'e, or the tutamina oculi, include : — 
 
 The eyebrows (supercilia), Lachrymal gland. 
 
 The eyelids (palpebrw). Lachrymal sac, 
 
 CJonjunetiva, Nasal duct. 
 
 The eyebrows are the elevated arches of skin surmounting 
 the upper margins of the orbits, covered with short, thick hairs. 
 
 The eyelids are two movable fokls, covering and protecting 
 the front of the eye. The upper lid is larger, longer, and most 
 movable, being supplied with a special muscle — the levator pal- 
 pebrae superioris. 
 
 The lids are separated by an elliptical lissure — the fissuia 
 palpehiwum — and connected at their angles of junction bv the 
 Older and inner cantlii. 
 
ORGANS OF SPECIAL SENSE. 357 
 
 ' On the nasal side the lids are separated by a triangular 
 space — the lacus lachrymalis — at the outer angles of which are 
 the lachrymal papillcB, surmounted by the puncta lachrymalm, 
 the commencements of the lachrymal canal. The lacus lachry- 
 malis is filled by the coruncula lachrymalis, a mass of follicles 
 resembling the Meibomian glands, and covered by the con- 
 junctiva. 
 
 The structure of the eyelids, from without inward, is as 
 follows : — 
 
 Skin, subcutaneous areolar tissue, fibres of the orbicularis muscle, 
 tarsal cartilage, fibrous membrane, Meibomean glands, vessels, and 
 nerves; 
 
 The sMn is thin, and attached by a very loose areolar tissue to the 
 muscle beneath; 
 
 The fibres of the orbicularis are pale, thin, and act involuntarily; 
 
 The tarsal cartilages are two plates of firm connective tissue; the 
 superior, the larger, is semilunar in shape, the inferior is elliptical. The 
 inner margins are fixed to the orbit by tendo oculi; 
 
 The fibrous merribrane of the lids, or tarsal ligament, passes over 
 the anterior surface of the tarsal cartilage, being attached to its free 
 margin below and to the margin of the orbit externally; 
 
 The Meibomian glands, about thirty in number in the upper, a few 
 less in the lower lid, are arranged vertically on the inner surface of the 
 cartilages; they axe straight, sebaceous follicles, into which open a 
 number of secondary follicles, terminating above in a blunt extremity, 
 and opening below on the free margin of the lids by small foramina, cor- 
 responding to the number of tubules; 
 
 The eyelashes, or cilia, are arranged on the free border of the lids 
 in two or three rows. 
 
 The conjunctiva is the mucous lining membrane of the 
 front of the eye. It consists of two portions — the ocular, re- 
 flected over the sclerotic and cornea, and the palpebral portion, 
 lining the internal surface of the lids. 
 
 The ocular portion is loosely connected with the sclerotic, 
 but over the cornea it becomes very thin, consisting only of the 
 epithelial layer. 
 
 The palpebral portion is thick, highly vascular, and contains 
 many papillae. At the inner angle of the eye it forms a semi- 
 lunar fold, the plica semilunaris — the rudiment of the nictitating 
 membrane of birds, the membrana nictitans. 
 
 The point of reflection is •called the fornix conjunctivae, 
 and the reflected portions the superior and inferior palpebral 
 folds. 
 
 The lachrymal apparatus consists of the lachrymal gland, 
 canals, sac, and nasal duct. 
 
 The lachrymal gland is an oval, glandular body, about 
 the shape and size of an almond, situated in a depression in the 
 upper surface of the orbit near the external angular process. 
 
358 
 
 HUMAN ANATOMY. 
 
 The anterior portion of the gland is sometimes described 
 as a separate lobe — the palpebral portion of the gland, or ac- 
 cessory gland of Bosenmuller. 
 
 The gland is attached to the bony roof of the orbit by the 
 tarso-orhital fascia. 
 
 The ducts, seven to ten in number, open upon the con- 
 junctiva near its point of reflection by minute orifices arranged 
 in a row. 
 
 The lachrymal canals commence at the puncta lachrymalia, 
 at the summits of the papilla3 lachrymales, and descend by two 
 canaliculi to empty into the lachrymal sac. 
 
 DUCTS OF 
 
 LACHRYMAL 
 
 GLAND 
 
 VIMAL s»e 
 
 -NASAL DUCT 
 
 Fig. 162. 
 The lachrymal apparatus. (.Oerrish, after Testut.) {Eckley.) 
 
 The superior canal descends obliquely inward and down- 
 ward, while the inferior descends at first and then passes nearly 
 horizontally inward. 
 
 The lachrymal sac is the oval, dilated^ upper portion of 
 the nasal duct, lodged in a deep groove formed by the nasal 
 process of the superior maxilla, and the lachrymal bone. It is 
 crossed by the tensor tarsi muscle, which acts as a compressor, 
 and receives a fibrous expansion from the tendo oculi. 
 
 Its structure is made up of a fibrous elastic coat, lined by 
 mucous membrane continuous with the nose and conjunctiva. 
 
 The nasal duct is a membranous tube about three-quarters 
 of an inch in length, extending from the lachrymal sac to the 
 inferior meatus of the nose, and lining the bony lachrymo-nasal 
 
ORGANS OF SPECIAL SENSE. 359 
 
 canal. It passes backward, downward, and outward, and is pro- 
 tected at its inferior extremity by a valve of mucoTis membrane — 
 the valve of Hasner. 
 
 The mucous lining is continuous with that of the sac, but 
 instead of having squamous epithelium it is ciliated in the duct. 
 
 THE EAE. 
 
 The eab — the organ of hearing — is contained in the petrous 
 and mastoid portions of the temporal bone, and consists of three 
 divisions, — external ear, middle ear or tympanum, and internal 
 ear or labyrinth: — ■ 
 
 , _, . , f Auricle, or pinna, 
 
 1. J!.-xternal ear, ^ External auditory canal or meatus; 
 
 2. Middle ear or tympanum. 
 
 Membrana tympani. 
 Tympanic cavity. 
 Mastoid sinuses, 
 , Eustachian tube; 
 
 3. Internal ear or 
 labyrinth. 
 
 {Vestibule, 
 Semicircular canals, 
 Cochlea; 
 
 (Utricle, 
 Semkircular canals. 
 Cochlea. 
 
 The external ear includes two parts, the auricle and the 
 external auditory canal. 
 
 AUEIOLB, OR PINNA. 
 
 The external prominent portion is composed of cartilaginous 
 segments, comieeted together by ligaments and muscles richly 
 supplied with blood-vessels, nerves, and lymphatics, and covered 
 with skin. It presents the following elevations and depres- 
 sions : — 
 
 Fossa of the helix, a depression between the helix and anti- 
 helix ; 
 
 Fossa of the antihelix, a depression above the bifurcation of 
 the antihelix; 
 
 Tragus, the prominence in front of the concha, usually cov- 
 ered with hair; 
 
 Antitragus, a small, conical eminence behind the tragus, 
 from which it is separated by the incisura intertragica ; 
 
 Lobule, the soft, rounded portion depending below the anti- 
 tragus ; 
 
360 
 
 HUMAN ANATOMY. 
 
 Concha, a deep cavity, surrounded by the helix, and leading 
 into the exteraal meatus. 
 
 Muscles. — The muscles of the auricle include two sets, the 
 extrinsic muscles, already described {vide Muscles), of which 
 there are three — the attolens aurem, attrahens aurem, and re- 
 trahens aurem — and the intrinsic muscles, but slightly devel- 
 oped, of which there are two sets, four on the anterior surface 
 of the auricle — the tragicus, antitragicus, helicis major, and 
 
 Fig. 163. 
 
 External, middle, and internal ear. 1, external ear; 2, middle earj 
 S, internal ear; 4, pinna; 6, helix; 6, antihelix; 7, fossa navicularis; 
 8, fossa innominata; 9, tragus; 10, antitragus; 11, concha; 12, lobe; 
 13, meatus auditorius externus; 14, tympanic membrane; 16, promon- 
 tory; 16, foramen rotundum; 17, posterior wall of the tympanum; 18, 
 ossicula auditus; 19, Eustachian tube; 20, narrow canal; 21, vestibule; 
 22, semicircular canals, the superior, posterior, and horizontal; 23, 
 ampullae; 24, cochlea; 25, prominence caused by the scala vestibuU, 
 26, scala tympani. (Boennmg.) 
 
 helicis minor — and two on the posterior surface, transversus 
 auricula and obliquus auriculae. 
 
 Arteries, auricular branch, from the occipital; posterior 
 auricular, from the external carotid; and anterior auricular, 
 from the temporal. The veins correspond to the arteries. 
 
 Nerves, auricular branch, from the pneumogastric ; auriculo- 
 temporal branch, from the inferior maxillary; occipitalis major 
 
ORGANS OF SPECIAL SENSE. 361 
 
 and occipitalie minor; auricularis magnus, from the cervical 
 plexus ; and posterior auricular, from the facial. 
 
 Auditory canal, or meatus auditorius externus, is an osseo- 
 cartilaginous canal, about one and one-fourth inches in length, 
 extending from the concha to the tympanic membrane. 
 
 The osseous portion forms about two-thirds of the passage, 
 and consists in greater part (anterior and lower) of a curved 
 plate of bone — the annulus tympanicus. 
 
 The anterior and upper part of the ring present two spines — 
 spina tympanica, major and minor, for the ligaments of the 
 malleus. 
 
 The sulcus iympanicus is a furrow on the inner edge of the 
 ring, for the attachment of the tympanic membrane. 
 
 The cartilaginous portion forms about one-third of the pas- 
 sage, and consists of the inverted cartilage of the tragus and 
 concha, the upper and back part of which is deficient, the cleft 
 being filled with fibrous tissue. 
 
 The canal, including the tympanic membrane, is lined 
 throughout with skin, containing short hairs, vascular papillae, 
 sebaceous and ceruminoxis glands. 
 
 Arteries — branches of the internal maxillary, posterior 
 auricular, and temporal branches of external carotid. 
 
 Nerves — from the auriculo-temporal branch, the inferior 
 maxillary, and auricular branch of the pneumogastric. 
 
 MIDDLE EAR, OR TYMPANUM, 
 
 is an irregular cavity, situated between the auditory canal and 
 the labyrinth, communicating with the pharynx through the 
 Eustachian tube, and also with the mastoid cells. It contains 
 a chain of movable bones, part of the chorda tympani nerve, and 
 is filled with air. Its average diameters are about half an inch 
 in height and width, and a line or two in depth from without 
 inward. It is lined with mucous membrane, continuous with 
 that of the Eustachian tube and mastoid cells, and which is 
 reflected over all the tympanic contents. It is bounded by a 
 roof, floor, and four walls, which present the following points : — 
 
 Boof, a very thin plate of bone, separates the tympanum 
 from the cranial cavity, and corresponds to a depression on the 
 anterior wall of the petrous bone ; 
 
 Floor, forms the bottom of the jugular fossa, and pre- 
 sents : — 
 
 The opening for Jaco'bson's nerve, the tympanic branch of the 
 glosso-pharyngeaL 
 
362 HUMAN ANATOMY. 
 
 Outer wall, formed by the tympanic membrane, Shrapnell's 
 membrane, and the annulus tympanicus surrounding it : — 
 
 'Notch of Bivinus, incomplete upper ring of bone ; 
 
 Iter chordw posterius, gives entrance to chorda tympani nerve; 
 
 Iter chorda) anterius, or canal of Hugier, givea exit to same ; 
 
 Olaserian fissure, above and in front of annulus tympanicus, re- 
 ceives the anterior ligament of the malleus, the long process of the 
 malleus, and the tjTUpanic arterj' ; 
 
 Pouches of the memtrana tympani, are two or three pockets formed 
 by the doubling of the mucous membrane around the chorda tympani 
 nerve. 
 
 Inner wall, separates the tympanum from the labyrinth : — 
 
 Fenestra ovalis, an oval window, leading to the vestibule, closed 
 by the membrane to which the base of the stapes is attached; 
 
 Fenestra rotunda, a round window, leading to the scala tympani, 
 but closed also by a membrane — membrana tympani secundaria. 
 
 Promontory, two grooves, marking the first turn of the codilea, 
 and separating the fenestrse ovalis and rotunda; 
 
 Prominentia canalis facialis, a small conical eminence above the 
 fenestra ovalis, which contains within it the aquaeductus Fallopii, the 
 long canal for the facial nerve. 
 
 Posterior wall: — 
 
 Openings of the mastoid cells, three or four in number, connect 
 these sinuses with the tympanum. 
 
 Anterior wall, is a thin plate of bone, which separates the 
 tympanum from the carotid canal. 
 
 Openings of the canal for tensor tympani, lies above and parallel 
 with the canal for the Eustachian tube, and transmits the tensor tym- 
 pani muscle; 
 
 Opening of Eustachian tube, the larger of the two, is separated 
 from the former by a thin plate of bone, the processus cochleariformis. 
 
 The tympanum is divided into two parts — the attic of the 
 tympanum and the atrium. The former is situated on a plane 
 directly above the atrium, and is bounded above by the tegmen, 
 externally by auditory plate, and internally by prominence of the 
 tympanum. On the outer part of the atitic is a smooth surface 
 called the sciite (Leidy). 
 
 The ErsTACHiAN tube is an nssco-cartilaginous canal, one 
 and one-half to two inches in length, extending from the tym- 
 panum to the pharynx. 
 
 It is about one-third osseous and two-thirds cartilaginous, 
 and lined with ciliated epithelium continuous with the pharvnx 
 
ORGANS OF SPECIAL SENSE. 363 
 
 and tympanum. Its pharyngeal orifice is trumpet-shaped, and 
 opens at the side of the pharynx, behind the inferior meatus. 
 
 Muscles of the Eustachian tube: — 
 
 Tensor palati (tensor veli), the most important has been 
 described (vide Palatal Eegion). Its action is to pull the ante- 
 rior wall of the tube outward and downward, and widen the canal. 
 
 Internal Pterygoid {vide Muscles). — Some fibres are in- 
 serted into the floor of the tube. It acts as tensor of the fascia. 
 
 Ligamenta salpingo-pharyngeal, arises from the superior and 
 middle constrictors of the pharynx, and is inserted by three to 
 five tendinous cords into the pharyngeal orifice of the tube. 
 Action, opens the tube. 
 
 Arteries of Eustachian Tvhe. — Pharyngeal from the ex- 
 ternal carotid, middle meningeal from the internal maxillary, 
 and small branches from the internal carotid. 
 
 Nerves, by branches from the glosso-pharyngeal, inferior 
 maxillary, otic ganglion, and facial nerve. 
 
 Membrana tympani is a thin, parchment-like membrane, 
 stretched upon the annulus tympanicus, forming the bottom of 
 the external auditory canal, and separating it from the tym- 
 panum. It is placed obliquely downward and inward at an angle 
 of 45°. 
 
 Structure. — Its three layers are : — 
 
 External or cuticular, derived from the skin of the meatus ; 
 
 Middle or fibrous, consisting of two sets of fibres, radiating 
 and circular, the latter forming a tendinous ring around the 
 margin ; 
 
 Internal or mucous, continuous with the mucous membrane 
 of the tympanum. 
 
 Its outer surface presents : — 
 
 Manubrium of malleus, projecting downward and backward ; 
 
 Processus gracilis of malleus, projecting outward above the 
 manubrium ; 
 
 Umbo, a depression of the membrane formed by the lower 
 end of the manubrium ; 
 
 Yellow spot, the cartilaginous end of the manubrium ; pyra- 
 mid of light, a triangular cone of reflected light in the antero- 
 inferior quadrant of the membrane. 
 
 Inner surface (vide Outer Wall of Tympanum). 
 
 Arteries, tympanic branch of iaferior, branch from the in- 
 ternal carotid. 
 
 Nerves, from the superficial temporal branch of the trifacial, 
 and from the tympanic plexus. 
 
364 
 
 HUMAN ANATOMY. 
 
 OSSICLES OF THE TYMPANUM. 
 
 The small bones of the tympamim are three in number, and 
 connect the membrana tympani with the membrane closing the 
 fenestra ovalis. They are the 
 
 1. Malleus, or hammer, consists of a head, neck, manubrium 
 or handle, processus gracilis, and processus brevis. The manu- 
 brium is attached to the membrana tympani, and has the tendon 
 of the tensor tympani attached. Processus gracilis is lodged in 
 the Glaserian fissure. 
 
 A 
 
 "^'^'"miim^^. 
 
 Fig. 164. 
 
 The auditory ossicles. A. G., external meatus; M, membrana tym- 
 pani; n, handle of the malleus and its short process (p); h, head of 
 the malleus; a, incus; K, its short process, with its ligament; 1, long 
 process; s, os orbiculare; S, stapes; Ax, Ax, the axis of rotation of 
 the ossicles, shown in perspective; t, line of traction of the tensor 
 tympani. The other arrows show the movements of the ossicles when 
 the tensor contracts. (Boenning.) 
 
 2. Incus, or anvil, consists of a body and long and short 
 processes. The body articulates with the malleus and the long 
 process by means of a rounded process. The os orbiculare ar- 
 ticulates with the head of the stapes. 
 
 3. Stapes, or stirrup, has a head, neck, two branches (or 
 crura) which unite into a cross-piece or base. The neck has in- 
 serted into it the stapedius muscle, and the base is fitted to the 
 fenestra ovalis. 
 
ORGANS OF SPECIAL SENSE. 365 
 
 Ligaments of the Ossicles: — 
 
 Lig. mallei anterius, extends from the neck of the malleus to the 
 outer wall of the tympanum; 
 
 Lig. mallei suspensorium, suspends the head of the malleus to the 
 roof; 
 
 Lig. incudi posticum, attaches the short process to the posterior 
 wall ; 
 
 Lig. incudi suspensorium, suspends the incus to the roof; 
 
 Lig. stapedi annularum, connects the base to the margin of the 
 fenestra ovalis. 
 
 Muscles. — The tensor tympani, stapedius. 
 
 Tensor tympani (already described). 
 
 Stapedius arises from the hollow of the pyramid on the inner 
 wall, and its tendon is inserted into the neck of the stapes. 
 Nerve from the tympanic branch of facial. 
 
 Arteries : — 
 
 Tympanic branch of internal maxillary; 
 Stylo-mastoid branch of posterior auricular; 
 Petrosal branch of middle meningeal; 
 Tympanic branch from internal carotid; 
 Branch from ascending pharjTigeal. 
 
 Veins accompany the corresponding arteries and empty into 
 middle meningeal and pharyngeal. 
 
 Nerves: — 
 
 Chorda tympani, from the facial, enters the iter chordae 
 posterius, crosses the tympanum between the long process of the 
 incus and the handle of malleus, and makes its exit at the iter 
 chordfE anterius; 
 
 Tympanic branch of glosso-pharyngeal (Jacobson's nerve) 
 enters the floor, supplies the fenestrse and mucous membrane of 
 tympanum and Eustachian tube; 
 
 Tympanic branch from facial to the stapedius ; 
 
 Branch from the otic ganglion to the tensor tympani. 
 
 The tympanic plexus is formed upon the surface of the 
 promontory, from the following nerves : — 
 
 Jacobson's nerve, tympanic branch of the glosso-pharyngeal j 
 Branch of the superficial petrosal, from the facial ; 
 Branches from the carotid plexus of the sympathetic 
 
 INTERNAL EAE, OK LABTEINTH. 
 
 The internal ear, the essential part of the organ of hearing, 
 consists of three complex cavities within the petrous portion of 
 the temporal bone, filled with fluid, the perilymph, and contain- 
 
366 HUMAN ANATOMY. 
 
 ing a membranous sac filled also with fluid, the endolymph, which 
 receives the distributions of the auditory nerve. 
 Its divisions are : — 
 
 Vestibule, 
 Osseous portion, -i Semicircular canals. 
 
 tion, -i 
 
 Cochlea J 
 
 I Utricle, 
 Semicircular canals. 
 Cochlea. 
 
 Vestibule, is a common cavity of communication between 
 the bony parts of the internal ear. It is situated betvreen the 
 tympanum without, the cochlea behind, and the semicircular 
 canals in front, and measures one-fifth of an inch in its antero- 
 posterior and vertical diameters, and less from without inward. 
 It presents : — 
 
 Fenestra ovalis on its outer wall, closed by the stapes and 
 its ligament; 
 
 Fovea hemisph erica, a circular depression on its inner wall 
 for the saccule, and perforated by the macula cribrosa, for the 
 vestibular filaments of the auditory nerve; 
 
 Orifice of the aquceductus vestibulce, on the inner wall for 
 the transmission of a small vein; 
 
 Eminentia pyramidalis, a vertical ridge on the inner wall 
 separating the two foveas. 
 
 Fovea semi-elliptica, in the roof lodges the utricle. 
 
 Semioieoulae canals are three canals, forming each two- 
 thirds of a circle one-twentieth of an inch in diameter, and 
 named, from their position, the superior, posterior, and external. 
 They are placed nearly at right angles to each other, and open 
 into the vestibule by five apertures — two extremities uniting to 
 form one. 
 
 The superior and posterior are both vertical, the former 
 being more anterior. 
 
 The external is placed horizontally, its arch directed back- 
 ward. 
 
 AmpuUcB, are the dilated, flask-shaped extremities of the 
 tubes, and are about one-tenth of an inch in diameter. 
 
 The cochlea resembles closely a common snail's shell, 
 placed with the base corresponding to the bottom of the meatus 
 auditorius internus, and its apex directed outward and forward. 
 It consists of two parallel tubes one and one-half inches in length, 
 one-tenth of an inch in diameter, wound spirally for two and one- 
 half turns around a central pillar — the modiolus. 
 
UKUANS OF SPECIAL SENSE. 
 
 367 
 
 The modiolus, or columella, is broad at the base, but tapers 
 gradually toward the apex, where it terminates within the last 
 turn or cupola in the infundibulum, a funnel-shaped lamina of 
 bone. Its interior is traversed by numerous canals for vessels 
 and nerves, one of which — the canalis centralis modioli — ^nins 
 nearly the whole length, and transmits the arteria centralis 
 modioli. 
 
 Lamina spiralis, the partition between the two tubes, con- 
 sists of two thin laminse of bone filled with cancellous tissue — 
 
 Fig. 165. 
 
 Organ of Cortl. N, cochlear nerve; K, inner and, P, outer halr- 
 ceUs; n, nerve-flbrils terminating in F; a, a, supporting cells; d, cells 
 In sulcus-spiralis; z, inner rod of Cortl; Mb. Corti, membrane of Corti. 
 or the membrana tectoria; o, the membrana reticularis; H, Q, cells 
 filling up the space near the outer wall. (Boenning.) 
 
 lamina spiralis ossea — ^projecting from the modiolus half-way to 
 the outer wall, the lamina being completed by the membrana 
 basilaris. The osseous lamina terminates in the cupola in a 
 hook-like process — ^the hamulus. 
 
 The spiral canal, between the modiolus and the outer wall, 
 is divided by the lamina spiralis ossea and membrana basilaris 
 into two canals, or scales — ^the upper scala vestibuli, and the lower 
 Bcala tympani. 
 
368 HUMAN ANATOMY. 
 
 The first turn of the spiral canal presents three openings : — 
 
 1. Fenestra rotunda, a circular aperture communicating 
 with the tympanum, and closed by the membrana tympanum 
 secundaria. 
 
 3. Fenestra ovalis, an oval opening, commimicating with 
 the vestibule. 
 
 3. Aquceductus cochlearis, a small foramen openipg on the 
 inferior surface of the petrous portion of the temporal bone, 
 and transmitting a small vein from the cochlea to the jugular 
 vein. 
 
 Scala vestibuli, begins at the fenestra ovalis, and ascends 
 in a spiral course above the lamina spiralis and membrana 
 basilaris, to communicate vrith the scala tympani, through the 
 helicotrema within the vestibule. It contains perilymph. 
 
 Scala tympani begins at the fenestra rotunda, and ascends 
 in a spiral course below the scala vestibuli, from which it is 
 separated by the osseo-membranous lamina. It also contains 
 perilymph. 
 
 Helicotrema is an opening within the cupola, by which the 
 two scalse communicate. It is formed by a deficiency of the 
 osseous lamina. 
 
 Canalis spiralis modioli, is a small canal which winds around 
 the modiolus at the attachment of the osseous laminse. It con- 
 tains a gangliform swelling — ganglion spirale — ^from which 
 nerves pass to the organ of Corti. 
 
 The mbmbkanous labyrinth corresponds closely to the 
 osseous, the vestibule consisting of two membranous sacs — ^the 
 utricle and saccule — communicating with each other, and the 
 former receiving the five openings of the membranous semicir- 
 cular canals, the latter communicating with the membranous 
 cochlea through the canalis reuniens. The membranous labyrinth 
 is surrounded everywhere with perilymph, filled with endolymph, 
 and is composed of three coats — an outer fibrous layer, middle 
 or tunica propria, and inner epithelial layer. 
 
 Utricle, the larger of the two, is an elliptical sac lodged in 
 the fovea hemi-elliptica. The semicircular canals communicate 
 with it by five openings. Its wall is the thickest near the crista 
 vestibuli, where the filaments of the nerve enter, the macula 
 acoustica. 
 
 Saccule, is a hemispherical sac lodged in the fovea hemi- 
 spherica. It communicates with the cochlea through a small 
 duct — the canalis reuniens. 
 
 The otoliths, or otoconia, are small masses of crystals of 
 lime carbonate, contained in the inner wall of the utricle and 
 saccule opposite the distribution of the nerves. 
 
ORGANS OF SPECIAL SENSE. 369 
 
 Semicircular Canals. — These are three membranous tubes 
 corresponding exactly in shape, number, and form to the bony 
 canals in which they are contained. They are surrounded every- 
 where with perilymph, except at the ampullae, where they are 
 in contact with the bony canals. The inner, or epithelial "/ayer 
 of- the membrane in the ampullae, is covered with columnar 
 ciliated epithelium — auditory hairs. 
 
 The membeanous cochlea begins at the base and ascends 
 in a spiral course within the osseous cochlea to terminate in the 
 cupola. It includes only the canalis cochlea — a part of the scala 
 vestibulae. As before stated, the membrana basilaris extends 
 from the margin of the lamina spiralis ossea to the outer wall of 
 the cochlea, dividing the cavity into the two sealae — ^the scalae 
 vestibulse above, the seals tympani below. The former is again 
 subdivided by the membrane of Eiessner into two parts, the outer 
 of which forms the canalis cocMece, or scala media — the mem- 
 branous cochlea proper — on the floor of which is the organ of 
 Corti covered by the membrana tectoria. The scalse are lined 
 with periostium, and filled with perilymph. The scala tym- 
 pani ends at the fenestra rotunda, but the scala vestibula com- 
 municates freely with the vestibula. 
 
 Limhus laminw spiralis is the periosteal margin of the 
 lamina spiralis ossea, and consists of an upper lip — -the labium 
 vestibulare — and a lower lip — ^the labium tympanicum — sepa- 
 rated by a groove — the sulcus spiralis. 
 
 Membrana basilaris extends from the labium tympanicum 
 to the outer cochlear wall, to which it is attached by the liga- 
 mentum spirale of Henle. 
 
 Membrane of Reissner arises from the middle of the vestibu- 
 lar lamina and passes obliquely at an angle of 40° to the outer 
 cochlear wall, separating the canalis cochleae from the scala 
 vestibula. 
 
 Canalis cochlem extends as a spiral sac closed at both ends 
 through the osseous cochlea, and contains the most important 
 part of the labyrinth — the ultimate distribution of the auditory 
 nerve in the organ of Corti. It is triangular on section, the 
 membrana basilaris forming the base, the membrane of Eiessner 
 the inner side, and the periosteum of the cochlea its outer side. 
 
 Membrana tectoria, or membrane of Corti, commences as a 
 delicate membrane, at a point between the origin of the mem- 
 brane of Eiessner and the labium vestibule, and arches over to 
 the -outer cochlear wall, inclosing the organ of Corti, but not in 
 contact with it. 
 
 Organ of Coeti consists of two sets of pillars — ^the inner 
 and outer rods of Corti — extending upward upon the vestibular 
 
370 HUMAN ANATOMY, 
 
 surface of the membrana basilaris, and forming a series of 
 arches. Between the bases of the arches is the zona arcuata. 
 There are over three thousand arches, and within them is formed 
 a tunnel extending the entire length of the lamina spiralis termi- 
 nating at the hamular process. 
 
 Inner rods of Gorti, rest upon the basilar membrane. Their 
 upper extremities resemble the proximal extremity of the ulna, 
 and each has on its inner side a row of epithelial cells — the 
 inner hair-cells. 
 
 Outer rods of Corti, are attached in a similar manner at 
 the bases, and their extremities each resemble the head and bill 
 of a swan, the former fitting into the cavity in the inner rods. 
 On the outer side are four rows of ciliated cells — ^the outer hair- 
 cells. 
 
 Reticular memhrane, or lamina reticularis, is a delicate 
 complex net-work of phalanges — fiddle-shaped structures — ex- 
 tending from the inner rods to the external row of the outer 
 hair-cells. 
 
 The internal auditoet canal, is a short canal about one- 
 third of an inch in length, extending outward from the meatus 
 auditorius internus, on the posterior surface of the petrous por- 
 tion of the temporal bone to terminate at a vertical, perforated 
 plate — the lamina cribrosa. This plate is divided by a horizontal 
 ridge into a lower and upper portion. The lower is perforated 
 by numerous foramina for passage of the auditory artery and 
 branches of the auditory nerve, some of which are arranged into 
 a spiral-shaped depression, called the tractus spiralis foraminu- 
 lentus; the upper has one large opening — ^the commencement 
 of the aquaeductus Fallopii for portio dura, or seventh nerve. 
 
 Auditory Nerve. — The auditory nerve enters the internal 
 auditory meatus in company with the facial, and at the bottom 
 divides into two branches — the vestibular and cochlear. 
 
 Vestibular nerve subdivides into three branches, as fol- 
 lows : — 
 
 Superior, distributed to the utricle and ampullse of the superior 
 and external semicirculax canals; 
 
 Middle, enters the bottom of the fovea hemispherica, and is dis- 
 tributed to the saccule; and the 
 
 Inferior, is distributed to the ampulla of the posterior semicircular 
 canal. 
 
 Cochlear nerve, ascends in the canals in the modiolus, and 
 divides into numerous branches which pass between the plates 
 of the lamina spiralis ossea, forming a plexus which contains 
 the ganglia spirale, from which filaments are distributed to the 
 outer and inner hair-cells of the organ of CortL 
 
ORGANS OF SPECIAL SENSE. 371 
 
 Arteries of Labyrinth: — 
 
 Internal auditory, from the basilar, divides into vestibular 
 and cochlear branches, which accompany the corresponding 
 nerves ; 
 
 Stylo-mastoid, from the posterior auricular, enters through 
 the stylo-mastoid foramen. 
 
 THE TONGUE.* 
 
 The tongue is the organ of the sense of taste, and lies in 
 the floor of the mouth. It is composed of a mass of muscles, 
 the free surface of which is entirely invested with mucous mem- 
 brane. It consists of three parts : — 
 
 Base, or root, attached to the hyoid bone, the epiglottis and 
 the soft palate ; 
 
 Body, the back or dorsum of which is marked by a median 
 line or raphe, terminating behind in a cavity — ^the foramen 
 cwcum; 
 
 Apex, or tip, narrow and pointed, directed forward. 
 
 The mucous membrane resembles skin, consisting of a 
 corium or mucosa, containing numerous papilla, and covered 
 with epithelium. The papillae are most numerous over the ante- 
 rior two-thirds of the dorsum, and consist of three varieties : — 
 
 Circumvallate, or largest, about ten in number, about one- 
 twelfth inch wide, are arranged at the back part of the dorsum 
 like the letter V, with the apex directed backward ; 
 
 Fungiform, or medium, are scattered over the organ, espe- 
 cially at the tips and sides ; 
 
 Filiform, conical, or smallest, are distributed over the an- 
 terior two-thirds of the dorsum. 
 
 Mucous and serous glands and simple papillae, such as are 
 found in the skin, are also present. 
 
 Taste bulbs, or taste goblets, minute, flask-shaped bodies, 
 about one three-hundredths of an inch in length, are situated in 
 the circumvallate and fungiform papillae. 
 
 Arteries, are branches of the lingual, facial, and ascending 
 pharyngeal. 
 
 1. Nerves. — Hypoglossal, the principal motor nerve. 
 
 2. Lingual branch of glosso-pharyngeal, the special nerve of 
 taste. 
 
 3. Lingual branch of the trifacial, to sides and anterior 
 part; nerve of common sensation. 
 
 4. Chorda tympani, probably nerve of special sense. 
 
 * Tide Lingual Muscles, page 119. 
 
372 HUMAN ANATOMY. 
 
 5. Superior laryngeal, filaments from its internal branch to 
 the base. 
 
 THE SKIN AND APPENDAGES. 
 
 The skin, besides being the special organ of the sense of 
 touch, is an absorbing and excretory organ, and protects the 
 underlying structures. 
 
 It consists of two layers — ^the epidermis or cuticle, and 
 the derma or true skin. The appendages are the nails, hair, 
 sudoriferous and sebaceous glands, and their ducts. 
 
 The epidermis, or cuticle, is an epithelial structure consist- 
 ing of four layers : — 
 
 1. Rete Malpighii, the deepest layer, in contact with the corium, is 
 composed of several layers of round or polyhedral epithelial cells. This 
 layer is pigmented in the negro and other dark races. 
 
 2. Granular layer, is a single layer of compressed, spindle-shaped 
 cells. 
 
 3. Stratum lucidum, are still more compressed into scales. 
 
 4. Stratum corneum, several layers of horny scales. 
 
 The derma, or true skin, has two layers, the reticular or 
 deeper, and the papillary or superficial. 
 
 Eeticular layer is composed of interlacing bands of white 
 fibrous tissue, mixed with yellow elastic fibres, and some un- 
 striated muscular fibres where hairs are found, together with 
 blood-vessels, lymphatics, and nerves. 
 
 Papillary layer is covered with minute, vascular, highly sen- 
 sitive elevations — ^the papillae — from one one-hundredth to one 
 two-hundred-and-fiftieth of an inch in diameter. These papillae 
 are in places arranged into parallel curved ridges, and have in 
 the most sensitive situations some one of the "peripheral end 
 organs" (already described) added to their structure. 
 
 Nails are horny plaques of modified epidermis, firmly 
 adapted to the derma on the dorsal surfaces of the terminal 
 phalanges. Each nail is firmly implanted by its root into a fold 
 of skin. 
 
 The matrix is the derma beneath the body, which is vascular 
 and highly sensitive. 
 
 The lunula is the white, less vascular portion of the matrix 
 near the root. 
 
 Haies are a cylindrical modification of the epidermis, and 
 consist of a root imbedded in the skin, a shaft, and a point. 
 
 Boot is lodged in a pouch-like involution of epidermis — the 
 hair-follicle. This is composed of an inner or cuticular and an 
 
ORGANS OF SPECIAL SENSE. 373 
 
 outer or dermic layer, and presents at the bottom a vascular 
 papilla, on which the hair rests, and from which it grows. 
 
 Shaft, consists of a pith or medulla in the centre, sur- 
 rounded by a fibrous part containing pigment, and covered with 
 a layer of scaly epithelium. 
 
 Point, contains the two latter elements, but has no medulla. 
 
 Sebaceous glands are minute, glandular bodies, situated in 
 the substance of the corium, and each opening by a single duct 
 into a hair-follicle, or upon the surface of the skin. They are 
 most abundant where hairs are found. The Meibomian glands 
 in the eyelids are the largest. 
 
 SuDOEiFERODS or SWEAT GLANDS are minute, reddish, 
 glandular bodies, situated usually in the subcutaneous connective 
 tissue, each consisting of a single convoluted tube. Each gland 
 opens on the surface of the skia. 
 
SURGICAL ANATOMY. 
 
 THE TRIANGLES OF THE NECK. 
 
 The general outline of the neck is somewhat quadrilateral. 
 Bounded in front by the median line, behind by the trapezius 
 muscle, above by the lower border of the body of the maxilla, and 
 below by the clavicle. It is divided by the sterno-mastoid muscle 
 running obliquely through it into two large triangles, an ante- 
 rior and a posterior triangle. These are again subdivided by 
 the crossing of the omo-hyoid muscle into two smaller triangles 
 each. The anterior into the superior and inferior carotid tri- 
 angles, and the posterior into the occipital and subclavian tri- 
 angles. The digastric muscle, at the upper part of the anterior 
 triangle, separates a triangular space called the submaxillary 
 triangle. , 
 
 The anterior triangle of the neck is hounded as follows: — 
 
 Front, median line of the neck ; 
 
 Behind, anterior border of the sterno-mastoid muscle; 
 
 Above, lower border of the body of the lower jaw, and a line 
 from its angle to the mastoid process, forming the base of the 
 triangle ; 
 
 Below, the top of the sternum, forming the apex. 
 
 The floor is formed by the sterno-hyoideus, sterno-thy- 
 roideus, thyro-hyoideus, inferior and middle constrictors of the 
 pharynx, the anterior belly of the digastrieus, the mylo-hyoideus, 
 stylo-hyoideus, and hyoglossus muscles. The roof is formed by 
 the skin, superficial fascia, platysma myoides, and deep fascia. 
 
 The inferior carotid triangle is the most inferior subdivision 
 of the anterior triangle, and is hounded as follows : — 
 
 Front, median line of the neck; 
 
 Behind, anterior border of the sterno-mastoideus ; 
 
 Above, anterior belly of the omo-hyoideus ; 
 
 Below, the apex of the anterior triangle. 
 
 It contains the following structures : — 
 
 Thyroid gland and lower part of the trachea and larynx ; 
 
 Inferior thyroid and common carotid arteries ; 
 
 Inferior thyroid and internal jugular veins; 
 
 Pneumogastric, recurrent laryngeal, descendens noni, com- 
 municans noni, and sympathetic nerves. 
 (374) 
 
SURGICAL ANATOMY. 
 
 375 
 
 The superior carotid triangle is the middle subdivision of 
 the anterior triangle of the neck, and has the following bound- 
 aries : — 
 
 Above, posterior belly of the digastricus ; 
 
 Below, anterior belly of the omo-hyoideus; 
 
 Behind, anterior border of the stemo-mastoideus. 
 
 It contains the following structures : — 
 
 Termination of the common carotid; 
 
 Pig. 168. 
 Triangles of the neck. (Boenning.') 
 
 The internal carotid; 
 
 The external carotid, and the following branches : — 
 Superior thyroid, lingual, facial, ascending pharyngeal, and 
 occipital ; 
 
 The internal jugular vein, and the following tributaries : — 
 Lingual, facial, superior thyroid, pharyngeal, and occa- 
 sionally the occipital ; 
 
376 HUMAN ANATOMY. 
 
 The pneumogastric, superior laryngeal, external laryngeal, 
 descendens noni, spinal accessory, hypoglossal, and sympathetic 
 nerves. 
 
 The submaxillary triangle is the most superior of the sub- 
 divisions of the anterior triangle, and has the following bound- 
 aries : — 
 
 Above, the lower border of the body of the jaw, and the 
 imaginary line behind ; 
 
 In front, the median line of the neck ; 
 
 Behind, the posterior belly of the digastricus. 
 
 It contains the following structures : — 
 
 External carotid, internal carotid, facial, submental, mylo- 
 hyoidean arteries; 
 
 The internal jugular, the commencement of the external 
 jugular, branches of the anterior jugular, and the facial vein and 
 its branches ; . 
 
 The inframaxillary branches of the facial nerve, the ascend- 
 ing branches of the superficial cervical nerve, and the pneumo- 
 gastric and glosso-pharyngeal and mylo-hyoid nerves; 
 
 Portions of the parotid and submaxillary glands, and also 
 submaxillary lymphatic glands and vessels. 
 
 The posterior triangle of the neck occupies the space behind 
 the posterior border of the sterno-mastoideus, and is hounded 
 as follows: — 
 
 Front, posterior border of the sterno-mastoideus; 
 
 Behind, anterior border of the trapezius; 
 
 Below, upper border of the middle third of the clavicle, 
 forming its base; 
 
 Above, the occiput, forming the apex. 
 
 Its floor is formed from above downward, by the following 
 muscles : — 
 
 Splenius capitis, levator anguli scapuli, scalenius medius, 
 scalenius posticus, and the upper portion of the serratus magnus. 
 
 Its roof is formed by the superficial and deep fascia, and 
 below by the platysma myoides. 
 
 It contains the following structures : — 
 
 The trans versalis colli artery and vein; 
 
 Spinal accessory and superficial plexus of the cervical nerve; 
 
 Lymphatic glands and vessels. 
 
 The subclavian triangle, or the inferior division of the poste- 
 rior triangle, is hounded — 
 
 In front by the margin of the sterno-mastoideus, behind by 
 the posterior belly of the omo-hyoideus, below by the clavicle. 
 
 It contains the following structures : — 
 
 The subclavian, transversalis colli, and transversalis humeri 
 or suprascapular arteries; 
 
SURGICAL ANATOMY. 377 
 
 The transversalis colli, suprascapular, and external jugular 
 veins ; 
 
 The descending branches of the superficial cervical plexus, 
 and the brachial plexus of nerves; 
 
 Lymphatic neives and vessels. 
 
 Triangle in Front of the Elbow-joint. 
 
 Bounded — 
 
 Externally, by supinator longus; 
 
 Internally, by pronator radii teres; 
 
 Base, above, by a line (imaginary) down through the con- 
 dyles ; 
 
 Apex, below, by crossing of supinator longus and pronator 
 radii teres. 
 
 It is covered in by skin, superficial fascia, and bicipital 
 fascia; the floor is formed by oblique fibres of the supinator 
 brevis and lower part of brachialis anticus muscles. 
 
 It contains: — 
 
 From within outward, median nerve, brachial artery, and 
 venae comites, biceps tendon, and museulo-spiral nerve. 
 
 Scarpa's Triangle 
 
 is a large triangular space situated in the upper part of the 
 anterior surface of the thigh, through which the femoral vessels 
 descend. It is hounded — 
 
 Externally by sartorius, internally by adductor longus, above 
 by Poupart's ligament; below, apex is formed by crossing of 
 boimding muscles. 
 
 It is covered in by skin, superficial fascia lata, and cribri- 
 form fascia, and its floor is formed by the following from with- 
 out inward: iliacus, psoas, pectineus, and portion of adductor 
 brevis muscles. 
 
 It contains: — 
 
 The femoral artery (with its profunda and cutaneous 
 branches), inclosed in the femoral sheath, femoral vein (Joined 
 by profunda and long saphenous veins), anterior crural nerve and 
 its branches [from within outward being vein, artery, and nerve], 
 deep lymphatic glands and vessels, and adipose tissue. 
 
 Axilla. 
 
 This is a pyramidal space between the upper and lateral 
 part of the chest and the inner side of the arm. It is bounded — 
 
 In front, by the pectoralis major and minor muscles; be- 
 hind, by latissimus dorsi, teres major, and subscapularis; in- 
 
378 HUMAN ANATOMY. 
 
 temally, by the upper four ribs and intercostal and upper part of 
 serratus magnus muscles, and its apex is directed upward, and 
 is formed by the space between the first rib, clavicle, and upper 
 border of the scapula, and its base by the skin and axillary fascia 
 stretched across between the lower borders of the pectoralis 
 major and latissimus dorsi muscles. 
 
 no. 167. 
 
 The axilla. 1, axillary artery; 2, brachial artery; S, acromlo- 
 thoracic artery; 4, superior thoracic artery; 5, subscapular artery; 8, 
 dorsalis scapulae artery; 7, posterior circumflex artery; 8, superior pro- 
 funda artery; 9, posterior thoracic nerve; 10, long subscapular nerve; 
 11, median nerve; 12, cephalic vein; 13, musculo-cutaneous nerve; 14, 
 teres major muscle. {Boenning.) 
 
 It contains: — 
 
 The axillary artery and vein, and their branches; the 
 brachial plexus of nerves, and the branches given off below the 
 
SURGICAL ANATOMY. 379 
 
 clavicle; branches of the intercostal nerves; ten or twelve lym- 
 phatic glands, and a quantity of loose adipose and areolar tissue. 
 
 Popliteal Space. 
 
 The popliteal space is a lozenge-shaped space situated at 
 the back of the knee, and forms the ham. It is hounded — 
 
 Externally, above the joint, by the biceps; below the joint, 
 by outer head of gastrocnemius and plantaris; internally, above 
 the joint, semitendinosis, semimembranosis, gracilis, and sar- 
 torius; below the joint, by inner head of the gastrocnemius. 
 
 It is covered in by the skin, superficial fascia, and fascia lata. 
 
 Its floor is forined by the lower part of the posterior surface 
 of the femur, the ligamehtum posticum Winslowi, and the pop- 
 liteus muscle and its fascia. 
 
 It contains: — 
 
 The popliteal artery and branches ; popliteal vein receiving 
 the external saphenous vein (vein to the outer side) ; internal 
 and external popliteal nerves and branches ; articular branch of 
 obturator nerve; branch of small sciatic nerve; four or six 
 lymphatic glands, and a quantity of adipose and areolar tissue. 
 
 ANATOMY OF HERNIA. 
 
 Hernia is the protrusion of any' part of a viscus from its 
 natural cavity through the enclosing walls of the cavity. As 
 usually understood, it refers to the protrusion of the intestine or 
 mesentery, or both, from the abdominal cavity. The most com- 
 mon forms are: — 
 
 External or oblique inguinal hernia; 
 Internal or direct inguinal hernia; 
 Femoral hernia; 
 Umbilical hernia. 
 
 1. Oblique inguinal hernia escapes from abdominal cav- 
 ity at the internal abdominal ring, carrying before it a pouch 
 of peritoneum, descends along the inguinal canal in front of the 
 cord, and emerges at the external opening. The anatomical 
 parts concerned are the inguinal canal, with its internal and 
 external abdominal rings, the transversalis fascia {vide Fascia), 
 the peritoneum (vide Peritoneum), and Poupart's ligament. 
 
 The inguinal or spermatic canal is about one and a half 
 inches in length, extending from the internal abdominal ring 
 to the external abdominal ring. It serves for the passage of the 
 
380 
 
 HU.MAN ANATOMY. 
 
 spermatic cord in the male, and the round ligament with its 
 vessels in the female. Its boundaries are: — 
 
 In front, skin, superficial fascia, the aponeurosis of the 
 external oblique muscle, the lower border of the internal oblique, 
 and a small portion of the cremaster muscle; 
 
 Fig. IGS. 
 
 Dissection ot the inguinal canal: A, external oblique; B B, in- 
 ternal oblique; C, transversalis; D, conjoined tendon; B, rectus ab- 
 dominis witli sheath opened; F, fascia transversalis; H, cremaster; 
 I, infundibular fascia. 
 
 Behind, the fascia transvei'salis, tlic conjoined tendon of the 
 transversalis and internal oblique muscles, the transversalis fascia, 
 and subperitoneal fat and peritoneum ; 
 
 Above, by the arched Ijorder of the internal oblique and 
 transversalis muscles ; 
 
 Below, l)y the connection between Poupart's ligament and the 
 transversalis fascia. 
 
SURGICAL ANATOMY. 381 
 
 The internal abdominal ring is an oval opening in the 
 transversalis fascia about half an inch above Poupart's ligament, 
 midway between the symphysis pubis and the anterior superior 
 spinous process of the ilium. It is bounded — 
 
 Above and externally by the arched fibres of the transversalis 
 muscle; below and internally by the deep epigastric vessels. 
 
 It transmits a funnel-shaped fascia from its margins, the 
 infundibuliform fascia. 
 
 The external abdominal ring is a triangular opening between 
 the two pillars in the aponeurosis of the external oblique muscle, 
 to the outer side and just above the spine of the pubes. It is 
 about half an inch wide and one inch long, and is bounded — 
 
 Above, by the intercolumnar fascia ; below, by the spine and 
 crest of the os pubis, and on either side by the pillars or columns 
 of the ring formed by the free margins of the aponeurosis of 
 the external oblique. 
 
 From the margins of the external abdominal ring arises the 
 intercolumnar fascia. 
 
 Poupart's ligament, or the femoral arcli, is the rounded 
 lower fibrous margin of the external oblique muscle, extending 
 between the anterior superior spine of the ilium and the spine 
 of the pubes. The portion of the aponeurosis which is inserted 
 into the pectineal line. has received the name of Gimbernat's 
 ligament. 
 
 The triangular ligament or ligament of Colles is the 
 reflected inner portions of Gimbernat's and Poupart's ligaments 
 attached to the sheath of the rectus. 
 
 The epigastric artery holds a very important anatomical 
 relation to the inguinal canal and internal abdominal ring. It 
 ascends between the peritoneum and transversalis fascia to reach 
 the sheath of the rectus muscle along the inner and lower margin 
 of the internal ring and beneath the spermatic cord. 
 
 The coverings of oblique inguinal hernia are : — • 
 
 (1) Skin; (2) superficial fascia ; (3) intercolumnar fascia ; 
 (4) cremaster muscle, and fascia; (5) fascia transversalis, or 
 infundibuliform fascia; (6) subserous connective tissue; (7) 
 peritoneal sac. 
 
 2. Direct inguinal hernia escapes through the abdominal 
 wall, within Hesselbach's triangle, internal to the epigastric 
 artery, and through the external abdominal ring, pushing before 
 it a pouch of peritoneum. 
 
 Hesselbach's triangle is a space situated at the lower ante- 
 rior part of the abdominal wall on either side. It is bounded 
 as follows : — 
 
 Externally, epigastric artery ; 
 
382 HTJMAN ANATOMY. 
 
 Internally, the outer margin of the rectus abdominis muscle ; 
 
 Below, Pouparfs ligament, forming its base. The struc- 
 tures forming the abdominal wall at this cavity are, from with- 
 out inward : — 
 
 1. Skin; 
 
 2. Superficial fascia; 
 
 3. Intercolumnar fascia ; 
 
 4. Conjoined tendon of the transversalis and internal ob- 
 lique ; 
 
 5. Fascia transversalis; 
 
 6. Subserous tissue; 
 
 7. Peritoneum. 
 
 The anatomical parts concerned in direct inguinal hernia 
 are the same as those in the indirect, already given. The cover- 
 ings of direct inguinal hernia are those just given. 
 
 3. Pbmoeal hernia escapes through the femoral ring, 
 carrying before it a pouch of peritoneum, descends through the 
 femoral canal and emerges through the saphenous opening in 
 the fascia lata. The anatomical parts concerned in this hernia 
 are: — 
 
 The femoral ring, the femoral or crural canal, the septum 
 crurale, crural sheath and deep crural arch, and the saphenous 
 opening. 
 
 The femoral or crural ring is an oval opening, about an 
 inch and a half in diameter, larger in the female and situated 
 below Pouparfs ligament, between the inner side of the femoral 
 vein and the margin of Gimbernat's ligament. It is the abdom- 
 inal opening of the femoral canal and it is closed in the recent 
 state by the septum crurale and a small lymphatic gland. It is 
 bounded — 
 
 In front, by the deep femoral arch and Pouparfs ligament ; 
 
 Behind, by the pubes, covered by the pubic portion of the 
 fascia lata and the pectineus muscle; 
 
 Externally, by the femoral vein, from which it is separated 
 by a fibrous septum ; 
 
 Internally, by the deep femoral arch, Gimbernat's ligament, 
 the transversalis fascia, and the conjoined tendon. 
 
 The femoral canal is a space from a quarter to half an inch 
 in length, extending from Gimbernat's ligament to the upper 
 margin of the saphenous opening. Bounded above by the femoral 
 ring and below by the saphenous opening. It is the innermost 
 compartment of the femoral sheath. 
 
 Anterior wall — transversalis fascia, separated liy the falci- 
 form process of the fascia lata ; 
 
SURGICAL AXAlOiiy. 
 
 383 
 
 Fig^. I'lG.— Deep Femoral Region — the Femoral "Vessels, etc.. Cut Across as 
 they Emerge Under Poupart's Ligament, AC, anterior crural nerve; CT, edge 
 of the conjoiDed tendon; OE, crural ring; E, dotted line indicates the course 
 of the deep epigastric artery; FS, femoral sheath; G, Gimbcrnat's ligament; 
 IP; ilio-pectineal ligament; P, Poupart's ligament; PS, pectineus muscle. 
 This muscle rests upon the pubic bone and is covered by its fascia,— the 
 pectineal fascia,— which is somewhat thickened immediately beneath Poupart's 
 ligament, where it is known as the pubic ligament of Cooper. It will be 
 noticed that the femoral sheath is divided into three compartments; the 
 outer for the femoral artery; the middle for the femoral vein; the Inner (CR) 
 is the crural ring, the mouth of the crural canal. (McG-ratfi.) 
 
384 HUMAN ANATOMY. 
 
 Posterior wall — iliac fascia and pubic portion of the fascia 
 lata; 
 
 External wall — ^fibrous septum of the femoral vein; 
 
 Internal wall — Gimbernat^s ligament, deep crural arch, and 
 the junction of the iliac and transversalis fascia. 
 
 The septum crurale is a layer of dense areolar tissue, sup- 
 porting small lymphatic glands and closing in the femoral ring. 
 It is perforated by numerous lymphatic vessels, and forms a bar- 
 rier to the escape of hernia at this point. 
 
 The crural or femoral sheath is a prolongation downward of 
 the fascia lining the abdomen (transversalis fascia in front, iliac 
 fascia behind the vessels), closely adhering to the femoral vessels 
 to about an inch below the saphenous opening. Its upper part 
 is funnel-shaped and its lower part continuous with the sheath 
 of the vessel. It is divided by septa into three compartments; 
 ia the outer is lodged the femoral artery; the middle is occu- 
 pied by the femoral vein ; and the innermost, the femoral canal, 
 is empty, or occupied by a lymphatic gland. Its outer border is 
 pierced by the genito-crural nerve, its inner by the internal 
 saphenous vein. 
 
 The deef femoral arch is a fibrous thickening of the trans- 
 versalis fascia which forms the anterior wall of the femoral 
 sheath. It is also known as the deep crural arch. 
 
 The saphenous opening is an oval aperture of half an inch 
 in width, an inch and a half in length in the upper and inner 
 part of the fascia lata, between its two divisions, the iliac and 
 pubic portions. It is bounded externally by the falsiform 
 process of Burns, internally by the pubic portion of the fascia 
 lata, which curves upward behind the saphenous vein. The open- 
 ing is covered externally by the cribriform fascia and the skin. 
 
 The coverings of femoral hernia are : — 
 
 1. Skin; 
 
 3. Superficial fascia; 
 
 3. Cribriform fascia; 
 
 4. Femoral sheath, crural sheath, or fascia propria; 
 
 5. Septum crurale ; 
 
 6. Subserous connective tissue; 
 
 7. Peritoneal sac. 
 
 ISCHIO-RECTAL REGION AND PERINEUM. 
 
 The outlet of the pelvis is a lozenge-shaped space divided 
 by an imaginary line drawn in front of the anus, transversally 
 between the anterior margin of the tuber ischii, into two parts, 
 the ischio-rectal region behind and the perineum in front. 
 
SURGICAL ANATOMY. 
 
 385 
 
 The ischio-rectal region contains the external and internal 
 sphincters, the cornigator cutis ani and the ischio-rectal fossa. 
 The latter is a pyramidal cavity, its apex reaching to the junction 
 of the obturator and anal fascia, and its base formed by the 
 skin. It is bounded — 
 
 Behind, by the edge of the great sacro-sciatic ligament and 
 gluteus maximus muscle ; internally, by the levator ani, covered 
 by the anal fascia, sphincter ani, and coccygeus muscle; exter- 
 nally, by the tuber ischii and obturator fascia. 
 
 
 
 Fig. 170. 
 Male perineum, superficial dissection. (.Lydston.) 
 
 It contains: — 
 
 The internal pudic artery, nerve and veins enclosed in the 
 fascial canal or canal of Alcock ; 
 
 The inferior hsemorrhoidal vessels and nerves ; 
 The perineal and fourth sacral nerves ; and 
 A mass of areolar tissue. 
 
 PEEINEUM. 
 
 The perineum is the triangular space between the anus and 
 scrotum in the male, and between the anus and vulva in the 
 female. The skin is dark, thin, and supplied with sebaceous and 
 sudoriparous glands, and is marked by middle line or raphe. 
 
386 
 
 HUMAN ANATOMY. 
 
 FascicB of the Perineum. 
 
 The pelvic fascia at the brim of the pelvis is continuous 
 with transverse and iliac fascia; covers sacrum and pyriformis 
 muscle, external iliac artery, and sacral nerves. It forms the 
 anterior and lateral ligament of bladder (true) . It forms arcus 
 tendinse, or white line, corresponding to division of pelvic fascia 
 into two layers, the obturator and recto-vesical, extending from 
 pubis to spine of ischium, from vrhich originates the levator ani 
 muscle, -with recto-vesical and ischio-rectal or anal fascise above 
 and below the muscle respectively. 
 
 Jlftf^ of CarpuM CatftHutrnm 
 
 ^nttpnai P<utic Artery. 
 
 CWfimr^a Glati^' 
 
 Fig. 171. 
 Male perineum, deep dissection. [Lydston.) 
 
 The olturator fascia, the continuation of the pelvic fascia, 
 incloses the pudic vessels and nerve in a sheath, covers the in- 
 ternal obturator muscle, and forms the posterior layer of the 
 triangular ligament. 
 
 Recto-vesical or visceral layer of the pelvic fascia, the con- 
 tinuation of the pelvic fascia, descends into the pelvis investing 
 the prostate gland and the vesico-prostatic plexus of veins, the 
 bladder (forming the anterior and lateral true ligaments) and 
 the rectum. It is perforated in the female by the vagina. 
 
SURGICAL ANATOMY. 387 
 
 Superficial perineal fascia consists of superficial fat layer 
 and deep membranous layer, the fascia of Colles. The former is 
 continuous with subcutaneous layer of buttocks, thigh, and labia, 
 and posterior to anus become continuous with tissue of ischio- 
 rectal fossa. The superior layer passes from rami of pubis and 
 ischium to the tuberosity of ischia, covering ischio-cavernous and 
 bulbo-urethral muscles, and becomes continuous with the deep 
 perineal fascia. 
 
 The deep perineal fascia (triangular ligament of the per- 
 ineum or the trigonum urogenitale) is a strong triangular mem- 
 brane extending between the rami ischii et pubis, its apex attached 
 to the under surface of the symphysis. It is often described as 
 consisting of two layers, the superior and inferior. It is pierced 
 by the membranous urethra, and sends a fascia surrounding the 
 urethral glands to the spongy body. In the female it is weaker, 
 the urethra also pierces it, and it is continuous with the fascia of 
 the vagina. 
 
 Muscles of the Perineum. 
 
 IscHio-CAVEENOSUS (erector penis) arises in the inner sur- 
 face of the tuberosity of the ischium, and is inserted into the 
 side and under surface of the crus penis. In the female there is 
 a similar insertion into the clitoris. It serves to maintain the 
 organ erect. Nerve, perineal. 
 
 Erector clitoeidis corresponds to erector penis muscle in 
 the male, but smaller. 
 
 BuLBO-CAVERNOSDS (accelerator uringe, ejaculator seminis) 
 arises from central tendon of perineum and from median raphe 
 in front. It spreads out and is inserted from behind forward to 
 anterior surface of triangular ligament, bulb and adjacent part 
 of corpus spongiosum, to join fibres of opposite side, and to 
 sides of corpora cavernosa; anterior to erector penis and in 
 fibrous expansion over dorsal blood-vessels of penis, muscle of 
 Houston. 
 
 It accelerates the flow of urine and semen and contributes 
 to erection of the penis. Nerve, perineal. 
 
 Vaginal constrictor (sphincter vaginae), analogous to 
 foregoing muscle, surrounds the orifice of vagina. It arises 
 from the central tendon and passes forward on either side of 
 vagina to be inserted into the corpora cavernosa and body of 
 clitoris. It compresses the dorsal vein of the clitoris. 
 
 Teansveesus perin^i arises from inner part of ramus of 
 ischium, and is inserted into perineal centre in male, into the 
 side of sphincter vaginas in the female. It steadies the perineal 
 centre. Nerve, perineal. 
 
388 HUMAN ANATOMY. 
 
 Compressor urethra arises from the rami pubis, passes 
 inward and with its fellow of the other side unites above and 
 below the urethra, surrounding it from the bulbous portion to the 
 prostate gland in the male. In the female it is inserted into 
 the vaginal walls. 
 
 External sphincter ani muscle arises from the apex of 
 the coccyx and the superficial fascia, and is inserted into the 
 perineal centre, blending with the levator ani, accelerator urinse. 
 
 Fig. 172. 
 
 Female perineum: A, anus; B, bulbo- vaginal ; C, coccyx; G, glu- 
 teus maximus; P, perineal body; U, urethra; V, vagina; G, tuIto- 
 vaginal gland; 1, clitoris; 2, its suspensory ligament; 3, crura clito- 
 ridis; 4, erector clitoridis; 5, bulbo-cavernosus ; 7, transversus perinsei; 
 8, sphincter ani; 9 and 10, levator ani; 11, coccygeus; 12, obturator 
 externus. 
 
 and transversus perinsei. It closes the anus. Nerve, fourth 
 sacral. 
 
 Internal sphincter ani is an aggregation of circular 
 fibres of the intestine, forming a muscular ring one inch in 
 breadth, surrounding the lower portion of the rectum. 
 
 The external sphincter ani, the two bulbo-cavernosi and the 
 two transversus perinsei unite one-half inch in front of the anus 
 in the median line in the so-called central tendon of the perineum. 
 
 Anal elevator (levator ani) arises in front from body 
 and ramus of pubis and symphysis, posteriorly from spine of 
 ischium, and on either side from angle of arcus tendiase (white 
 
SURGICAL ANATOMY. 389 
 
 line). It is inserted by posterior fibres into coccyx, and ante- 
 rior fibres into the muscle of opposite side in a median raphe 
 extending from coccyx to anus ; middle fibres into, rectum, join- 
 ing with sphincter ; anterior to prostate, blending with external 
 sphincter and transverse fascia. In the female it is inserted into 
 the vagina instead of the prostate. 
 
 It helps with its fellow to form the floor of the pelvis, and 
 supports the vagina, rectum, and pelvic viscera. Nerves, infe- 
 rior hsemorrhoidal and fourth sacral. 
 
 CoccYGEUs MUSCLE (coccjgei), from the spine of the 
 ischium and lesser sacro-sciatic ligament, and is inserted into 
 the margin of coccyx and side of lower two segments of sacrum. 
 It raises the coccyx and forms the posterior part of the pelvic 
 floor. Nerve, anterior division of the fourth and fifth sacral. 
 
 The muscles of the female perineum are : — 
 
 Superficial Set. 
 
 Sphincter vaginas, or bulbo-eavernosus ; 
 
 Erector clitoridis; 
 
 Transversus p'erinsei superficial ; 
 
 Sphincter ani; 
 
 Levator ani ; 
 
 Coccygeus. 
 
 Deep Set. 
 
 Transversus perinaei (profundus) ; 
 
 Constrictor vaginae ; 
 
 Compressor urethrse. 
 
 The structures beneath the deep layer of the superficial 
 fascia are : — 
 
 Erector penis muscle ; 
 
 Accelerator urinas muscle ; 
 
 Transversus perinaei muscle and arteries; 
 
 Superficial perineal vessels. 
 
 The structures between the two layers of the deep perineal 
 fascia are : — 
 
 Compressor urethras muscle; 
 
 Membranous urethra ; 
 
 Subpubic ligament; 
 
 Dorsal vein of penis ; 
 
 Pudic vessels and nerves; 
 
 Venous plexus; 
 
 Cowper's glands and ducts; 
 
 Arteries and nerves of bulb. 
 
390 HUMAN ANATOMY. 
 
 ANATOMY OF LATERAL LITHOTOMY. 
 
 The incision is made through a triangular interval formed 
 by the transversus perinsei, accelerator urinsB, and erector penis 
 muscles, and divides the following structures in the order 
 named : — 
 
 Skin and superficial fascia ; 
 Inferior heemorrhoidal vessels and nerves ; 
 Accelerator urinee muscle ; 
 
 Superficial perineal vessels and nerve (sometimes) ; 
 Transversus perinaei artery and muscle ; 
 Deep perineal fascia ; 
 Anterior part of levator ani ; 
 
 Part of compressor urethras and accelerator urinse muscles ; 
 Membranous and prostatic positions of urethra; 
 Left lobe of prostate gland. 
 The structures to be avoided are : — 
 In median line, rectum and bulb of corpus spongiosum ; 
 Externally, internal pudic artery; 
 Forward, artery of the bulb ; 
 
 Backward, posterior part of prostatic gland and neck of the 
 bladder. 
 
Missing Page 
 
INDEX. 
 
 Abdomen, 226 
 
 muscles of, 146 
 
 regions of, 227 
 Acervulus cerebri, 301 
 Acetabulum, 59 
 AlveolHof lower jaw, 29 
 
 of upper jaw, 26 
 Amphiarthrosis, 112 
 Anastomoses, 173 
 Anatomy, descriptive, 1 
 
 general, 1 
 
 of hernia, 379 
 
 of lateral lithotomy, 389 
 
 surgical, 374 
 Angle of jaw, 30 
 Anterior perforated space, 294 
 Annulus ovalis, 171 
 
 of subscapular fossa, 48 
 Antrum of Highmore, 24 
 Anus, 236 
 Aorta, 177, 191, 192 
 Appendicies epiploic^, 237 
 Appendix auricula, 170, 171 
 
 ensiform, 41 
 
 vermiformis, 235 
 Aponeuroses, 132 
 
 pharyngeal, 224 
 Apophysis, 4 
 Aqueduct of Sylvius (iter e tertio, 
 
 etc.), 299, 301 
 Aqueductus cochlea, 16 
 
 fallopil, 16, 313 
 
 vestibule, 16 
 Arachnoid, of brain, 285 
 
 of spinal cord, 317 
 Arbor vitse, 274, 290 
 Arch, deep palmar, 190 
 
 plantar, 200 
 Areola of mammae, 281 
 Arm, 47 
 
 Arnold's ganglion, 336 
 Arteriffi propriae renales, 259 
 Arterial anastomoses, 173 
 
 system, table of, 200 
 Arteries, helicine, 270 
 
 hepatic, 192, 241 
 
 lingual, 180 
 
 pharyngeal, 182 
 
 sublingual, 180 
 Arteries of the ankle-joint, 129 
 
 auditory canal, 361 
 
 auricle, 360 
 
 bone, 5 
 
 choroid, 348 
 
 elbow-joint, 122 
 
 Eustachian tube, 363 
 
 eye, 355 
 
 eyelids, 356 
 
 hip-joint, 126 
 
 iris, 349 
 
 kidney, 259 
 
 knee-joint, 128 
 
 labyrinth, 365 
 
 Arteries of the larynx, 250 
 lung, 255 
 mammae, 281 
 membrana tympani, 363 
 nasal fossae, 342 
 nose, 340 
 cesophagus, 192 
 ovaries, 277 
 pancreas, 238 
 penis, 270 
 pharynx, 225 
 retina, 362 
 shoulder-joint, 122 
 spleen, 243 
 stomach, 232 
 suprarenal capsules, 244 
 testicle, 268 
 thymus gland, 244 
 thyroid gland, 243 
 tympanum, 363 
 uterus, 274 
 wrist-joint, 124 
 Artery, anastomotica magna, 190 
 aorta, 177, 191, 192 
 arteria receptaculi, 184 
 auricular, posterior, 182 
 axillary, 188 
 basilar, 187 
 brachial, 189 
 carotid, common, 178 
 
 external, 179 
 
 internal, 184 
 carotid (external), 179 
 (Internal), 184 
 cerebral, anterior, 185 
 
 middle, anterior, 185 
 
 posterior, 187 
 choroid, anterior, 185 
 circumflex, anterior, 189 
 
 posterior, 189 
 communicating, anterior, 186 
 
 posterior, 185 
 coronary, 178 
 dental, inferior, 184 
 digital, 191, 200 
 dorsalis, hallucis, 199 
 
 pedis, 199 
 epigastric, deep, 196 
 
 superficial, 197 
 facial, 180 
 gastric, 192 
 femoral, 197 
 gluteal, 196 
 haemorrhoidal, inferior, 195 
 
 middle, 195 
 
 superior, 194 
 hepatic, 192 
 iliac, circumflex, deep, 196 
 
 common, 194 
 
 external, 196 
 
 internal, 194 
 
 superficial, 197 
 ilio-lumbar, 196 
 
 (391) 
 
392 
 
 INDEX. 
 
 Artery, infraorbital, 184 
 innominate, 178 
 intercostal, 188 
 lingual, 180 
 lumbar, 194 
 
 mammary, internal, 188 
 maxillary, internal, 183 
 meningeal, anterior, 185 
 
 middle, 183 
 
 posterior, 187 
 
 small, 184 
 mesenteric, superior, 193 
 
 inferior, 194 
 
 obturator, 195 
 
 occipital, 182 
 
 ophthalmic, 185 
 
 palmar arches, 190, 191 
 
 peroneal, 199 
 pharyngeal, ascending, 182 
 phrenic, 192 
 plantar, external, 200 
 
 internal, 199 
 popliteal, 198 
 profunda femoris, 197 
 
 inferior, 190 
 
 superior, 190 
 pudic, deep external, 197 
 
 superficial external, 197 
 
 internal, 195 
 
 pulmonary, 205 
 radial, 190 
 renal, 194, 259 
 sacral, lateral, 196 
 
 middle, 194 
 sciatic, 195 
 spermatic, 194 
 splenic, 193 
 pubclavian, 186 
 subscapular, 189 
 suprarenal, 194 
 suprascapular, 187 
 temporal, 182 
 thoracic, acromial, 189 
 
 alar, 189 
 
 long, 189 
 
 superior, 189 
 thyroid, inferior, 187 
 
 superior, 180 
 thyroidea ima, 251 
 tibial, anterior, 198 
 
 posterior, 199 
 transversalis colli, 188 
 tympanic, 183, 184 
 ulnar, 191 
 uterine, 196 
 vaginal, 196 
 vertebral, 187 
 vesical, 195 
 Arthrodial joints, 112 
 Articulations, 111 
 
 acromio-clavicular, 120 
 atlo-axoid, 113 
 carpal, 124 
 
 carpo-metacarpal, 125 
 costo-sternal, 116 
 costo-transverse, 115 
 costo-vertebral, 114 
 gleno-humeral, 122 
 occipito-atloid, 114 
 occipito-axold, 114 
 phalangeal, of toot, 131 
 
 of hand, 125 
 radlo-ulnar, 122 
 
 Articulations, sacro-coccygeal, 117 
 
 sacro-iliac, 116 
 
 sacro-ischiatic, 117 
 
 sacro-vertebral, 116 
 
 sterno-clavicular, 120 
 
 tarsal, 129 
 
 tarso-metatarsal, 130 
 
 temporo-maxillary, 112 
 
 tibio-flbular, 128 
 
 vertebral, 113 
 Arytenoid cartilages, 246 
 Atlas, 44 
 Auricle, 359 
 Axilla, 377 
 Axis, 44 
 
 cerebro-spinal, 284 
 
 cceliac, 192 
 
 optic, 344 
 
 thyroid, 187 
 
 visual, 344 
 Axis cylinder, 283 
 Azygos veins, 210 
 
 uvul£e, 139 
 
 Bartholin, duct of, 224 
 
 glands of, 281 
 Bauhin, valve of, 235 
 Bell, external nerve of, 320 
 
 internal nerve of, 320 
 Bladder, 261 
 Bodies, Malpighian, 258, 259 
 
 Pacchionian, 285 
 
 geniculate, 299 
 
 restiform, 287 
 Body, ciliary, 349 
 
 olivary, 287 
 
 perineal, 372 
 
 pituitary, 294 
 
 restiform, 287 
 Bone, astragalus, 68 
 
 calcaneum, 68 
 
 clavicle, 47 
 
 coccyx, 46 
 
 cuboid, 68 
 
 cuneiform, 57, 70 
 
 ethmoid, 21 
 
 femur, 63 
 
 fibula, 67 
 
 frontal, 8 
 
 humerus, 51 
 
 ilium, 60 
 
 incus, 364 
 
 hyoid, 31 
 
 innominate, 59 
 
 ischium, 61 
 
 lachrymal, 22 
 
 malar, 23 
 
 malleus, 364 
 
 maxillary, inferior, 29 
 superior, 24 
 
 nasal, 22 
 
 occipital, 11 
 
 OS calcis, 68 
 
 OS magnum, 57 
 
 palate, 26 
 
 parietal, 10 
 
 patella, 65 
 
 peroneal, 67 
 
 phalanges of foot, 71 
 of hand, 58 
 
 pisiform, 57 
 
 pubic, 62 
 
 radius, 55 
 
INDEX. 
 
 393 
 
 Bone, sacrum, 45 
 
 scaphoid, 57, 69 
 
 scapula, 48 
 
 semilunar, 57 
 
 sessamoid, 71 
 
 sphenoid, 17 
 
 stapes, 364 
 
 sternum, 41 
 
 structure, microscopic, 5 
 
 temporal, 13 
 
 tibia, 65 
 
 trapezium, 57 
 
 trapezoid, 57 
 
 turbinated, inferior, 28 
 middle, 21 
 superior, 21 
 
 ulna, 53 
 
 unciform, 57 
 
 vomer, 28 
 Bones of the body, 3 
 
 of the carpus, 56 
 
 of the cranium, 7 
 
 of the (ace, 22 
 
 of the foot, 68 
 
 of the hand, 56 
 
 of the lower extremity, 59 
 
 of the metacarpus, 58 
 
 of the metatarsus, 70 
 
 of the tarsus, 68 
 
 of the trunk, 41 
 
 of the upper extremity, 47 
 
 Wormian, 32 
 Bonnet, capsule of, 345 
 Bowman, capsule of, 259 
 Brain, commissures of, 295 
 
 development, 286 
 
 divisions of, 286 
 
 ventricles, 296 
 
 weights, average, 286 
 Bronchi, 251 
 Brunner's gland, 234 
 Bulb of corpus cavernosum, 270 
 
 of corpus spongiosum, 270 
 Bulbi vestibuli, 280 
 Bulbs, olfactory, 310 
 Burns, process of, 384 
 Bursae of hip, 126 
 
 of knee, 128 
 
 Caecum, 234 
 
 Calamus scriptorlus, 300 
 Calices of kidney, 259 
 Canal, alimentary, 218 
 
 auditory external, 361 
 internal, 16, 370 
 
 carotid, 16 
 
 central, of the cord, 318 
 
 crural, 383 
 
 dental, 25 
 
 femoral, 383 
 
 for tensor tympani, 362 
 
 Hunter's, 197 
 
 hyaloid, 353 
 
 infraorbital, 25 
 
 inguinal, 379 
 
 nutrient, 5 
 
 of Huguler, 362 
 
 of Nuck, 230 
 
 of Petit, 353 
 
 of Schlemm, 348 
 
 of Stlling, 353 
 
 of the modiolus, 367 
 
 palatine, 27 
 
 Canal, pterygopalatine, 19 
 
 sacral, 45 
 
 spiral, of the cochlea, 367 
 
 Vidian, 20 
 Cauallculi, 358 
 Canalis reuniens, 368 
 Canals, membranous, 368 
 
 semicircular, 366 
 Canthus, 356 
 Capillaries, 174 
 Capsule, external, 298 
 
 internal, 297 
 
 of Bonnet, 345 
 
 of Glisson, 238 
 
 of Tenon, 345 ■ 
 
 of the lens, 353 
 Capsules, suprarenal, 244 
 Caput coll (csecum), 235 
 
 gallinaginis, 271 
 Carpus, 56 
 Cartilages of the larynx, 246 
 
 of Santorini, 246 
 
 of Wrisberg, 247 
 
 tarsal, 357 
 Cartilago-triticea, 247 
 Caruncula lachrymalis, 357 
 
 myrtiformes, 279 
 Cauda equina, 317 
 Cavity, cotyloid, 59 
 
 glenoid, of scapula, 51 
 
 orbital, 34 
 
 peritoneal, 228 
 
 sigmoid, greater, 54 
 lesser, 54 
 of radius, 56 
 Cells, auditory, 370 
 
 ethmoid, 21 
 
 hepatic, 233 
 
 of Purkinie, 304 
 
 mastoid, 15, 361 
 Cement, 220 
 Cerebellum, 288, 303 
 Cerebro-spinal system, 283 
 Cerebrum, 290, 308 
 
 convolutions of, 292 
 
 Assures of, 291 
 
 lobes of, 292 
 Cervix of penis, 269 
 
 of uterus, 273 
 Chordae tendinae, 172 
 Choroid plexus, 298 
 Cilia, 357 
 
 Circle of Willis, 185 
 Clrculus arteriosus iridis, 348 
 
 venosus, 281 
 Cisterna basolis, 285 
 
 magna, 285 
 
 pontls, 285 
 Claustrum, 298 
 Clavicle, 47 
 Clinoid processes, 18 
 Clitoris, 280 
 
 Clivus Blumenbachii, 18 
 Cloquet, canal of, 353 
 Coccyx, 46 
 Cochlea, membranous, 369 
 
 osseous, 366 
 CcBliac axis, 192 
 Collar-bone, 47 
 Colon, 236 
 
 flexures of, 236 
 Columnae carnese, 172 
 
 papillares, 172 
 
394 
 
 INDEX. 
 
 Columns of spinal cord, 317 
 Commissures, cerebral, 295 
 
 anterior, 299 
 
 middle, 299 
 
 posterior, 299 
 Concha, 360 
 Condyles of femur, 64 
 
 of humerus, 52 
 Coni vasculosi, 266 
 Conjunctiva, 357 
 Conus arteriosus, 172 
 
 medullaris, 317 
 Convolutions of cerebrum, 292 
 Coracoid process, 51 
 Corium, 372 
 Cornea, 346 
 
 Cornicula laryngis, 248 
 Cornua of thyroid cartilage, 246 
 
 of ventricles, 296 
 Corona glandis, 269 
 Coronoid process, 30 
 Corpora albicantia, 294 
 
 cavernosa, 270 
 
 quadrigemina, 301 
 
 mammillaria, 294 
 
 striata, 296 
 Corpus Arantii, 172 
 
 callosum, 
 
 dentatum of cerebellum, 303 
 
 fimbriatum, 298 
 
 Highmorianum, 295 
 
 luteum, 277 
 
 spongiosum, 270 
 
 striatum, 296 
 Corpuscles, Malpighian, 242, 259 
 
 of the blood, 175 
 
 tactile, 284 
 Corti, organ of, 369 
 Cortical substance of kidney, 257 
 Cotyloid cavity, 69 
 Coverings of the testicle, 264 
 Cowper's glands, 272 
 Crest, lachrymal, 22 
 
 nasal, 26 
 
 of the ilium, 60 
 
 of the pubes, 62 
 
 of the tibia, 65 
 
 turbinated, 25 
 Cricoid cartilage, 246 
 Crista galli, 21; crista terminalis, 170 
 Crura, anterior, 298 
 
 cerebri, 294 
 
 of clitoris, 280 
 
 of penis, 270 
 
 posterior, 298 
 Crusta petrosa, 220 
 
 pontis, 303 
 Crypts of LieberkUhn, 234 
 Cuneifcfrm cartilages, 247 
 Cuneus, 294 
 Cupola of cochlea, 367 
 Cuticle, 372 
 
 Dartos, 264 
 
 Declivity, IS 
 
 Dentine, 220 
 
 Derma, 372 
 
 Descemet, membrane, 346 
 
 Diaphragm, 149 
 
 Diaphragma, sella, 285 
 
 Diaphysis, 3 
 
 Diarthrosis, 112 
 
 Digestion, organs of, 218 
 
 Discus proligerus, 276 
 Disk, optic, 349 
 Dorsum of scapula, 49 
 
 sellEe, 18 
 Douglas cul-de-sac, 230, 274 
 Duct, cystic, 241 
 
 hepatic, 241 
 
 lymphatic, 215 
 
 nasal, 368 
 Duct of Bartholin, 224 
 
 of Muller, 266, 277 
 
 of Rivini, 224 
 
 of Steno, 223 
 
 of Wharton, 224 
 
 of Wirsung, 238 
 
 pancreatic, 238 
 
 thoracic, 215 
 Ducts, biliary, 241 
 
 ejaculatory, 268 
 Ductus cochlearis, 357 
 
 communis choledochus, 241 
 Duodenum, 233 
 Dura mater of cerebrum, 284 
 
 of spinal cord, 317 
 
 Ear, 350 
 
 internal, 365 
 Earstones, 368 
 Eminentia articularis, 14 
 
 collateralls (pes accessorius), 299 
 Enamel, 220 
 Enarthrosis, 112 
 Encephalon, 286 
 Endocardium, 173 
 Endolymph, 356 
 Endosteum, 6 
 Epidermis, 372 
 Epididymis, 264, 266 
 Epigastric region, 227 
 Epiglottis, 246 
 Epiphysis, 3, 4 
 Equator of eyeball, 344 
 Eustachian tube, 362 
 Eye, 343 
 
 appendages of, 344 
 Eyebrows, 356 
 Eyelashes, 357 
 Eyelids, 356 
 
 Fallopian tubes, 277 
 Falloplus, aqueduct of, 16 
 
 hiatus of, 16 
 Falx cerebelli, 285 
 
 cerebri, 285 
 Fascia, abdominal, 167 
 
 cremasteric, 264 
 
 cribiform, 168 
 
 denta, 299 
 
 iliac, 167 
 
 intercoluranar, 264 
 
 lata, 169 
 
 lumbar, 167 
 
 obturator, 386 
 
 of Colles, 387 
 
 of the head and face, 166 
 
 of the lower extremity, 168 
 
 of the neck, 167 
 
 of the trunk, 167 
 
 of the upper extremity, 168 
 
 palmar, 168 
 
 pelvic, 167 
 
 perineal, 386 
 
 plantar, 169 
 
INDEX. 
 
 395 
 
 Fascia, recto-vesical, 386 
 Fasciae, 166 
 Fauces, 223 
 Femus, 63 
 Fenestra ovalis, 326 
 
 rotunda, 362 
 Ferrein, pyramids of, 259 
 Fibro-cartilage, 111, 113, 128, 246 
 Fibula, 67 
 Fillet, decussation of, 302 
 
 mesial, 303 
 
 lateral, 303 
 FimbrlsB, 277 
 
 Fimbriated extremity, 277 
 Fissure, auricular, 17 
 
 calcarine, 294 
 
 calloso-marginal, 291, 294 
 
 collateral, 291 
 
 dentate, 291, 294 
 
 Glaserian, 14 
 
 of Rolando, 291 
 
 of Sylvius, 291, 294 
 
 palpebral, 356 
 
 paracentral, 291 
 
 parieto-occipital, 291 
 
 pterygo-maxillary, 33 
 
 spheno-maxillary, 33, 35 
 
 sphenoidal, 20, 35 
 
 transverse, 291 
 Fissures of cerebellum, 289, 290 
 
 of cerebrum, 291 
 
 of liver, 239 
 
 of spinal cord, 317 
 Foetal circulation, 177 
 Folds, palpebral, 345, 357 
 Fontanelles, 32 
 Foot, 68 
 Foramen for Arnold's nerve, 16 
 
 CEBCum, 9 
 
 condyloid, 12 
 
 ethmoidal, 21, 36 
 
 for Jacobson's nerve, 16 
 
 infraorbital, 24, 36 
 
 intervertebral, 43 
 
 lacerum anterius, 20, 38 
 
 magnum, 12, 40 
 
 mastoid, 15 
 
 medium, 38 
 
 mental, 29 
 
 molar, 36 
 
 nutrient, 5 
 
 obturator, 59 
 
 of Monro, 299 
 
 of Scarpa, 25 
 
 of Stenson, 25 
 
 of Winslow, 288 
 
 oltactory, 37 
 
 orbital, 20 
 
 ovale, 19 
 
 palatine, 27 
 
 posterius, 12 
 
 pterygo-palatine, 19 
 
 rotundum, 19 
 
 saoral, 46 
 
 spheno-palatine, 28 
 
 spinal, 44 
 
 spinosum, 19 
 
 stylo-mastoid, 17 
 
 supraorbital, 8, 36 
 
 suprascapular, 50 
 
 thyroid, 59 
 
 Vesalii, 19 
 Foramina at the base of the skull, 38 
 
 Foramina Thebesii, 171 
 Forearm, 53, 152 
 Formatio reticularis, 302 
 Fornix, 298 
 Fossa, canine, 24 
 
 caronoid, 52 
 
 digastric, 15 
 
 digital, 64 
 
 glenoid, 14, 51 
 
 hyaloid, 353 
 
 incisive, 24, 29 
 
 infraspinous, 49 
 
 ischo-rectal, 384 
 
 jugular, 16 
 
 lachrymal, 9 
 
 navicularis of penis, 271 
 
 of vulvo, 279 
 
 olecranon, 52 
 
 ovalis, 171 
 
 pituitary, 18 
 
 pterygoid, 20 
 
 scaphoid, 20 
 
 spheno-maxillary, 34 
 
 sublingual, 29 
 
 submaxillary, 29 
 
 subscapular, 48 
 
 supraspinous, 49 
 
 temporal, 32 
 
 zygomatic, 32 
 FossEe, nasal, 36 
 
 of the skull, 32 
 Fourchette, 279 
 Fovea centralis, 349 
 
 hemispherica, 366 
 
 semi-elliptica, 366 
 Frsenulum, 301 
 FrEEnum preputii, 270 
 
 Gall-bladder, 241 
 Gall-duct, 241 
 Ganglia, 284 
 
 basic, 298 
 
 cervical, 337 
 
 cranial, 335 
 
 lumbar, 338 
 
 of fifth nerve, 335 
 
 of the sympathetic, 335 
 
 sacral, 338 
 
 thoracic, 337 
 Ganglion, Arnold's, 336 
 
 Gasserian, 312 
 
 impar, 335 
 
 Meckel's, 335 
 
 of Ribes, 335 
 
 ophthalmic, 335 
 
 otic, 336 
 
 spheno-palatine, 335 
 
 spirale, 368 
 
 submaxillary, 337 
 Gasser, ganglion of, 312 
 Geniculate bodies, 299 
 Ginglymus, 112 
 Gladiolus, 41 
 Gland, lachrymal, 357 
 
 mammary, 281 
 
 parotid, 223 
 
 pineal, 301 
 
 prostate, 272 
 
 sublingual, 224 
 
 submaxillary, 224 
 
 thymoid, 243 
 
 thymus, 243 
 Glandula coccygea, 245 
 
396 
 
 INDEX. 
 
 Glandula intercarotica, 245 
 Glands, Brunner's, 234 
 
 Cowper's, 272 
 
 ductless, 242 
 
 gastric, 232 
 
 intestinal, 234 
 
 lachrymal, 357 
 
 lymphatic, 215 
 
 Meibomian, 357 
 
 of Bartholine, 281 
 
 of Tyson, 270, 281 
 
 peptic, 232 
 
 salivary, 223 
 
 sebaceous, 361 
 
 solitary, 234 
 
 sweat, 361 
 Glans clitoridis, 280 
 
 penis, 269 
 Glenoid, 14, 51 
 Glisson's capsule, 238 
 Glottis, 248 
 Gomphosis, 112 
 Graafian vesicle, 275 
 Groove, bicipital, 52 
 
 carotid, 18 
 
 cavernous, 18 
 
 infraorbital, 25 
 
 musculo-spiral, 51 
 
 mylo-hyoid, 30 
 
 naso-palatine, 28 
 
 optic, 18 
 Gubernaculum testis, 266 
 Gums, 219 
 Gyri of brain, 292 
 
 Hairs, 372 
 Hamstrings, 161 
 Hamular process, 22 
 Hand, 56 
 Haversian canals, 5 
 
 system, 6 
 Head of the femur, 63 
 
 of the humerus, 52 
 
 of the ulna, 54 
 Heart, 170 
 Helicotrema, 355 
 Helix, 369 
 
 Henle, tubes of, 259 
 Hernia, anatomy of, 379 
 
 femoral, 383 
 
 inguinal, 379 
 Hiatus Fallopii, 16 
 Hilus of kidney, 257 
 Hippocampus major, 299; minor, 299 
 His, bundle of, 170 
 Hasner, valve of, 346 
 Houston, valves of, 237 
 Huguier, canal of, 15 
 Humerus, 51 
 Humor, aqueous, 352 
 
 vitreous, 353 
 Humors of the eyeball, 352 
 Hunter's canal, 197 
 Hydatids of Morgagni, 266, 277 
 Hymen, 279 
 Hypochondrium, 227 
 Hypogastrium, 227 
 
 Ileum, 233 
 
 Ilium, 60 
 
 Incisura intertraglca, 347 
 
 Infundibulum of brain, 294 
 
 Inguinal regions, 227 
 
 Intestine, large, 235 
 
 small, 233 
 Internal capsule, 297 
 Iris, 348 
 Ischium, 61 
 
 Iter chordae anterius, 362 
 posterius, 362 
 
 e tertio ad guartum ventriculum 
 300 
 Ivory, 220 
 
 Jacob's membrane, 352 
 Jacobson's nerve, 316, 336, 365 
 Jejunum, 233 
 Joint, ankle-, 129 
 
 elbow-, 122 
 
 hip-, 126 
 
 rotators of the, 160 
 
 knee-, 126 
 
 shoulder, 122 
 
 wrist-, 124 
 Joints, motions in, 112 
 
 structures of. 111 
 
 Kidneys, 257 
 
 Labia majora, 279 
 
 minora, 280 
 Labium tympanicum, 369 
 
 vcstibulare, 369 
 Labyrinth, membranous, 368 
 
 osseous, 365 
 Lacteals, 215 
 Lacuna magna, 272 
 Lacunse, 5 
 
 Lacus lachrymalis, 357 
 Lamellas, 5 
 Lamina cinerea, 294 
 
 cribrosa (of sclerotic), 346 
 (of temporal bone), 16 
 
 fusca, 345 
 
 reticularis, 370 
 
 spiralis, 367 
 Laminae of cornea, 346 
 Lancisi, nerves of, 295 
 Larynx, 246 
 Layer, dermoid, 372 
 
 ganglionic, 351 
 
 molecular, 339, 351 
 Leg, 65 
 
 Lens, crystalline, 352 
 LieberkUhn, crypts or follicles of, 234 
 Ligament, annular, of foot, 169 
 of hand, 168 
 
 chondro-xiphoid, 115 
 
 conoid, 121 
 
 coronary, 128 
 
 cotyloid, 126 
 
 crucial, of knee-joint, 127 
 
 deltoid, 129 
 
 falciform, 383 
 
 Gimberna,t'8, 146, 381 
 
 glenoid, 122 
 
 ileo-femoral or Y, 126 
 
 of Burns, 384 
 
 of Colles, 381 
 
 of Hey, 381 
 
 of Zina, 353 
 
 orbicular, 123 
 
 Poupart's, 146, 381 
 
 rhomboid, 120 
 
 round, of the liver, 241 
 of the uterus, 274 
 
INDEX. 
 
 397 
 
 Ligament sacro-sciatic, 117 
 
 stellate, 115 
 
 stylo-maxillary, 113 
 
 suspensory, of lens, 341 
 
 of liver, 241 
 
 of penis, 270 
 
 of spleen, 242 
 
 transverse, of hip-joint, 126 
 
 trapezoid, 121 
 
 triangular, of perineum, 387 
 Ligaments of tlie bladder, 262 
 
 broad, of uterus, 274 
 
 check, 114 
 
 of the knee-joint, 126 
 
 of the larynx, 247 
 
 of the liver, 240 
 
 of the ossicles, 365 
 
 of the ovaries, 274 
 
 of the sternum, 115 
 
 of the uterus, 274 
 
 peritoneal, 228 
 
 tarsal, 357 
 Ligamentum latum pulmonis, 255 
 
 mucosum, 128 
 
 nuchae, 113 
 
 patellae, 126 
 
 pectinatum iridis, 337 
 
 suspensorium, 114 
 
 teres, 126 
 
 Winslowii, 126 
 Limbus laminae spiralis, 355 
 Line, intertrochanteric, 64 
 Linea-aspera, 63 
 
 ilio-pectinea, 61 
 
 quadrati, 64 
 Lingula, 18 
 Liquor Morgagni, 341 
 Lithotomy, structures affected, 376 
 Liver, fissures of, 239 
 
 ligaments, 240 
 
 lobes of, 240 
 
 structure of, 238 
 
 vessels of, 241 
 Lobes of the cerebellum, 289 
 
 of the cerebrum, 292 
 
 of the liver, 240 
 Lobule of the ear, 359 
 Lobules of the liver, 238 
 
 of the lung, 254 
 Lobulus caudatus, 240 
 
 quadratus, 240 
 
 Spigelii, 240 
 Lower, tubercle of, 171 
 Lumbar regions, 227 
 Lung, broad ligament of, 255 ' 
 Lungs, 252 
 Lymphatics, 214 
 
 hepatic, 217, 241 
 
 of lung, 265 
 
 of penis, 271 
 
 of trachea and bronchi, 252 
 
 of uterus, 274 
 Lymph spaces of eyeball, 345 
 Lyra, 298 
 
 Macula acoustica, 368 
 
 crlbrosa, 366 
 
 lutea, 349 
 Malleolus, 67 
 Malpighi, bodies of, 242 
 
 pyramids of, 258 
 Malpighian corpuscles, 242, 259 
 
 tuft, 259 
 
 Mamms, 281 
 
 Manubrium of the malleus, 364 
 
 of the sternum, 41 
 Marrow of bone, 5 
 Masses, lateral, of ethmoid, 21 
 Mastoid process, 15 
 Meatus auditorius externus, 17 
 internus, 18, 370 
 
 nasi, 37 
 
 urinarius, 271, 280 
 Meckel's ganglion, 335 
 Mediastinum, 256 
 
 testis, 265 
 Medulla, 5 
 
 oblongata, 287, 302 
 Medullary sheath, 283 
 
 substance, 257 
 Membrana basillarls, 355 
 
 granulosa, 276 
 
 pupillaris, 349 
 
 Ruyschiana, 348 
 
 tectoria, 369 
 
 tympani, 363 
 
 secundaria, 362 
 Membrane, hyaloid, 353 
 
 interosseous, 123, 124, 128 
 
 Jacob's, 351 
 
 limiting, 351 
 
 of Descemet, 346 
 
 of Reissner, 369 
 
 Schneiderian, 342 
 
 Shrapnell's, 362 
 
 vitelline, 277 
 Membranes of brain, 284 
 
 of the spinal cord, 317 
 
 synovial. 111 
 
 tarsal .synovial, 131 
 
 wrist synovial, 125 
 Meridians of eyeball, 333 
 Mesencephalon, 301 
 Mesenteries, 230 
 Metacarpus, 58 
 Metatarsus, 70 
 Midbrain, 304 
 Modiolus, 355 
 Monro, foramen of, 299 
 Mons veneris, 279 
 Montgomery, glands of, 281 
 Morgagni, hydatids of, 266, 277 
 
 liquor, 353 
 Mouth, 218 
 
 Muller, duct of, 266, 277 
 Muscle, ciliary, 349 
 
 cremaster, 264 
 
 dilator pupillae, 349 
 
 levator glandulae thyroideae, 243 
 
 of the auricle, 347 
 
 sphincter pupillae, 349 
 Muscles of the abdomen, 146 
 
 of Hilton, 250 
 
 of Houston, 387 
 
 of the arm, 150 
 
 of the back, 141 
 
 of the ear (external), 133 
 
 of tbe epiglottis, 249 
 
 of the Eustachian tube, 350 
 
 of the eyeball, 342 
 
 of the face, 135 
 
 of the forearm, 152 
 
 of the foot, 164 
 
 of the hand, 155 
 
 of the head, 133 
 
 of the hip, 154 
 
398 
 
 INDEX. 
 
 Muscles of the larynx, 249 
 
 of the leg, 161 
 
 of the neck, 137 
 
 of the .palate, 139 
 
 of the perineum, 373 
 
 of the pharynx, 139 
 
 of the shoulder, 149 
 
 of the stomach, 232 
 
 of the thigh, 157 
 
 of the thorax, 148 
 
 of the tongue, 138 
 
 of the tympanum, 365 
 Muscular fibre, 132 
 Musculi pectinati, 171 
 
 Naboth ovules of, 274 
 
 Nails, 372 
 
 Nares, 36 
 
 Nates of cerebrum, 301 
 
 Neck of femur, 63 
 
 of humerus, 52 
 
 muscles of, 137 
 
 triangles of, 374 
 Nerve, abducens, 313 
 
 Arnold's, 316 
 
 auditory, 314 
 
 Bell's external respiratory, 320 
 internal respiratory, 320 
 
 cells, 283 
 
 chorda tympani, 314, 365 
 
 circumflex, 322 
 
 cochlear, 314 
 
 crural, anterior, 324 
 
 facial, 313 
 
 fibres, 283 
 
 genito-crural, 324 
 
 glosso-pharyngeal, 314 
 
 gluteal, superior, 325 
 
 hypoglossal, 316 
 
 ilio-hypogastric, 324 
 
 ilio-inguinal, 324 
 
 intercostal, 323 
 
 intercosto-humeral, 324 
 
 internal cutaneous, 322 
 
 interosseous, 322, 323 
 
 Jacobson's, 316, 336, 365 
 
 laryngeal, 260, 316 
 
 maxillary inferior, 313 
 superior, 313 
 
 median, 322 
 
 motor oculi, 312 
 
 musculo-cutaneous. 322, 327 
 
 musculo-spiral, 323 
 
 uonus or ninth pair, 314 
 
 obturator, 324 
 
 of Wrisburg, 322 
 
 olfactory, 309 
 
 ophthalmic division of fifth, 312 
 
 optic, 312 
 
 par vagum, 316 
 
 patheticus, 312 
 
 petrosal, external, 336 
 large deep, 336 
 large superficial, 336 
 small, 336 
 
 popliteal, 326 
 
 phrenic, 326 
 
 pneumogastric, 316 
 
 pterygo-palatiue, 336 
 
 pudic, 325 
 
 radial, 323 
 
 sciatic, great, 326 
 small, 325 
 
 Nerve, spinal accessory, 316 
 
 subscapular, 322 
 
 suprascapular, 320 
 
 sympathetic, 335 
 
 tibial, anterior, 327 
 posterior, 326 
 
 thoracic, 320 
 
 trigeminus, 312 
 
 trochlear, 312 
 
 tympanic, 314 
 
 ulnar, 322 
 
 vestibular, 314, 370 
 
 Vidian, 336 
 Nerve-fibres, optic, 312 
 
 tissue, 284 
 Nerves, 284 
 
 cranial, 309 
 
 hepatic, 338 
 
 of ankle-joint, 129 
 
 of auditory canal, 361 
 
 of auricle, 360 
 
 of bladder, 263 
 
 of choroid, 348 
 
 of elbow-joint, 122 
 
 of Eustachian tube, 363 
 
 of eye, 356 
 
 of eyelids, 356 
 
 of eye-muscles, 353, 355 
 
 of hip-joint, 126 
 
 of iris, 349 
 
 of Jacobson, 316 
 
 of kidney, 261 
 
 of knee-joint, 128 
 
 of Lancisi, 295 
 
 of larynx, 250, 316 
 
 of lung, 255 
 
 of membrana tympani, 363 
 
 of nasal fossse, 343 
 
 of nose, 340 
 
 of ovaries, 277 
 
 of pancreas, 238 
 
 of pharynx, 225 
 
 of shoulder-joint, 122 
 
 of spleen, 243 
 
 of stomach, 232 
 
 of suprarenal capsules, 244 
 
 of taste, 371 
 
 of testicles, 268 
 
 of thymus gland, 244 
 
 of tongue, 371 
 
 of trachea and bronchi, 252 
 
 of tympanum, 363 
 
 of uterus, 274 
 
 of wrist-joint, 124 
 
 petrosal, 336 
 
 popliteal, 326 
 
 sciatic, 325, 326 
 
 spinal, 31S 
 
 splanchnics, 337 
 
 table of, 328 
 
 thyroid, 243 
 Nervous system, 282 
 Neurilemma, 282 
 Neuroglia, 2S4 
 Neuron, 284 
 Nipple, 281 
 Nose, 340 
 Notch, cotyloid, 69 
 
 interclavicular, 41 
 
 intercondyloid, 64 
 
 popliteal, 66 
 
 Rivinus, 362 
 
 sacro-sciatic, 61 
 
INDEX. 
 
 399 
 
 Notch, sigmoid, 30 
 
 supraorbital, 8 
 
 suprascapular, 50 
 Nuck, canal of, 230 
 Nucleus, red, 304 
 Nymphae, 280 
 
 Occipital cross, 13 
 
 protuberance (external), 11 
 (internal), 13 
 Odontoblasts, 220 
 Odontoid ligaments, 114 
 
 process, 44 
 CEsophagus, 225 
 Omentum, 228 
 Opening saphenous, 169, 384 
 Optic thalami, 298 
 Ora serrata, 349 
 Orbital cavities, 34 
 Organ of Corti, 369 
 
 of hearing, 359 
 
 of Rosenmiiller, 277 
 
 of sight, 343 
 
 of smell, 340 
 Organs of generation, female, 272 
 male, 263 
 
 of taste, 371 
 
 of voice and respiration, 246 
 
 peripheral end, 286, 361 
 
 urinary, 257 
 Os calcis, 68 
 
 orbiculare, 364 
 
 planum (orbital of ethnoid), 21 
 
 tincae, 273 
 
 uteri, 273 
 Ossa innomlnata, 59 
 
 triquetra, 32 
 Ossification, 7 
 
 table of, 72 
 Ossicles of tympanum, 364 
 Osteology, 3 
 Otoliths, 356 
 Ovaries, 274 
 Oviducts, 277 
 Ovisacs, 276 
 Ovules of Naboth, 274 
 Ovum, 276 
 
 Pacchionian bodies, 285 
 Palate, 223 
 Palpebrae, 356 
 
 Pampinaform plexus, 268, 277 
 Pancreas, 237 
 
 lesser, 237 
 Papilla lachrymal, 358 
 Papillae of skin, 372 
 Parovarium, 277 
 Pars ciliaris retinae, 349 
 
 intermedia, of vulva, 280 
 Peduncles of cerebellum, 290 
 
 of corpus callosum, 295 
 Pelvic girdle, 59 
 Pelvis, lis 
 
 of the kidney, 259 
 Penis, 269 
 Perforated space, anterior, 294 
 
 posterior, 294 
 Pericardium, 170 
 Perilymph, 356, 368 
 Perineum, 385 
 
 female, 388 
 
 central tendon of, 388 
 Periosteum, 5 
 
 Peritoneum, 228 
 Peronet muscles, 163, 264 
 Pes accessorius, 299 
 
 hippocampi, 299 
 Petit, canal of, 341 
 Peyer's patches, 234 
 Phalanges of ear, 370 
 
 of foot, 71 
 
 .of hand, 58 
 Pharynx, 224 
 Pia mater of brain, 285 
 
 of spinal cord, 317 
 
 of the testes, 266 
 Pinna, or auricle, 359 
 Pituitary body, 244, 294 
 Plane, equatorial, 344 
 
 meridional, 344 
 Plantar arch, 169 
 Plate, cribriform, 21 
 
 perpendicular, 21 
 
 pterygoid, 20 
 Pleurse, 255 
 Plexus, brachial, 320 
 
 cardiac, 338 
 
 carotid, 337 
 
 cavernous, 337 
 
 cervical, 318 
 
 choroid, 298 
 
 of fourth ventricle, 298 
 
 hypogastric, 338 
 
 lumbar, 324 
 
 pampiniform, 268, 277 
 
 pelvic, 339 
 
 sacral, 325 
 
 solar, 338 
 
 splenic, 338 
 
 tympanic, 363 
 Plexuses of the sympathetic, 338 
 Plica semilunaris, 345, 357 
 Point, nodal, 344 
 Poles of the eyeball, 344 
 Pomum Adami, 246 
 Pons Varolii, 287, 303 
 Portal system, 192, 211, 241 
 Porus opticus, 346 
 Pouches of membrana tympani, 362 
 Poupart's ligament, 146, 368, 381 
 Prepuce . of clitoris, 280 
 
 of penis, 269 
 Process, acromion, 51 
 
 alveolar, 26, 29 
 
 angular, 8 
 
 articular. 111 
 
 auditory, 17 
 
 basilar, 12 
 
 clinoid, 18 
 
 condyloid, 30, 52 
 
 coracoid, 51 
 
 coronoid, 30, 54 
 
 ethmoidal, 28 
 
 falciform, 370 
 
 hamular, of cochlea, 367 
 
 Ingrassias, 20 
 
 jugular, 12 
 
 lachrymal, 28 
 
 malar, 25 
 
 mastoid, 15 
 
 maxillary, 27, 28 
 
 mental, 29 
 
 nasal, 25 
 
 odontoid, 44 
 
 of pterygoid .plate of sphenoid, 22 
 
 olecranon, 54 
 
400 
 
 INDEX. 
 
 Process, olivary, 18 
 
 orbital, 23, 27 
 
 palate, 25 
 
 pterygoid, 20, 27 
 
 sphenoidal, 27 
 
 spinous, 4, 20, 44 
 
 styloid, 16 
 
 transverse, 44 
 
 unciform, 21 
 
 vaginal, 16, 21 
 
 vermiform, 235 
 
 zygomatic, 13 
 Processes, ciliary, 349 
 
 clinold, 18 
 
 of Ingrassias, 20 
 Processus, coohleariformis, 17 
 
 a cerebello ad meduUam (inferior 
 peduncles), 290 
 ad potem (middle peduncles), 
 
 290 
 ad testes, 290, 301 
 
 gracilis, 364 
 Prominentia canalis facialis, 362 
 Promontory of sacrum, 45 
 
 of tympanum, 362 
 Prostate gland, 272 
 Prostatic sinus, 271 
 
 urethra, 271 
 Pterygoid processes, 20 
 Pubes, 62 
 
 Punctum, lachrymale, 357 
 Pupil, 348 
 Pylorus, 231 
 Pyramid, anterior, 287 
 
 posterior, 287 
 
 of tympanum, 362 
 Pyramids of Ferrein, 259 
 
 of Malpighi, 258 
 
 of Wistar. 19 
 
 Radius, 55 
 
 Rami of inferior maxillary, 30 
 
 Ramus of ischium, 62 
 
 of the pubes, 62 
 Receptaculum chyli, 215 
 Rectum, 236 
 
 Regions of abdomen, 227 
 Reil, Island of, 293 
 Reissner, membrane of, 357 
 Renal vessels, 259 
 Retina, 349 
 
 Ribes, ganglion of, 335 
 Ribs, 41 
 Ridge, mylo-hyoid, 29 
 
 pterygoid, 19 
 
 superciliary, 8 
 Rima glottidis, 248 
 Ring, abdominal, 381 
 
 crural, 383 
 
 femoral, 383 
 Rivinus, duct of, 224 
 Rods and cones (Jacob's), 351 
 
 of Corti, 370 
 Rolando, Assure of, 291 
 RosenmiiUer, organ of, 277 
 Rostrum of the sphenoid, 19 
 
 Sac, lachrymal, 358 
 
 Saccule, 368 
 
 Sacoulus, laryngis, 249 
 
 Sacrum, 45 
 
 Sacs of the peritoneum, 228 
 
 Santorini, cartilages of (corniculo 
 
 laryngis), 246 
 Scala media, 369 
 
 tympani, 368 
 
 vestibuli, 368 
 Scapula, 48 
 Scarpa, foramen of, 25 
 Scbindelysis, 112 
 Schlemm, canal of, 348 
 Schwann, substance of, 283 
 Sclerotic, 345 
 Scrotum, 264 
 Scute, 362 
 Sella turcica, IS 
 Septum, crurale, 384 
 
 lucidum, 296 
 
 nasi, 36 
 
 pectiniforme, 270 
 Sheath, crural, 384 
 Shin, 65 
 Shoulder-joint, 122 
 
 blade, 48 
 
 girdle, 47 
 Sight, organs of, 343 
 
 Sigmoid flexure, 236 
 Sinus aortici or sinus of Valsalva, 172 
 
 circularis iridis, 348 
 
 of kidney, 259 
 
 of Morgagni (sacculus laryngis), 
 249 
 
 pocularis, 271 
 Sinuses, frontal, ,9 
 
 of the dura mater, 207 
 
 of Valsalva, 172 
 
 sphenoidal, 19 
 Skin, 360 
 
 Smell, organ of, 340 
 Space, anterior perforated, 294 
 
 popliteal, 379 
 
 posterior perforated, 294 
 
 of Retzius, 262 
 
 subarachnoid, 285 
 
 subdural, 285 
 Spermatic cord, 269 
 Sphincter vesicae, 262 
 Spinal cord, 317 
 
 nerves, table of, 328 ' 
 Spine, ethmoidal, 18 
 
 nasal anterior, 26 
 
 of the ischium, 61 
 
 of the pubes, 62 
 
 of the scapula, 49 
 
 of the sphenoid, 20 
 
 of the tibia, 66 
 
 pharyngeal, 12 
 
 posterior, 27 
 Spines of the ilium, 60, 61 
 Spinous processes, 4, 20, 44 
 Spleen, 242 
 
 Splenic flexure of colon, 236 
 Splenium, 295 
 Spot, blind, 347 
 
 germinal, 277 
 
 light, 363 
 
 yellow, 349 
 Squamous, 13 
 Steno's ducts, 223 
 Stenson's foramina, 25, 40 
 Sternum, 41 
 Stilling, canal of, 353 
 Stomach, 231 
 Styloid, 16 
 Substance, gray, 283 
 
INDEX. 
 
 401 
 
 Substance of Schwann, 283 
 
 medullary, 257 
 
 ■white, 283 
 Substantia gelatinosa Rolandi, 302 
 
 nigra, 304 
 Sulci, 290, 291 
 Sulcus spiralis, 369 
 
 tympanicus, 361 
 Suprarenal capsules, 244 
 Surface, articular. 111 
 
 trochlear, 52 
 Sustentaculum tali, 68 
 Sutura, 31 
 Suture, basilar, 31 
 
 coronal, 31 
 
 intermaxillary, 32 
 
 laohrymo-ethmo-trontal, 32 
 
 lambdoidal, 31 
 
 masto-occlpital, 31 
 
 masto-parietal, 31 
 
 petro-occipital, 31 
 
 petro-sphenoidal, 31 
 
 sagittal, 31 
 
 spheno-parietal, 31 
 
 squamo-parietal, 31 
 
 squamo-sphenoidal, 31 
 
 zygomatic, 32 
 Sutures, facial, 32 
 
 of the orbit, 34 
 
 of the skull, 31 
 Sylvius, fissure of, 291 
 Sympathetic system, 335 
 Symphysis pubis, 118 
 
 of inferior maxillary, 29 
 Synarthrosis, 112 
 Synovial membranes. 111 
 
 Tarsus, 68 
 
 Taste, nerves of, 371 
 Taste goblets, 371 
 Tsenit hippocampi, 298 
 
 semicircularis, 298 
 Teeth, 219 
 Tendo-oculi, 345 
 Tendons, 132 
 Tenon, capsule of, 345 
 Tentorium cerebelli, 285 
 Testes, 263 
 
 of the cerebrum, 301 
 
 descent of, 266 
 Thebesius, foramina of, 171 
 Thigh, 59 
 Thorax, 115 
 Thyroid axis, 187 
 
 cartilage, 246 
 
 gland, 243 
 Tongue, 371 
 Tonsils, 223 
 Trachea, 251 
 Tract, lateral, 388 
 
 optic, 294 312 
 Tracts, olfactory, 294, 309 
 Tractus spiralis foraminulentus, 370 
 Tragus, 359 
 
 Triangle, Hesselbach's, 381 
 Trigonum urogenitale, 387 
 
 vesicae, 263 
 Trochanters of femur, 63, 64 
 Trochlea, 52 
 Tube, Eustachian, 362 
 Tuber annulare (pons VarioUi), 287, 303 
 
 cinereum, 294 
 Tubercle, 4 
 
 Tubercle, genial, 29 
 
 lachrymal, 25 
 
 of Lower, 171 
 
 of tibia, 66 
 Tuberosities, 4 
 
 of femur, 64 
 
 of humerus, 52 
 
 of ischium, 61 
 
 maxillary, 25 
 Tubes of Henle (convoluted tubes), 259 
 
 spiral, of Schachowa, 259 
 Tubuli lactiteri, 281 
 
 seminiferi, 266 
 
 uriniferi, 259 
 Tuft, Malpighian, 259 
 Tunica adventitia, 173 
 
 albuginea, 264 
 
 intima, 173 
 
 media, 174 
 
 Ruyschiana, 336 
 
 vaginalis, 264 
 
 vasculosa, 266 
 Tunics of eyeball, 334, 345 
 Tutamina oculi, 356 
 Tympanum, 350, 361 
 Tyson, glands of, 270, 281 
 
 Ulna, 53 
 
 Umbilical region, 227 
 Umbilicus, 227 
 Umbo, 363 
 Urachus, 262 
 Ureters, 259 
 Urethra, 271, 280 
 
 bulb of, 271 
 Uterus, 273 
 
 masculinus, 271 
 Utricle, 356, 271 
 Uvea, 348 
 Uvula, 223 
 
 vesicEB, 263 
 
 Vagina, 278 
 
 Valley of cerebellum, 289 
 Valsalva, sinuses of, 172 
 Valve, Eustachian, 171 
 
 Hasner, 359 
 
 ileo-caecal, 235 
 
 mitral, 172 
 
 of Baulin, 235 
 
 of Vieussens, 301 
 
 pyloric, 232 
 
 semilunar, 172 
 
 tricuspid, 172 
 Valves of Kirkring (valvulas conni- 
 ventes, 234 
 
 semilunar, 172 
 Valvulae conhiventes, 234 
 Vas aberrans, 266 
 
 deferens, 266 
 Vasa eflerentia, 266 
 
 recta, 266 
 
 vasorum, 174 
 Vein, axillary, 210 
 
 basilic, 210 
 
 cephalic, 210 
 
 cerebral, 208 
 
 cerebellar, 208 
 
 femoral, 213 
 
 iliac, 212, 213 
 
 median, 210 
 
 popliteal, 213 
 
 portal, 211 
 
402 
 
 INDEX. 
 
 Vein, radial, 210 
 
 splenic, 211 
 
 subclavian, 210 
 
 suprarenal, 211 
 
 ulnar, 210 
 
 vertebral, 211 
 Veins, 174 
 ' azygos, 211 
 
 cardiac, 206 
 
 choroid, 208 
 
 hepatic, 211 
 
 iliac, 212, 213 
 
 innominate, 206 
 
 interlobular, 241 
 
 jugular, external, 208 
 internal, 207 
 
 of bone, 5 
 
 ol Galen, 299 
 
 of head and neck, 209 
 
 of lower extremities, 213 
 
 of oesophagus, 211 
 
 of suprarenal capsules, 211, 244 
 
 of thymus, 243 
 
 of trachea and bronchi, 252 
 
 of the eye, 356 
 
 of the kiddey, 259 
 
 of the larynx, 250 
 
 of the lung, 255 
 
 of the pancreas, 238 
 
 of the penis, 271 
 
 of the stomach, 232 
 
 of the thorax, 211 
 
 pulmonary, 214 
 
 saphenous, 213, 214 
 
 spinal, 211 
 
 thyroid, 209 ' 
 
 uterine, 274 
 
 without valves, 174, 214 
 Velum, anterior medullary, 301 
 
 interpositum, 299 
 Vena cava, superior, 206 
 
 inferior, 211 
 VenEB comites, 174, 232 
 
 proprise renales, 259 
 
 rectse, 259 
 
 vorticosse, 337 
 Venter of the ilium, 61 
 
 Venter of the scapula, 48 
 Ventricle of the cord, 300, 318 
 
 fifth, 301 
 
 fourth, 300 
 
 of the larynx, 249 
 
 third, 299 
 Ventricles, lateral, 296 
 Vertebra promiuens, 44 
 Vertebrae, 43 
 Verumontanum. 271 
 Vesalii, foramen, 19 
 Vesical, germinal, 277 
 
 Graafian, 275 
 V'esiculse seminales, 269 
 Vestibule, 280 
 
 of the ear, 366 
 Vidian canal, 20 
 
 nerve, 336 
 Vieussens, valve of, 301 
 Villi, 234 
 
 Viscera, covered by peritoneum, 230 
 partially, 230 
 
 wholly, 230 
 Vitellus, 277 
 Vocal cords, 248 
 Vomer, 28 
 
 Vortex of heart, 173 
 Vulva, 279 
 
 Walls of the tympanum, 362 
 Wharton's ducts, 224 
 Whorl of heart, 173 
 Willis, circle of, 185 
 Wings of the sphenoid, 19, 20 
 Winslow, foramen of, 228 
 
 ligament of, 126 
 Wirsung, duct of, 238 
 Wistar, pyramids of, 19 
 Wormian bones, 32 
 Wrisberg, cartilages of, 247 
 
 nerve of, 322 
 
 Zina, zonula of, 353 
 Zona pellucida, 277 
 Zonula of Zinn, 333 
 Zygoma, 13, 23