Class ^F4 6 Book V F&7 Gofpglil X" COPYRIGHT DEPOS1 VERTICAL ANTEROPOSTERIOR SECTION OF UPPER RESPIRATORY TRACT. DISEASES OF THE Nose, Throat and Ear. FOR STUDENTS AND PRACTITIONERS IN WHICH PARTICULAR ATTENTION IS GIVEN THE TREATMENT OF DISEASES BY ECLECTIC MEDICATION BY KENT O. FOLTZ, M. D. Professor of Ophthalmology, Otology, Rhinology and Laryngology in the Eclectic Medical Institute, Cincinnati ; Assistant Editor the Eclectic Medical Journal ; Author of a Manual on Diseases of the Eye. ILLUSTRATED. (I NCINNATI: THE SCUDDER BROTHERS COMPANY 1906. LIBRARY of CONGRESS Two C«oies Received | JUL 16 190 6 ^Copyright Entry t^CL> XXfc- N0.I iLf-C 7 /7 COPY B. Copyrighted, 1906, by The Scudder Brothers Company. TO THE MEMORY OF MY FATHER, minm %. Jffelfe, JR. ^ INTRODUCTION. I HAVE no apology to offer for this book. For some unaccountable reason there has been a tendency among writers on these subjects to ignore practically everything but local measures in treating the conditions which are so prevalent in the upper respiratory tract and the structures more or less directly dependent upon this region for their proper functional action. Why-, with a few notable ex- ceptions, internal medication has been ignored, is impos- sible to say. In the majority of inflammatory conditions of the upper respiratory tract and the ears, if proper systemic measures are instituted during the second stage, a cure will result. Later, relief is in many cases all that can be expected, but this can not be obtained by the use of sprays, gargles, douches, etc., excepting a very transi- tory amelioration of the condition. Proper constitutional measures will give more or less permanent relief in prac- tically all but malignant cases. My experience has been that the selection and admin- istration of drugs from the Eclectic standpoint of specific medication will give more satisfactory results than the generally-accepted method of local treatment only. How- ever, to follow the precepts of specific medication, specific diagnosis is of the utmost importance, and it has been my aim to emphasize these features in this volume. The in- dications for the use of drugs have been as explicit as seemed necessary. 8 Introduction. It must not be inferred that no other drugs are re- quired in treating these diseases, but the ones mentioned are the basis of treatment, and it is presumed the prac- titioner will use such other remedies as may be indicated, common sense being a requisite in handling specialties as well as in general practice. A knowledge of embryology will be an aid to a more comprehensive study of morbid changes in these structures, and I can not too strongly in- sist upon this important branch of biology being given more attention. The liquid drugs employed are the product of the laboratory of Lloyd Brothers, viz., specific medicines, un- less otherwise stated. The preference is given these on account of the uniformity of strength and because I have been able to get results from these preparations that I could not always obtain from other tinctures. I wish to thank W. B. Saunders & Company for per- mission to reproduce several plates ; also Max Wocher & Sons Company for the use of cuts of instruments. I also wish especially to thank Miss Margaret Stewart for assist- ance in proofreading, and Miss Tillie K. Hannah for work on the manuscript. I have endeavored to give credit to the different authors throughout the body of the work, but some of the investigations referred to were in journal articles where the name had inadvertently been lost or overlooked. As for the style of the book, the author has endeav- ored to state the subject clearly and concisely, often at the expense of smoothness, but with a desire to impress the important points in making the diagnosis and prescribing the proper remedies. The Upper Respiratory Tract. CHAPTER I. THE NOSE. ANATOMY. THE nose is divided into the external and internal por- tions. The nasal organ possesses several functions. The external portion being necessary only for the adorn- ment of the face, while the internal is for the distribution of the olfactory nerve, and also constitutes the upper portion of the respiratory tract. The peculiar anatomical structure not only prepares the inspired air for entrance into the lungs, but supplies the necessary moisture, regulates the tempera- ture, and also removes the coarser foreign material usually floating in the atmosphere. From the arrangement of not only the olfactory, but also the other nerves in the nasal cavity, a warning of the presence of injurious substances is often given. What is also of especial importance, is the power to determine the properties and character of food and drink, as the nasal region is actually the seat of what is usually called the sense of taste. The embryologicai development of the nose in detail is not perfectly understood, but the structures derived from the ectoderm are, the integument ; vibrissas ; sebaceous and sweat glands ; the nasal mucous membrane, including the glands and mucous membranes of the accessory nasal cavi- ties. The nervous tissues are also derived from this layer, as well as the sensory epithelia of the special sense organs. io Nose, Throat and Ear.' The mesoderm supplies the muscular and adipose tissue, cartilages and bony structures. Besides the division into the external and internal- por- tions, another division of this tract is made, posterior or postnasal space, sometimes called the vault of the pharynx. In front of this portion is the anterior region, which is di- vided into two fossae by the septum. These fossa? extend from the postnasal space forward to the nostrils. Each fossa is bounded internally by the septum, which is formed by the perpendicular plate of the ethmoid and spine of the DIVISION OF NOSTRILS. 'Septum Narium.) Sjtina nasal.su oss. front. Os nasalt Cart. Can. naso-patat.- FlG. 2. frontal bone above, posteriorly by the vomer, and anteriorly by cartilage. The septum is generally perpendicular until about the seventh year; after this age deviation often occurs and generally to the left. The anterior and posterior portions of the roof slope downward, the central portion being nearly horizontal. The roof consists of the nasal process of the frontal and nasal bone in front, the central The Nose. n portion by the cribriform plate of the ethmoid and the posterior part by the inferior surface of the sphenoid and the sphenoidal turbinates. The anterior three-fourths of the floor consists of the palate process of the superior maxillary; the posterior por- tion of the horizontal plate of the palate bone. The outer anterior wall is formed by the nasal process of the superior maxillary and lacrimal bones, the middle portion by the ethmoid and inner surface of the superior Fig. 3. maxillary and inferior turbinates, and posteriorly by the vertical plate of the palate and internal pterygoid plate of the sphenoid bone. Extending from the bony walls to the nostrils, the fossae are called the vestibules, the outer wall of each vestibule is formed by an upper and lower lateral cartilage, and two or three smaller plates of cartilage, the inner wall being formed by the triangular cartilage of the septum. Each fossa contains three, and sometimes four, thin, somewhat triangular bony structures, which extend from the outer wall toward the median line, but do not come 12 Nose, Throat and Kar. in contact with the septum. These bony processes are the turbinated bodies, and are more or less curved, the convex surface being upward, inward, and somewhat forward. The line of attachment of each is approximately horizontal and are nearly equidistant from each other. Cell, Sulc. ethmoidal Olfact. post. Sinus front. K i & yyfl^ 1 Optic nerve. Cell, ethmoidal, posterior. Middle meatus. Cell, middle tur- binate. Maxillary sinus. I Inferior turbi- nate. Septum Molar, narium. Fig. 4. This section is made vertically through the nasal cavi- ties and maxillary antra on a plane with the first molars. The arrow on the right side indicates an accessory maxillary opening. On the left side are seen the posterior ethmoidal cells opening into the ol- factory cleft, and a middle turbinate cell into the middle meatus. The frontal sinuses are shown extending backwards along the or- bital roof. The superior turbinate, which is the smallest, is often divided horizontally, thus forming the fourth turbinate, or The Nose. 13 ''concha Santoriniana." The superior turbinate originates from the lateral mass of the ethmoid, and projects down- ward nearly perpendicularly. The anterior margin is coa- lescent with the middle turbinate, the posterior being free. The middle turbinate is from the lateral mass of the ethmoid, is of larger size, more rolled at the center and projects horizontally. The anterior free margin presents the "agger nasi," a slight elevation projecting downward, and is opposite a corresponding septal elevation. These are important, marking the boundary between the olfactory re- gion above and the respiratory tract below. The inferior turbinate, as the name indicates, is the low- est; and also the largest. Its structure is more compact, and it is a separate bone. It articulates with the ethmoid, supe- rior maxillary, palate, and lacrimal bones. The space comprised between each pair of turbinates, and between the inferior turbinate and floor of the nose, is called a meatus, and according to location are designated as superior, middle, and inferior. If through division of the superior turbinate a fourth meatus is formed, it is disre- garded, as it is of no particular importance. Communicating with the meatuses are the accessory si- nuses, and as a result of this communication any of these sinuses may become affected in morbid conditions of the nasal fossae through the continuity of tissue. These si- nuses form four, groups : the sphenoidal, ethmoidal, frontal, and maxillary, or antra of Highmore. The sphenoidal sinuses, or cells, are two irregular cavi- ties in the body of the sphenoid, separated from each other by a thin bony septum. They vary in size and are not de- veloped in infancy, but at about the age of three years begin forming, and increase in size with advancing age. In front and below they are partially closed by two thin plates of bone, the sphenoidal turbinated bones, round openings be- ing left at their upper parts, which are located in the upper 14 Nose, Throat and Ear. and posterior portion of each superior meatus. The roof of the sinuses, which separates them from the brain, is about I- 12 of an inch thick at the thinnest part. Fig. 5. Vertical section of skull, showing the right accessory si- nuses, about two-thirds natural size. (1) Left frontal sinus, separated from right frontal sinus (2) by bony septum ; (3) Crista galli ; (4) Cribriform plate; (5) Sella turcica; (6) Optic foramen; (7) Sphe- noidal sinus ; (8, 9) Posterior ethmoidal cells ; (10) Portion superior turbinate; (n) Portion middle turbinate; (12) Superior meatus; (13, 14) Anterior ethmoidal cells ; (15) Bulla ethmoidalis; (16) Pro- cessus unciformis ; (17) Ostium maxillare; (18) Spheno-palatine foramen; (19) Portion inferior turbinate; (20) Location of nasal orifice of nasal duct in inferior meatus ; (22) Fronto-nasal duct ; (23) Inferior meatus ; (24) Sphenoid bone. The dotted line extends from the nasal orifice to the posterior wall of the sphenoidal sinus. The Nose. 15 The ethmoidal sinuses, or cells, are located in the lateral mass of the ethmoid, and consist of a number of thin walled cellular cavities, which are enclosed between two vertical plates of bone, the external of which forms part of the orbit, and the internal part of the nasal fossa of the correspond- ing side. These cells are divided anatomically into the an- terior, middle, and posterior. The anterior cells, which are the most numerous, open into the infundibulum, or canal, from the frontal sinus, by means of small openings, ostia ethmoidalia, reaching the middle meatus at the hiatus semi- lunaris in its extreme anterior part. The posterior cells open into the superior meatus and sometimes connect with the sphenoidal sinus. In some instances the anterior cells may open into the frontal sinuses or even into the orbit. The frontal sinuses are two irregular cavities, and are larger than the sphenoidal ; they are situated in the frontal bone over the anterior portion of the nasal cavity, and ex- tend laterally over the orbits, forming the prominences over the supraorbital arches, the superciliary ridges, and also form the prominences over the root of the nose. These sinuses, like the sphenoidal, are usually absent in children, but develop with advancing years. They are larger in men than in women, and the right is usually the largest. The sinuses are separated by a bony lamina, which is often de- flected, usually to the opposite side from the septal devia- tion. The maxillary sinuses, or antra of Highmore, are sit- uated one in each superior maxillary bone, and are some- what pyramidal in form. The apex of each is directed out- wards and is formed by the malar process ; the base by the outer wall of the nose ; the roof by the orbital floor, and the floor by the alveolar process. The external wall is the faeial surface, and the posterior wall the zygomatic surface of the maxillary. Each maxillary sinus connects by a circular opening with the middle meatus near the posterior part of i6 Nosk, Throat and Ear. the hiatus semilunaris. The opening is called the ostium maxillare. A secondary opening, situated behind this, is sometimes present and is called the ostium maxillare acces- Antrum of Highmore Fig. 6. The external bony wall is removed to show the relation of the roots of the teeth to the antral floor. sorius. Racial as well as individual differences are found to influence the size of these cavities. Thin laminae of bone frequently cross these sinuses. The nerves of the teeth and The Nose. 17 posterior dental vessels are contained in canals situated in the posterior wall, while the floor is frequently irregular through encroachment of the first and second molars. The anterior portion of the inferior meatus contains the opening of the nasal duct, which is more or less closed by the valve of Hasner. This duct represents the lower por- tion of the lacrimal drainage apparatus, being a downward continuation of the lacrimal sac. The mucous membrane of the accessory cavities varies somewhat from that of the nasal fossae. The epithelial lin- ing is composed of a single layer of pavement epithelium. The basement membrane and submucosa are thinner than in the exposed regions, while the glands are more numerous at the openings into the nasal fossae. As all portions of the body, which communicate with the atmosphere are lined with mucous membrane, differentiated according to the character of the work required, it becomes necessary to study each region separately. The variation in the character of the epithelium is a bar to the ready extension of inflammatory action, although through continuity of tissue, one would suppose that no hindrance would be interposed. The walls of the nasal fossae are lined with mucous membrane continuous in front at the nostrils with the skin, posteriorly with the pharyngeal mucous membrane. The nasal mucous membrane is variously designated as the pituitary, nasal mucosa, or Schneiderian membrane, and varies in its characteristics according to location, and also changes the lumen of the nasal fossae, the accessory cavities and their openings as compared with the denuded skull. The membrane is thick- est on the convex surface of the turbinates, and quite thin on the floor of the nose and accessory sinuses. The membrane varies in color according to location. It is a yellowish pink in the olfactory, or upper portion, which includes the roof and superior turbinates, superior meatus, 2 18 Nose, Throat and Ear. upper third of the convex surface of the middle turbinates, and the corresponding part of the septum. The lower, or respiratory portion, presents a light pink color, the posterior ends of the turbinates being whitish. The color of the mem- brane in the accessory cavities is a pale pink. These tints \ary in different individuals, as well as in various systemic conditions, and the character of the light used in the exam- ination will also cause a difference in the appearance. The respiratory, exposed, or epithelial portion, ectoder- mic in origin, consists of the stratified ciliated columnar type, goblet cells being distributed throughout the super- ficial layer. The second layer, mucosa or tunica propria, consists of fibrous connective tissue. Lymphoid tissue nodules are found in this portion. The surface of the tunica propria 'is smooth through lack of sub-epithelial papillae. Small racemose glands opening on the free sur- faces of the membrane are numerous and may be detected by macroscopic inspection. These are mucous glands, some secreting serous fluid and some mucous secretion. The glandular elements are most freely distributed over the in- ferior turbinates, but the external walls and lower portion of the septum are also freely supplied. The third, or inner layer, as usually designated, con- sists of the veins of the mucosa, which are so numerous and wide that this region is often spoken of as cavernous, or erectile tissue, and when the veins become engorged with blood, the fossae may be nearly or entirely occluded. The olfactory surfaces differ from the respiratory, not only in color as already mentioned, but in the character of the epithelial cells, which are sustentacular or support cells, and olfactory elements, and also the tunica propria. The sustentacular cells consist of an outer cylindrical division. Near the inner end of each cell there is an oval nucleus. In the same location yellowish pigment, and numerous gran- ules are arranged, forming more or less distinct rows. The The Xose. 19. round nuclei of the olfactory cells forms a broad zone ad- joining the band of oval nuclei. The olfactory cells are inconspicuous, elongated, at- tenuated bodies, surrounded by the supporting elements. The nuclei of the olfactory cells are at different levels. The deepest part consists of small nucleated cells forming the inner boundary of the epithelial layer, and rests upon the tunica propria. The tunica propria in this region consists of fibrous connective tissue, in bundles, as well as delicate elastic fibers. The mucosa contains numerous branched tubular or Bowman's glands. The veins of the nasal mucous membrane are numerous and of large size, especially over the posterior part of the inferior turbinates. The arterial system is in the deeper layers of the tunica propria, sending branches to the super- ficial layers, where the sub-epithelial capillary net- work is formed. The lymphatic circulation is maintained by a net work of numerous vessels around the lymphoid nodules and in the deeper portion of the tunica propria. In the olfactory re- gion perineurial lymph channels form a net work in the mucosa. The nerve supply of the nasal mucous membrane con- sists of the nerves of common sensation and the special, or olfactory sense. The larger filaments of the olfactory nerve lie in grooves in the bony walls, and give off smaller bundles which pass toward the epithelial surface. Perineurial sheaths, prolongations from the intercranial investment of the olfactory nerve, are often found in the mucosa surround- ing the nerve twigs. When the epithelium is reached, the nerve fibers divide into their component fibrillar and pass as naked, often varicosed axis-cylinders between the ele- ments of the neuro-epithelium. The fibrillar probably are in close contact or continuous with the inner ends of the olfactory cells. The trifacial nerve also supplies some 20 Nose, Throat and Ear. medullated fibers to the olfactory region, but these probably do not come into direct relation with the olfactory cells. The membrane lining the vestibule is cutaneous in charac- ter, the epithelium being squamous. Blood Supply. — Each fossa receives its blood from the spheno-palatine branch of the internal maxillary, and a small vessel from the small meningeal branch of the internal maxillary, and the anterior and posterior ethmoidal branches of the ophthalmic. The artery of the septum from the supe- rior coronary and the alveolar branch of the internal maxil- lary which supplies the membrane lining the maxillary an- trum. The spheno-palatine enters the fossa just back of the superior meatus, through a foramen of the same name, and divides into an internal and external branch, the first, the naso-palatine, or superior artery of the septum, passes downwards and forwards along the septum, supplying the membrane. The external sub-divides into several branches and supplies the lateral mucous membrane, the antrum, sphenoidal, and ethmoidal sinuses. The anterior and poste- rior ethmoidal arteries enter the corresponding ethmoidal cells, and are distributed throughout the cavities, they then enter the cranium, dividing into smaller nasal branches, and pass through the cribriform plate of the ethmoid and down the walls of the fossa a short distance. The frontal sinuses are also supplied by the anterior branches. The anterior portion of the septum receives its supply from the septal artery, a branch of the superior coronary of the facial which enters the nose at the junction of the nostril and lip. The free anastomosis and profuse arterial supply renders most operative procedures in this region very annoying, on ac- count of the excessive hemorrhage. Nerves. — The olfactory nerves proceed from the under surface of the olfactory bulb, and passing through the foramina in the cribriform plate, divide into three more or less distinct sets, the inner distributed to the upper third of The Nasopharynx. 21 the septum ; the outer supplying the superior turbinate, the olfactory portion of the middle turbinate, and the ethmoidal surface anterior to them ; the middle division supplying the roof between the distribution of the other two. The spheno- palatine ganglion of the sympathetic supplies branches which are distributed to the upper, middle, and posterior parts of the septum, the lower edges of the superior and the sur- faces of the middle inferior turbinates. General sensation results from the distribution to the upper and anterior part of the septum, the nasal floor, outer walls and anterior surfaces of the inferior turbinates of the nasal branches of the fifth pair. The inferior turbinate and inferior meatus by filaments from the anterior dental branch cf the superior maxillary ; the upper and back part of the septum and superior turbinate by the Vidian nerve. The Naso-Pharynx, or Post-Nasal Space. This comprises the portion of the upper respiratory tract between the plane of the superior nares and the plane extend- ing horizontally backward at the level of the free margin of the soft palate. In front it is continuous with the nasal fossae, below with the oropharynx, and on the sides with the tym- panic cavities through the Eustachian tubes. The roof slopes from the upper borders of the nasal fossae in front to the posterior and lateral walls, forming a dome-shaped cav- ity, the dome or vault of the pharynx. The bony borders are, above the vault of the pharynx, the body of the sphenoid and basilar process of the occipital bone with the so-called basilar fibro^cartilage. Behind is located the first cervical vertebra, and laterally the internal pterygoid plates of the sphenoid and petrous portions of the temporal. Anteriorly by the posterior bony margins of the nasal cavities. The tissues of this region are divided into mucous, fibrous, and muscular. The epithelium of this region is stratified ciliated columnar, with goblet cells interspersed, 12 Nose, Throat and Ear. but the portion below the level of the soft palate is stratified squamous cells, similar to those found in the oral cavity. The tunica propria consists of fibrous bundles with a varia- ble amount of elastic tissue, sometimes called the pharyn- geal aponeurosis. Numerous small papillae are contained in the sub-epithelial surface of the mucosa, which is covered by the squamous cells, but they are absent beneath the ciliated epithelium. Small mucous pharyngeal glands are found in many places, being especially numerous in the deeper layers of the mucosa surrounding the mouths of the Eustachian tubes. In the upper part of the cavity, arranged as lymph follicles, is a quantity of adenoid tissue, which is especially prominent in the posterior pharyngeal wall be- tween the orifices of the Eustachian tubes. This is called the pharyngeal, or Euschka's tonsil, on account of the similarity of structure to the faucial 'tonsils. This structure extends in both directions from the median line to a marked de- pression, Rosenmuller's fossa, or recessus pharyngeus, which separates it from the orifice of the Eustachian tube. The fossa is important in locating the mouth of the tube. The surface of the mass is more or less irregular on account of the depressions formed by the lacunae or crypts and the minute elevations representing the glandular openings. A slit-like orifice in the lower part leading to a small sac be- neath, which Euschka calls the pharyngeal bursa, is found in the majority of cases. The mucous membrane is con- nected with the fibrous coat by sub-mucous tissue. The pos- terior part of the fibrous coat is thickened, forming a raphe, which serves as an attachment for the constrictor muscles. The muscular coat, consisting of striped fibers, com- prises the constrictor and other muscles of this region. Ex- ternal to this, areolar tissue of varying thickness forms the attachment for the surrounding structures. The color of the mucous surface in the vault is a deeper pink than that of the nasal fossae. Around- the Eustachian eminences it Fauces axd Oropharynx. 23 is a lighter color, shading to a yellowish tint surrounding the orifices. Blood Vessels. — The arteries supplying this region are derived from the external carotid. Branches of the ascend- ing pharyngeal being distributed to the greater part. The anterior portion is supplied by the terminal branches of the descending palatine, and spheno-palatine from the internal maxillary. The soft palate and the palatine glands are sup- plied by the ascending palatine branch of the facial. The venous return is through sub-divisions of the internal jugu- lar vein. Nerve Supply. — Branches of the second division of the fifth nerve supply the greater portion. Branches from the glossopharyngeal, spinal accessory, and the superior cerv- ical ganglion of the sympathetic through the pharyngeal plexus. The lymphatics are very numerous in the vicinity of the lymph follicles, forming net works which are continuous with those of the nasal fossae, esophagus and larynx. Fauces and Oropharynx. The roof of the oral cavity is formed by the hard palate anteriorly and the soft palate posteriorly. The hard palate is confined in front and on the sides by the alveolar processes, behind being continuous with the soft palate. The mucous membrane of the hard palate is thin and closely adherent to the periosteum, form- ing a firm resisting membrane. Corresponding to the suture of the palatal bones is a ridge, which terminates anteriorly in a small papilla corresponding to the orifice of the anterior palatine fossa. On each side of the median line, the mucous membrane presents a corrugated or rugose appearance, and is covered by squamous epithelium. Glands in this region are limited in number. The soft palate, or velum, is a pen- dulous body and consists of muscular tissue enclosed in H Nose, Throat and £ar. mucous membrane, it is attached to the posterior portion of the. hard palate and partially separates the mouth from the pharynx. The sides merge with the faucial pillars, but the PHARYNGEAL MUSCLES oss. hyo Cart. Writ Cart vantorin Posterior view. (Pharynx opened) Fig. 7. lower border is free. As a rule, the raphe of the soft palate is not as marked as that of the hard palate. The muscles consist of five pairs : the levator palati, ten- sores palati vel dilator tubse; the palato-glossi, which not Tonsils. 25 only form the anterior pillars of the fauces, but also act as constrictors of the fauces ; the palato-pharyngei, which form the posterior pillars and the azygos uvulae, consisting of a pair of cylinder-like bundles placed side by side and parallel to the median line of the velum. This pair of muscles with the connective and glandular tissue forms the elongated portion called the uvula. The functions of the palatal mus- cles are aids in deglutition and vocalization, while the ten- sor and levator influence the opening of the Eustachian tube allowing free ventilation of the tympanic cavities, and for this reason play an important part in normal hearing. The action of the uvula has been a matter of much specu- lation, it undoubtedly acts as a drag or anchor in the act of swallowing, preventing the velum from passing upward into the post-nasal space which would allow food and fluids to enter the nasal fossae. It also, probably, in connection with the rest of the palatine tissues and epiglottis, partially occludes the oral cavity from the respiratory region in nor- mal breathing. Another function may be that of directing the nasal secretions to the glosso-epiglottic fossae. (Dobell). When much relaxed or absent, either through ulceration or a faulty operation, phonation is not distinct, and swallowing is liable to be followed by the passage of food into the nasal space. Paresis of the palatal muscles is generally present when the uvula is much elongated or absent. Tonsils. The tonsils represent compound lymphatic glands. The size and shape varies, although they approximate an obovate form, and consist of from ten to eighteen lymph follicles contained within a diffuse adenoid tissue. A fibrous capsule not only envelops the mass, but serves to sepa- rate it from the surrounding tissues. The oral epithelium is continuous on the mucous surface. Lymphoid cells are dis- tributed throughout the epithelium covering the folds and 26 Nosh, Throat and Ear. depressions of the gland. Mucous glands are numerous in "the vicinity of the tonsils, which are situated in the faucial ring and occupy a portion of the triangular space formed by the anterior and posterior pillars of the fauces. The free surface projects into the faucial isthmus. The supra- tonsillar fossa is a variable depression lying behind the an- terior pillar. The tonsil is usually separated from the pharyngeal por- tion of the tongue by a deep sulcus which may be obliterated, giving then a continuous appearance to the lingual and faucial tonsils. Externally the location of the faucial ton- sil is determined by having the head in the normal position, then a spot corresponding to the interval between the angle of the inferior maxillary and the sterno-cleido-mastoid mus- cle, and the tip of the great cornu of the hyoid bone will be over the gland. Inward pressure on the neck at this point with the finger will press the tonsil towards the median line, thus facilitating tonsillotomy. External to the tonsil is a strong fibrous membrane, a portion of the amygdalo-epiglot- tic fold, which here lines the fossa of the tonsil. Next to this membrane lies the superior constrictor muscle. These two structures are all that separate the tonsil from the sheath of the internal carotid artery. As a result of this thin barrier, motion is often imparted to hypertrophied or inflamed tonsils by the pulsation of the artery. Arteries. — The arterial circulation is derived from the facial by the ascending palatine and its tonsillar branches ; the lingual ; and the ascending pharyngeal. In some cases also there are twigs from the descending palatine, a branch of the internal maxillary. The proximity of the carotid, ascending pharyngeal, and ascending palatine, should be remembered in operative measures. The lingual artery also passes forward close to the lower end of the tonsil, and. com- pression may easily be made at this point. The veins correspond to the arteries, but form a net The Pharynx. 27 work on the external or carotid side before accompanying their respective arteries. Large branches from this net work also pass to the pterygoid and post-pharyngeal -veins. Lymphatics are numerous and are divided into super- ficial and deep, they perforate the pharyngeal wall and con- nect with the upper carotid cervical glands. The nerves are derived from the glosso-pharyngeal, the fifth, and the sympathetic. A plexus formed by these nerves surrounds the tonsil and also give off branches. The Pharynx As usually designated, is the portion seen at the back of the mouth, but really includes the vault of the pharynx, and extends downward until opposite the fifth cervical vertebra and on a level with the cricoid cartilage, where it is continued as the esophagus. The pharynx may be considered as a musculo-membranous structure, four or five inches in length, and capable of more or less con- traction or expansion. The boundaries are, behind by the cervical vertebrae and coverings ; laterally the internal and external carotid arteries, internal jugular veins; vagus, glosso-pharyngeal, pneumogastric, and hypoglossal nerves. Anteriorly the boundary is interrupted by the structures which have already been described and also the larynx (the laryngo-pharynx), this portion being separated by the epiglottis. Marked morbid changes in any part of the pharynx may change the quality of the voice, as well as interfere with normal deglutition, and may affect the hearing either through faulty action of the Eustachian tubes or by exten- sion of the morbid state through the tubes to the tympanic cavities. The pharyngeal aponeurosis investing the pharyngeal structures consists of strong fibrous tissue. This aponeuro- sis is covered with mucous membrane which is continuous 28 Nose, Throat and Ear. with the nasai fossae, Eustachian tubes, mouth, larynx, and esophagus. In the upper portion the epithelium consists of the columnar ciliated form to the level of the nasal floor, below this it is squamous. Acinous glands are numerous throughout the membrane, while the lymphoid glands are grouped, especially in the upper part (pharyngeal tonsils), and surrounding the orifices of the Eustachian tubes. In ifojutffi Fig. 8. the latter location they are sometimes called Eustachian tonsils. Rosenmuller's fossa is opposite the tip of the petrous bone, one on each side of the pharyngeal wall, extending as a cul-de-sac. Each fossa is in relation behind with the recti muscles, in front with the Eustachian tubes, above with the sphenoid and petrous bones, and externally with the middle meningeal artery and otic ganglion. A thick, soft mucous membrane lines these fossae, which are supplied with glands and considerable lymphoid tissue. This tissue, as Larynx. 29 already mentioned, constitutes the Eustachian tonsil. The character and function of this tissue is similar to that of the other tonsils. One of the principal functions of the pharynx in the existence of the individual, is its action in the deglutition of food after mastication. The pharynx is raised by the stylo- pharyngei to meet the descending bolus, which is then grasped and carried downward by the action of the three constrictor muscles of the pharynx, the inferior, middle, and superior constrictors. The inferior, or laryngo-pharyn- geus is the thickest of the three, and arises from the sides of the cricoid and thyroid cartilages, and then spreads back- wards and inwards, being inserted into the fibrous raphe on the posterior pharyngeal wall. The fibers of the inferior portion are horizontal in direction and are continuous with the fibers of the esophagus. The middle, or oropharyngeus, is smaller and fan shaped, and the origin is from the hyoid bone and stylo-hyoid ligament. The fibers diverge from their origin and are also inserted into the fibrous raphe. The superior, or naso-pharyngeus, constitutes the upper, or supe- rior, and is quadrilateral, thinner, and paler in color. Its origin is from the sphenoid and palate bones, and ligament- ous and tendinous tissue in this location. The insertion is also into the fibrous raphe, and also by a fibrous aponeurosis to the pharyngeal spine on the basilar process of the occip- ital bone. Larynx. This structure is located at the upper and fore part of the neck, being more or less prominent in the median line, and is easily palpated as it is comparatively close to the cutaneous surface. It is suspended from the hyoid bone, and is behind and below the base of the tongue. The mucous membrane is continuous with that of the pharynx and mouth, and passing downward, forms the tracheal and bronchial mucous membrane. 3o Nose, Throat and Ear. Surface Landmarks. — The hyoid bone, the central prom- inence of the thyroid, pomum Adami, and the cricoid can always be discerned. At the level of the lower jaw and just below the mid-line, the body of the hyoid bone can be felt, and traced backward, ending in the greater cornua. Lower down in the median line there is a distinct de- JLesser Bom Iht beneath 2?yo- thyroid Membrane JjcUeral Thyro- hyoid CRICO THYROID {superficial port?) Crcco -thyroid Membrane Fig. 9. pression, corresponding to the central thyro-hyoid ligaments. This point usually designates the apex of the epiglottis. Below this is the prominence of the thyroid cartilage, varying in size and more marked in males, youth, and thin people. A large bursa is located in the subcutaneous cellu- lar tissue immediately in front of the anterior thyro-hyoid ligament and pomum Adami, which permits freedom of mo- tion of the larynx. Below the pomum the median ridge of Larynx. 3 1 the thyroid cartilage can be distinctly determined. Still lower in the median line the depression corresponding to the crico- thyroid membrane and prominence of the cricoid cartilage can be felt. This is one of the most valuable landmarks. The upper border of the crico-thyroid membrane is on the level of the rima glottidis, the most narrow portion of the respiratory tract. The cricoid cartilage corresponds with the fifth cervical vertebra, when the head is in a normal position. It also marks the point of crossing the common carotid by the omo-hyoid, the lowest border of the larynx, and narrowest portion of the esophagus. The inferior laryngeal vessels and nerves have their entrance to the larynx at a point corresponding to the upper border. The lateral lobes of the thyroid gland can be detected at the sides of the thyroid and cricoid cartilages. The gland, adherent to the laryngeal structures and trachea, moves with the larynx in swallowing. In the median line and below the cricoid cartilage, one can feel the upper portion of the trachea. The upper two rings are close to the cutaneous surface, but those on a plane with the upper border of the sternum are one and one-half to two inches from the surface. Extreme extension of the head and neck will practically add another inch of trachea within reach, as well as making it more prominent. The second, third, and fourth tracheal rings are more or less curved by the thyroid isthmus. A large plexus of veins is always present in this region. The larynx is composed of rfine distinct parts, viz. ; four cartilages, the thyroid, cricoid, and two arytenoid ; one large fibro-cartilage, the epiglottis, and four smaller fibro- fcartilages, two of Wrisberg and two of Santorini. The latter are practically supplementary to the arytenoids. Luschka describes an inter-arytenoid cartilage as sometimes occurring, and oftener two pairs of small cartilages, anterior and posterior sesamoid. The thyroid, cricoid, and arytenoid 32 Nose, Throat and Ear. cartilages frequently undergo ossification in the aged or in some diseases, but the fibro-cartilages are not thus affected. All the cartilages are connected by ligaments and articula- tions which permit of the various movements required of this organ. Thyroid Cartilage. — This is the largest of the cartilages, and the name means a shield. The thyroid contains and pro- tects the vocal cords. C. Ludwig terms it the stretching car- tilage, as the lever-like movements of the structure control the tension of the cords. It consists of two alse, or wings, united in front at a sharp angle by the lamina mediana car- tilaginis thyroidese. The vocal cords and the thyro-ary- tenoidei interni muscles are attached to this median lamina. The wings of the thyroid extending outwards and back- wards forms the lateral laryngeal walls. Their superior cornua, or horns, are connected with the hyoid.bone by the thyro-hyoid ligaments. The thyro-hyoid membrane, which extends from the cornua to the hyoid bone, unites these structures still more closely. The epiglottis is attached by its stalk to the inner sur- face of the thyroid cartilage in the receding angle and just below the median notch. From above the lower border posteriorly, and on each side of the median line, is the crico- thyroid membrane which joins the thyroid to the cricoid cartilage. The two inferior cornua of the thyroid articulate with the cricoid by capsular ligaments lined with synovial membrane. The vocal cords and the thyro-arytenoid mus- cles connect the thyroid and arytenoid cartilages. Cricoid Cartilage (a ring). — Ludwig terms this the foun- dation cartilage, as practically it sustains the laryngeal structure. The thyroid rests upon it through the articula- tions of the inferior cornua, and the arytenoid cartilages rotate upon it. The cricoid is smaller, but thicker and stronger than the thyroid, and is connected with the upper ring of the trachea by fibrous tissue. The anterior portion is Larynx. 33 narrow vertically, but posteriorly is broad and deep. The inferior rim is nearly horizontal, while the superior inclines upwards and backwards. The posterior portion, the lamina cartilaginis cricoidse is hexagonal in outline. In the median line at the back and internally an elevated ridge separates QrectierCbrnu Lesser Comu Capsu/a Fig. io. two slight depressions which receive the insertion of the posterior crico-arytenoid muscles, and serves for the at- tachment of the esophageal aponeurosis. Anteriorly the crico-thyroid membrane closes the space between the two cartilages. Two broad saddle-shaped articular surfaces for the bases of the arytenoid cartilages, are on the posterior and superior border. 3 34 Nosk, Throat and Ear. Arytenoid Cartilages. — There are two of these. They are pyramidal in form, and each has three surfaces, a base and an apex. The posterior surface is triangular, smooth, and concave. The arytenoid muscle is attached to this sur- Vocal cord Tke Ventricle Cartilage ofWrtsberg Arytenoid CcLrtilage LATERAL CmCO-ARYTeNOlD Epiglottis Crico thyroid membrane Thyroid Cartilage THYRO EPIG-IOTTIDCAN Fasiculus THYRO ARYTENOIO m us-rfe Cricoid Cartilage in section, Fig. ii. face. The antero-external surface is rough and convex. The thyro-arytenoid muscle, and also the false vocal cords, are attached to this surface; the latter just above a depres- sion, the fossa triangularis. The internal surface is smooth, Larynx. 35 narrow, and flattened, covered with mucous membrane, and (almost touches its fellow cartilage. The base is broad, concave antero-posteriorly, and smooth for articulation with the cricoid. Two processes project from the base', one postero-externally, the muscular process, which is short, rounded, and prominent, and to which the posterior and lateral crico-arytenoid muscles are attached. The second-vocal-process projects anteriorly, it is prominent, but more pointed and flattened. The true \ocal cord is attached to this process. Between the two processes is the base of the antero-external surface. The apex of each is pointed and curved upwards and inwards. Cornicula Laryngis (cartilages of Santorini). — These are above the upper pointed ends of the arytenoids and located in the substance of the ary-epiglottic folds. They are conical, small, and flexile, being composed of yellow fibro-cartilage. They probably prevent pressure of the epi- glottis against the apices of the arytenoid cartilages during deglutition. Cuneiform Cartilages (Cartilages of Wrisberg). — These are two small wedge-shaped cartilages contained within the ary-epiglottic fold and in front of the arytenoids. Posterior Sesamoid Cartilages. — These are not always present. Luschka describes them as very small, oblong bodies, attached by delicate ligaments to the Santorini car- tilages above and the arytenoids below. They are located near the lateral margin of the 'arytenoids. Anterior Sesamoid Cartilages. — These are frequently present. Each is about the size of a pin-head, and embedded in the anterior part of the vocal cords. A tough tissue unites them to the thyroid. Inter-arytenoid Cartilage. — This is very infrequent, but when it does occur it will be found as a small body be- tween the arytenoids. Epiglottis. — This is a thin leaf-like lamella of yellow 36 Nose, Throat and Ear. fibro-cartilage, located between the base of the tongue and the superior opening of the larynx. The upper free ex- tremity is broad and rounded ; its stalk, or attached end, is long and narrow, and is firmly connected to the thyroid TongiA.e fold Over Carktiaxfi brtiecea. Jry- epiglottic fold Cartilage ofWrisberQ exposed XesserTwrn cfTkyroic? Cart'dago triticecc exposed Over Cartilage of Wrisbe-rg. Over A ryferwixl (XwtvlcLge Crico -thyroid Zip Fig. 12. cartilage at the receding angle and just below the median notch by the thyro-epiglottic ligament. It is also attached to the posterior surface of the hyoid bone by the hyo-epiglottic ligament which forms part of the central thyro-hyoid liga- ment. The body of the epiglottis is retained in position by five Larynx. 37 bands, three of which pass forwards to the base of the tongue, and two backwards to the arytenoid cartilages. The central ligament in front consists of a fold of mucous mem- brane reinforced by fibro-elastic tissue, extending from the center of the body to the base of the tongue, where it ex- pands and merges into the lingual fibrous covering. The central glosso-epiglottic ligament unites with a strong white fibrous membrane which covers the entire front surface of the epiglottis. The membrane is attached to the entire length of the hyoid bone, and extends from the sides of the epiglottis in two conspicuous folds, spreads laterally and lines the tonsillar fossae. Lennox Browne designates the membrane as the epiglottic membrane, and the lateral folds as amygdalo-epiglottic ligaments. The so-called lateral °dosso-epiglottic ligaments exist only when the mouth is open and the tongue considerably extended. They consist simply of two folds of mucous membrane extending from the sides of the tongue to the epiglottis. The posterior, or aryteno-epiglottidean folds are two thick bands consisting of muscle and mucous membrane, ex- tending backwards from the recurved sides of the epiglottis to the arytenoid cartilages. They separate the cavity of the larynx from the hyoid fossae. The hyo-epiglottic ligament unites the epiglottis with the basi-hyal. The epiglottis as a body is curved upon itself from above downwards as well as from side to side. The lingual sur- face is concave from above downwards and convex from side to side. The superior margin is curved forward over the base of the tongue. The laryngeal surface is concave from side to side, and concavo-convex from above down- wards. The degree of curvature varies considerably. A more or less well marked eminence is found on the laryngeal surface at the. junction of the stalk and blade. 38 Nose, Throat and Ear. The interior of the larynx is divided into three divisions ; •the supraglottic is the upper and largest, and is the space above the ventricular bands. It is heart-shaped, the broad- est part being in front, corresponding with the line of the epiglottis. The lateral walls are formed by the folds con- necting the epiglottis with the arytenoid cartilages. The glottic, or second space, includes the ventricular bands, vocal cords, and ventricles of Morgagni. Ventricular bands, sometimes called the false vocal cords, are two folds of mucous tissue containing a little fibrous tissue, the superior thyro-arytenoid ligaments. In front they are attached to the thyroid cartilage, and behind to the anterior surface of the arytenoids. They may be closely approximated. The closure occurs in the act of swallowing, as well as some other muscular efforts, as ;coughing, straining, etc. Vocal Cords. — These consist of bands of pure yellow, elastic tissue, the inferior thyro-arytenoid ligaments. The cords are attached to and continuous with the upper free margin of the crico-thyroid membrane. As the cords and ci*ico-thyroid membrane are practically continuous struc- tures, it will be necessary to describe the latter first. Crico-thyroid Membrane. — This is a thin fibro-elastic tissue attached to the upper and inner margin of the anterior two-thirds of the circoid cartilage. It passes upwards, and converging behind the thyroid cartilage, is attached to the angle of the thyroid cartilage on its inner surface about a quarter of an inch from the inferior border ; behind it is attached to the vocal processes of the arytenoid cartilages, and part of the external border of their base. The upper free margin of the membrane, reinforced by antero-posterior bands of yellow elastic tissue, and placed as a movable band, comprises the inferior thyro-arytenoid ligaments or true vocal cords. The inner surface of the membrane is smooth and cov- lyARYNX. 39 ered by an adherent mucous membrane. The thyroary- tenoid muscles also cover this surface. Fibers of muscular tissue pass to, and are attached to the voca*l cords and upper portion of the thyro-hyoid membrane. These fibers are important in influencing the vibration and position of the vocal cords. The length of each cord when at rest is approximately three-fourths of an inch in the adult male, and half an inch in the female. A section of the cord shows a triangular form, the acute angle or apex being directed toward the median line. The upper and lower surfaces are not per- fectly free, only the edges being so. The vocal cords are really a fold of the crico-thyroid membrane. In color the cords are white, this being most pronounced in the female. The yellow elastic tissue of the cords is necessary for pre- serving tension without muscular effort, and wrinkling when relaxation occurs. Ventricles of M or gagni.— These are the two spaces be- •tween the ventricular bands and vocal cords, and constitute the inferior openings of the saccules. The ventricles are elliptical in form, and vary considerably in size. Sacculus Laryngis. — In man this is a comparatively un- important structure. The sacculi are lined with muciparous glands and a considerable amount of lymphoid tissue, and extend down to the lateral attachments of the vocal cords. The third, or infra-glottic space, comprises the portion of the larynx from the inferior surface of the vocal cords •to the inferior border of the cricoid cartilage. Physiologically and clinically the second, or middle divi- sion, is the most important. Not only phonation is repre- sented at this point, but the vocal cords perform a special action in respiration. This opening is termed the glottis or rima glottidis. In repose the shape is more or less elliptical, being nearly an inch long in the male, and two or three lines less in the female. The shape of the rima glottidis varies 40 Nose, Throat and Ear. according to requirements ; in full inspiration it is irregu- larly triangular, the apex forward at the thyroid angle, at the origin of the vocal cords — anterior commissure of the vocal cords — the two posterior angles being at the arytenoid cartilages, the insertion of the cords ; the base is more or less curved, and is formed by the space between the carti- lages — inter-arytenoid space, or posterior commissure of the vocal cords. In the production of high notes, as the upper register in singing the cords are almost closed. All variations are found between these two extremes. The vocal cords are controlled by certain muscles, the intrinsic are usually grouped as follows : ACTION. i. Narrowing the vestibule. Thyro-ary-epiglottidei { ThyrTepSotlidei ] K ^ ira ' Arytenoideus ) 2. Governing the shape of the Rima Glottidis. Thyro-arytenoidei ~) ex- and interni ! ~. , , , . . ~ ■ ■ -, • > Close true glottis AT 1 , Cnco-arytenoidei [ I ° a laterales J respiratory. Arytenoideus . . . closes cartilaginous glottis Crico-arytenoidei postici^open glottis — Respirator}-. 3. Governing the pitch of the voice. Crico-thyroidei Tense the vocal cords. f Shorten, relax and bring in a^, -j . . . • ! apposition various sections rhyro-arytenoidei interni < Z\ x . , , . of the vocal cords and act as local extensors. (Browne.) Crico-arytenoidei Postici. — These are the abductors of the vocal cords, being active on inspiration. They consist of two triangular muscles, the bases having their origin on tyARYNX. 41 the posterior surface of the cricoid cartilage, they converge upwards and outwards until they reach the processus mus- culares of the arytenoids. The action of drawing these back- wards and inwards causes the processus vocales to move outwards, opening the rima glottidis. This motion varies according to individual needs. Crico-arytenoidei Later ales. — These muscles have their origin along the upper border and outer surface of the sides of the cricoid cartilage. They pass obliquely upwards and backwards, and are attached to the outer angles of the bases of the arytenoid cartilages and adjacent parts of the anterior surfaces in front of the posterior crico-arytenoid. The upper fibers are occasionally mingled with the fibers of the thyroarytenoids. Arytenoideus. — This muscle is square and is attached to the posterior concave surface of the arytenoid cartilages. The action is that of an aid to the crico-arytenoidei lat- erales in closing the glottis. The opinion now held by many is that this muscle is a continuation of the thyro-arytenoi- deus. When the arytenoideus acts first, the rima glottidis assumes momentarily a rhomboid shape ; when the crico- arytenoidei laterales act first, the vocal cords are approxi- mated and the space between the arytenoid cartilages re- mains open. Thyro-arytenoidei. — These two muscles are broad, flat, and fan-shaped, parallel with but external to the vocal cords, being partially inserted into them. The anterior at- tachment of the muscles is to the internal surface of the thyroid cartilage, the inferior fibers lying close to the angle of the thyroid. Each muscle is composed of two distinct divisions. The upper is thin, inserted high up on the anterior sur- face and outer border of the arytenoid cartilage, partially encircling the laryngeal pouch, some of the fibers pass round the outer border of the arytenoid cartilage, and intermingle 42 Nose, Throat and Kar. with the transverse fibers of the arytenoideus, and under- neath the oblique .fibers of the ary-epiglottideus. The lower division is a thick, well defined fleshy bundle, and is reinforced by a. few fibers from the outer surface of of the crico-thyroid membrane. It extends backwards and is inserted into the anterior projection, or vocal process of the arytenoid cartilage, external and close to the vocal cord, also to the adjacent surface and close to the insertion of the corresponding lateral crico-arytenoid muscle. Occasionally there is a small third division — the thyro- arytenoideus of Soemmering — having its origin from be- hind the thyroid notch, close to the median line and passing internally to the pouch, to be inserted into the antero-ex- ternal surface of the arytenoid cartilage near its base. Ary-epiglottici. — These are two thin, flat muscles, hav- ing their origin from the outer and posterior border of the apex of the corresponding arytenoid cartilage, and pass up- wards and over to the opposite side through the ary-epi- glottic folds to the epiglottis. These muscles are called the constrictores vestibuli laryngis. Their action is to approxi- mate the tips of the arytenoid cartilages and to cause the edges of the epiglottis to turn inwards during the act of swallowing, and probably also in phonation. Crico-thyroidei. — Each muscle presents a fan-like shape and consists of two divisions. The lower ends of each sec- tion are pointed and have their origin from the antero-lat- eral portions of the cricoid cartilage. The fibers diverge as they pass obliquely upwards and backwards, and are in- serted into the inferior border of the thyroid cartilage, the anterior borders of the lower cornua and into the internal and external surfaces near the margin. The function of these muscles is to draw the thyroid forwards and down- wards, tilt the cricoid and arytenoid cartilages backwards, thus producing tension on the vocal cords. Arteries. — The laryngeal blood supply is through Larynx. 43 branches from the superior and inferior thyroid, the former being a branch of the external carotid, the latter of the thyroid axis from the subclavian. Small branches are de- rived from the lingual and ascending pharyngeal. The superior laryngeal artery from the upper thyroid passes upwards, inwards,, and downwards, accompanying the superior laryngeal nerve penetrating the thyro-hyqid membrane to the interior of the larynx. Inside the larynx the artery lies between the thyroid cartilage and thyro-afy- tenoid muscles, and distributes branches to the intralaryn- geal structures, uniting above with twigs from the lingual and tonsillar, and below with twigs from the superior laryn- geal, a branch of the inferior thyroid. The inferior laryn- geal artery varies in size and ascends along the back of the trachea and larynx, being distributed to the small muscles and mucous membrane in the region of the arytenoid car- tilages connecting with the superior laryngeal. Veins. — The laryngeal veins correspond with the arteries. The upper laryngeal veins, penetrating the thyro-hyoid membrane, empty into the internal jugular, lower facial, or the superior thyroid. Lymphatics. — The laryngeal lymphatics join the cervical glands. Nerves. — The superior, and recurrent or inferior laryn- geal, are branches from the pneumogastric, the motor being of spinal accessory origin. Filaments from the sympathetic accompany the arteries. Plexuses are formed by the junc- tion of quite large branches. Prominent anastomoses occur at the back of the arytenoid cartilages beneath the pharyn- geal mucous membrane, also at the sides of the larynx be- tween the wings of the thyroid cartilages and the thyro- arytenoidei. The superior laryngeal supplies the laryngeal mucous membrane and the crico-thyroid muscles. The recurrent 44 Nose, Throat and Ear. laryngeal supplies the rest of the muscles. The arytenoicleus is supplied by both nerves. Minute Anatomy. The laryngeal mucous membrane is similar to the pharyngeal in being composed of epithelium, tunica propria, and submucosa. Stratified squamous epithelium covers the epiglottis and the inner surface of the larynx as far as the lower edge of the false vocal cords. Below this the epi- thelium is of the stratified ciliated columnar variety, except- ing over the true vocal cords where it is again of the strati- lied squamous type. The tunica propria of the larynx con- sists of fibrous connective tissue with a network of elastic fibers. Longitudinal bundles of elastic tissue, with some fibrous tissue, constitute the true vocal cords, which are covered with stratified squamous epithelium, reinforced externally by fasciculi from the thyro-arytenoideus muscle. The thyroid, cricoid, and greater part of the arytenoid car- tilages are composed mostly of hyaline cartilage. The epi- glottis, apex of the processus vocales of the arytenoid car- tilages, the cartilages of Wrisberg and Santorini are of the yellow elastic variety. The fibrous connective tissue of the external surface of the larynx connects the perichondrium with the surrounding tissues, muscular attachment being by tendinous tissue continuous with the cartilaginous invest- ment. CHAPTER II. EAR. Physiologically the ear may be divided into two parts, the conducting and receptive portions, but anatomically three divisions are made, (i) External (auricle or pinna, and external auditory canal). (2) Middle (tympanic cav- ity, membrana tympani, ossicles, Eustachian tube, and mas- Fossa vsstv of Helix: x-b^iicdilon/ Meatus \ Fig. 13. toid process). These two anatomical divisions constitute the physiological first or conducting apparatus. (3) The inner or internal (labyrinth) consisting of the vestibulum, the three semi-circular canals and cochlea, the latter being the receptacle for the expansion of the auditory nerve. This constitutes the second physiological division, or receptive portion. 45 4.6 Nosk, Throat and Ear. The auricle, or pinna, is ovoid or pyriform. the larger end being above. The external surface is irregularly con- cave, and directed a little forward. A number of irregular- ities, the effect of the foldings of the fibro-cartilaginous frame-work are noticeable. The outer rim is the helix. Parallel and in front of the helix is another curve, the antihelix. The latter divides above and encloses a triangular depression, the fossa of the antihelix. The narrow, depres- sion between the helix and antihelix is the fossa of the helix. The antihelix curves round a deep depression, the concha, which is partially divided by the beginning of the helix. In front of the concha, and extending backwards over the meatus, is a prominent structure, the tragus. A little below and posteriorly from the tragus, and separated from it by a deep notch (incisura intertragica), is a small prominence, the antitragus. Below is the lobule. The cartilage of the auricle is one piece, but is not con- tinuous throughout. It is lacking in the lobule and practi- cally so between the tragus and helix, the space being filled by dense fibrous tissue. At the front part of the auricle where *the helix curves upward, the cartilage forms a small projection, the process of the helix. Several fissures are also present in various parts of the cartilage. The walls of the auricle gradually converge and form the cartilag- inous meatus. Cartilaginous Meatus. — The shape of the canal is oval. The inner extremity of the cartilaginous portion is united to the bony canal by firm bands of connective tissue. Supe- liorly and posteriorly the cartilaginous structure is lacking,, and becomes more marked until at the junction with the bony portion, the inferior wall only contains cartilage, this extending a short distance along the floor of the bony canal. Firm connective tissue fills the space in the cartilaginous portion where cartilage is lacking. This tissue is continu- ous with the periosteum of the corresponding part of the Ear. 47 bony canal. Two verticle fissures are present in the anterior cartilaginous wall. These fissures, incisures of Santorini, [ire filled with connective tissue. The larger is at the base of the tragus, the second deeper in the canal. Sometimes a third fissure, still deeper, is present. These fissures permit of some mobility of the cartilaginous portion, and also on account of less resistance at these points, sometimes allow of spontaneous rupture into the auditory canal in deep ab- scesses of the parotid gland. Surgically they are important, Tegment. tympani Stapes Incus ,_-/« Fallopi -Fenestra ovatis rvr-Canalis Fallopiac — Fenesti L-Umbo tet* <* "romontortum, a — Memhr. tympani \ Ca-vwrn. tympani tens, ttpp. membr. tymp. Transverse vertical section through Right Ear. Fig. 14. as they allow the tinning forward of the auricle and fibro- cartilaginous canal after the posterior, inferior, and superior attachments have been loosened. Bony Canal. — A consideration of the development of the temporal bone is necessary. This part of the skull is devel- oped from four centers; the squamous, petromastoid, audi- tory or tympanic and stylomastoid. At birth the osseous canal is lacking, fibrous tissue taking its place. At the inner end this terminates in the auditory 48 'Nose, Throat and Ear. process, or tympanic ring. This consists of a thin bony strip, annulus' tympanicus, oval in shape and about an eighth of its circumference being lacking. The concave margin of the ring is grooved, sulcus tympani, for the insertion of the membrana tympani. The squamous portion of the temporal bone is developed from a single center. In early fetal life it presents a flat, bony -scale, with a ridge upon the outer surface, which later forms the zygomatic process. Below the root of the zygoma is a shallow depression, the glenoid fossa. Behind this the 4$W - : ^h ww -,/.'. Incut JP*Jb • Membrana %\ tympani S^^>' Membrana Tympani and Ossicula of new Lorn child from inner side Fig. 15. bony plate divides into two lamelbe, the inner projecting almost horizontally inward, later forms the roof of the tympanum and mastoid antrum. The outer lamella extends downward and a little inward and presents a deep notch upon the inferior border. The annulus tympanicus joins the latter lamella at this notch, which by the manner of attachment completes the circle. This completed circle gives attachment to the inner end of the fibrous canal. As the fetus develops, this fibrous tissue is replaced by bony tissue, and the annulus tympanicus becomes a bony groove through ossification outwards, Ear. 49 In the adult the deep groove formed by the outward growth of the tympanic ring is called the auditory process. In front it is separated from the squamous portion of the temporal bone by the Glaserian fissure. Posteriorly the audi- tory process helps in forming the mastoid squamous suture, its postero-superior point being the spinum supra-meatum. The outer plate of the squama, which completes the outline oi the bony meatus, grows almost directly outward horizon- tally, and almost at right angles to the part of the temporal bone above the zygomatic process during development. The third portion of the temporal bone, the petro-mas- toid, is an oblique triangular pyramid, the apex forward and inward, the base closing the space between the free margin of the squamous plate of the temporal bone and the posterior crus of the annulus tympanicus. The junction of the mastoid portion to the external squamous lamella forms the mastoid squamous suture. The petrous portion uniting with the inner lamella, forms the petro-squamous suture. Tympanic Cavity. — This is a chamber more or less sur- rounded by bony walls. The inner wall is formed by the external surface of the petrous portion of the temporal bone. It is marked by a rounded elevation, the promontory, cover- ing the first turn of the cochlea. Behind and a little below the promontory, is the niche of the round window, into which the fenestra rotunda opens. Above, in the upper and posterior part of the inner wall, is an oval fossa, the pelvis ovalis, at the bottom of- which is the oval window. The posterior wall of the pelvis ovalis is abrupt, but the anterior wall gradually slopes forwards, merging into the surface of the promontory. The inferior wall is longer and steeper than the superior. Above the oval window a distinct bony arch is formed by the prominent outer wall of the aqueductus Fallopii protruding into the tympanic cavity. This canal transmits the facial nerve. The outer wall of this canal is 5o Nose, Throat and Ear. sometimes defective and the facial nerve is then uncovered at this point. It is important to remember this in treating suppurative diseases of the middle ear, as often paralysis results from too energetic measures. Just above the aqueductus Fallopii is a smaller ridge, caused by the horizontal semi-circular canal. Posteriorly to the pelvis ovalis, and where the inner and posterior walls of the tympanum join, is a small bony pyramid. The tendon ■mastoid. H. rACIMJS Inner Wall of Tympanum, x 3. Fig. 16. of the stapedius muscle passes through its apex. The inner wall of the tympanum is more nearly in the median antero- posterior vertical plane of the body than the plane of the tympanic ring; for this reason the cavity is broader above and behind than below and in front. In front of the prom- ontory the inner wall is smooth and merges into the tympanic orifice of the Eustachian tube. The Anterior Wall. — The Eustachian tube opens at about the center of the anterior wall. The canal for the tendon of the tensor tyrnpani muscle is above the Eustachian Ear. 5 1 opening, being separated by a thin, bony plate, the processus cochleariformis. A thin plate of bone separates the ante- rior wall from the internal carotid artery. The floor of the cavity is bony, the structure sometimes being fairly compact bone, but often cancellus. The floor is considerably below the lower border of the tympanic ring, and is close to the jugular fossa. Openings sometimes ex- ist between the floor and the fossa, and the bulb of the in- ternal jugular vein may be injured by instrumental manipu- lation. The posterior wall presents, besides the pyramid, the \Emtnence for superior Vscmicircitlar Cbuictl- r sthrnus7u£& AqueRcUictusTcdlo, STAPEDIUS EustczdiAarvTube Fig. 17. opening into the mastoid antrum. This opening is directly above the pyramid. The external wall is formed principally by the mem- brana tympani, the inner surface of the tympanic ring, and above, the inner margin of the external plate of the squama and the angle formed by the inner and outer plates also enter into the formation. The vault of the tympanic cavity, or epitympanic space, is considerably above the plane of the superior wall of the external auditory canal. The portion below this plane is the atrium. Vault of the Tympanum. — This is more or less pyramidal in shape, the apex being at the angle between the plates 52 Nose, Throat and Ear. of the squama. These, with the adjoining parts of the petrous bone and petro-squamous suture, form two bony surfaces of the pyramid. The remaining surfaces and base are incomplete, the openings into the mastoid behind and the tympanum below corresponding to these two portions. Normally the base is partially rilled in by the ossicles and their ligaments, as well as by reduplications of the tympanic Fenestra n?i rtadri*' 1 Tub* FlG. i 8. Vertical section through tympanum. The dotted oval shows the relation of the memhrana tympani to the tympanum. mucous membrane, partially dividing the tympanum into two parts. OSSICUS. — These are three in number; malleus, incus, and stapes. These bones aid in transmitting and modifying" the vibrations of sound by imparting to the labyrinthine fluid increased intensity, but the waves are diminished in amplitude. Ear. 53 The Malleus. — This is the largest of the three bones, and consists of a head, neck, and shaft, or manubrium. The manubrium is classed by some as a process, the same a.s the processus gracilis and processus brevis. The head is irregularly oval, presenting posteriorly the surface for articulation with the incus, and anteriorly a groove for the attachment of the anterior ligament. The neck is a narrow constricted part joining the head and handle at an obtuse angle. The manubrium, also called the handle, shaft, or long process, is flattened from within outward, and gradually tapers from about the neck to the tip, which occasionally projects slightly forwards, forming a hook. From the junction of the handle with the neck, is the short process, processus brevis, a conical bony projection, directed for- ward and outward and in contact with the membrana tym- pani. The external border of the handle furnishes attach- ment to the tympanic membrane, while the inner border is toward the inner wall. The anterior and posterior surfaces are comparatively broad. Projecting from the anterior sur- face just below the short process and passing forward and outward to the Glaserian fissure, is the long delicate pro- cessus gracilis or folianus, which is often embedded in the fibers of the anterior ligament in adults. The external surface of the neck of the malleus is roughened, giving attachment for the external ligament. The anterior surface of the neck and contiguous portion of the head are grooved for the insertion of the anterior liga- ment. The Incus. — This bone consists of a body and two proc- esses. The body is somewhat quadrilateral, but the height is nearly double the width. The anterior surface presents a concavo-convex facet for articulation with the malleus. This surface is covered with cartilage and lined with synovial membrane. 54 Nose, Throat and Ear. The two processes form nearly a right angle with each other. The short, or horizontal, process, conical in form, is really a continnation of the body, and extends backwards, the apex resting in a depression — sella incudis — in the pos- terior tympanic wall immediately below the opening into the mastoid, having a ligamentous attachment. The long or descending process is a tapering, slender bone, passing nearly vertically downward from the antero- inferior angle of the body. The lower portion bends in- ward, the rounded tip being toward the internal wall. This staged. Ossicula. x 3. Fig. 19. tip is the lenticular process and articulates with the head of the stapes. The Stapes. — This, the third of the series, is a stirrup- shaped bone, consisting of a head, two branches — crura — and base. The head is rounded and presents on the external surface a depression for articulation with the lenticular proc- ess of the incus. Just below the, head is a constricted part of the bone — the neck — the crura diverging from it. The posterior crus is the most curved and longest. The crura terminate in a flattened, oval-shaped bone, the base or foot- plate, which is fixed to the margin of the fenestra ovalis by ligaments. Bar.. 55 The stapes lies almost entirely within the pevis ovalis, so is well shielded from injury when instruments are used through the external auditory canal. The position of the hone is oblique, and is nearer the inferior and posterior walls of the fossa than the anterior and superior. As the posterior wall is nearly vertical, the posterior crus of the stapes is in close relation to it, and adhesions between these two struc- tures are common. Ligaments of the Ossicles. Ligaments of the Malleus. — These consist of the anterior, external, posterior, and superior or suspensory. The anterior is the strongest. Its origin is from the spina tympanica major and wails of the Glaserian fissure. The ligament passes outward, upward, and backward, to be inserted into the anterior surface of the neck and de- pression on the anterior surface of the head of the malleus. The External Ligament. — This is rather fan-shaped. Its origin is from the external roughened surface of the neck of the bone, the fibers diverging and being inserted into the free margin of the inner extremity of the superior wall formed by the external plate of the squama. Helmholtz describes the posterior fibers as a distinct band, the posterior ligament. This band, with the anterior ligament comprises the axis band of the malleus. The Superior Ligament. — This is a rounded delicate band of fibrous tissue passing from the tegmen tympani downward to the head of the malleus. Ligaments of the Incus. — The incus is attached to the tympanic wall by a single fibrous band, the posterior liga- ment. At its origin from near the tip of the lateral surfaces of the short process, it is a dense structure, but the fibers rapidly diverge, and divide into two bundles, which are in- serted into a broad area on the posterior tympanic wall. 56 Nose, Throat and Ear. Ligaments of the Stapes. — The base of the ossicle is held in position in the oval window by means of the annular or stapedio-vestibular ligament. The borders and vestibular surface of the base and periphery of the oval window are covered with hyaline cartilage. The annular ligament is de- veloped from the perichondrium. Inter ossicular Ligaments. — The articular surfaces- of the ossicles are covered with cartilage. The malleus and incus are united by a loose capsular ligament. The Eustachian Tube — This might be called an acces- sory portion of the middle ear. The function of this tube is for ventilation of the middle ear and to equalize the pressure between the tympanic cavity and the external atmosphere. The tube consists ot two portions, the bony or tympanic, and cartilaginous or pharyngeal. The junction of these two is called the isthmus. The bony portion is about half an inch in length, extend- ing from a comparatively wide opening just above the mid- dle of the internal tympanic wall, and rapidly narrowing as it passes downward, forward, and inward through the petrous portion of the temporal bone to the isthmus, where the diameter is from one-twenty-fifth to one-twelfth of an inch. The bony portion of the canal is somewhat triangular in shape, the vertical line being about double the horizontal. Fibrous tissue joins the bony and cartilaginous portions of the tube at an obtuse angle. The cartilaginous portion of the tube is about an inch in length. From the isthmus it extends downward to the pharynx increasing in width until at the orifice it is from cne-eighth to one-fifth inch in diameter, the vertical still being the greatest. This portion of the canal is fibrocartilag- inous. A plate of cartilage, the upper portion of which is curved forward and then downward, forms the posterior walL A transverse section is hook-shaped. The space be- tween the end of the hook and the lower edge of the cartilag- Ear. 57 inous plate is filled with fibrous and muscular tissue. The lumen of the cartilaginous portion is slitlike. The mem- branous tube is connected to the inner end of the bony canal the posterior plate of cartilage uniting with an extension of the corresponding "bony wall. Membrana Tympani. — Principally for the protection of Incus* Itfanubruwv TynipcinicMembrane Fig. 20. Eustachian Tube and Tympanum. (Right Ear.) the intra- tympanic structures, and secondarily for the pur- pose of assisting in the transmission of sound waves, a par- tition is placed, dividing the external auditory parts from the middle ear. This is the membrana tympani. This is a fibrous membrane and forms the greater part of the outer wall of the tympanic cavity. It is located at 58 Nose, Throat and Ear. the inner extremity of the bony portion of the auditory canal, and at birth is nearly horizontal, gradually assum- ing a more perpendicular position until adult life. The normal position of the membrane in the adult is obliquely with the long axis of the bony canal, thus making the ante- rior and inferior auditory canal walls the longest. The membrana tympani is attached at its margin to z groove, sulcus tympanicus, in the bony canal. The fibrous tissue is somewhat thickened at the point of attachment, the annulus tendinosus, or cartilaginous ring. From this ring some fibers pass outward to the periosteum of the bony FlG. 21. External Surface of Right Membrana Tympani. x 3^. canal and others go in the opposite direction, mingling with /the periosteum of the tympanum. The manubrium is attached to the substantia propria by means of a thin cartilaginous lamella, which passes along its outer border from the processus brevis to. the umbo, the fibers of the membrane being continuous with the perichon- drium of the cartilaginous lamella. The circular and ra- diating fibers are attached directly to the tip of the manu- brium. The superior border of the lamina propria joins the anterior and posterior extremities of the annulus tympan- icus, forming a tense fibrous band, which is divided into two parts by the short process of the malleus. The pos j Bar. 59 terior fold is the sharply defined superior margin of the membrane extending from the short process to the posterior extremity of the annulus. Shorter and less distinct is the anterior fold. The fibrous septum is lacking where the curved outline of the annulus is completed by the auditory plate of the tem- p-oral bone. This space constitutes the Rivinian segment, and is closed by the cutaneous lining of the external audi- tory canal. As compared with the rest of the membrana tympani, this portion is loose, and is called the membrana ■'•'■>^y : i*f Short process m F ani ^^gp^ Handle of Malleus Right Membrana Tympani. External view. Fig. 22. flaccida, or Shrapnell's membrane. The fibrous layer is especially well developed along the anterior and posterior borders, which cause it to be somewhat triangular in shape. These distinct fibrous bands are the fibers of Prussak, and pass from the two extremities of the Rivinian segment to the base of the short process and continuing along the manubrium are merged into the external layer of the mem- brana propria. The normal membrane is somewhat oval in outline, and is drawn inward, the most concave point being at the umbo, where the tip of the manubrium is attached directly to the 6o Nose, Throat and Kar. membrana propria. The anterior and inferior segments bulge outward somewhat, so that although the membrane in its entirety is concave, it is convex from the center to the periphery. The Muscles. — The muscular structures of the conduct- ing portion are the extrinsic, connecting the auricle to the skull ; intrinsic, comprising those of the auricle and canal ; the intratympanic, and those of the Eustachian tube. Posteriorly the auricle is connected to the skull by the mastoid fascia, and anteriorly by the temporal fascia. Extrinsic Muscles. — There are three, which in man are usually rudimentary so far as' action is concerned. The retrahens aurem, attollens aurem, and attrahens aurem. The retrahens has its origin from the' mastoid region by short aponeurotic fibers, and is inserted into the auricular cartilage at the posterior and inferior portion. The attrahens has its origin from the lower edge of the epicranial aponeurosis and converges to be inserted into the cranial surface of the spine of the helix. The attollens has its origin from the aponeurosis of the occipito-frontalis, and converges to the insertion at the upper part of the cranial surface of the auricle. The Intrinsic Muscles. — These are practically rudimen- tary muscles in man, consisting of incompletely developed muscular fiber bundles arranged between the cartilaginous processes of the auricle. The Intratympanic Muscles. — Two muscles comprise this group, the tensor tympani and stapedius. The Tensor Tympani. — The origin of this muscle is from the upper wall of the cartilaginous Eustachian tube and also the bony walls. It enters the tympanum through a bony canal just above the tympanic opening of the Eusta- chian tube, being separated from the latter by the processus cochleariformis. This process in the tympanum is pyra- midal and is sometimes called the anterior pyramid. The Ear. 6 i tendon twists almost at a right angle around this process, passes across the tympanum and is inserted along the inner border of the shaft of the malleus just below the neck, some of the fibers pass down for some distance along the handle and extend somewhat upon the anterior surface. The Stapedius. — The origin of this muscle is from the interior of the pyramid upon the postero-internal wall in front of and below the aqueductus Fallopii. The fibers con- verge to form a tenden which passes through the pyramidal apex and is inserted into the neck of the stapes at its junc- tion with the posterior crus. The muscles of the Eustachian tube are two, the tensor palati and levator palati. The tensor palati controls in a measure the lumen of the Eustachian tube. Its origin is from the scaphoid fossa and spine of the sphenoid anteriorly to the membranous portion of the tube, some fibers coming from the inferior border of the cartilaginous hook. The muscle passes down- ward in front of the membranous portion and converges into a tendon which encircles the hamular process of the sphenoid, then expands into a broad aponeurosis to be in- serted into the anterior surface of the soft palate and the posterior bony edge of the hard palate. The union of the fibers of the two muscles form the median raphe. The levator palati has its origin from the under surface and near the apex of the petrous portion of the temporal bone, and passes downward, forward, and inward to be in- serted in the posterior and superior surface of the soft palate. The body of the muscle is situated along and loosely attached to the inferior edge of the cartilaginous piate which constitutes the posterior tubal wall. It also is in contact with the fibrous inferior wall. The Arteries. — The arterial supply is principally from the branches of the external carotid, as well as a few branches from the internal carotid. The external carotid 62 Nose, Throat and Ear. blanches supplying the auricle, canal, and tympanum, are the posterior auricular, superficial, temporal, occipital, in- ternal maxillary and ascending pharyngeal. The posterior auricular supplies the posterior portion of the auricle and canal. The stylomastoid branch passes through the stylomastoid foramen, supplying the mastoid cells and a special branch passes to the stapedius muscle and stapes. The superficial temporal supplies the anterior portion of the auricle and canal by means of the superior and inferior anterior auricular branches. Anastomoses of these branches with those of the posterior auricular practically complete the arterial supply of the auricle and canal. A small branch from the superficial temporal passes through the Glaserian fissure to the tympanum. The Occipital Artery. — Branches from this artery pass to the concha, entering from the cranial surface. The Internal Maxillary. — The most important blood sup- ply, especially in early life, is through the middle meningeal and tympanic branches. A few twigs are distributed to the Eustachian tube before entering the cranium. Inside the skull is the superficial, petrosal branch, which passes through the petro-squamous suture to the tympanum, to be distributed to the tympanic roof, malleus, incus, and part cf the internal tympanic wall, anastomosing with the laby- rinthine vessels. (Politzer.) Within the Fallopian canal it connects with the stylomastoid. The Tympanic Branch of the Internal Maxillary. — This branch passes through the Glaserian fissure and is distrib- uted to the anterior portion of the tympanum, anastomosing with the stylomastoid upon the periphery of the mcmbrana tympani. The internal tympanic wall is supplied by anastomoses of the tympanic artery with the tympanic branches of the internal carotid and the Vidian branch of the internal maxil- Ear. 63 lary. Additional branches are from the internal maxillary, the Vidian, descending palatine, and pterygopalatine, which send small branches to the Eustachian tube and its muscles. Veins. — As a rule they accompany the arteries. The majority of the veins of the deeper structures form a plexus upon the superior and upper portion of the posterior wall of the external auditory canal. Those of the posterior wall and auricle empty into the external jugular and mastoid veins, the anterior branches joining the temporal and facial veins. A few of the deeper veins enter the pterygoid plexus. The veins of the Eustachian tube accompany the arteries and empty directly into the internal jugular vein, or some- times join the facial, lingual, or superior thyroid veins. There is a comparatively large venous trunk between the internal pterygoid muscle and adjacent wall of the tube, which passes to the cavernous sinus. Lymphatics. — The lymphatic canals are plentifully distrib- uted and anastomose with the superficial lymphatic glands and also those of the submucous system of the pharynx. The lymphatic channels of the canal and tympanum are in- timately associated with the superficial lymphatics over the mastoid, the lymph nodules in front of the auricle and those in the cervical region between the platysma and sterno-mas- toid muscles. There is also free lymphatic anastomoses through the glands of the lateral pharyngeal walls. The membrana tympani possesses three systems, one for each layer, which connect with each other and with the lymphatic system of the external canal. Nerves. — The nerve supply to the muscles of the con- ducting portion of the ear are from branches of the trigem- inus, facial, and cervical plexus. The attollens aurem is supplied through the occipitalis minor branch of the cervi- cal plexus. The tensor tympani and tensor palati muscles are supplied by the trigeminus through the otic ganglion, 64 Nosk, Throat and Ear. and the rest of the muscles are supplied directly by the facial or through its ganglionic communications. The sensory nerves are from the cervical plexus, trigem- inus, pneumo-gastric, and glossopharyngeal. The auricle, superior portion of the meatus and tympanic membrane are supplied by the ariculo-temporal, a branch of the trigem- inus. The posterior portion of the auricle and meatus are supplied principally by the auricularis magnus derived from the cervical plexus, this branch anastomosing with the auricular branch of the pneumogastric upon the posterior wall of the canal. The auricular branch of the vagus supplies both the car- tilaginous portion of the canal and part of the posterior sur- face of the auricle. The tympanic branch of the glosso-pharyngeal reaches the tympanum through a foramen in the tympanic floor, and supplies the mucous membrane and Eustachian tube. It divides upon the internal wall, one branch anastomosing with the twigs of the carotid plexus from the sympathetic system, and forming the tympanic plexus. The second branch, the small, deep petrosal, passes through a foramen in the tegmen tympani to the small superficial petrosal nerve, which is the facial branch to the otic ganglion. The third branch passes from the tympanum and unites with the great superficial petrosal, the facial root of the Vidian nerve, the posterior branch of Meckel's ganglion. This branch is the great deep petrosal. The chorda tympani passes from the aqueductus Fallopii above the pyramid, crosses the tympanum from behind for- ward, and passes between the long process of the incus and the handle of the malleus. It passes from the tympanum through a separate canal close to the Glaserian fissure, and joins the lingual branch of the trigeminus. Histology. — The structures giving form to the external ear consist of bony and cartilaginous tissue, excepting the Ear. 65 lobule, which is composed of dense fibrous tissue and fat. Subcutaneous tissue covers these structures and the whole i* covered by integument. The cartilage is the yellow elastic variety, forming a thin, tough plate, the irregulari- ties of which give the characteristic form to the ear. The skin covering the auricle is similar to the contigu- ous integument, but within the auditory canal some changes occur. The skin over the cartilaginous portion and part of the roof of the bony portion is quite thick as is the subcu- taneous tissue. Fine hairs, sebaceous and ceruminous glands are distributed in this portion pf the canal. The skin cov- ering the most of the bony portion of the canal, however, is thin and closely connected with the periosteum. Glands and hairs are absent in this portion, as well as in the integu- ment reflected over the external surface of the membrana tympani. The membrana tympani consists of three layers; (1) outer or reflected cutaneous layer, (2) middle or lamina propria, consisting of fibrous connective tissue; (3) inner or mucous layer, consisting of a portion of the lining of the tympanic cavity. The outer layer is composed of the epi- dermis and connective tissue corium, the latter being about one-half as thick at the epithelial layer. The lamina propria composes the fibrous structure of the membrane and rep- resents its mesodermic portion. It consists of two strata of finely felted fibrous tissue bundles. In the radial or outer, the tendency is for the bundles to radiate from the. tip of the malleus toward the periphery, while the circular, or inner, are concentrically arranged bundles, the greatest de- velopment being at the periphery near the annular attach- ment of the membrana tympani. The mucous layer, a con- tinuation of the tympanic mucous membrane, comprises a thin connective tissue ground work of delicate fibro-elastic tissue bundles, covered by a single layer of low cuboidal polyhedral celled epithelium destitute of cilia. 5 66 Nose, Throat and Bar. The blood supply is from two sources ; the external from the branches supplying the external auditory canal, the capillaries being distributed within the cutaneous layer, while the internal is derived from the vessels of the tympanic cavity, which are distributed to the mucous layer. The lymphatic system corresponds to the principal strata. The nerve supply is similar to that of the blood, being external and internal; the external, or cutaneous, being more or less from the tympanic branch of the auriculotem- poral, which passes beneath the manubrium and divides at the lower third of the process into two terminal twigs. Be- sides these central nerves, filaments enter the periphery of the membrane at different points, and uniting with the others form a wide meshed plexus, which sends filaments to and surrounds the blood vessels. A sub-epithelial plexus is also formed from this net work. The tympanic plexus sends nerves to the mucous layer, being distributed to the lymphatic and blood systems, as well as a sub-epithelial plexus, and a few twigs into the lamina propria. The: MiddIvE Ear. — This constitutes the entodermic di- vision of the ear, and comprises the tympanic cavity with the communicating mastoid cells, the ossicles and Eusta- chian tube. The tympanic cavity is enclosed within bony structures covered with periosteum, over which is the mu- cous membrane which is indirectly continuous with the pharyngeal mucous membrane. The mucous membrane is closely adherent to the periosteum, but also covers the os- sicles and their ligaments, as well as the nerves and blood- vessels crossing the middle ear. The mucosa is composed of a thin fibrous tissue resembling in some places the re- ticulum of adenoid tissue ; the mucous layer is closely con- nected with the fibrous structure of the periosteum. The epithelial surface of the tympanic cavity varies in structure ; that covering the ossicles, membrana tympani, promontory and the mastoid cells, is a single layer of low Ear = 67 cuboidal, polygonal non-ciliated cells, the rest of the sur- face consisting of the ciliated columnar type. Where nerve trunks or blood vessels are located, the mucosa is much thickened, forming ridges over them. Small tubular glands are sparsely located in the mucous membrane of the an- terior portion of the cavity. The mucous membrane cover- ing the antrum and mastoid cells is very thin and delicate. The structure of the secondary tympanic membrane which closes the fenestra rotunda is ; externally the tym- panic mucous membrane, composed of a layer of flattened non-ciliated polyhedral cells, and a thin fibrous tunica pro- pria ; the lamina propria consists of radially placed bundles of fibrous tissue passing from the indurated point of the base towards the periphery; the inner consists of a thin layer of sub-endothelial fibrous tissue covered by a layer of endothelial plates. The blood vessels of the tympanic mucous membrane are situated in the deeper periosteal layer of the mucosa, sending branches to the membrane. Lymphatics. — Within the deep periosteal layer are sit- uated the lymphatics. In the reticular connective tissue of the mucosa are found groups of lymphoid cells giving the appearance of lymphatic nodules. Nerves. — The principal nerves of this region are derived from the tympanic plexus, and consist almost entirely of medullated fibers lying within the periosteal layer of the mucosa. A sub-epithelial net work of pale non-medullated fibers is derived from a plexus formed by the deeper trunks. Ganglion cells are sometimes found along the course of the larger trunks and their branches. The ossicles are compact bone, the thicker parts con- taining Haversian canals and concentric lamellae. Hyaline cartilage invests all surfaces of contact. A minute intra- articular plate of fibrous cartilage is interposed in the cavity of the ambo-malleal articulation. The malleus throughout 68 Nose, Throat and Ear. its entire attachment with the membrana tympani is cov- ered by an investment of cartilage, the perichondrium and fibrous tissue of the lamina propria becoming firmly united. A plate of cartilage also covers the base of the stapes which connects with the fenestra ovalis. The annular ligament, consisting of fibrous tissue, occupies the remainder of the fenestra ovalis. The: Eustachian Tube:. — This consists of two parts, bone and cartilage composing the frame work, and the mucous membrane. Complete walls are not formed, the completion of the tube being by means of fibrous and other tissues. Mucous membrane lines the entire tube, the por- tion below the firm structure having a layer of sub-mucous tissue, but in the upper part it is intimately united with the periosteum of the bony walls. The epithelium of the tube is of the ciliated stratified columnar type, that of the pharyngeal portion being of the tall columnar, and that of the tympanic portion the low cuboidal type. The tunica propria is composed of loose connective tissue. Lymphoid cells in many places are distributed in the reticular connective tissue constituting an adenoid structure. This distribution varies with age, being most generally dis- tributed in childhood, but in adolesence being confined al- most entirely to the lower third. At the pharyngeal end small mucous glands are constant, but they may occur throughout the entire tube. Sub-mucous Layer. — In the cartilaginous portion of the tube the sub-mucous layer is well developed and is com- posed of fibro-elastic tissue. Blood Vessels. — The blood supply to the mucous mem- brane is from the tympanic and pharyngeal vessels. Nerves. — These are derived from the tympanic and pharyngeal plexuses, and are situated in the deeper mucosa layers, filaments reaching the epithelial surface. tun Inner Ear. 6 9 The Inner Ear, or Receptive Portion. Under this heading the inner ear, auditory nerve and its origin ai e necessarily included. The internal ear proper consists of the bony and mem- branous labyrinth. The bony portion consists of a series of communicating cavities in the petrous portion of the tem- poral bone, filled with fluid, the perilymph, in which the membranous labyrinth is suspended. This latter portion is composed of a series of membranous tubes which corre- jerri^g- Hamulus cochUat The bony Labyrinth. Fig. 23. spond in general contour to the bony portion, and these tubes are also filled with fluid, the endolymph. The Bony Labyrinth. — This may be Considered as a cen- tral cavity, the vestibule, from which tortuous canals di- verge. This central cavity is ovoid in shape, the vertical diameter being the longest, measuring about a quarter of an inch. The short diameter is about one-fifth of an inch. The outer wall presents the foramen ovale, which normally is closed by the foot-plate of the stapes. The inner wall contains two fossae, separated by a bony spine, the crista vestibuli. The anterior fossa, the recessus 7o Nose, Throat and Ear. sphericus, lodges the saccule. The posterior fossa, the re- cessus ellipticus, lodges the utricle. The posterior wall contains the openings of the three semi-circular canals. There are five openings, as the supe- rior and posterior canals enter the vestibule by one opening. The cochlear canal entrance occupies the place of the an- terior wall of the vestibule. Near the border of the re- Cessus ellipticus is a small opening, the orifice of the aque- ductus vestibuli, through which the cavities of the mem- branous labyrinth communicate with the subdural space. x SupF semicircular Canal. rsermctrcu-lcvr Canal J?jc£± ' semi<