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 Functional diagnosis; the application of 
 
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FUNCTIONAL DIA GNOSIS 
 
 THE 
 
 Application of Physiology to Diagnosis 
 
 By THOMAS G. ATKINSON, M.D.. 
 Associate Professor of Neurology and Physiology, Chicago College 
 of Medicine and Surgery; Professor and Head of Departmcn 
 of Physiology, Chicago College of Dental Surgery; Editor of the 
 Medical Standard; Author of "Essentials of Refraction. " 
 
 FIRST EDITION 
 
 CHICAGO: 
 New Medicine Publishing Company 
 
 T 
 
X <~. ■ 'i 4 "i -x 
 
 Copyright' 1909, 
 New Medicine Publishing Company 
 
 /c'C 
 7/ 
 ft 67 
 
CONTENTS 
 
 INTRODUCTION 1 
 
 RESPIRATION 9 
 
 CIRCULATION 40 
 
 DIGESTION 78 
 
 ELIMINATION 116 
 
 INNERVATION .... 137 
 
 SPECIAL FUNCTIONS. 
 
 Vision 175 
 
 Hearing 187 
 
 Smell 192 
 
 Taste 194 
 
 Reproduction 197 
 
INTRODUCTION. 
 
 Two considerations have led to the compilation 
 of this work. 
 
 1. The author's experience as a teacher of physi- 
 ology to first and second year students, and of neu- 
 rology to third and fourth year men, has forced 
 upon him the conclusion that, no matter how thor- 
 oughly the former subject may be instilled into 
 the student during the early years of his course, or 
 how intelligently received by him, the teacher of 
 diagnosis in the latter years is always obliged to re- 
 trace a great deal of the ground in order to eluci- 
 date the relations betewen the normal and the ab- 
 normal, and above all, the working value of symp- 
 toms in interpreting functional perversion. 
 
 The accomplishment of this retracement with the 
 maximum directness and economy, it seemed to the 
 writer, would be greatly facilitated by the use of 
 a text book which should set forth these relations 
 in a sequential and systematic form — a thing which 
 no text book on diagnosis has thus far attempted 
 Or possibly a yet more excellent way would be to 
 use this book in teaching freshmen and sophomores 
 physiology, so that by the time they were ready to 
 take up diagnosis they would already have a basic 
 understanding of the sequential relations between 
 normal and deranged function, as manifested in the 
 symptoms of various diseases. 
 
 2. In the maturer practice and literature of diag- 
 
2 FUNCTIONAL DIAGNOSIS 
 
 nosis precisely the obverse of the above condition 
 prevails. There is an obvious hiatus in the current 
 teaching and practice of the subject — a missing link, 
 so to speak, between physiology and pathology. 
 Current text books base their diagnostics upon the 
 isolated, objective, morbid conditions which consti- 
 tute the disease-complex, and which too often rep- 
 resent the last structural changes wrought by dis- 
 ease, rather than the functional derangement in 
 which disease usually has its beginnings. The spirit 
 of the times calls for a prophylactic type of diag- 
 nosis — one that shall detect disease in its functional 
 outposts. 
 
 It is of prime importance that the diagnostician 
 be able to reason back his symptoms to their func- 
 tional premises, and to state his pathologic condi- 
 tion in terms of physiology. It is of equal import- 
 ance that he be able to establish this functional 
 relation as directly and as' close to the normal as 
 possible, so that his diagnosis may be as nearly as 
 possible a proximate principle. This is where, in the 
 author's judgment, all of the many excellent works 
 on diagnosis now in the field are lacking, and it is 
 in the hope of making good this lack, and establish- 
 ing a direct, sequential connection between normal 
 physiology and disease symptoms, that this work 
 on functional diagnosis is offered. It attempts the 
 task of translating the normal functions of the 
 body, through their various derangements, into 
 terms of disease. 
 
FUNCTIONAL DIAGNOSIS 3 
 
 Those parts of the book which treat of pure 
 physiology are so arranged and printed as to con- 
 stitute in themselves a fairly complete text book on 
 that subject, though necessarily condensed. The 
 avowed purpose of the work being to point out the 
 functional significance of symptoms, it deals purely 
 with function and not at all with anatomy. The 
 reader is presumed to be already acquainted with 
 anatomy, or must gain his acquaintance from an- 
 other book. 
 
 No attempt is made to elaborate, far less to argue, 
 the pros and cons of those disputed theories which 
 still divide the ranks of physiologists. Where a de- 
 cision is necessary, the author has carefully can- 
 vassed the concensus of opinion, as reflected in re- 
 cent literature, and has boldly adopted the theory 
 which commands the preponderance of evidence. 
 
 A consideration of the optics of the eye and the 
 acoustics of the ear has purposely been omitted. In 
 their pure intent, these phases of vision and hearing 
 have no bearing upon pathology, and are therefore 
 not germane to a study of functional diagnosis. 
 Convergence and accommodation, being integral 
 parts of the physiology of vision, are dealt with. 
 
 Naturally the function of reproduction, in its 
 strict interpretation, does not lend itself very exten- 
 sively to pathologic application. The only patho- 
 logical question in this connection, having a strictly 
 physiologic value, is "to reproduce or not to re- 
 produce?" The other phases of the subject belong 
 
4 FUNCTIONAL DIAGNOSIS 
 
 to a consideration of embryology and obstetrics. 
 However, the point has been strained to the extent 
 of considering the commoner disturbances of men- 
 struation, and the elementary aspects of abnormal 
 parturition, such as muscular inertia, and the like. 
 No very detailed application has been attempted in 
 this direction. The line had to be drawn some- 
 where, or it would have necessitated a text book on 
 gynecology and obstetrics. 
 
 The author hopes that his efforts will be found 
 helpful to both student and practitioner in establish- 
 ing a sequential link between physiology and mor- 
 bid function, and enabling him to make an intelli- 
 gent functional interpretation of the symptom-com- 
 plex of disease. 
 
FUNCTIONAL DIAGNOSIS 5 
 
 NOVEL ADVANTAGES OF THE WORK. 
 
 It presents — as no other book on diagnosis does — 
 the normal function, and the derangement of it 
 which constitutes disease, in sequential relation. 
 Every normal function of the body and its organs 
 is briefly but clearly described, its mechanism and 
 significance explained; immediately following are 
 given the various derangements to which, in the 
 nature of them, these functions are subject; the 
 symptoms to which, because of their influence upon 
 the normal function these derangements give rise; 
 the diseases in which these derangements occur, and 
 why. 
 
 This is an entirely new and much-needed stand- 
 point of diagnosis, and offers the following valuable 
 practical features : 
 
 1. It bridges the gap, left by current works 1 on 
 diagnosis, between normal function and the symp- 
 toms of disease. The mere symptoms themselves, 
 detached from the normal of which they are a per- 
 verted index, are made the ordinary basis of diag- 
 nosis. 
 
 2. It enhances the functional element in diag- 
 nosis, giving it a dynamic rather than a static char- 
 acter, regarding the body as a going machine, whose 
 diseases are aberrations of function rather than 
 structural changes. 
 
 3. It enables the student and practitioner to rea- 
 son back the pathologic findings to their functional 
 
6 FUNCTIONAL DIAGNOSIS 
 
 premises, and thus to gain an intelligent conception 
 of the fundamental trouble, irrespective of the 
 name-classification of the disease. 
 
 4. It furnishes a functional, rather than a patho- 
 logical classification of diagnostic data, by which 
 symptoms may be interpreted according to their 
 physiological import. 
 
 (For example, a derangement of respiration is 
 often not directly due to a defect in the respiratory 
 organs, and its explanation cannot therefore be 
 found under Diseases of the Eespiratory System, as 
 ordinarily classified. In this bok all derangements 
 of the respiration are expounded under Respiration, 
 because respiration is treated as a function, and 
 everything that influences or modifies it is included 
 under that heading. 
 
 5. It furnishes a combined text book on physiol- 
 ogy and diagnosis — two subjects which are funda- 
 mentally related — a distinct advantage to the stu- 
 dent of these subjects, and no less advantageous to 
 the physician who practices diagnosis. 
 
FUNCTIONAL DIAGNOSIS 7 
 
 FUNCTIONAL DIAGNOSIS. 
 
 The ascendancy of the micro-organism and the 
 marvelous advances in laboratory methods have of 
 late years lent an exaggerated importance to these 
 agencies of diagnosis, to the discounting of the func- 
 tional element. Symptomatology has almost wholly 
 given place to objective and especially to labora- 
 tory findings. Further than this, there has been a 
 growing tendency toward scientific specialism, and 
 while physiology as an independent science has of 
 late made gigantic strides, and greatly enlarged the 
 scope of its jurisdiction, there has been an equally 
 growing tendency to divorce it from its mutual re- 
 lations with other branches of medicine which have 
 undergone similar expansion. 
 
 It is in the hope of contributing, however feebly, 
 to the re-establishment of these neglected relation- 
 ships upon a practical clinical footing that this 
 work on applied physiology is offered. Disease is, 
 after all, essentially a phenomenon of function, of 
 which structural aberrations are but the resulting 
 manifestations. As Dr. Putnam said, in his mas- 
 terly address before the Congress of Arts and Sci- 
 ences : "No anatomical research can pierce the secret 
 of broken co-ordinations, and yet it is in these that 
 a great part of disease begins, or eventually comes 
 to consist. " It is therefore of prime importance that 
 the diagnostician be able to reason back his symp- 
 tomalogical data to their functional premises, and to 
 
8 FUNCTIONAL DIAGNOSIS 
 
 state his pathological condition in terms of physiol- 
 ogy. And it is with a view of assisting him in the 
 process that the writer has here attempted the in- 
 verse task of translating physiological phenomena, 
 through functional aberration, into term^ of path- 
 ology. 
 
FUNCTIONAL DIAGNOSIS ? 
 
 RESPIRATION. 
 
 The Lungs may be considered as two large sacs 
 which communicate with the external atmosphere 
 by means of the trachea, the external walls of the 
 sac being in adherent relation to the walls of the 
 thorax. The thorax, outside of the lung-sac, is com- 
 pletely shut off from communication with the at- 
 mosphere and with the abdomen. 
 
 Retractions. — Owing to the adherence of the lung 
 sac to the chest walls, a cicatrix in the former will 
 pull in the external covering of the chest and pro- 
 duce a depression. These depressions are often seen 
 in tubercular cases where there has been an old 
 cavity that has cicatricized. They may be found in 
 any of the intercostal spaces, but are most com- 
 mon in the clavicular and subclavicular spaces, due 
 to apical cicatrices. 
 
 Pneumothorax. — In cases of tuberculosis and oth- 
 er processes of lung degeneration the lung sac fre- 
 quently ruptures under exertion or cough, and air 
 is forced into the thorax at each inspiration. This 
 condition is known as pneumothorax. It may, of 
 course, also result from a penetrating wound of the 
 chest wall. 
 
 Respiratory Sounds. — The two types of sound 
 heard in normal respiration are (1) that produced 
 by the passage of the air through the bronchi, called 
 bronchial breathing, and (2) that produced by the 
 
10 FUNCTIONAL DIAGNOSIS 
 
 inflation of the lung alveoli, called vesicular breath- 
 ing. 
 
 Bronchial breathing sounds, as might be expected, 
 are rough and sonorous, and are equally prominent 
 in inspiration and expiration, except for the differ- 
 ent force with which the air is driven through the 
 tubes. 
 
 Vescicular breathing sounds are softer and more 
 blowing in character; and inasmuch as they are 
 caused by alveolar inflation, they are confined al- 
 most entirely to inspiration, the almost sudden re- 
 coil of the lungs in expiration putting a rapid end 
 to the vescicular sound. 
 
 Normal breathing sounds heard through the chest 
 wall are made up of a combination of these two 
 elements. The bronchi being at almost every point 
 overlaid with lung (always containing more or less 
 air) the bronchial sounds are not well conducted 
 to the chest wall, and are therefore in normal breath- 
 ing greatly subordinated to the vescicular sounds. 
 This is especially the case in inspiration, when the 
 alveoli are filling with air. In expiration, when the 
 alveoli are recoiling and emptying, the bronchial 
 sounds become more dominant. 
 
 In infants and young children, in whom the lung 
 tissue is relatively undeveloped, the bronchial 
 sounds are normally much more dominant than in 
 adults. 
 
 Bronchial Breathing.— Anything which lessens the 
 layer of air-containing lung between the bronchi 
 
FUNCTIONAL DIAGNOSIS 11 
 
 and the chest wall, or increases the conductivity of 
 the medium, exaggerates the bronchial element in 
 the respiratory sounds, and gives what is known as 
 bronchial breathing. Chief among these influences, 
 of course, is consolidation of lung tissue, which has 
 both the effects enumerated above. 
 
 Bronchial breathing is therefore found in pneu- 
 monia, tuberculosis, syphilis of the lung, etc., over 
 the areas consolidated by the process. 
 
 Vescicular Breathing is found in just the re- 
 verse premises to those which cause bronchial 
 sounds, i. e., in those which increase the amount of 
 air-containing lung between the bronchi and the 
 chest wall. Such a type of breathing is heard in 
 emphysematous conditions, especially vicarious and 
 surgical emphysema, and asthma. 
 
 Stridulous Breathing, a harsh whistling sound 
 during inspiration, is frequently heard in cases of 
 tracheal and laryngeal obstruction by spasm, oede- 
 ma, membranous croup, severe catarrhal inflamma- 
 tion, etc., the sound being due to stenosis of the air 
 passage. 
 
 Hiccough. — Sometimes the glottis closes spasmod- 
 ically before inspiration is completed, producing a 
 sudden stenosis of the air passage and thus causing 
 a spasmodic stridor. This is familiarly known as 
 hiccough. 
 
 Vescicular Breathing is exaggerated by any con- 
 ditions which increase the amount of air lying be- 
 tween the bronchi and the chest wall, as, for instance, 
 
12 FUNCTIONAL DIAGNOSIS 
 
 emphysema, before the elasticity of the lining is 
 impaired, especially vicarious emphysema. Vesci- 
 cular sounds are diminished without any special ex- 
 aggeration of bronchial sounds, (1) by any condi- 
 tions which impair lung elasticity, as emphysema in 
 later stages, oedema, etc., (2) by the presence of air 
 or water in the surrounding thorax (hydro or pneu- 
 mothorax), owing to pressure exerted on the lung; 
 (3) by pleuritic pains limiting the movements of 
 the chest; (4) by occlusion of air passages, lessen- 
 ing the entrance of air into the lungs. 
 
 In bronchitis the breathing is of a bronchial type 
 in the early stages, because of the exaggerated 
 roughness of the tubes; later, it becomes vescicular, 
 owing to the emphysema and loss of elasticity of 
 the lungs. 
 
 Suppressed Breathing Sounds. — Where the lungs 
 are surrounded with air or water, as in pneumo or 
 hydro-thorax, both tubular and vesicular sounds 
 are muffled and in many cases almost inaudible. 
 
FUNCTIONAL DIAGNOSIS 13 
 
 PERCUSSION. 
 
 The principles of percussion are based upon ana- 
 tomical, rather than upon physiological, premises. 
 In general, percussion sounds may be said to de- 
 pend upon the anatomical conditions corresponding 
 to the physiological conditions accounting for aus- 
 cultatory sounds. Generally speaking, in instances 
 and locations where the bronchial sounds predomi- 
 nate, as in consolidations of pneumonia, tuberculo- 
 sis, syphilis, gangrene, etc., the percussion note is 
 dull or flat ; where the vescicular sounds are in the 
 ascendant, percussion gives a hyper-resonant note, 
 as in emphysema, asthma, etc. 
 
 However, as the pitch and quality of the per- 
 cussion note depend upon the relative resistance of 
 the part percussed rather than upon its conductivity, 
 there are exceptions to this correspondence between 
 auscultation and percussion. For example, a cavity 
 in the lung will give bronchial sounds, because the 
 vescicular tissue is gone from between the bronchi 
 and the chest wall, but percussion over a cavity will 
 yield hyper-resonance. Pneumothorax and hydro- 
 thorax alike diminish both vesicular and bronchial 
 sounds, but the former gives a hyper-resonant note 
 because of its elasticity, upon percussion and the 
 latter a flat note because of its solid resistance. 
 
14 FUNCTIONAL DIAGNOSIS 
 
 INSPIRATION AND EXPIRATION. 
 
 Inspiration is accomplished by enlarging the ca- 
 pacity of the thorax by means of the muscles ; the 
 lungs, being adherent to the walls of the thorax, 
 are expanded and air rushes in by way of the glot- 
 tis and trachea to fill the vacuum thus created. In- 
 spiration is therefore an active muscular process. 
 
 Expiration, is accomplished by the elastic recoil 
 of the lung and the weight of the ribs — purely 
 physical forces — and is a passive return to equi- 
 librium. 
 
 Delayed Expiration. — Any condition which inter- 
 feres with the free expiration of air from the lungs 
 exerts increased resistance to the recoil of the elas- 
 tic tissues and to the gravity of the ribs, and hence 
 prolongs the passive process of expiration. Bron- 
 chitis, asthma, nasal and laryngeal catarrh, enlarged 
 tonsils and growths^ all of which block the air pass- 
 ages, are prominent illustrations. The same result 
 attends any pathological lesion which impairs the 
 elasticity of the lungs. Delayed expiration, if long 
 continued, eventually results in undue retention of 
 air in the lungs (Emphysema. See below), and the 
 external circumference of the thorax is enlarged 
 (barrel chest). 
 
 Prolonged Inspiration is seen in any condition 
 which interferes with the free passage of air into 
 the lungs through the glottis and trachea. As the 
 same causes, however, usually interfere equally with 
 
FUNCTIONAL DIAGNOSIS 15 
 
 expiration, the relative lengths of the functions is 
 the same as those described under delayed expira- 
 tion. Movable tumors of the larynx occasionally 
 interfere with inspiration and not with expiration. 
 Forced Inspiration. — Under any pathological con- 
 dition which renders the performance of inspiration 
 difficult, or which necessitates a greater number of 
 inspirations in a given time, the ordinary muscles 
 of inspiration have to be reinforced by the acces- 
 sory muscles of respiration, namely, the sternocleido- 
 mastoid and those muscles which control the size 
 of the nasal and tracheal openings. The involve- 
 ment of the muscles in the act of inspiration will 
 be found an unfailing indication of seriously em- 
 barrassed respiration, such as occurs in pneumonia, 
 emphysema, pulmonary oedema, advanced tubercu- 
 losis, all those diseases of the heart and thorax which 
 impede inspiration (hydro and pneumothorax), and 
 all conditions which obstruct the air passages, as 
 laryngeal oedema, growths, membranous croup, 
 laryngismus, etc. 
 
 ■Si *m *m 
 
 Mechanism of Inspiration. — The enlargement of 
 the thorax takes place in its cross diameters by the 
 raising of the ribs and in its vertical diameter by 
 the lowering of the diaphragm by contraction. 
 
 In regard to the first process, it may be said that 
 all those muscles whose contraction elevates the ribs 
 are muscles of inspiration. However, all such mus- 
 cles are not haibtually used in normal inspiration. 
 
16 FUNCTIONAL DIAGNOSIS 
 
 Those which ordinarily take part in the process are 
 the costals, intercostals, scaleni and serrati. 
 
 It must be remembered that the ribs normally 
 slant downward from the spine ventrally, so that 
 when their ventral ends are raised the distance 
 between the spine and the sternum is increased. In 
 like manner, the line of junction between the rib 
 and the spinal tubercle is inclined downward later- 
 ally, so that elevation of the rib increases the lateral 
 diameter of the chest. 
 
 The second process, the descent of the diaphragm 
 is accomplished by the drawing downward of the 
 central tendon. The downward pressure of the dia- 
 phragm on the abdominal organs causes them to 
 bulge the abdomen outward. Diaphragmatic breath- 
 ing is, therefore, called abdominal breathing. 
 
 The lungs, being adherent on all sides to the chest 
 wall, expand in every direction that the chest en- 
 larges, and fill with air. The muscles, therefore, 
 have to overcome (a) the weight of the ribs and 
 (b) the elastic pull of the lungs. 
 
 Unequal Expansion of the two sides of the thorax 
 may be due to an impairment of the elasticity of 
 the lung tissue on one side or to an immobility due 
 to the binding down of the pleural sac by old ad- 
 hesions (in which case the outer wall will be re- 
 tracted as already described), or to effusions or 
 tumors in the thorax (in which case the immobile 
 side will be distended). 
 
FUNCTIONAL DIAGNOSIS 17 
 
 Litten's Phenomenon. — In the position of respira- 
 tory rest, the diaphragm lies flat against the thorax 
 from its attachment to about the sixth rib. Upon 
 inspiration this muscular layer "peels off," as Cabot 
 says, "as it descends and allows the lung to take 
 its place." This "peeling off" of the thick dia- 
 phragm and its replacement by the line of lighter 
 lung tissue can be seen, in a proper position and 
 light, as a shadow moving down the lower part of 
 the chest wall. 
 
 In order to perceive this phenomenon, the pa- 
 tient must lie flat on his back, his entire chest bared, 
 his feet turned toward the only source of light in 
 the room, the observer seated at his side, and must 
 take a full breath. The shadow, of course, depends 
 upon the ripple of different level that passes over 
 the chest surface as the thick diaphragm recedes 
 and gives place to the thin lung tissue. 
 
 In pleuritic adhesions, the movements of the dia- 
 phragm are prevented ; in effusions, emphysema and 
 pneumonia, the diaphragm is separated from the 
 chest wall, hence the shadow is not seen. Solids 
 or fluids under the diaphragm, unless extremely 
 large, do not interfere with its movements. 
 
18 FUNCTIONAL DIAGNOSIS 
 
 TYPES OF BREATHING. 
 
 The natural type of breathing is that which starts 
 with the diaphragm, the first perceptible movement 
 being an obtrusion of the abdomen. Thence the 
 process spreads upward, involving the ribs and 
 shoulders. This type is called the abdomino-costal 
 type, and is almost universal among men. In civil- 
 ized women, on the contrary, the diaphragm takes 
 but little part in respiration and the ribs in conse- 
 quence acquire an exaggerated importance; this is 
 called costal breathing. Investigation demonstrates 
 that it is due to a difference of dress, and not to 
 genuine sexual differences. The types may be, and 
 often are, modified by disease. 
 
 Pathological Variations of Type are seen in cer- 
 tain diseases. In diseases of the chest, where costal 
 expansion causes pain, as in pleurisy, pneumonia, 
 etc., and where intrapulmonary pressure is in- 
 creased, as in hydro or pneumo-thorax and emphy- 
 sema, the diaphragm is the main factor in respira- 
 tion, producing the abdominal type of breathing. 
 
 In abdominal lesions, on the contrary, such as 
 tumors, ascites or visceral enlargement impeding the 
 movements of the diaphragm, the breathing is most- 
 ly costal. 
 
 In paralysis of the phrenic nerves the breathing 
 is, of course, costal, and in paralysis of the inter- 
 costals the reverse. The latter is, however, rare 
 except immediately preceding death. 
 
FUNCTIONAL DIAGNOSIS 
 
 19 
 
 Reflex Inspiration. — We have already discussed 
 the question of the automaticity of the respiratory 
 centre. But whether it is normally an automatic 
 center or not, it is undoubtedly a reflex one, in di- 
 rect connection with and subject to reflex stimulation 
 by most, if not all, of the spinal and cranial sensory 
 nerves. This is familiarly illustrated by the muscle- 
 sense, etc. That it is also subject to reflex stimula- 
 tion from the cerebrum is shown by the effects of 
 emotion upon breathing. 
 
 Naturally, however, one would expect the sen- 
 sory nerves of the respiratory tract to exert the 
 most powerful and constant reflex influence upon 
 the centre, and this is the fact. The branch of the 
 vagus nerve especially, which is distributed to the 
 lung itself, furnishes very important sensory reflex 
 stimulation. Experiment makes it probable that 
 this nerve contains both inhibitory and accelerator 
 fibres, regulating the rhythm of the lungs in much 
 the same way that the inhibitory and accelerator 
 nerves regulate the rhythm of the heart. Peripheral 
 stimulation for this reflex regulation is, of course, 
 furnished by opposite conditions of the lung, col- 
 lapse calling into play the accelerator and disten- 
 sion the inhibitory fibres. 
 
 Rapid, Shallow Breathing. — The above is un- 
 doubtedly one of the explanations of rapid breath- 
 ing in pathological conditions where only shallow 
 inspirations are possible, as in pneumonia, from 
 consolidation of lung tissue, atelectosis, from alveo- 
 
20 FUNCTIONAL DIAGNOSIS 
 
 lar collapse, pleurisy, from the pain caused by in- 
 spiration, hydro and pneumo-thorax, from compres- 
 sion, and all diseases of the heart which exert a 
 backward pulmonary pressure. Of course a further 
 explanation is found in the relation of blood oxi- 
 dation to circulation (see below). 
 
 Pain in the Chest. — As the lungs themselves are 
 supplied with no nerve fibres of pain, any thoracic 
 pain connected with respiration and referred to as 
 "pain in the lungs" must have its seat in one or 
 other of the serous sacs surrounding the lungs (the 
 pleurae) or in the bronchi. Hence, when any pul- 
 monary disease is accompanied by pain on respira- 
 tion, it is due to an attendant bronchitis or pleurisy. 
 
 Asthma is a conspicuous illustration of perverted 
 reflex influence upon respiration. Asthma is the re- 
 sult of spasm of the bronchi, and may be excited by 
 nasal obstructions and abnormalities, irritations of 
 fauces and larynx, indigestion and other peripheral 
 stimuli, acting through the respiratory centre in the 
 medulla. 
 
 Asthma of Renal Diseases is produced by the 
 toxic influence of the blood upon the centre of res- 
 piration direct. 
 
 ■V H. -W 
 
 Expiratory Centre. — In normal respiration,, in- 
 spiration is the only active factor, expiration being 
 a purely passive physical process, needing no in- 
 nervation. Hence the automatic centre of respira- 
 tion must be regarded as an inspiratory centre only. 
 
FUNCTIONAL DIAGNOSIS 21 
 
 However, under certain conditions active expiration 
 does take place, and is always rhythmical and co- 
 ordinated, so that we must suppose it is controlled 
 by a centre; and as after section of the medulla, 
 no expiratory movement has ever been demon- 
 strated, it is reasonable to locate the centre in the 
 medulla. Wherever it is located, it is not normally 
 automatic; and, as Howell points out, "its activity 
 must be dependent in some way upon that of the 
 inspiratory centre, as even our most violent res- 
 piratory movements show an orderly sequence of 
 inspiration and expiration." This author suggests 
 that "the action of the expiratory centre is con- 
 ditioned upon the previous discharge of the in- 
 spiratory centre, just as in the heart beat the con- 
 traction of the ventricle is conditioned upon the 
 previous systole of the auricle. ' ' The stimulation of 
 the expiratory centre may, in general, be said to con- 
 sist in exaggerations of the stimuli which normally 
 excite the inspiratory centre. 
 
 Automatic Stimulus. — Automacy is, of course, 
 only another term for "constant reflex produced 
 by a stimulus originating within the organism." 
 The automatic action of the respiratory centre de- 
 pends upon such a stimulus. We should naturally 
 expect to find the source of the stimulus in the 
 function which the centre controls, namely, the in- 
 terchange of the gases in the blood, and experiment 
 has demonstrated that it consists chiefly in the ac- 
 cumulation of carbon dioxid in the blood, although 
 
22 FUNCTIONAL DIAGNOSIS 
 
 the diminution of oxygen also undoubtedly plays a 
 part. 
 
 The reflex is set going in the newborn child 
 doubtless by the severance of placental circulation 
 and the consequent increase in the carbon dioxid of 
 the blood. Possibly the stimulus of the air and 
 tactile influences to the skin help. 
 
 Haldane and Priestley (Journal of Physiology, 
 xxxii. p. 225) advance what seems to be definite 
 proof that the activity of the respiratory centre is 
 normally governed by the pressure of carbon diox- 
 ide in the alveolar air and consequently in the ar- 
 terial blood. The experiments consist of careful 
 analyses under a variety of conditions of (a) sam- 
 ples of air at the end of a quick, deep expiration, 
 following inspiration; and (b) samples of air at the 
 end of a deep expiration at the usual time, the aver- 
 age of (a) and (b) being taken as the average 
 alveolar air. Making these tests in conditions of 
 bodily rest (1) at ordinary atmospheric pressure, 
 (2) on top of a mountain, (3) at the bottom of a 
 mine, and (4) in a pressure-chamber they found that 
 the percentage of C0 2 of the alveolar air reduced 
 to a pressure of one atmosphere and a temperature 
 of zero degrees was a constant; the oxygen, how- 
 ever, varied all the way from 10.4 to 26.8 per cent. 
 The ventilation in these cases is to be considered 
 constant. In case of a voluntary increase of fre- 
 quency of respiration the percentage of C0 2 in the 
 alveolar air remains constant; that is, the increase 
 
FUNCTIONAL DIAGNOSIS 23 
 
 in frequency is balanced by decrease in depth. If 
 the percentage of C0 2 in the inspired air was varied, 
 it was found that so small an increase as .2 per cent 
 in the C0 2 of the alveolar air doubled the ventila- 
 tion of the lungs. Under such conditions the oxy- 
 gen of the alveolar air was always above normal. 
 On doing work the percentage of C0 2 in the alve- 
 olar air is found to be increased. In apnoea the C0 2 
 of the alveolar air was diminished. 
 
 Zuntz and Geppert found that the arterial blood, 
 in case of work, contained less C0 2 than when no 
 work was done, and therefore they thought that 
 C0 2 was not the cause of the hyperpnoea of work. 
 But Haldane and Priestley state that while the 
 total C0 2 is diminished in the arterial blood during 
 work because of increased acid production, the pres- 
 sure of free C0 2 on the contrary is increased. They 
 thus dispose of the supposition that some other 
 product of muscular action is the cause of work 
 hyperpnoea and make it probable that C0 2 is the 
 active agent in the stimulation of the respiratory 
 centre. 
 
 Rapid Breathing in Fevers. — Doubtless the in- 
 creased frequency of breathing in fevers, especially 
 infectious and low grade fevers, where the meta- 
 bolism is rapid, is due in some measure to the ac- 
 cumulation of C0 2 in the blood, acting as an abnor- 
 mally powerful stimulus to the respiratory centre. 
 It would seem, however, that this centre, like most 
 others, can be over-stimulated, for C0 2 narcosis in 
 
24 FUNCTIONAL DIAGNOSIS 
 
 such fevers slows and enfeebles the respirations and 
 finally paralyzes them. 
 
 Impure Air. — The same remarks apply to cases of 
 respiring air poor in oxygen and rich in C0 2 . 
 ■W \ %. 
 
FUNCTIONAL DIAGNOSIS 
 
 25 
 
 PRESSURE CONSIDERATIONS. 
 
 Intrapulmonic and Intra-Thoracic Pressure. — 
 Since the lungs are in communication with the ex- 
 ternal atmosphere, it follows that the air pressure 
 in the lungs at any time of rest, whether at the end 
 of inspiration or expiration, is equal to that of the 
 atmosphere. When the lungs are expanded in in- 
 spiration, their capacity increases more rapidly than 
 the air coming through the narrow glottis can keep 
 pace with, and there is a temporary fall in pressure 
 until the pause at the end of inspiration. Contrari- 
 wise, the recoil of the chest is a little too rapid for 
 the outgoing air to equalize, and there is a rise in 
 pressure. This variation, however, is in normal 
 respiration very slight. 
 
 In the part of the thorax outside the lungs, on 
 the other hand, since it is protected from atmospheric 
 pressure from outside by the chest-wall, and that 
 which reaches it through the lung-sac is modified by 
 the elastic recoil of the lung, the pressure is always 
 negative. The more the thorax is enlarged, stretch- 
 ing the lungs with it, the more forcibly this elastic 
 recoil is brought into play and the more negative 
 becomes the intra-thoracic pressure. It may at any 
 given moment be represented as that of one atmos- 
 phere less the elasticity of the lungs. 
 
 Emphysema. — Any influence which interferes with 
 the free expulsion of air through the trachea in- 
 
26 FUNCTIONAL DIAGNOSIS 
 
 creases the intrapulmonary pressure, and opposes 
 extra resistance to the elastic recoil of the lungs, 
 bringing into play the muscles of forced expiration 
 to drive out the air. If this intrapulmonary pres- 
 sure is kept up for any considerable length of time, 
 the elasticity of the lungs at last becomes seriously 
 impaired and they are no longer properly emptied. 
 As a consequence they are in a constant state of 
 more or less inflation which is known as emphysema. 
 The same result occurs from any pathological proc- 
 ess in the alveoli themselves, which impairs their 
 elasticity ; also physiologically in old age. 
 
 This condition is seen notably in chronic bron- 
 chitis, and bronchial asthma. 
 
 Vicarious Emphysema is seen in parts of the 
 lungs where the other portions are temporarily or 
 permanently incapacitated, or in one lung where the 
 other is out of commission. The extra duty en- 
 tailed upon the sound area causes an undue infla- 
 tion and retention. 
 
 Cardiac Involvements. — Sooner or later, of course, 
 the extraordinary and constant expansion of the 
 lung causes a backward pressure upon the pulmo- 
 nary artery and interrupts the cardiac cycle, me- 
 chanically and also by virtue of inadequate oxida- 
 tion of the blood. This is compensated for a time 
 by hypertrophy of the right ventricle, but eventu- 
 ally compensation is broken and stasis ensues. 
 
 Pneumothorax. — In tuberculosis and other degen- 
 erative processes the pleural sac occasionally rup- 
 
FUNCTIONAL DIAGNOSIS 27 
 
 tures under slight exertion and air is forced into 
 the thoracic cavity at each inspiration. Or the same 
 result is produced by a penetrating wound of the 
 chest, admitting air from outside. This, of course, 
 immediately raises the intrathoracic pressure to that 
 of the atmosphere, and as this entrapped air does 
 not escape as readily as it enters, the pressure is 
 soon raised above that of the lungs, embarrassing 
 their expansion and the heart action, and causing 
 death if not relieved. 
 
 Coughing. — Any attempt at expiration with clos- 
 ure of the glottis of course raises the intrapulmonic 
 pressure. A conspicuous and extreme example is 
 seen in the familiar phenomenon of coughing. The 
 irritation of the tubes causes a spasmodic closure 
 of the glottis at the same time a violent effort is 
 made at forced expiration, raising the pressure con- 
 siderably, and resulting in the explosive opening of 
 the glottis and expulsion of air under high pressure 
 which constitutes the noisy "cough." During the 
 period of compression pulmonary circulation is in- 
 terfered with, general venous stasis occurs, and if 
 long continued causes cyanosis, and occasionally 
 rupture of one of the vessels. 
 
 •m *m "W 
 
 Suction Effect of Negative Pressure. — From the 
 foregoing it is seen that the large veins above and 
 below the thorax are subject to atmospheric pres- 
 sure; the venae cavae and the right auricle, on the 
 eontrary. are wider a pressure of less than one at- 
 
28 FUNCTIONAL DIAGNOSIS 
 
 mosphere. This difference in pressure levels acts 
 as a suction influence, assisting the flow of venous 
 blood to the heart. It is, of course, more marked 
 with every expansion of the lung in inspiration 
 which makes the pressure still more negative. 
 
 In pneumo and hydro-thorax, of course, this suc- 
 tion phenomenon is lacking, because the intratho- 
 racic pressure is raised to the level of, and some- 
 times even higher than, the intrapulmonic. This 
 helps to explain the venous stasis occurring in these 
 conditions. 
 
 Respiratory Waves of Blood Pressure. — Experi- 
 ments show that during inspiration there is first, at 
 the beginning of the inspiratory act, a slight fall 
 in blood pressure, then a rise; at the beginning of 
 expiration there is a slight rise, followed by a notice- 
 able fall. These phenomena are explained as fol- 
 lows: 
 
 At the commencement of inspiration the capacity 
 of the lung-capillaries is suddenly increased, lessen- 
 ing peripheral resistance and causing a momentary 
 fall in pressure. This is quickly out-balanced by the 
 following occurrences, both of which tend to raise 
 the pressure: (1) Suction of increased negative 
 pressure in the thorax, causing increased flow of 
 blood into the heart; (2) difference of atmospheric 
 pressure level in the pulmonary artery and vein, 
 causing an increased flow of blood out of the heart. 
 
 At the beginning of expiration the sudden con- 
 traction of the lung-capillaries causes a momentary 
 
FUNCTIONAL DIAGNOSIS 29 
 
 rise in pressure, which is quickly overwhelmed by a 
 reversal of the conditions described under (1) and 
 (2) in the previous paragraph, producing a distinct 
 fall in pressure. 
 
 Respired Air. — The air respired by the lungs is 
 classified in various fractions of its volume accord- 
 ing to their exchange under various physiological 
 conditions. The classification is as follows: 
 
 Tidal Air. — The amount of air breathed in and 
 out during a normal respiration. 
 
 Complemental Air. — The amount of air that can 
 by forced inspiration be taken in in excess of the 
 tidal air. 
 
 Supplemental Air. — The amount that can by 
 forced expiration be expelled in excess of tidal air. 
 
 Residual Air. — The amount which remains in the 
 lungs even after the supplemental air is expelled. 
 
 Minimal Air. — The small amount which is cap- 
 tured by the collapse of the small bronchi in an ex- 
 posed and collapsed lung. A lung that has once 
 breathed never thereafter becomes entirely airless; 
 it always retains the minmial air even after death. 
 
 Vital Capacity is the term used to express the 
 amount of air that a person can inspire and expire, 
 and is, of course, equal to the tidal air plus the com- 
 plemental and supplemental. 
 
 Pressure Conditions of Oxygen in Respiration. — 
 The pressure of the atmosphere is equal to a column. 
 of mercury 760 mm. high, and is expressed as 760 
 
30 FUNCTIONAL DIAGNOSIS 
 
 mm. Hg. According to the law of partial pressure 
 of gases, the oxygen in the atmosphere, forming 
 one-fifth of its volume, exerts one-fifth of its pres- 
 sure — i. e., 152 mm. Hg. This pressure determines 
 the point of equilibrium at which oxygen is held in 
 solution or dissociable combination by a liquid in 
 the presence of atmospheric air. At this pressure, 
 the hemoglobin of the blood is saturated with oxy- 
 gen and as long as the oxygen-pressure in the atmos- 
 phere is maintained the oxygen equilibrium between 
 the blood and the air is maintained at saturation 
 point. If the proportion of oxygen in the atmos- 
 phere is increased the equilibrium is disturbed and 
 oxygen flows from the air to the blood (to the limit 
 of absorption by the plasma) ; if the proportion of 
 oxygen in the atmosphere is diminished the equilib- 
 rium is disturbed the other way, and oxygen flows 
 from the blood to the air. The same condition ob- 
 tains if for the air is substituted another environ- 
 ment containing a more or less pressure of oxygen. 
 
 The blood at the surface of the lungs is practically 
 under 152 mm. Hg. oxygen pressure (i. e., one-fifth 
 atmospheric pressure.) In its course along the ar- 
 teries this oxygen pressure is gradually lowered as 
 it comes into contact with greater and greater areas 
 of tissue devoid of oxygen. By the time it reaches 
 the capillaries the oxygen pressure has come down 
 to 76 mm. Hg. In its passage through the capillaries, 
 where this low pressure area is greatly increased, the 
 oxygen pressure is rapidly reduced, and the oxygen 
 
FUNCTIONAL DIAGNOSIS 31 
 
 just as rapidly given off to preserve the oxygen 
 equilibrium. When it reaches the lungs again, with 
 very little oxygen in it, it is suddenly subjected once 
 more to an oxygen pressure of 152 mm. Hg. and sat- 
 urated with the gas. 
 
 Difference of Pressure at Lungs. — Experiment 
 shows that the relative pressures of oxygen in the 
 alveolar air, where the exchange is made, and the 
 venous blood that is brought to the lungs by the pul- 
 monary arteries are as follows: 
 
 Alveolar air — 83 to 129 mm. 
 
 Venous blood — 40 mm. ■ 
 
 It is evident that the exchange takes place from 
 the air toward the blood. 
 
 Insufficient Oxidation. — It will be readily seen 
 that any diminution in the oxygen pressure at the 
 lungs will result in an abnormally small impartation 
 of this gas to the venous blood, and consequently in 
 poor oxygenation of the tissues. This may occur 
 either from (a) poverty of the surrounding air in 
 oxygen or (b) any condition of the respiratory mech- 
 anism which tends to rarify the air as it enters the 
 lungs — e. g., stenosis of the trochea or bronchi — 
 causing undue negative pressure during inspiration ; 
 or emphysema, in which the inspired air is continu- 
 ally diluted by an excess of residual air. 
 
 Chemical and Physical Changes in Respired Air. 
 — Expired air differs chemically from inspired air 
 in having lost a part of its oxygen and acquired 
 
32 FUNCTIONAL DIAGNOSIS 
 
 carbon dioxid. This is indeed the chief end of res- 
 piration, the carrying of oxygen to the blood and the 
 removal of carbon dioxid. The proportion of gain 
 and loss depends, of course, upon the character of 
 the inspired air, depth of inspiration, etc. Under 
 normal conditions, however, the exchange is about 
 as follows: 
 
 
 
 
 C0 2 
 
 
 Insp 'd. 
 
 Bxp'd. 
 
 OLost. Gained. 
 
 Oxygen 
 
 21 
 
 16 
 
 .05 
 
 Carbon dioxid. 
 
 ... 00.4 
 
 4.5 
 
 .04 
 
 
 79 
 
 79 
 
 . . 
 
 It will be seen that more oxygen is lost than is 
 represented by the carbon dioxid which replaces it. 
 The excess oxygen is utilized in oxydizing hydro- 
 gen in the body to form water. 
 
 Physically the expired air differs from inspired 
 air in being warmer (equal to body temperature) 
 and saturated with water vapor from the lung sur- 
 face. This loss of heat and water is a subsidiary 
 function of respiration in regulating the tempera- 
 ture and moisture of the body. 
 
 Pressure Conditions of Carbon Dioxid. — The par- 
 tial pressure of carbon dioxid in the atmosphere, 
 on the other hand, is only four-hundredths of the 
 atmospheric pressure, or 30.4 mm. Hg. At this pres- 
 sure the blood contains 38 per cent by volume of car- 
 bon dioxid. During the passage of the blood through 
 the arteries and capillaries, the carbon dioxid pres- 
 
FUNCTIONAL DIAGNOSIS 33 
 
 sure increases, just as the oxygen pressure decreases, 
 and carbon dioxid flows to the blood, taking the 
 place of the oxygen which under decreased pressure 
 has passed to the tissues. "When the blood reaches 
 the lungs again, containing 45 per cent of carbon 
 dioxid, it is suddenly subjected to the low C0 2 pres- 
 sure of the atmosphere, and parts with enough to 
 adjust C0 2 equilibrium with the atmosphere. 
 
 Difference of Pressure at Lungs. — The relative 
 pressures of carbon dioxid in the alveoli and in the 
 venous blood are as under : 
 
 Venous blood — 45 mm. 
 
 Alveolar air — 28 to 41 mm. 
 Showing an inevitable exchange in favor of the air. 
 
 Insufficient Decarbonization. — Any increase of C0 2 
 pressure in the alveoli will, of course, result in an in- 
 sufficient diffusion of this gas from the blood. 
 
 ^ ^ -y 
 
 Pressure Condition of Nitrogen. — Experiment has 
 shown the amount of nitrogen in arterial blood and 
 in venous blood to be the same — namely, 1.7 per cent 
 — and as this quantity corresponds with the co- 
 efficient of absorption of nitrogen for blood at body 
 temperature — i. e., the amount absorbed by 1 ce. at 
 a pressure of 1 atmosphere — it may safely be con- 
 cluded that nitrogen enters into merely physical so- 
 lution in the blood, in accordance with Dalton's 
 law, and plays no part in the respiratory function. 
 
 Internal Respiration. — It is, of cource, in the tis- 
 sues supplied by the blood that the exchange of 
 
34 FUNCTIONAL DIAGNOSIS 
 
 gases which constitutes respiration actually takes 
 place. In the tissues surrounding the capillaries C0 2 
 is being rapidly formed by metabolism, and the C0 2 
 pressure is therefore high. Oxygen, on the contrary, 
 is being constantly utilized for carbo-hydrate com- 
 pounds (too stable to be dissociated) and pressure 
 is therefore low. In the blood, as it enters the capil- 
 laries, the pressure conditions of the two gases are 
 the reverse of this — hence the flow of oxygen to the 
 tissues and of carbon dioxid to the blood. Both of 
 the exchanges take place through the plasma of the 
 blood and the surrounding lymph. 
 
 C0 2 Narcosis. — Any interference with the process 
 of respiration, unless compensated for, will ulti- 
 mately result in an accumulation of C0 2 in the tis- 
 sues to an extent which will render them inert and 
 unable to perform their proper functions. This con- 
 dition is known as C0 2 Narcosis, and is the cause of 
 death in all diseases which kill by impeding res- 
 piration. 
 
 "• -W *m 
 
 Variations in Respiratory Frequency. — From what 
 has gone before it is evident that the rapidity of res- 
 piration may be modified by either one of two gen- 
 eral conditions : 
 
 (1) By any condition influencing the expansion 
 and recoil of the lungs, acting as a stimulant of the 
 accelerator or depressor nerves of the lungs. 
 
 (2) By any condition influencing the quantity of 
 
FUNCTIONAL DIAGNOSIS 35 
 
 carbon dioxid in the blood, acting as a direct stimu- 
 lant of the respiratory centre. 
 
 Physiological variations are probably rarely, if 
 ever, primarily due to the first of these groups of 
 conditions, as it is hard to conceive of any set of 
 normal conditions which could directly cause an ex- 
 aggerated or diminished expansion of the chest. The 
 pathological conditions which influence this feature 
 of respiration are described elsewhere. 
 
 The latter group includes (a) varying degrees of 
 metabolism and consequent variations in carbon 
 dioxid production, (b) conditions influencing the 
 gaseous exchange in the lungs or tissues, and thus 
 influencing the quantity of C0 2 in the blood, (c) the 
 velocity and pressure of the blood, and its oxygen- 
 carrying power. These influences may all be, and 
 continually are, exerted in varying degree in the 
 ordinary course of physiological activity, causing 
 continual variations in the frequency of respiration, 
 which are familiar to everyone. 
 
 The increased frequency of breathing during mus- 
 cular exercise, the diminished frequency during rest 
 and sleep, the increased rate under vitiated atmos- 
 pheric conditions and decreased rate under pure air, 
 the differing effects of heat and cold, hunger and sa- 
 tiety, are well-known phenomena. Of these, the in- 
 fluences of metabolism, and especially muscular ex- 
 ercise, where C0 2 is very rapidly produced, are the 
 most common. 
 
 It is a well-known fact that the respiration is 
 
36 FUNCTIONAL DIAGNOSIS 
 
 relatively rapid in infancy, 35 to 40 per minute, 
 gradually diminishing in frequency until in adults 
 it remains pretty constant at 18 to 24 per minute. 
 This is doubtless due in large measure to the rela- 
 tively smaller available lung capacity in children, 
 which increases in greater ratio than the growth of 
 the body; and to the relatively greater metabolic 
 activity of the tissues in childhood consequent upon 
 growth. 
 
 Fevers. — Undoubtedly the increased freqneucy of 
 respiration in fevers, as already explained, is largely 
 due to accumulation of carbon dioxid. 
 
 Pleurisy causes rapid respiration because the lim- 
 ited expansion of the time chest due to the pain sets 
 in motion the reflex mechanism of the vagus accel- 
 erators. 
 
 Pneumonia, phthisis, etc., exhibit rapid breathing 
 because of the small amount of available lung area, 
 operating both by way of the vagus and by the accu- 
 mulation of C0 2 in the blood. 
 
 In hydro and pneumothorax the movements of the 
 lungs are limited by the pressure in the thorax ; here 
 both the vagus reflex and the excess C0 2 in the blood 
 operate to increase the frequency of respiration. 
 
 In emphysema and atelectasis the excess C0 2 ap- 
 pears to be the causative factor. 
 
 In paralysis of the phrenic nerves (innervating 
 diaphragmatic respiration) or paralysis of the costal 
 nerves (innervating thoracic respiration) the expan- 
 sion of the thorax is much limited, hence the pul- 
 
FUNCTIONAL DIAGNOSIS ^7 
 
 monary branch of the vagus is stimulated and the 
 group of motor nerves which are intact call their 
 mechanism into increased play to compensate for 
 the inactivity of the other group. 
 
 ■V -U «!■ 
 
 Modified Variations. — Many of the causes of in- 
 creased respiratory frequency only manifest them- 
 selves when some extra demand is made upon the 
 respiration, such as exertion, which in health would 
 not embarrass the breathing at all. Especially is 
 this the case in those conditions where it depends 
 upon an insufficient oxidation and compensated 
 heart lesions. 
 
 In chronic lesions which would otherwise tend to 
 induce rapid breathing the process may be so grad- 
 ual that the system adapts itself to the disability. 
 In tuberculosis, for example, the lessened lung area 
 is frequently offset by the reduction of body weight, 
 thus lessening the necessity for oxygen and C0 2 
 elimination. 
 
 C0 2 Narcosis. — In all those cases where increased 
 frequency is caused by accumulation of C0 2 in the 
 blood, this condition if prolonged sufficiently to in- 
 duce C0 2 narcosis will eventually slow the respira- 
 tion. 
 
 Brain Compressions and Toxemias produce a di- 
 minuation in the frequency of respiration. 
 
38 FUNCTIONAL DIAGNOSIS 
 
 Variations in Rhythm are also quite common in 
 health. It is difficult to assign any definite or single 
 explanation for the physiologic irregularities that 
 are frequently seen, sometimes even in sleep, espe- 
 cially among children and nervous people. It is 
 highly probable that they depend largely upon cen- 
 tral and reflex disturbances of the inhibitory and 
 accelerator factors of the nervous mechanism, of the 
 same kind, only differing in degree, as those inhibi- 
 tions of the centre which arise from powerful emo- 
 tions and cause prolonged variations in rapidity. 
 
 Cheyne-Stokes Breathing is the most notable ex- 
 ample of pathological abnormality in respiratory 
 rhythm. In this type of breathing there is a rapid 
 cresendo and diminuendo, both as to frequency and 
 depth, the paroxysms lasting from thirty seconds to 
 a minute, and intervened by a pause in respiration. 
 The cause of the phenomenon is unknown, but it 
 doubtless has its explanation in some disturbance of 
 the central nervous system. It is usually of grave 
 import. In children, however, it occasionally occurs 
 physiologically during sleep. 
 
 Cabot describes a very irregular gasping respira- 
 tion, accompanied by a nodding of the head, "the 
 chin being thrown quickly upward at each inspira- 
 tion, and falling slowly during expiration," which 
 he attributes to nervous dissociation, and regards as 
 a precursor of death. This is seen in Uremia, and 
 certain Diseases of the Brain. 
 
FUNCTIONAL DIAGNOSIS 39 
 
 Asthma is a common illustration of disturbed 
 rhythm; the exciting cause is usually reflex, as de- 
 scribed under Reflex Inspiration. 
 
 Variations in Amplitude or Depth are quite com- 
 mon within physiological limits, depending upon 
 practically the same conditions that determine the 
 rapidity of the process. 
 
40 FUNCTIONAL DIAGNOSIS 
 
 THE VASCULAR SYSTEM. 
 General. 
 
 The Circulation. — The blood of the body is con- 
 tained in a closed set of tubular vessels, through 
 which it is propelled by the beat of the heart; the 
 coats of the vessels are muscular, elastic, and micro- 
 scopically permeable. The blood leaves the ventricle 
 of the heart by one artery of large lumen (aorta), 
 which, in its passage to the peripheries, subdivides 
 continually into more numerous arteries of less cali- 
 ber but of a constantly increasing total capacity. At 
 the peripheries the arteries quite suddenly subdivide 
 into innumerable capillaries, of very small caliber, 
 which with equal suddenness widen out again into 
 the veins, and these, by a reverse progression to that 
 of the arteries, viz., by coalescence into a less and 
 less number of veins of increasing caliber, finally 
 unite in two large veins (venae cavae) and empty 
 again into the heart. The vessels lie in numerous 
 planes, changing with the various movements and 
 postures of the body, and their contents are of 
 course subject to the influences of gravity. This 
 combination of conditions gives rise to all the dy- 
 namic and static phenomena of the circulation. 
 
 If to the above set of premises we add that the 
 blood carries oxygen and nourishment to the tissues, 
 removes waste gases and products, and equalizes 
 the heat of the body, and that the muscular features 
 of the system are under the control of various nerve 
 
FUNCTIONAL DIAGNOSIS 41 
 
 centers and fibers, we have the data for the physio- 
 logical rationale of the vascular function. 
 
 The Blood. — Histologically the blood consists of 
 a fluid (plasma) in which are floating cellular bodies 
 known as the corpuscles. These comprise — 
 
 (1) Red Corpuscles. 
 
 (2) White corpuscles. 
 
 (3) Blood plates. 
 
 Of these the white corpuscles are the only true cellu- 
 lar structures, with nuclei and stroma. The red cor- 
 puscles contain nuclei at the early stages of develop- 
 ment of the fetus, but they disappear at the seventh 
 month. In certain conditions of excessive formation 
 of red corpuscles in the blood — e. g., after excessive 
 hemorrhage — these nucleated red corpuscles may be 
 seen in goodly numbers. The blood plates are homo- 
 geneous, elliptical bodies, whose only function, so far 
 as known, is to assist in coagulating the blood. 
 
 Reaction and Specific Gravity. — The normal re- 
 action of the blood is alkaline, due no doubt to the 
 preponderance of carbonate of potassium and phos- 
 phates in the plasma. This alkaline reaction is a 
 necessary factor in the maintenance of life. Specific 
 gravity is about 1060, that of the corpuscles being 
 greater than that of the plasma; the red corpuscles 
 have the greatest specific gravity. 
 
 •m •m ■!• 
 
 Red Corpuscles. — Chemically the properties of the 
 blood resolves itself into a study of the properties 
 of the red corpuscles, as they are the only specialized 
 
42 FUNCTIONAL DIAGNOSIS 
 
 constituent of the blood, whose chemistry plays an 
 important part in the physiology of the circulation. 
 
 The red corpuscles are by far the most numerous 
 of the microscopic elements of the blood. Separately 
 their color is a pale yellow, but in large numbers 
 they give the red hue to the blood. The proportion 
 of the number of red to that of white corpuscles is 
 as 1,000 to 1. The average number of red corpuscles 
 in health is 4,500,000 to 5,000,000 to the square milli- 
 meter. 
 
 Function of Red Corpuscles. — The red corpuscles 
 carry oxygen to the tissues from the lungs. This 
 function they perform by virtue of a chemical con- 
 stituent in their make-up, called hemoglobin, which 
 forms a very ready but exceedingly loose combina- 
 tion with oxygen, thus forming an ideal carrier of 
 this gas. 
 
 Hemoglobin. — This forms the most important con- 
 stituent of the red corpuscle. Its exact chemical 
 composition is unknown, for it is understood in that 
 form it exists in the normal corpuscle. It is not in 
 solution, nor is it in crystal form. Corpuscles in 
 which the hemoglobin is intact are relatively opaque ; 
 blood in which the hemoglobin has been discharged 
 from the corpuscles into the plasma (laked blood) 
 although of a far darker crimson is relatively trans- 
 parent. Hence it is probable that its normal condi- 
 tion in the corpuscle is one of solidity. 
 
 "When hemoglobin combines with oxygen the re- 
 sulting compound is known as oxyhemoglobin, and 
 
FUNCTIONAL DIAGNOSIS 43 
 
 is of a bright scarlet color, giving to arterial blood 
 its characteristic vivid red. This compound readily 
 parts with its oxygen to the tissues which lack it, 
 and the remaining chemical is called reduced hemo- 
 globin. 
 
 Hemoglobin combines with carbon dioxid inde- 
 pendently of its bonds with oxygen, the former 
 probably uniting with some other constituent of the 
 hemoglobin than the latter. On the other hand, the 
 taking up of carbon dioxid appears to increase the 
 readiness with which the hemoglobin parts with its 
 oxygen. These conditions give bases for two physi- 
 ological processes: (1) The hemoglobin carries oxy- 
 gen to and carbon dioxid from the tissues simul- 
 taneously; (2) the further along the process is con- 
 tinued, the more carbon dioxid the hemoglobin re- 
 moves, the more readily it delivers oxygen. Both 
 these statements of course are limited by the ca- 
 pacity of hemoglobin to take up both oxygen and 
 carbon dioxid. 
 
 Anaemia. — The essential morbid element of anae- 
 mia is a diminution of the number of red corpuscles 
 in the blood, associated with important abnormalties 
 in the character of these corpuscles. Sometimes the 
 number is scarcely lessened at all, but the amount of 
 hemoglobin contained by them is greatly reduced. 
 Nucleated red cells are usually formed in great quan- 
 tities. Some of these are undeveloped forms of red 
 blood corpuscles, doubtless due to nature's attempt 
 
44 FUNCTIONAL DIAGNOSIS 
 
 to repair the rapid destruction of red corpuscles by 
 hurrying out new ones. Others (megoblasts) re- 
 semble blood plates but are considerably larger. 
 Their significance is unknown. 
 
 Hemolysis. — It has already been stated that the 
 form in which hemoglobin exists in the red cor- 
 puscles is unknown. It is known, Ibwever, that the 
 hemoglobin is maintained in this combination by 
 virtue of the osmotic pressure in the surrounding 
 plasma, and a lowering of this osmotic pressure, ^y 
 diluting the plasma, results in a discharge of tha 
 hemoglobin from the corpuscle into solution in the 
 plasma. This discharge of the hemoglobin is called 
 hemolysis. 
 
 Hemolysis may also be effected by the action of 
 certain drugs and toxins upon the corpuscles them- 
 selves, destroying the stroma and liberating the con- 
 tained hemoglobin. Notably is this result produced 
 by the action of the serum of one animal upon the 
 red corpuscles of an animal of a different species — 
 the influence of the various species toward one an- 
 other varying greatly in intensity. Moreover, this 
 influence is artificially transferable; i. e., by re- 
 peatedly injecting into the blood of one animal the 
 serum of a second whose hemolysis reaction is ex- 
 ceptionally strong toward a third, the blood of the 
 injected animal will presently become as positive in 
 its hemolytic reaction upon the third as is that of the 
 animal whose serum was injected. 
 
 Transfusion.— The discovery of the hemolytic in- 
 
FUNCTIONAL DIAGNOSIS 45 
 
 fluence of one species of blood toward that of an- 
 other species has resulted in an abandonment of the 
 practice of blood transfusion from animals which for 
 a time seemed likely to obtain as a means "of repair- 
 ing hemorrhages. The measure is still occasionally 
 practiced from human being to human being, but 
 this is almost entirely superseded by 
 
 Normal Saline Infusion, an infusion of salt and 
 water, mixed in such proportions (one-tenth of one 
 per cent of salt) as to exactly correspond to the 
 osmotic density of the plasma. 
 
 Drugs and Toxins. — Certain drugs have marked 
 hemolytic action on the blood, notably ammonia and 
 chloroform. So also have numerous toxins, of which 
 the venom of the snake is a conspicuous example. 
 To this toxic hemolysis must be attributed most of 
 the secondary anaemias resulting from infectious 
 diseases and malignant growths. 
 
 ■y W "m 
 
 Metabolism o£ Red 0?rpiwctes.— 7&eve is % con- 
 tinual production and destruction of red corpuscles, 
 the former process going on in the red marrow of 
 the bones, where nucleated erythroblasts by Kary- 
 okinesis beget daughter cells containing hemoglobin. 
 The nucleus is lost before the cells pass into the cir- 
 culation. The scene of their destruction is a matter 
 of question. For a long time it was thought that the 
 spleen was the graveyard of red corpuscles, but later 
 investigations make it probable that they are disin- 
 tegrated and dissolved in the bloodstream. No hema- 
 
46 FUNCTIONAL DIAGNOSIS 
 
 tin is found in the splenic venous blood, as would be 
 the case if hemoglobin were disintegrated there ; and 
 the occasional finding of a partly disintegrated red 
 corpuscle in a leucocyte of the spleen is probably ex- 
 plicable by post-mortem ingestion, owing to the im- 
 mobility of the red and the amoebic motility of the 
 white corpuscle after death. 
 
 Repair o!f Hemorrhage. — After severe hemorrhages 
 the watery part of the blood is quickly replaced by 
 absorption from the tissues, and an excessive prolif- 
 eration of red corpuscles takes place in the red mar- 
 row to make good the loss. These corpuscles are 
 hurried out into the circulation without waiting for 
 destruction of their nuclei ; hence nucleated red cor- 
 puscles are found in the blood after severe hemor- 
 rhages. 
 
 Saline Solution. — One of the beneficial effects of an 
 injection of normal salt solution in cases of hemor- 
 rhage and shock is probably that it keeps the remain- 
 ing red corpuscles circulating more rapidly and pro- 
 mote their usefulness as oxygen carriers. (Howell.) 
 
 Anemia. — The same is true in any condition where 
 red corpuscles are destroyed in large numbers, as in 
 secondary and pernicious anemias, as long as the pro- 
 liferating capacity of the marrow holds out. In these 
 disorders the marrow is usually found in a dark red 
 congested condition, due to excessive functionating. 
 
 •m "W *m 
 
 Influence of Altitude on Red Corpuscles. — Removal 
 of a mammal to a high altitude is always followed in 
 
FUNCTIONAL DIAGNOSIS 47 
 
 a comparatively short time by an increase in the 
 count of red corpuscles, but whether this increase is 
 real, or only proportional, i. e., whether there is an 
 actual increased proliferation of red corpuscles or 
 whether they become more concentrated owing to 
 removal of water from the plasma, is a disputed 
 point. In either case the phenomenon is doubtless a 
 provision of nature to compensate for the rarity of 
 the oxygen in the atmosphere, and we must suppose 
 that this same rarity of oxygen operates as the neces- 
 sary stimulus to set this compensatory process in mo- 
 tion. 
 
 •* •* •* 
 
 The White Corpuscles. — The white corpuscles, as 
 already stated, are the only true cellular type of 
 body among the blood elements, possessing a nucleus, 
 and all the other typical structure of a true cell. 
 Their numerical proportion to the red corpuscles in 
 normal blood is as 1 to 750-1,000, there being from 
 4,500 to 7,000 to the cubic millimetre. The number 
 varies under different physiological conditions. They 
 are most numerous during digestion, exercise, preg- 
 nancy and other conditions of increased physiological 
 activity. 
 
 Varieties of White Corpuscles. — There are several 
 different varieties of white corpuscles in normal 
 blood, distinguished by their histological anatomy 
 and also by their function. The latter distinction di- 
 vides them into two classes : 
 
 (1) Lymphocytes. 
 
 (2) Leucocytes. 
 
48 FUNCTIONAL DIAGNOSIS 
 
 The characteristic differences between these two 
 classes are that the former have no granules and very 
 little ameboid faculty; the latter exhibit granules 
 and their power of ameboid locomotion is so marked 
 as to gain for them the nickname of the ' ' wandering 
 cells." 
 
 Subdivisions of these two classes indicate various 
 stages of their development, lymphocytes being rec- 
 ognized as small and large lymphocytes, and leuco- 
 cytes as transition (uninuclear), jolynuclear, and 
 heart cells; the last named variety is exceedingly 
 few. 
 
 Functions of Leucocytes. — The lymphocytes form 
 but thirty to thirty-five per cent of the total white 
 corpuscles, and their function is unknown. Many 
 physiologists regard them as the immature forms 
 which later develop into leucocytes. 
 
 The polynuclear leucocytes are the only class of 
 whose function we have any understanding. As 
 might be expected from their histology, their func- 
 tion is an elementary one as compared with that of 
 the red corpuscles. They stand, as it were at the 
 lower gateway of the circulation and (1) protect the 
 tissues from foreign and pathogenic bacteria and (2) 
 furnish proteids to the plasma. They also aid in the 
 absorption of fat and peptones from the intestines, 
 hence their proliferation during digestion, and assist 
 in the coagulation of blood. The latter can hardly 
 be classed as a physiological function. 
 
FUNCTIONAL DIAGNOSIS 49 
 
 Diapedesis. — Leucocytes possess the ability to pen- 
 etrate the coats of the arteries and vessels. This 
 faculty they exercise constantly in health and much 
 
 more markedly in certain pathological conditions. 
 
 ■v -v > 
 
 Coagulation of the Blood.— The actual process of 
 coagulation of blood is familiar, at all events in its 
 microscopic phases, to everyone. In a few minutes 
 after it is shed, the fluid becomes first of a viscous 
 consistency, then sets in a jelly-like mass, the clot 
 shrinking during the process and pressing out a clear 
 straw colored liquid called serum. This serum con- 
 sists of the plasma, less a hypothetical substance 
 called fibrinogen, which has gone to form the clot. 
 Hence the metamorphosis may be expressed histolog- 
 
 Dr Atkinson 20p July 21 Stolze Twelve 
 
 ically as follows : 
 
 ! Serum 
 Fibrinogen 
 Fibrin-ferment Fibrin Clot 
 
 Red Corpuscles 
 White Corpuscles 
 Process of Coagulation. — Considered more minute- 
 ly the process consists of the rapid formation of a 
 stringy substance called fibrin, in the form of a net- 
 work of threadlike strands, which catches the cor- 
 puscles in its meshes and, shrinking, compresses them 
 into a clot, squeezing out the serum. The red cor- 
 puscles, being immobile, remain in the position they 
 are caught in ; the motile leucocytes, on the contrary, 
 may wriggle out of the meshes and be found in the 
 serum. If the blood be stirred during coagulation 
 
50 FUNCTIONAL DIAGNOSIS 
 
 some red corpuscles may be broken away from the 
 network and the serum contain some of these cells. 
 
 If freshly shed blood be whipped briskly with a 
 rod the fibrin, as it forms, will cling to the rod, and 
 may all be removed from the blood, which will then 
 remain fluid and is called defibrinated blood. 
 
 Theories of Coagulation. — Many have been the ex- 
 periments made for the purpose of determining the 
 nature of the process, and many the theories built 
 up on these experiments and the matter is still far 
 from satisfactory elucidation. 
 
 It is generally conceded that coagulation depends 
 upon the presence of an albuminoid substance in the 
 plasma, to which the name of fibrinogen is given, for 
 when blood is heated sufficiently to coagulate this 
 element, the coagulating power of the blood is gone, 
 and the power is restored by the addition of arti- 
 ficially prepared fibrinogen. This fibrinogen (a sol- 
 uble substance) is supposed to be converted into 
 fibrin (an insoluble compound) by the action of a 
 ferment elaborated after the blood is shed, and called 
 fibrin-ferment or thrombin. It has also been shown 
 that soluble calcium salts are necessary to the proc- 
 ess, for blood received into a solution of oxylates 
 which precipitates these salts, does not clot. 
 
 It is assumed that the ferment necessary to the 
 clotting process is derived from the disintegration of 
 leucocytes and blood plates, and as these cannot be 
 supposed to disintegrate to any extent until after the 
 blood is shed, this theory accounts for the failure of 
 
FUNCTIONAL DIAGNOSIS 51 
 
 blood to clot within the vessels. It also probably 
 explains why introduction of foreign bodies into the 
 living vessels causes coagulation, and why shed blood 
 coagulates faster when so disposed as to come in 
 more extensive contrast with the sides of the con- 
 tainer. 
 
 Anemia. — In pernicious and secondary anemias, 
 where large quantities of red corpuscles are de- 
 stroyed, hemoglobin is liberated. This hemoglobin 
 destroys the white corpuscles, producing fibrin-fer- 
 ment, which coagulates the blood and gives rise to 
 thrombi, emboli, petechial and capillary hemor- 
 rhages. 
 
 Ligatures. Aneurisms. — The influence of a foreign 
 substance in inducing coagulation is taken advantage 
 of in surgery for the purpose of arresting hemor- 
 rhages and curing aneurisms by means of ligatures. 
 The constricted circle acts as a foreign body and in- 
 duces coagulation in the vessel, thus forming a nat- 
 ural plug. In order to be effective the ligature must 
 rupture the inner coat of the vessel. 
 
52 FUNCTIONAL DIAGNOSIS 
 
 BLOOD PRESSURE. 
 
 Velocity and Pressure. — Two elements enter into 
 the mechanical features of circulation, namely, ve- 
 locity of the blood flow, and blood pressure. The 
 former represents the amount of force that is ex- 
 pending itself in the direction of the axis of the ves- 
 sel, driving the blood along it and may be measured 
 at any point by inserting a bent graded tube parallel 
 to the axis of the vessel and noting the height to 
 which the blood rises. The latter represents the force 
 expended in a direction at right angles to the axis of 
 the vessel, and may be measured at any point by in- 
 serting a tube at right angles to the axis and noting 
 the height to which the blood arises. 
 
 Factors. — The factors which take part in and 
 modify these mechanical phenomena are (1) the 
 heart beat, (2) the friction in the vessels, (3) the re- 
 sistance of the vessel walls, (4) the constriction or 
 dilatation of the vessels by vasomotor influences. 
 
 The heart beat, which throws the blood into the 
 vessels and distends them, may be regarded as fur- 
 nishing the total power or force. A part of the force 
 thus exerted is employed in overcoming the friction 
 inside the vessels ; another portion is utilized in neu- 
 tralizing the centrifugal resistance of the vessel wall, 
 exerted in a radiating direction; (this centripetal 
 resistance is due partly to the passive opposition of 
 the walls themselves, and partly to their active mus- 
 
FUNCTIONAL DIAGNOSIS S3 
 
 cular constriction by vaso-motor influences) ; the re- 
 mainder of the force is represented by the velocity of 
 the blood stream. 
 
 Thus, all that part of the force supplied by the 
 heart beat which goes to neutralize resistance to the 
 blood stream represents blood-pressure; that which 
 is in excess of resistance represents the velocity of 
 the current. 
 
 Variations in Velocity. — From what has been said 
 it is evident that the velocity of the blood current 
 varies directly as the force of the heart beat and 
 inversely as the resistance, and as the latter differs in 
 different parts of the vascular channel the velocity 
 naturally exhibits corresponding variations in these 
 several locations. 
 
 As already stated, every successive subdivision of 
 the primal artery (aorta) into arteries of smaller cali- 
 ber involves an increase in the total circumferential 
 area of the channel ; in the capillaries the total area 
 is estimated at 800 times that of the aorta. This means 
 that the blood is subjected to a progressive increase 
 of peripheral resistance and a corresponding diminu- 
 tion of its velocity. By the time it passes through 
 the capillaries and enters the veins its velocity is 
 very much reduced; thereafter, however, it under- 
 goes a reverse process in regard to area, namely, a 
 successive passage into a less and less number of 
 vessels, of larger caliber, representing a progressive- 
 ly decreasing total area; and furthermore, it gets 
 more and more into the suction influence of the intra- 
 
54 FUNCTIONAL DIAGNOSIS 
 
 thoracic negative atmospheric pressure. (See Chap- 
 ter on Respiration.) 
 
 The relations thus described between the velocities 
 of the various parts of the vascular channels, and all 
 other relations, are subject to variation at any mo- 
 ment by the action of various conditions influencing 
 the blood flow or peripheral resistance. Marcy sums 
 the matter up in two general laws: (1) Velocity is 
 influenced directly by the force of the heart and in- 
 versely by resistance. (2) Pressure is influenced di- 
 rectly by both the force of the heart and resistance ; 
 is indeed the resultant of the two. 
 
 The velocity in the arteries is temporarily in- 
 creased and diminished during systole and diastole; 
 the variations are called systolic and diastolic veloci- 
 ties, and the average between the two, the mean ve- 
 locity. This mean velocity, as indicated, varies for 
 each artery. 
 
 The velocity in any channel can of course be modi- 
 fied by the constriction or dilatation of the vessel by 
 the vaso-motor mechanism, thus relieving or increas- 
 ing periphereal resistance. 
 
 Variations in Pressure. — From the foregoing it is 
 plain that blood pressure, like velocity, is different in 
 different parts of the vascular system. Generally 
 speaking it may be said that it varies in about a co- 
 incident manner with velocity, as far as the arteries 
 and capillaries are concerned. 
 
 Thus while the increasing periphereaM-esistance 
 due to the multiplication of vessels tends to increase 
 
FUNCTIONAL DIAGNOSIS 55 
 
 pressure, the ever diminishing heart impetus, due to 
 its distribution over an increasing area and its ex- 
 penditure in overcoming resistance, furnishes a more 
 than corresponding reduction of the other factor in 
 pressure, with the net result that the pressure in the 
 capillaries is lower than in the arteries, although the 
 resistance is greater. 
 
 In the veins, however, this coincidence between ve- 
 locity and pressure is lost. From causes already ex- 
 plained, the velocity of the blood stream increases 
 from the capillaries to the heart, and the pressure, 
 on the contrary, steadily diminishes, owing to de- 
 creasing resistance (less and less vessels) until the 
 pressure in the venae cavae is practically nil. 
 
 The pressure in the arteries, like the velocity, is 
 increased and diminished during systole and dias- 
 tole, the difference being the mean arterial pressure. 
 
 Pressure is also increased by constriction and di- 
 minished by dilatation of the vessels through the 
 vaso-motor mechanism, the former increasing and 
 the latter diminishing periphereal resistance. 
 
 Adjustment of Pressure. — The well-being of the 
 body demands a more or less constancy of blood pres- 
 sure, and, more urgently still, demands the main- 
 tenance of a minimum pressure. This condition is 
 preserved by means of a physiological adjustment 
 between heart beat and resistance, sometimes ef- 
 fected by the heart, sometimes by the vaso-motors, 
 often by both. 
 
 Thus in digestion, when the abdominal vessels con- 
 
56 FUNCTIONAL DIAGNOSIS 
 
 tain an extra amount of blood, and during muscular 
 exercise when the blood is largely determined to the 
 muscle-vessels, the fall in pressure which would 
 otherwise occur in the other vessels is forestalled by 
 an increase in the heart's action. Other examples 
 will occur to the student, or will appear in discussing 
 other functions. 
 
 High Blood Pressure results from any pathological 
 condition which (a) increases the volume of blood in 
 the vessels; (b) increases the force of the heart beat; 
 or (c) offers abnormal resistance to its passage. Con- 
 ditions which increase the total volume of blood are 
 rare, the increase usually occurring either on the 
 venous or arterial side, at the expense of the other. 
 
 Simple Cardiac Hypertrophy throws an abnormal- 
 ly large quantity of blood into the aorta at each sys- 
 tole, at the expense of the veins, thus raising arterial 
 and lowering venous pressure. The impetus with 
 which the blood is propelled also contributes to the 
 increase of pressure. 
 
 Drugs and Toxins of certain kinds exaggerate the 
 force of the heart and thus raise pressure. Most of 
 these agencies also cause constriction of the vessels, 
 which contributes to the increase of pressure. 
 
 Nephritis raises blood pressure primarily by vaso- 
 constriction in the kidney, thus increasing peripheral 
 resistance, and secondarily by toxic sclerosis of the 
 artery walls, abolishing their expansibility. 
 
 Arteriosclerosis increases the rigidity, hence the 
 
FUNCTIONAL DIAGNOSIS 57 
 
 resistance of the vessel walls, and thus raises pres- 
 sure. 
 
 Low Pressure. — Conversely, any influence which 
 (a) weakens the heart beat, (b) lessens the volume 
 of the blood, or (c) diminishes resistance to its pass- 
 age, lowers pressure. 
 
 Myocarditis, Dilatation and Fatty Degeneration of 
 the heart are attended with low arterial pressure, 
 both because of diminished impetus and because an 
 abnormally small quantity of blood is thrown into 
 the aorta at each systole. 
 
 Hemorrhage lowers pressure by taking blood out 
 of circulation. 
 
 Low Fevers (typhoid, typhus, etc.) and Constitu- 
 tional Diseases which inhibit nutrition without any 
 sclerotic changes in the blood vessels, rob the vessel 
 walls of their tone, thus abolishing their elastic re- 
 coil and lowering pressure. 
 
58 FUNCTIONAL DIAGNOSIS 
 
 PULSE. 
 
 The Pulse.— If the vascular system consisted of a 
 set of rigid tubes, each discharge of blood from the 
 ventricle would push the whole mass of blood for- 
 ward and simultaneously empty from the venae 
 cavae into the auricle a similar quantity of venous 
 blood. The elasticity of the aorta wall makes it 
 easier to distend the artery than to move the whole 
 mass of blood forward, and this is what happens nm 
 marily to make room for the blouu arscn-orgrju oy tne 
 heart beat. 
 
 As soon as the semi-lunar valves close, the elastic 
 coat of the aorta recoils, and drives the columns of 
 blood onward. This succession of distension and re- 
 coil passes down the entire arterial system, in the 
 form of a wave, diminishing as the total area of the 
 channel increases, until in the capillaries, where the 
 total area suddenly increases many times, the wave 
 is lost. This wave of distension and recoil consti- 
 tutes the pulse and, for the reason described, is only 
 seen in the arteries. 
 
 Abnormal Pulse. — The normal propagation of the 
 pulse wave may be interfered with by (a) conditions 
 within the heart, or (b) conditions in the vessels. 
 Such interference may make itself manifest in (a) 
 the amplitude, (b) the regularity, (c) the velocity of 
 the wave. These factors constitute the character of 
 the pulse. The pressure in the vessel is frequently 
 
FUNCTIONAL DIAGNOSIS 59 
 
 included in the character of the pulse, but is really 
 an entirely different phenomenon to that of the pulse 
 proper, pressure being a static condition at any given 
 moment, while the pulse is a dynamic condition re- 
 quiring time as one of its elements. 
 
 Hypertrophy. — In general, anything which in- 
 creases the force of the heart beat increases both 
 the amplitude and velocity of the pulse wave. Hy- 
 pertrophy of the heart, especially of the ventricle, 
 in its early effects, is one of those influences. Later, 
 when compensation fails, the amplitude of the wave 
 is diminished and generally the velocity also. But 
 it must not be forgotten that the effect of increased 
 heart force on the wave may be offset by conditions 
 of the vessels. 
 
 Myocarditis and Fatty Degeneration weaken the 
 muscular force of the heart, and therefore diminish 
 both amplitude and velocity of the pulse-wave, un- 
 less offset by vascular conditions. 
 
 Mitral Insufficiency, as long as compensation is 
 good, has no perceptible effect upon the pulse wave, 
 as the disturbances are all back of the ventricle. 
 
 In mitral stenosis the amplitude and velocity of 
 the pulse wave is diminished because of the less 
 quantity of blood poured into the ventricle at each 
 systole. 
 
 Aortic insufficiency has a very characteristic effect 
 upon the pulse wave. The hypertrophied condition 
 of the ventricle augments the force behind the pulse 
 and increases its amplitude, giving a high incline of 
 
60 FUNCTIONAL DIAGNOSIS 
 
 ascent, but the decreased resistance offered by the 
 leaky valve to the aortic recoil induces a rapid, al- 
 most sudden collapse of the artery, giving a steep 
 incline of descent. This excessive backward collapse 
 may even be seen in the capillaries, evidenced by 
 capillary pallor at each diastole. This pulse is called 
 the Corrigan pulse, and is pathognomonic of aortic 
 insufficiency. It may, of course, be absent in this 
 lesion, if conditions of the vessels offset the valvular 
 influence. (Quincke pulse.) 
 
 In aortic stenosis, on the other hand, the amount 
 of blood thrown into the artery is smaller than nor- 
 mal, in spite of the hypertrophy of the ventricle, 
 hence the amplitude of the pulse wave is reduced. 
 The smallness of the pulse in contrast with the force 
 of the ventricle, is very characteristic of this lesion. 
 
 Failure otf Compensation. — In all of the valvular 
 lesions, as soon as compensation fails, all of the char- 
 acteristic effects of the compensated lesions disap- 
 pear and the effect common to them all becomes one 
 of enfeebled heart force, namely, small amplitude 
 and low velocity. 
 
 •m 1. "b 
 
 Velocity of Pulse Wave. — As already stated, in a 
 rigid system of tubes the pulse wave inaugurated 
 by the discharge from the ventricle would be in- 
 stantaneously propagated to the venae cavae. Hence, 
 it follows that the velocity of the pulse wave is in 
 direct proportion to the rigidity of the artery wall. 
 It is, of course, in inverse proportion to the volume 
 
FUNCTIONAL DIAGNOSIS 61 
 
 of blood concerned, and therefore, to the calibre of 
 the vessel. The velocity of the pulse wave must be 
 carefully distinguished from the velocity of the blood 
 stream, and from the rapidity of the heart beat. 
 
 Catacrotic Pulse Waves. — The elasticity (elastic 
 recoil) of the arterial walls produces some modifica- 
 tions of the arterial pulse wave just described, by 
 means of reflected waves set in motion by the recoil- 
 ing wall of the artery. These are called catacrotic 
 waves. The most significant of them is the dicrotic 
 wave, which occurs immediately after the recoil has 
 started, and noticeably interrupts the downward in- 
 cline of the pulse. It is caused as follows: When 
 the aorta begins to recoil it propagates the blood 
 in both directions, toward the peripheries and to- 
 ward the heart. The latter organ has shut its semi- 
 lunar valves against which the proximalward wave 
 strikes and is reflected as a distalward wave, once 
 more producing a slight arterial distension. 
 
 Exaggeration and Diminution. — In extremely rigid 
 conditions of the artery walls, as in arteriosclerosis 
 and atheroma, the effect of the secondary wave is, 
 of course, hardly perceptible, and in these conditions, 
 therefore, there is a notable absence of the dicrotic 
 wave. The same is true when the blood in the 
 artery is under high pressure, so that the artery 
 wall is already, by virtue of the fundamental wave, 
 under tension, hence in cases of high arterial tension 
 the dicrotic pulse is diminished. 
 
 On the other hand an easily distensible artery and 
 
62 FUNCTIONAL DIAGNOSIS 
 
 a low blood pressure favors the perceptible effect of 
 the secondary wave, and in these conditions the 
 dicrotic wave is very noticeable — e. g., typhoid fever, 
 tuberculosis, malignancy, etc. 
 
 In aortic insufficiency, of course, the dicrotic pulse 
 is absent, because at the recoil of the artery the 
 blood, instead of striking the semi-lunar valves and 
 producing a secondary wave, passes through the 
 leaky valves into the ventricle. The collapse of the 
 pulse, as already stated, is sudden, with no cataerotic 
 waves. 
 
FUNCTIONAL DIAGNOSIS 63 
 
 THE HEART-BEAT. 
 
 Theories of the Heart-Beat. — Two opposing theo- 
 ries hold the field in regard to the cause of the 
 heart-beat. One, the neurogenic theory, holds that 
 the contraction of the heart muscle is due to the 
 influence of nerve cells contained in the muscle ; the 
 other, the myogenic theory, attributes the function 
 to an inherent property of rhythmic eontractity pos- 
 sessed by the muscle itself. The strongest argument 
 in favor of the neurogenic theory seems to be the 
 presence of nerve cells in the heart tissues, as no 
 experiment or observation has ever demonstrated 
 that these nerve cells take any part in the origina- 
 tion of the heart-beat. For the myogenic theory it 
 may be said that it can be demonstrated that the 
 wave of contraction follows the musculature, and 
 also that it can be made to travel in either direction 
 at will — a fact which is incompatible with nervous 
 control in the light of the polarity of neurons. The 
 only serious objection to the myogenic theory, name- 
 ly, the absence of muscular connection between the 
 auricle and ventricle, has recently been removed by 
 the demonstration of the auriculo-ventricular bun- 
 dle, or bridge of Hiss. 
 
 Automaticity of Heart-Beat. — Whatever may be 
 the difference of views as to the origination of the 
 heart-beat, there is unanimity of agreement that it 
 is an automatic function, i. e., that it is independent 
 of the cerebro-spinal nervous system, and that al- 
 
64 FUNCTIONAL DIAGNOSIS 
 
 though the central nervous system, exercises a cer- 
 tain species of control and regulation of the heart's 
 action, it has nothing whatever to do with the causa- 
 tion of its rhythmical beat. For the heart continues 
 to beat when it has been completely cut off from all 
 connection with the nerve centres; and contractions 
 which have ceased in a heart thus isolated may be 
 reinaugurated. 
 
 The Heart-Beat. — The muscular contraction which 
 results in the heart-beat begins in the muscular coats 
 at the mouths of the venae cavae and the pulmonary 
 veins, spreading over the auricles it causes a simul- 
 taneous contraction of the two auricles, thence passes 
 by the bundle of His to the ventricles, which also 
 contract simultaneously. This is the end of the 
 heart-beat, and a pause intervenes between its con- 
 clusion and the commencement of the next contrac- 
 tion wave, called the period of rest. The period dur- 
 ing which the auricles are in contraction is called 
 the auricular systole, the time they are relaxed the 
 auricular diastole. Corresponding periods for the 
 ventricles are called ventricular systole and diastole. 
 The passage of the contraction wave over the heart 
 is accompanied by the passage of a simultaneous 
 electric wave, the potential of the muscle in con- 
 traction being higher than that of the muscle in 
 relaxation. 
 
 Heart Block. — In rare instances a pathological 
 condition is seen consisting in an interruption, by 
 means of a tumor, gumma, degeneration, or other de- 
 
FUNCTIONAL DIAGNOSIS 65 
 
 structive process, in the muscular isthmus between 
 the auricle and ventricle (the bundle of His). The 
 functional aberration resulting from this lesion is a 
 disconnection of the auricle and ventricle in regard 
 to their rhythmicity, each maintaining a rhythmic 
 beat of its own, and is known as heart block. Some- 
 times the block is complete, in which case the 
 rhythmicity of the auricle and ventricle bear abso- 
 lutely no relation to each other j in others the block 
 is only partial, and the respective rhythmicities then 
 bear some regular proportion to each other, e. g., the 
 ventricles will beat twice to the auricle's once. 
 
66 FUNCTIONAL DIAGNOSIS 
 
 HEART ACTION. 
 Change in Form and Position of Heart During 
 Beat. — The contraction of the heart muscle of course 
 diminishes, and probably in health completely oblit- 
 erates the cavity of the ventricle, driving the con- 
 tained blood into the artery. The change in the form 
 of the ventricle thus produced differs with the posi- 
 tion of the heart, i. e., with the position of the body, 
 but in general it is decreased in its vertical and trans- 
 verse, and increased in its dorso-ventral diameters. 
 The spiral arrangement of the superficial muscles 
 causes a rotation of the ventricles in systole. This 
 rotation compensates for such vertical shortening as 
 occurs, and maintains the apex of the heart in its 
 normal position against the chest wall, while the sud- 
 den contracting of the heart muscle produces the 
 apex impulse. The impulse is also augmented by the 
 sudden straightening of the curved aorta by its dis- 
 tension with blood. 
 
 Hypertrophy. — When from any cause, such as in- 
 creased resistance or forced acceleration, the heart 
 muscle is hypertrophied, one of the earliest and most 
 characteristic manifestations of its hyperthophy is 
 an exaggeration of the apex beat against the chest 
 wall, especially in cases (most common) where the 
 hypertrophy either begins in or is confined to the 
 ventricles. 
 
 This phenomenon is seen in those valvular diseases 
 
FUNCTIONAL DIAGNOSIS 67 
 
 which produce ventricular hypertrophy, viz., insuffi- 
 ciency and stenosis of the semilunar valves, as well 
 as in so-called idiopathic hypertrophy. 
 
 ■U *m •* 
 
 Heart Sounds. — The heart beat is accompanied by 
 two sounds, corresponding to the ventricular systole 
 and diastole, succeeded by a pause corresponding to 
 the period of rest. The first sound is a dull booming 
 character, the second of a sharper tone, and a minor 
 third higher in pitch. The following occurrences are 
 synchronous with the first sound and probably enter 
 into its composition: (1) Closure of the auriculo- 
 ventricular valves. (2) Contraction of the heart 
 muscle. That the first of these elements is not the 
 sole factor is proved by the occurrence of the first 
 sound in a bloodless beating heart, and by the boom- 
 ing nature of the sound. The second sound is doubt- 
 less caused by the closure of the semilunar valves, 
 as it disappears on hooking back these valves in the 
 living heart. 
 
 Careful experiment has shown that the first sound 
 occurs at the beginning of the systole, and the second 
 at the end of the systole (diastolic). 
 
 Hypertrophy. — In hypertrophy of the heart mus- 
 cle in the early stage, the hypertrophy is accom- 
 panied by an exaggeration of its contractility, mani- 
 fested by an exaggeration of the muscular element 
 of the first sound. Later, when compensation be- 
 gins to fail, this gives place to an enfeeblement of 
 the first sound, which, however, retains a more boom- 
 
68 FUNCTIONAL DIAGNOSIS 
 
 ing character than normal because of the greater 
 volume of muscle involved. 
 
 Mitral Insufficiency. — The mitral valves close at 
 the beginning of the ventricular contraction, to pre- 
 vent any of the blood contained in the ventricle be- 
 ing driven back into the ventricle. If the mitral 
 valves are "insufficient," i. e., if they leak, at each 
 ventricular systole some of the blood is driven back 
 into the auricle (regurgitation). This backward 
 current, meeting the oncoming stream in the auricle, 
 causes a whirl of blood, which, impinging on the 
 edges of the valves, produces a peculiar blowing 
 sound, called a murmur. This murmur, of course, 
 occurs at systole, and is a systolic murmur. 
 
 If, on the other hand, the mitral orifice, from any 
 cause, such as thrombosis or inflammatory vegeta- 
 tion, is stenosed, the passage of the blood from au- 
 ricle to ventricle is impeded, and the rush of liquid 
 under increased tension through the narrow orifice 
 produces a rippling sound, never so loud or blowing 
 as in mitral leakage. This sound, of course, occurs 
 just prior to ventricular systole, and is called a pre- 
 systolic murmur. 
 
 Aortic Insufficiency. — When there is a leakage of 
 the semilunar valves of the aorta, at each recoil of 
 the aorta the blood is partially driven back into the 
 ventricle and, meeting the oncoming stream from 
 the auricle, produces a sound similar to that pro- 
 duced in mitral leakage, but it is, of course, heard 
 following systole; in other words, during diastole, 
 
FUNCTIONAL DIAGNOSIS 69 
 
 and is called a diastolic murmur. The first heart 
 sound is indistinct (though loud) because of the 
 overdistension and slow contraction of the ventricle. 
 
 Aortic Stenosis. — In stenosis of the aortic orifice 
 the blood is forced from the ventricle under in- 
 creased pressure through a very narrow opening, 
 and a sound is produced similar to that described in 
 mitral stenosis. It occurs, of course, during ven- 
 tricular contraction, and is a systolic murmur. 
 
 The sounds produced by the lesions above men- 
 tioned are propagated along the direction of the 
 blood current and as the valves themselves all lie 
 within a very small area the sounds are best differ- 
 entiated by listening to them at the surburban heart 
 points, to which they are transmitted. Thus the 
 sounds and their significance may be classed as fol- 
 lows: 
 
 (1) Systolic murmur, heard best at apex, indicates 
 mitral insufficiency. 
 
 (2) Pre-systolic murmur, heard best at apex, indi- 
 cates mitral stenosis. 
 
 (3) Diastolic murmur, heard best at aortic arch, 
 indicates aortic insufficiency. 
 
 (4) Pre-diastolic murmur, heard best at aortic 
 arch, indicates aortic stenosis. 
 
 Pulmonary Lesions. — The valves of the right heart 
 are subject to precisely the same conditions as here 
 described, and present a corresponding set of sounds, 
 but their occurrence is so rare as to demand no spe- 
 cial attention. 
 
70 FUNCTIONAL DIAGNOSIS 
 
 Haemic Murmurs. — Similar dynamic conditions to 
 those of valvular insufficiency may be brought about 
 by abnormalities of the blood, which decrease its 
 density, and murmurs are frequently thus produced. 
 Particularly is this the case in anemia. The sounds 
 are neither so loud nor so constant as in valvular 
 lesions, and are called haemic, or functional mur- 
 murs. 
 
 •w "I. «w 
 
 Accentuation. — Anything which augments the 
 force of the heart beat increases the muscular im- 
 petus and therefore accentuates the first sound of the 
 heart. We have already seen that hypertrophy is 
 the chief of these influences ; exercise, emotions, and 
 certain drugs also have this effect, and it is a not 
 infrequent practice among diagnosticians to admin- 
 ister strychnia in order to augment the first sound 
 and bring out suspected abnormalities. 
 
 The second sound, depending upon the closure of 
 the semilunar valves, is accentuated by anything 
 which increases the intra-arterial pressure, and its 
 accentuation is pathognomonic of diseases in which 
 peripheral resistance is increased, of which arterio- 
 sclerosis and kidney diseases are familiar illustra- 
 tions. Accentuation of second sound is, of course 
 physiologic in old age, because of atheroma of the 
 vessels. 
 
 Accentuation may occur from the causes described 
 in any of the valves separately, which together make 
 up the respective sounds. These separate accentua- 
 
FUNCTIONAL DIAGNOSIS 71 
 
 tions must be diagnosed by auscultating at the out- 
 lying points of sound transmission for the separate 
 valves. 
 
 Reduplication of the heart sound is due to the 
 asynchronous occurrence of the events which pro- 
 duce it. In the first sound, of course, the valvular 
 element is the only one which can be reduplicated 
 and as this element is completely overshadowed by 
 the muscular element, its reduplication is practically 
 unrecognizable. 
 
 Eeduplication of the second sound is not an infre- 
 quent symptom and is usually due to some patho- 
 logical condition of the coronary arteries. The two 
 sides of the heart, being unequally nourished, do not 
 functionate synchronously; the semilunar valves 
 close asynchronously, and give a double sound. 
 
 The same phenomenon results from an unequal 
 tension in the two ventricular cavities, due to valvu- 
 lar leaks and stenoses. 
 
 Myocarditis and Patty Degeneration reduce' the 
 force of the muscle contraction and therefore make 
 the first sound weak and indistinct. The second 
 sound, by contrast, seems accentuated; but in cases 
 of high blood pressure from other causes, the second 
 sound may of course be genuinely reduplicated. 
 
 •m -m "b 
 
 The Cardiac Cycle. — At the instant that the wave 
 of muscle contraction begins, at the mouth of the 
 pulmonary veins, the left auricle is full of oxygen- 
 ated blood which has been poured into it by the pul- 
 
72 FUNCTIONAL DIAGNOSIS 
 
 monary veins. As the contraction passes over the 
 auricle its capacity lessens, the pulmonary valve is 
 closed by the pressure of the blood, and the latter is 
 driven forward through the auricula-ventricular 
 valve into the ventricle. The contraction wave now 
 passing over to the ventricle, its capacity is reduced, 
 the pressure closing the mitral valve and driving the 
 blood out into the aorta. Meantime the auricle has 
 relaxed and refilled with blood from the pulmonary 
 veins. The blood being forced into the aorta dis- 
 tends its walls, which, however, promptly recoils and 
 closes the semilunar valves. This ends the cycle. A 
 precisely similar cycle of events takes place in the 
 right auricle and ventricle, except that the blood re- 
 ceived from the venae cavae is venous blood, and is 
 pumped by the ventricle into the pulmonary artery. 
 The regular sequence of this cycle may be inter- 
 fered with in many ways, or rather by many patho- 
 logical conditions, since the nature of the interfer- 
 ence is practically the same in every case, but owing 
 to the compensating faculty of the heart, it is only 
 after long and persistent interference that any actual 
 change occurs in the cycles. 
 
 Mitral Insufficiency.— Thus, if the mitral valve 
 leaks, at each ventricular contraction a portion of 
 its contained blood is forced back into the auricle 
 and an insufficient quantity pumped into the aorta. 
 The auricle is then receiving blood both from the 
 venae cavae and from the ventricle and becomes 
 much distended, and the tendency is for a backward 
 
FUNCTIONAL DIAGNOSIS 73 
 
 stasis of circulation. However, the auricular muscle 
 responds to this demand by hypertrophying (com- 
 pensatory hypertrophy) and contracting more forc- 
 ibly. In time, of course, hypertrophy can no longer 
 make up for the increased work, and compensation 
 fails. The result, as one would suppose, is backward 
 stasis in the veins, high venous and low arterial 
 pressure, the former causing dropsy and C0 2 poison- 
 ing, the latter insufficient oxygenation, shortness of 
 breath and general atony. (See Respiration and 
 Elimination.) 
 
 Aortic Insufficiency. — Leakage of the semilunar 
 valve produces, by the same dynamic process, a com- 
 pensatory hypertrophy of the ventricle and even- 
 tually backward stasis. 
 
 Mitral Stenosis. — Stenosis of the mitral orifice, al- 
 though a reverse condition to insufficiency, produces 
 the same results by a somewhat different mechanism. 
 Here the narrowness of the opening imposes a sys- 
 tolic pressure upon the auricle, which is compensated 
 by auricular hypertrophy, later producing backward 
 stasis. 
 
 Aortic Stenosis. — Narrowing of the aortic opening 
 operates upon the ventricle precisely as vertical ste- 
 nosis does upon the auricle, with the same back- 
 ward train of events. 
 
 Leakage and Stenosis of the Bight Heart. — Insuf- 
 ficiency and stenosis of the valvular mechanism of 
 the right heart produces a set of conditions precisely 
 corresponding to those described for the left heart. 
 
74 FUNCTIONAL DIAGNOSIS 
 
 In these cases, however, the pulmonary circulation is 
 the first to feel the effects of backward stasis due to 
 failing compensation, and respiratory difficulties are 
 the earliest and most direct results. Fortunately, as 
 already stated, they are much rarer, owing to the 
 less opportunity for functional derangement than in 
 the systemic circulation. 
 
 The Coronary Arteries. — Another source of inter- 
 ference with the cardiac cycle is frequently seen in 
 a lesion of the coronary arteries. In order to prop- 
 erly carry out their function all the heart muscles 
 must themselves be regularly and adequately sup- 
 plied with nutrient blood, and any condition of the 
 coronary arteries (e. g. sclerosis, embolism, throm- 
 bosis) will produce a disturbance in the performance 
 of the heart cycle. Sudden stoppage of the heart (in 
 diastole, of course) often results from this cause, 
 which is also thought to be the explanation of the 
 phenomenon known as angina pectoris. 
 
 Intrapulmonary Pressure. — Any condition produc- 
 ing an increase of intrapulmonary pressure will, if 
 continued long enough, embarrass the right ven- 
 tricle, and bring about its hypertrophy, with even- 
 tual failure of compensation and fatal stasis. Em- 
 physema is a notable example of this. (See Respira- 
 tion.) 
 
 Systemic Pressure, long continued, such as is 
 caused by chronic Blight's disease, diabetes, arterio- 
 
FUNCTIONAL DIAGNOSIS 75 
 
 sclerosis, etc., will bring about the same train of re- 
 sults in the left heart. 
 
 Tonicity and Maximal Contractions of Heart Mus- 
 cle. — The heart muscle, like the skeletal muscles, is 
 in a constant state of more or less contraction; un- 
 like the skeletal muscles, however, it appears to pos- 
 sess this tonicity independently of its connection 
 with any nerve centre. It exhibits a further dissimi- 
 larity to skeletal muscles in that its contractions are 
 always maximal, i. e., when it contracts at all it con- 
 tracts to the farthest limit of its contractility. 
 
76 FUNCTIONAL DIAGNOSIS 
 
 NEUROLOGY OF HEART. 
 
 Nervous Control of the Heart.— Although the orig- 
 ination of the heart's action is independent of the 
 central nervous systems, its performance is largely- 
 modified by two sets of efferent neurons. One, the 
 vagus, is received from the undulla, and inhibits the 
 action of the heart muscle, slowing its beat, and can- 
 celling its tonicity, so that when the heart (as occa- 
 sionally happens) is stopped by stimulation of the 
 vagus, it is arrested in exaggerated diastole. The 
 other set, the accelerators, come from the sympa- 
 thetic chain, and augment the velocity of the beat. 
 
 Cardio-Inhibitory Function. — Stimulation of the 
 vagus nerve inhibits the heart 's beat and cancels the 
 tonicity of its muscle, finally arresting it in exag- 
 gerated diastole. The activity of this nerve also les- 
 sens the conductivity of the heart muscle, causing a 
 condition known as heart block, i. e., where the con- 
 traction wave does not regularly pass over from the 
 auricle to the ventricle, so that there are two beats 
 of the former to one of the latter. Experiment 
 proves that the fibres of the vagus reach and influ- 
 ence both the auricles and ventricles direct, but their 
 distribution to and influence upon the ventricles are 
 less than to the auricles, while with the accelerator 
 nerves the reverse is the case. 
 
 Heart Block. — In this condition, already described, 
 the beat of the ventricles is always in excess of that 
 of the auricles, because of the distribution of accel- 
 
FUNCTIONAL DIAGNOSIS 77 
 
 erator and inhibitory influence above referred to, 
 and also because of interference with, the conduc- 
 tivity of the heart muscle described above. 
 
 Reflex Inhibition. — The cardio-inhibitory action of 
 the vagus may be called into play reflexly by stimu- 
 lation of various sensory neurons, notably by the 
 stimulation of those sensory fibres of the vagus which 
 are distributed to the thoracic and abdominal vis- 
 cera. 
 
 The cardio-inhibitory centre is in a constant state 
 of tonicity, acting as a continual automatic drag on 
 the heart, preventing it from beating as rapidly as 
 it would otherwise do, and this tonicity of the centre 
 is doubtless a reflex phenomenon, mediated appar- 
 ently by various sensory impulses. 
 
 Accelerators Balance. — The accelerator nerves, de- 
 rived from the sympathetic, whose influence is pre- 
 cisely the opposite to that of the vagus, are also 
 capable of being called into action by reflex means. 
 Thus it seems that the velocity of the heart is nor- 
 mally regulated by the influence of two antagonistic 
 nerve-currents, one accelerating and the other inhib- 
 iting its beat. It appears probable, however, that 
 the inhibitory mechanism is most often invoked, and 
 that even acceleration is more frequently the result 
 of inhibition of the function of the vagus than of 
 stimulation of the accelerators. 
 
78 FUNCTIONAL DIAGNOSIS 
 
 DIGESTION. 
 
 Mastication is performed by means of the digastric 
 muscle, which depresses the jaw; the masseters, tem- 
 porals, and internal pterygoids, which raise it; and 
 the external pterygoids, which move the jaw later- 
 ally (grinding). 
 
 Innervation. — All the muscles of mastication re- 
 ceive their motor power by way of the inferior max- 
 illary branch of the fifth cranial nerve. 
 
 Bulbar Paralysis. — One of the earliest manifesta- 
 tions of bulbar paralysis is dysarthria, or difficulty 
 of jaw movement, due to involvement of the root of 
 the fifth nerve. The lesion of this particular part is 
 probably no earlier in fact than that of other bulbar 
 areas, but its impairment is noticed first. Later, 
 there is complete inability to masticate. 
 
 Imperfect Mastication, from whatever cause, sends 
 the food to the stomach imperfectly prepared, thus 
 delaying its passage through that organ and giving 
 rise to fermentation, flatulence, and indigestion, and 
 is, in these days of hurry, a fertile cause of stomach 
 trouble. 
 
 i. i. % 
 
 Salivary Glands. — These consist of the parotid, 
 submaxillary and sublingual glands, all of which be- 
 long to the type of tubular glands. 
 
 The Saliva is a colorless viscid liquid of alkaline 
 reaction and a specific gravity of about 1.003. Its 
 principal ingredient is an enzyme called ptyalin, 
 
FUNCTIONAL DIAGNOSIS 79 
 
 which reacts upon starch to produce a diastase. It 
 also contains some proteid maltose, and sodium po- 
 tassium and calcium salts. In solution saliva con- 
 tains carbon dioxid, the product (and measure) of 
 the metabolic activity of the glands. 
 
 The secretion contributed by the parotid gland is 
 richer in ptyalin and poorer in mucin than the secre- 
 tion of the other two ; the latter is given a more alka- 
 line reaction than the parotid secretion. 
 
 Ptyalism is an excessive secretion of saliva. It is 
 rarely, if ever, a primary complaint, but depends 
 upon some other pathological condition, and the sa- 
 liva is usually altered in character as well as in- 
 creased in quantity. 
 
 Inflammations of the Mouth and Throat, unless ac- 
 companied by a high temperature, are always at- 
 tended by an increased flow of saliva, due partly to 
 vaso-dilator conditions and partly to increased reflex 
 stimulation. In such cases it is usually acid in re- 
 action, because of the increased absorption of C0 2 
 and other metabolic acid products. 
 
 Pregnancy is attended by a more or less degree of 
 ptyalism. 
 
 Mercurial Ptyalism is due to hyperstimulation of 
 all the salivary glands by the drug. 
 
 In Fevers the watery part of the saliva is rapidly 
 absorbed by the mucous membrance to compensate 
 for the general anhydrous condition of the tissues 
 and the secretion is therefore thick and viscid, and 
 feels dry and sticky. The same condition is found, 
 
80 FUNCTIONAL DIAGNOSIS 
 
 and for the same reason, in Diabetes and certain 
 forms of Nephritis. 
 
 The Reaction becomes acid in Fevers, Diabetes, 
 Gout, Rheumatism and Nephritis, because of the ab- 
 sorption of metabolic acid products, chiefly C0 2 in 
 the first two diseases and uric acid in the others. In 
 gonty subjects the acidity is sometimes so high as 
 to erode the chin and corners of the mouth. 
 
 *. W -m 
 
 Innervation. — The salivary glands receive their 
 stimuli both from the cerebral centres through the 
 chorda tympani and from the sympathetic by way of 
 the cervical ganglia. Experiment shows that cere- 
 bral stimulation produces a thin, watery secretion, 
 poor in solids, whereas sympathetic irritation causes 
 the secretion of a viscid thick substance, rich in 
 solids. 
 
 The present theory is that the cerebral fibers me- 
 diate the purely secretory element in the function, 
 i. e., the osmotic filtration of the gland, while the 
 sympathetic performs a trophic part, increasing the 
 metabolism of the cells and producing organic prod- 
 ucts. 
 
 Vaso-Motor Influences. — In addition to the above 
 nervous supply, the chorda tympani carries vaso- 
 dilator fibers, whose stimulation dilates the capil- 
 laries of the glands, and the sympathetic carries 
 vaso-constrictor fibers whose stimulation constricts 
 the capillaries. 
 
 Dry Mouth is a condition, described first by Hutch- 
 
FUNCTIONAL DIAGNOSIS 81 
 
 inson, in which the secretion of the saliva is inhibited 
 as the result of a central nervous disturbance. The 
 parotid glands become hard but painless. 
 
 In fevers the watery portion of the saliva is rap- 
 idly absorbed by the mucous tissues to compensate 
 for the general anhydrous condition of the body, and 
 the saliva is therefore thick and viscid. 
 
 % 1m •k 
 
 Reflex Mechanism. — The function of the salivary 
 glands is a reflex one, whose centre is in the medulla. 
 It receives afferent stimuli from numerous sources, 
 chief among which, of course, are the sensory of the 
 tongue and palate, by means of the glossopharyngeal 
 and lingual nerves. The stomach by means of the 
 vagus, and the nose by means of the olfactory nerve, 
 also furnish afferent stimuli, and that the cerebral 
 centres may both directly stimulate and inhibit the 
 salivary centre is evidenced by the well known ef- 
 fects of various emotions and ideas upon the secre- 
 tion. (Watering at the mouth and parched throat, 
 due to longing and fear respectively.) 
 
 Experiment demonstrates that the efferent part of 
 this reflex is mediated wholly by the chorda tympani, 
 the sympathetic of itself being ineffectual to do so. 
 
 Stomatitis and Glossitis. — Undoubtedly the ptyal- 
 isms of inflammations of mouth and tongue are part- 
 ly due to irritation of the afferent fibers of the 
 glosso-labio-laryngeal nerves. 
 
 Gastric Ptyalism, as seen in catarrhal gastritis, 
 gastric ulcer, before vomiting, etc., are due to stimu- 
 
82 FUNCTIONAL DIAGNOSIS 
 
 lation of the afferent fibers in the gastric branch of 
 the vagus. 
 
 Deficient Saliva is one of the results of imperfect 
 and hasty mastication, because the latter act is one 
 of the chief exciters of the salivary reflex. 
 
 The Function of the Saliva is both mechanical and 
 chemical. Mechanically, it moistens the food, ena- 
 bling it to be conveniently masticated and swallowed, 
 and dissolves certain parts of the material so as to 
 act upon the taste buds. 
 
 Chemically its principal function is to convert the 
 starch in the food into dextrin and sugar by means 
 of its diastase, ptyalin. This is supposed to be ac- 
 complished by the starch molecules taking up water 
 and splitting into more elementary molecules. The 
 reaction is not completed in the mouth, but the food, 
 thoroughly mixed with saliva, passes into the stom- 
 ach and remains there some little time untouched 
 by the gastric juices, while the diastase finishes its 
 work. 
 
 Heat increases the activity of the salivary process 
 up to about 40 degs. C. At 65 degs. C, however, the 
 ptyalin is destroyed. 
 
 Cold decreases its activity; at deg. C. it is in- 
 hibited; 
 
 Acids destroy the activity of ptyalin, even so small 
 a percentage as .003 free hydrochloric acid being 
 fatal to it. 
 
 Boiled starch is much more amenable to the dias- 
 tase than raw starch, as the starch takes up some 
 
FUNCTIONAL DIAGNOSIS 83 
 
 water in boiling, and the shells of cellulose surround- 
 ing its grains are broken up. 
 
 Imperfect Salivation. — "When mastication is hur- 
 ried and food is bolted, the diastatic action of the 
 saliva is not well begun before the stomach is 
 reached. This delays the stay of the food in the 
 stomach, causing fermentation and flatulency. 
 
 When food is coated with an impermeable layer of 
 fat or other substance upon which saliva has no 
 action, the same ill result occurs. 
 
 Diluted Saliva. — When drinking is indulged in at 
 the same time as eating, the saliva is diluted and the 
 intensity of its diastatic action greatly weakened. 
 This is a frequent cause of indigestion. 
 
 Inhibition. — The behavior of ptyalin under ex- 
 tremes of heat and cold is sufficient indication of the 
 evils of eating food too hot or too cold, which con- 
 tains starch or of drinking extremely hot or cold 
 fluids during eating. 
 
 Altered Reaction. — Inasmuch as the action of 
 ptyalin is favored by an alkaline medium and in- 
 hibited by acids, it is easy to understand the poor 
 diastatic quality of the saliva in fevers, diabetes, 
 rheumatism, gout, nephritis, in which the reaction of 
 the secretion is acid from containing C0 2 and uric 
 acid. 
 
 ■I. *m *m 
 
 Deglutition is partly a voluntary and partly an in- 
 voluntary reflex act. It is usually divided into three 
 
84 FUNCTIONAL DIAGNOSIS 
 
 stages, which, however, depend upon anatomical 
 rather than physiological differentiation. 
 
 First Stage. — This embraces the passage of the 
 substance swallowed from the mouth to the pharynx, 
 and is a voluntary motor phenomenon. It is per- 
 formed by the levator muscles of the tongue, which 
 elevate that organ against the soft palate and drive 
 the morsel between the anterior pillars of the fauces. 
 At this point voluntary control of the act ceases, and 
 it enters the 
 
 Second Stage, including the passage of the morsel 
 through the pharynx. The pharynx being primarily 
 a respiratory passage, and containing the entrance 
 to the larynx (glottis) it is essential that the pass- 
 age of food be as rapid as possible through this 
 region. The contraction of the mylohyoid muscle in 
 the floor of the mouth drives the morsel through the 
 pharynx into the esophagus, the elevation of the 
 tongue against the hard palate preventing any retro- 
 grade movement. This action is assisted by the hyo- 
 glossal, and by the contraction of the constrictor 
 pharyngeal muscles. Other muscles are called into 
 play to prevent the sidetracking of food into the air 
 passages. The levator and tenson palati shut off the 
 nasal cavities ; the laryngeal opening is closed by the 
 adduction of the vocal cords by the cricoarytenoids 
 and constrictor glottis, and by the elevation of the 
 larynx. Experiment demonstrates that the epiglottis 
 does not lie down flat during deglutition, as formerly 
 believed, but remains erect. 
 
FUNCTIONAL DIAGNOSIS 85 
 
 Third Stage. — The passage through the esophagus 
 into the stomach varies according to the physical 
 condition of the food. Liquids fall directly through 
 the esophagus by gravity, and there await the arrival 
 of the peristaltic muscular wave incited by their 
 presence, which opens the sphincter of the stomach. 
 Solids are moved downward by this peristaltic con- 
 traction and pass directly into the stomach. The 
 wave of constriction is furnished by the successive 
 contraction of the circular muscles, the longitudinal 
 muscles, contracting immediately in advance of the 
 circulars, dilate the tube in readiness for the oncom- 
 ing bolus. The sphincter of the stomach, which is 
 normally in a state of closure, opens upon the arrival 
 of the muscular wave, and admits the food into the 
 stomach. 
 
 Dysphagia (difficulty in swallowing) of course re- 
 sults from any impairment of any of the above de- 
 scribed factors in deglutition, or from any condition 
 making the performance of their part in the act 
 painful. 
 
 Inflammation of any portion of the alimentary 
 tract from the mouth to the stomach, including glos- 
 sitis, pharyngitis, tonsillitis, and esophagitis, make 
 swallowing difficult because of the pain caused by 
 the contact of the food and by muscular contractions. 
 
 Ulcers, Growths, etc., have the same effect for the 
 same reason. 
 
 Spasms of the passages offer an obstacle to swal- 
 lowing, both by closing the passage and by tempo- 
 
86 FUNCTIONAL DIAGNOSIS 
 
 rarily paralyzing the musculature. In spasms, oc- 
 curring during the act of deglutition the food is im- 
 mediately regurgitated. 
 
 ^ -^ ^ 
 
 Innervation of Deglutition. — First Stage. — The in- 
 auguration of the act is mediated by the twelfth 
 cranial nerve, the motor nerve of the tongue, which 
 controls the process as far as its entrance upon the 
 second stage, is the passage of the morsel into the 
 pharynx. Thereafter the act is a true reflex. 
 
 Second Stage. — The afferent stimulus of the 
 pharyngeal division of swallowing is mediated by 
 the sensory fibers furnished to the mucous membrane 
 of the pharynx by the glossopharyngeal and trigemi- 
 nus. The efferent impulse is carried by the motor 
 fibers of the same nerves. 
 
 Third Stage. — The esophageal stage of the act is 
 stimulated afferently by the sensory fibers of the 
 vagus and superior laryngeal, and efferently by the 
 motor fibers of these nerves and by the special acces- 
 sory. 
 
 The Centre, as already stated, resides in the me- 
 dulla, near the nuclei of the neurons concerned. 
 
 Bulbar Paralysis results in voluntary dysphagia 
 due to involvement of the medullary root of the 
 twelfth cranial nerve, one of the most distressing 
 symptoms of this lesion. The same lesion of course 
 paralyzes the reflex mechanism of the second and 
 third stages of deglutition, but these are subordinate 
 to the first or voluntary stage. 
 
FUNCTIONAL DIAGNOSIS 87 
 
 Choking. — In bulbar paralyses and central lesions 
 involving sensory paralysis of the laryngeal nerves, 
 the stimulus which protects the laryngeal opening at 
 the glottis is wanting, and particles of food fre- 
 quently enter the larynx and cause partial or com- 
 plete asphyxia. 
 
 •m *m "1. 
 
 Movements of the Stomach. — The fundus or car- 
 diac end of the stomach is not concerned in the mus- 
 cular movements of the organ. It is simply, so far as 
 its musculature is concerned, a continuation of the 
 longitudinal fibers of the esophagus, expanding for 
 the better reception of the food. It must be re- 
 membered that normally the cavity of the stomach is 
 precisely in accordance with its contents, being in a 
 state of collapse or distension as it is empty or full 
 of food. 
 
 The pyloric end of the organ is the persistaltic 
 portion. Here, a few minutes after the entrance of 
 food, waves of contraction in the transverse and 
 oblique fibers are set up, running distalward, and 
 pressing the food against the pyloric sphincter as 
 soon as any of the contents of the pylorus are ready, 
 physically and chemically, the proper reflex stimulus 
 is furnished, which opens the sphincter and ejects 
 the prepared food into the intestine. Cannon be- 
 lieves that this stimulus depends upon the consist- 
 ency of the food, since solid substances passed 
 against the pylorus prevent relaxation, while liquid 
 food taken into the stomach passes very quickly 
 
88 FUNCTIONAL DIAGNOSIS 
 
 into the intestine. The point is, however, far from 
 settled. 
 
 Fermentation and Flatulence. — When the motor 
 mechanism of the stomach is so interfered with as 
 to delay the passage of food through it, the carbo- 
 hydrates of the food are fermented by the action of 
 the bacteria of fermentation, forming organic acids 
 (lactic, butyric, acetic). These in turn form acid 
 gases, that are eructated through the mouth. The 
 occurrence of these fermentations is shown by the 
 establishment of the hyperacidity of the stomach due 
 to excess of the acids mentioned. 
 
 The conditions which most markedly diminish the 
 motility of the stomach and thus produce fermenta- 
 tion are dilatation, pyloric obstructions, malignant 
 growths, and chronic gastritis. 
 
 Excessive Food may also interfere with the mus- 
 cular movements of the stomach, and produce the 
 above train of symptoms, except that in such case 
 the acidity of the stomach contents will be relatively 
 below par, as enough is not secreted to take care of 
 the excessive amount of food. 
 
 Digestibility of food is usually gauged, so far as 
 the stomach is concerned, by the length of time it 
 remains in the stomach, and as it is discharged into 
 the duodenum as soon as it is liquified, this is equiva- 
 lent to estimating it by the ease with which the 
 stomach reduces the food in question to a fluid. 
 
 Atony of Stomach Walls. — Due to distension, (1) 
 putting greater strain on muscles, (2) compromising 
 
FUNCTIONAL DIAGNOSIS 89 
 
 the vessels and lowering nutrition, and (3) dragging 
 organ downwards and kinking pylorus. 
 
 Pyloric Stenosis, producing first hypertrophy and 
 late dilatation of muscular walls. 
 
 Defect in Nutrition of stomach walls. 
 
 Disease of Stomach Walls. — Gastritis, Carcinoma, 
 etc. 
 
 Passive Congestion of Stomach, interfering with 
 nutrition. 
 
 "Splashing" Sounds. — As already stated, the nor- 
 mal stomach is always distended in exact proportion 
 to the amount of solid or liquid food it contains, its 
 muscular coat contracting tightly around these con- 
 tents and promptly expelling all air and gas that 
 may be present or formed If the muscular walls be 
 atonic, however, the stomach will sag under the 
 weight of liquid; gas and air will be present, and 
 upon shaking the patient the contents may be heard 
 to "splash." This is pathognomonic of gastric 
 atony. Its exhibition in patients apparently free 
 from stomach trouble is explained by the fact that 
 in early stages of atony the stomach is still able to 
 empty itself regularly, and therefore gives no signs 
 of gastric indigestion. 
 
 Pyloric Insufficiency is seen sometimes in muscular 
 diseases and malignant infiltrations, the contractile 
 power of the pylorus being lost and the food pouring 
 through the orifice too quickly. Its results are, of 
 coarse, intestinal indigestion; one of the most notice- 
 able symptoms being a regurgitation of gas produced 
 
90 FUNCTIONAL DIAGNOSIS 
 
 by the action of the alkaline juices of the duodenum 
 on the acid chyme. 
 
 *m •* ^ 
 
 Muscular Innervation. — The stomach is furnished 
 with fibers from the vagus nerve and the splanchnic 
 ganglia of the sympathetics, but as its muscular con- 
 tractions continue after section of both these groups 
 of fibers it is hard to escape the conclusion, that the 
 stomach muscle is automatic either by virtue of an 
 intrinsic property of the muscle itself or of the nerve 
 ganglia which richly invest it. 
 
 However the movements of the stomach may orig- 
 inate, they are controlled and regulated by the vagus 
 and splanchnic, both of which furnish sensory and 
 motor fibers to the organ. Experiment shows that 
 the efferent effects of the vagus are directly motor, 
 while those of the splanchnic are inhibitory, causing 
 dilatation and relaxation. 
 
 Through these two media the movements and se- 
 cretions of the stomach can be modified or inhibited, 
 either reflexly or by the influence of the higher cen- 
 tres. 
 
 Eructation is a motor reflex, mediated as to its af- 
 ferent stimulus either by the sensory fibers of the 
 gastric vagus in the stomach itself, or by the glosso- 
 pharyngeal nerves. 
 
 Vomiting is a reflex, having its centre in the me- 
 dulla (q. v.). Its afferent paths are numerous. Brun- 
 ton enumerates them as follows: Pharyngeal 
 branches of glosso-pharyngeal ; pulmonary and gas- 
 
FUNCTIONAL DIAGNOSIS 91 
 
 trie branches of vagus ; gastric branches of splanch- 
 nic; renal, mesenteric, uterine, ovarian and vescical 
 nerves. Its efferent paths are the motor fibers of 
 the gastric vagus and splanchnic. 
 
 The centre is amenable to influences direct from 
 the brain (central vomiting) ; and to those of certain 
 conditions of the blood, as in infectious diseases. 
 
 Paresis of the Stomach Walls is a very rare occur- 
 rence, but is occasionally met with. The result is an 
 acute dilatation of the stomach, due to the complete 
 abolition of the "tonal" energy. 
 
 Spasm of the Cardia and Pylorus is a reflex phe- 
 nomenon, due to irritation of the stomach nerves by 
 hyperacid contents. It produces what is known as 
 pneumathosis, the gas in the stomach being caught 
 between the two spasmodic contractions and distend- 
 ing the stomach, causing great pain. 
 
 Dyspnea and Cardiac Failure. — Any sudden or se- 
 rious distension of the stomach may produce dyspnea 
 by undue pressure on the diaphragm and faintness 
 and palpitation by interference with the dynamics 
 and innervation of the heart. 
 
 Any condition which irritates the gastric nerves 
 can disturb the heart and respiration reflexly 
 through the vagus nerve. This is especially common 
 in hyperacidity of the stomach. 
 
 ^ ^ ^. 
 Stomach Juice. — The gastric secretion is a thin 
 colorless liquid, specific gravity about 1.002, acid re- 
 action and of a characteristic odor. Its essential in- 
 
92 FUNCTIONAL DIAGNOSIS 
 
 gredients are hydrochloric acid, pepsin, and rennin, 
 but it also contains mucin, inorganic salts, a trace of 
 proteids, and some lactic acid. 
 
 The percentages of its ingredients vary, of course, 
 under different physiological conditions. The aver- 
 age percentage of HC1. in a normal stomach is 0.3. 
 It is supposed that the acid is derived from the sodi- 
 um chlorids in the blood, by double reactions, liber- 
 ating free HC1. At the beginning of stomach diges- 
 tion the acidity of the juice is somewhat neutralized 
 by the alkaline saliva with which the food is mixed. 
 The acidity of the juice as secreted, however, is con- 
 stant, in health. 
 
 Anacidity. — In acute and chronic gastritis in 
 which there is excessive mucous secretion, the activ- 
 ity of the cover cells is interfered with and a defici- 
 ency in hydrochloric acid results. The cause here is 
 local. Later there is atrophic or cirrhotic destruc- 
 tion of the gland cells, resulting in complete failure 
 of HC1. and pepsin. 
 
 In. Anemia, Infectious and Wasting Diseases there 
 is a deficient secretion of HC1. due to constitutional 
 causes, probably nervous in character. 
 
 In Carcinoma of the stomach there is usually a 
 complete absence of free HCL, due to both local and 
 constitutional interference with cell activity. 
 
 Excessive Eating may produce temporary anacid- 
 ity of the gastric contents, on account of the inability 
 of the stomach to secrete a relatively sufficient 
 amount of acid for the quantity of food. 
 
FUNCTIONAL DIAGNOSIS 93 
 
 Hyperacidity may be due to increase of HC1. or of 
 organic acids, as lactic acid. 
 
 In gastric ulcer the secretion of HC1. is occasion- 
 ally increased by the hypersensitiveness and irrita- 
 tion of the cells surrounding the ulcer. More often 
 the irritative effect of the hyperacidity causes the 
 ulcer. 
 
 In the early stages of gastritis (dyspepsia) there 
 is hypersecretion of HC1. from the same causes. 
 
 Excess of lactic, butyric and acetic acids result 
 from fermentation of carbohydrates. These fermen- 
 tations occur where there is delay in the stomach due 
 to another impairment. Hence they are found in 
 dilatation, organic obstructions of the pylorus, ma- 
 lignant infiltrations, etc. 
 
 "Where lactic acid is constantly excessive and HC1. 
 constantly absent, carcinoma may be usually diag- 
 nosed. 
 
 Neurotic hypersecretion occurs in neurosis of the 
 stomach, such as neurasthenia, hysteria, and may be, 
 constant or periodic. The increased acidity fre- 
 quently irritates the sensitive sensory nerves of the 
 stomach, causing sensations of hunger and through 
 them the solar plexus, causing gastralgia, both of 
 which are usually relieved by food. 
 
 *m "^ *m 
 
 Innervation. — The nervous control of gastric se- 
 cretion is mediated from a medullary centre by 
 means of the vagus nerve. It is undoubtedly as a 
 rule a reflex act, whose afferent stimuli are derived 
 
94 FUNCTIONAL DIAGNOSIS 
 
 from various sources. Animal experiments demon- 
 strate that the smell, taste, and even the sight of 
 food operate as afferent stimuli to the secretory cen- 
 tre, depending of course on the conscious state for 
 their effectual influence. Pawlow calls the secretion 
 thus induced a "psychical secretion," and it is cer- 
 tain that this type of stimulus plays an important 
 role in the ordinary process of digestion. 
 
 It is also probable that afferent stimulus is fur- 
 nished by the sensory nerves of the stomach itself, 
 set up by the presence of food, and that this type 
 of stimulus is independent of consciousness, being 
 mediated by the sensory fibers of the vagus. 
 
 Experiment shows, however, that the character of 
 this stimulus is not mechanical, but due to the chem- 
 ical properties in the food. Different foods possess 
 the stimulating power in differing degrees, and some 
 lack it altogether, and can only be digested if the 
 psychical stimulus be present to start secretion. 
 Thereafter these foods, in their altered, partially- 
 digested condition, are capable of setting up the 
 stimulus. 
 
 Afferently the secretory centre is amenable to both 
 stimulus and inhibition from the higher centres di- 
 rect, as the emotions are potent factors in modifying 
 gastric digestion. 
 
 Nervous Dyspepsia is regarded by Leube as a 
 group of cerebral impressions made by the irritative 
 effect of an ordinary digestive process upon hyper- 
 sensitive nerves of the stomach, and the eructations 
 
FUNCTIONAL DIAGNOSIS 95 
 
 which occur in this condition as a form of motor 
 reflex from such irritation. Another afferent phe- 
 nomenon is the hypersecretion of HC1. referred to 
 under the preceding section, causing sensations of 
 hunger and gastric pain, relieved by food. 
 
 1. Glands Containing Chief of Peptic Cells. — 
 These are located mainly at the pyloric end of the 
 stomach and secrete pepsin and rennin, the digestive 
 enzymes. 
 
 2. Glands Containing Cover Cells. — These are 
 massed in the middle or pre-pyloric part of the stom- 
 ach and furnish hydrochloric acid. Peptic cells are 
 found intermingled with them. 
 
 In Chronic Intestinal Gastritis the chief and cover 
 cells are both largely replaced and supplanted by a- 
 proliferation of mucoid cells, the result being a di- 
 minution of normal secretion and an outpouring of 
 mucous, hence indigestion. Later there is either 
 atrophic or sclerotic degeneration, resulting in com- 
 plete absence of gland cells. 
 
 ■■.■■.■■. 
 
 In Chronic Interstitial Gastritis, the outpouring of 
 mucous gives the same sensation of hunger, but the 
 appetite is very quickly appeased on account of the 
 hypo-secretion of gastric juice. 
 
 Indigestion (i. e., an abnormal length of time nec- 
 essary for stomach reduction of food) may result 
 from eating unpalatable or insipid food, owing to 
 the deficiency of "psychic" secretion in the stomach. 
 
96 FUNCTIONAL DIAGNOSIS 
 
 Pepsin-Hydrochloric-Acid Digestion. — Pepsin is an 
 enzyme which, like other enzymes, is modified in its 
 action by temperature, high temperature up to 40 
 degs. C. hastening, and low temperature retarding its 
 activity. Unlike the enzyme, ptyalin, however, its 
 activity requires the presence of an acid ; hence pep- 
 sin digestion in the stomach is the joint result of pep- 
 sin and hydrochloric acid. 
 
 Pepsin converts proteids by a series of metabolic 
 steps into peptones. Howell indicates this process by 
 the following landmarks of transformation : Proteid, 
 acid albumine, primary proteoses, secondary pro- 
 teoses and peptones. 
 
 The process is not always completed, and the 
 chyme may be ejected into the duodenum in any one 
 of the above stages of transformation, whence it ap- 
 pears that pepsin digestion is not so important in 
 itself as in its preparatory influence on the food 
 looking to further digestion by the pancreatic juices. 
 
 Fat is not, as a rule, influenced by pepsin and hy- 
 drochloric acid, except that the breaking up of the 
 proteids frees the fats from their combination with 
 the proteids and prepares them for intestinal diges- 
 tion. 
 
 Rennin Digestion. — So far as is known, the only 
 action of this enzyme is to convert the casein of 
 milk and other casein-containing foods into para- 
 casein, by a process commonly known as curdling, 
 which we must suppose is beneficial to the ultimate 
 
FUNCTIONAL DIAGNOSIS 97 
 
 digestion of the casein, although the rationale of 
 the process is at present obscure. 
 
 Gastric Absorption. — Experiment demonstrates 
 that very few foodstuffs undergo absorption in the 
 stomach. "Water, formerly thought to be readily ab- 
 sorbed, is known to pass through almost unchanged. 
 Salt solutions are unabsorbed in any less concen- 
 trated solutions than 3 per cent. Sugars and pep- 
 tones are absorbed, but with difficulty. 
 
 Acidosis in Diabetes. — Bainbridge, in The Lancet, 
 points out that the onset of coma is usually pre- 
 ceded for a day or two and accompanied by a fall 
 in the output of the acetone bodies, the excretion of 
 b-oxybutyric acid may sink from 15 grammes or more 
 to as little as one gramme, and the acetone and di- 
 acetic acid may be either absent or present only in 
 traces. The decreased excretion of acetone in the 
 breath also indicates that the production of acetone 
 bodies is actually lessened and that the kidneys are 
 not able to carry out their functions. The fall in 
 the output of sugar and nitrogen, the fall of body 
 temperature, and the lessened intake of oxygen all 
 point to a decline in the total metabolism. Equally 
 characteristic features of coma are the diminished 
 alkalinity of the blood and its diminished content of 
 carbonic acid. 
 
 Acid intoxication, in the strict sense of the term — 
 that is, poisoning by hydrogen ions — never occurs, 
 since the tissues never lose their alkaline reaction; 
 the term is justifiable, however, if it is used to de- 
 
98 FUNCTIONAL DIAGNOSIS 
 
 scribe the metabolic disturbances resulting from the 
 abnormal production of acids in the body or from 
 the administration of mineral acids accompanied by 
 a fall in the alkalinity of the blood and tissues. The 
 tissues are very sensitive to even a slight diminution 
 in their alkalinity, and the acute intoxication pro- 
 duced by mineral acids is believed to be due to a fall 
 in the alkalinity of the blood and tissues or, in other 
 words, to a diminution in the concentration of hy- 
 droxyl ions relative to the hydrogen ions; this has 
 been proved to occur as far as the blood is con- 
 cerned. 
 
 1m J. % 
 
 Intestinal Movements. — The intestines are supplied 
 with both circular and longitudinal muscles. The 
 former furnish what is known as peristalsis, by 
 means of the successive contraction of the circular 
 muscles distalward, the effect of which is to drive 
 the contents of the bowel onward. Some physiolo- 
 gists hold that this wave of peristaltic contraction is 
 preceded by a wave of inhibition. That the progres- 
 sion of the wave depends upon the arrangement of 
 the musculature is shown by the fact that resection 
 of a piece of the intestine and replacement in the 
 opposite direction is followed by reversed peristalsis 
 in the portion whose polarity is thus changed. 
 
 Diarrhea and Constipation represent the two oppo- 
 site abnormalities of intestinal peristalsis, the former 
 being due to increased and the latter to diminished 
 
 peristalsis. 
 
FUNCTIONAL DIAGNOSIS 99 
 
 In Intestinal Obstruction, if complete, the peris- 
 talsis above the seat of obstruction is increased by 
 the accumulation of feces, and eventually the pres- 
 sure overcomes the distalward movement and fecal 
 vomiting ensues. 
 
 ■% ^i *m 
 
 Peristaltic Innervation. — Experiment and observa- 
 tion make it probable that the muscular activity of 
 the intestines, like that of the stomach, is automatic 
 in origin, and regulated by the cerebro-spinal and 
 sympathetic nerves. In both of these relationships 
 it is undoubtedly a reflex act, in the former case me- 
 diated by intrinsic ganglia, in the latter case by a 
 spinal centre. The stimulus is doubtless a mechan- 
 ical one, normally furnished by the entrance into the 
 bowel of the food matter. 
 
 The Small Intestine is innervated, both afferently 
 and efferently, by fibers of the vagi, and sympathetic 
 fibers from the dorsal vertibrae via the splanchnic 
 and semilunar ganglia. 
 
 The Large Intestine is innervated in its upper por- 
 tions by the same nerve supply as the small intes- 
 tine ; in its lower sections (descending colon and rec- 
 tum), it receives fibers from the second to the fourth 
 sacral nerves, and from the inferior mesenteric gan- 
 glia of the sympathetic. , 
 
 All of the cerebro spinal centres concerned in the 
 intestinal movements are subject to direct stimula- 
 tion and inhibition by the higher cerebral centres. 
 The effects of emotions and ideas upon bowel centres. 
 are familiar phenomena. 
 
100 
 
 FUNCTIONAL DIAGNOSIS 
 
 Diarrhea and Constipation, representing respect- 
 ively increase and diminution of intestinal peris- 
 talsis, are almost invariably due to a disturbance of 
 the nervous reflex governing this muscular function. 
 
 Diarrhea, the expression of an exaggerated peris- 
 talsis, is most frequently due to a catarrh, either pri- 
 mary or secondary, which renders the intestinal 
 nerve ends irritable and leads to overstimulation of 
 the peristaltic reflex. 
 
 Psychical Diarrhea, such as accompanies sudden 
 emotions, is doubtless brought about through vaso- 
 motor mechanism. Certain emotions, such as fright, 
 inhibit the splanchnic vaso-constriction, causing a 
 congestion of the splanchnic vessels and overstimula- 
 tion of the intestinal reflexes. 
 
 Intestinal Dyspepsia is attended with diarrhea, be- 
 cause the undigested food acts as a foreign irritant 
 to the intestinal nerve ends and excites peristalsis. 
 Undigested food is found in the stools. (Lienteria.) 
 
 In Typhoid Fever and Cholera the bacteria and 
 their toxins focus as a rule in the bowels, producing 
 intestinal catarrh and exciting peristaltic reflex. In- 
 testinal tuberculosis operates the same way. 
 
 Gall Stones induce diarrhea by mechanical irrita- 
 tion of the intestinal nerves. 
 
 Worms excite peristalsis both by mechanical and 
 chemical stimulus. 
 
 In Intestinal Obstruction the accumulation of ma- 
 terial above the obstruction acts as an abnormally 
 powerful mechanical stimulus and increases peris- 
 
FUNCTIONAL DIAGNOSIS 101 
 
 talsis, but naturally the increased peristalsis does not 
 result in diarrhea. The bowel being greatly dis- 
 tended, the vigorous peristalsis can frequently be 
 seen through the abdominal wall, and in connection 
 with absence of defecation makes a characteristic 
 syndrome, as well as a measure of the extent, of in- 
 testinal obstruction. 
 
 Exposure to Wet and Cold may produce diarrhea 
 by means of vaso-motor reflex, the skin stimulus 
 causing congestion of the splanchnic vessels and thus 
 overstimulating peristalsis. Burns of the skin fre- 
 quently act in the same way. 
 
 Gastric Indigestion causes diarrhea by reason of 
 the insufficient liquification of the chyme, which 
 therefore exerts too great a mechanical stimulus on 
 the nerves of the intestine. 
 
 Reflex Nervous Diarrhea may result from reflex 
 irritation from some other diseased organ. 
 
 Constipation, the expression of diminished peris- 
 talsis, is frequently due to, faulty innervation of the 
 peristaltic reflex, either in its afferent or efferent 
 phase. 
 
 Neurasthenia, Hysteria, Anemia, Chlorosis, etc., 
 are attended by constipation because of the diminu- 
 tion in nerve energy, coupled with a debility of the 
 muscles of the intestines. 
 
 In Chronic Constipation the nerves lose their pe- 
 ripheral sensibility on account of neglect to respond 
 to the reflex desire for defecation. Later the intes- 
 tinal muscles become flaccid. 
 
102 FUNCTIONAL DIAGNOSIS 
 
 In certain spinal diseases such as myelitis and 
 meningitis, constipation results from involvement of 
 the reflex arcs. 
 
 All fevers in which there is no specific intestinal 
 catarrh (as in typhoid, vida supra) are attended by 
 constipation. This is due partly to the rapid absorp- 
 tion of moisture from the bowel contents, making 
 their passage difficult, partly in diminution in the 
 amount of contents, lessening the reflex stimulus, 
 and partly to malnutrition of the intestinal muscles, 
 or weakening their intrinsic power. 
 
 Diabetes is attended by constipation, due partly to 
 rapid absorption of moisture and partly to diminu- 
 tion of bowel contents, much of their normal solid 
 constituents being eliminated by the kidneys. 
 
 Constitutional Diseases (Tuberculosis, Syphilis, 
 etc.) unless specifically attacking the bowel with ca- 
 tarrh, exhibit constipation, due to malnutrition of 
 muscle and faulty innervation. 
 
 i. •* ■% 
 
 Intestinal Absorption. — The intestines are the 
 chief absorbent portion of the alimentary tract. 
 Their absorptive capacity may in general be said to 
 range in precise ratio to the proximal topography — 
 being greatest in the duodenum and diminishing un- 
 til the least degree is reached in the rectum. This, 
 however, is necessarily subject to modification ac- 
 cording to the substances considered for absorption. 
 
 In the Small Intestine absorption is very active, 
 and proceeds simultaneously with digestion. The 
 
FUNCTIONAL DIAGNOSIS 103 
 
 process is accomplished by two forces (a) diffusion 
 and osmosis, and (b) the selective and absorptive 
 energy of the epithelial cells in the intestinal wall. 
 
 In the Large Intestine the unabsorbed remnant 
 from the small bowel remains a long time, during 
 which digestion proceeds by means of the digestive 
 juices derived from the upper bowel. No digestive 
 juices are secreted in the large intestine, but absorp- 
 tion takes place, especially of water and proteids, 
 the former accounting for the eventual consolidation 
 of the feces. 
 
 The large bowel has an alkaline reaction, which 
 favors the growth of putrefactive bacteria, so that 
 putrefaction is a usual phenomenon in this locality. 
 i. ?w "W 
 
 The Pancreas, a glandular body of the tubular 
 type (frequently called the salivary gland of the ab- 
 domen) secretes a thin watery fluid, alkaline in re- 
 action, of a specific gravity about 1.007, of which the 
 essential digestive ingredients are enzymes called 
 Trypsin, pancreatic diastase, and lipase. The first 
 breaks up proteids or rather the proteid products al- 
 ready prepared by the pepsin of the stomach; the 
 second breaks up starch ; the third fat. 
 
 Functional Pathology of the Pancreas is obscure 
 and indefinite, owing to the fact, first, that its physi- 
 ology is poorly understood and indissolubly blended 
 with that of other organs; second, that its complete 
 disablement is extremely rare and as long as partial 
 integrity remains it performs its work with reason- 
 able satisfaction. 
 
104 FUNCTIONAL DIAGNOSIS 
 
 Innervation. — The pancreas derives its nervous 
 motive energy from the cerebrospinal and sympa- 
 thetic systems by means of the vagus and fibers from 
 the celiac plexus. Vaso-motor fibers play an impor- 
 tant role in the proper functionating of the organ. 
 
 The stimulus is supplied in a rather unusual 
 fashion. The effect of the acid contents of the stom- 
 ach, when ejected into the duodenum, is the pro- 
 duction of a substance called secretion, which, being 
 absorbed by the blood and carried to the pancreas, 
 stimulates it to secretion. 
 
 The functional pathology of the organ is further 
 complicated and obscured by this nervous mechan- 
 ism. 
 
 Trypsin Digestion. — Trypsin is not elaborated as 
 such by the pancreas, but as a stable zymogen known 
 as trypsinogen, which is converted into trypsin by an 
 enzyme of the duodenum called by Pawlow entero- 
 kinase. 
 
 As already stated trypsin completes the work al- 
 ready begun by pepsin on the proteids. "While pep- 
 sin works only in the presence of an acid, trypsin 
 works best in an alkaline medium. The a.ction of 
 trypsin is much more rapid and thorough than that 
 of pepsin. The proteids, which are assumed to con- 
 tain two groups of molecules, the hemis and the 
 antis, are split up into primary and secondary pro- 
 teoses, and thence into peptones corresponding to 
 the proteid molecules hemi and anti-peptones. Tryp- 
 sin, however, does not stop there, but breaks these 
 
FUNCTIONAL DIAGNOSIS 105 
 
 peptones up still further into tyrosin, leucin, aspartic 
 acid, tryptophan, lysatinin, and other end products 
 whose number and character of course vary with the 
 length of time the food has been subject to tryptic 
 digestion. 
 
 No definite nutritive significance has yet been as- 
 signed to these various products. Lysatinin is prob- 
 ably the source of some of the urea formed in the 
 body. 
 
 Pancreatic Diastase Digestion is practically the 
 same as that of ptyalin, namely, a hydrolytic action 
 upon starch, converting it into maltose and dextrin. 
 It evidently deals with such starchy elements in the 
 food as escape the influence of the saliva. 
 
 Lipase Digestion comprises three stages : (1) The 
 enzyme splits up the fats of the food, by a hydrolytic 
 process, into glycerine and fatty acids. (2) The 
 fatty acids combine with the alkaline salts present 
 to form soaps. (3) The soaps are broken up into 
 minute globules which do not coalesce (emulsifica- 
 tion). The latter process is not due to the enzyme 
 lipase, but to the physical properties of the pancre- 
 atic juice. Lipase is found in other tissues of the 
 body where fats are concerned, notably the mam- 
 mary glands, muscles, liver, etc. Its action is greatly 
 assisted by bile. 
 
 Fat in the feces, to any abnormal amount, is usu- 
 ally regarded as presumptive evidence of pancreatic 
 disability, but can only bear this diagnostic interpre- 
 tation in the absence of symptoms pointing to sup- 
 
106 FUNCTIONAL DIAGNOSIS 
 
 pression of bile, intestinal tuberculosis, diarrhea, or 
 large ingestions of fat. (See Composition of Feces.) 
 Lipuria (fat in the urine) is subject to the same 
 provisional interpretation. 
 
FUNCTIONAL DIAGNOSIS 107 
 
 THE LIVER. 
 
 The function of the liver is threefold: (1) The 
 secretion of bile, (2) the elaboration of urea, and (3) 
 the formation and storage of glycogen. 
 
 Suppression of Bile is a frequent symptom in pa- 
 renchymatous diseases of the liver, notably in acute 
 yellow atrophy, hepatic cirrhosis, malignancy, syph- 
 ilis, and abscess. It is manifested as a rule by a more 
 or less severe jaundice. 
 
 Uremia, now generally recognized as a suppression 
 of urea rather than its retention, is undoubtedly the 
 direct result of abnormal hepatic metabolism al- 
 though the exciting cause is the failure of the kidney 
 to excrete urea. This phase of the hepatic function 
 is too obscure to furnish any definite contribution to 
 functional diagnosis. 
 
 Disordered Glycogen Metabolism, and consequent 
 starvation of the tissues, especially the muscular tis- 
 sues, accompanies almost every degenerative disease 
 of the liver. 
 
 Coma due to retention and toxemia of metabolic 
 products also accompanies all severe parenchyma- 
 tous diseases of the liver, such as yellow atrophy, 
 cirrhosis, etc. 
 
 i. ^. ^. 
 
 Bile. — This important secretion performs a two- 
 fold office; one of an excretory and the other of a 
 digestive character. Besides water and organic sol- 
 ids, it contains bile-pigments, bile acids, cholesterin, 
 
108 FUNCTIONAL DIAGNOSIS 
 
 lecithin, fats, soaps, inorganic salts, and a species of 
 aneho-albumin erroneously called mucin. 
 
 Suppression or Retention of Bile is always accom- 
 panied by disturbances of intestinal digestion, espe- 
 cially of fat-splitting ferment whose activity it in- 
 creases three-fold, and of the proteolytic and amy- 
 tolytic ferments whose activity it doubles. These di- 
 gestive disturbances are therefore always seen in 
 conditions which interfere with the elaboration or 
 discharge of bile, as yellow atrophy, malignancy, he- 
 patic abscess, cirrhosis, cholecystitis, gall stones, etc. 
 
 Nervous Disturbances also attend bile suppression 
 or retention, due to the suspension of the excretory 
 office of the bile and the consequent re-absorption of 
 pigments, cholesterin, licithin, and similar excretory 
 materials. 
 
 ■Si "I. "m 
 
 Bile Pigments. — The bile contains two principal 
 pigments, bilvinbin and bilverdin, the latter being an 
 oxidation of the former. These pigments are derived 
 from the hemoglobin of the blood as a product of the 
 disintegration of red corpuscles, the iron which is 
 separated from them being retained for the forma- 
 tion of new hemoglobin. The pigments are therefore 
 in the nature of an excretion, and are passed largely 
 with the feces in the form of urobilin and stercobilin. 
 Some portion of them, however, is known to be ab- 
 sorbed in the intestines and re-secreted by the liver, 
 though to what purpose is not clear. 
 
FUNCTIONAL DIAGNOSIS 109 
 
 Suppression or Retention of bile invariably mani- 
 fests itself by an absence of these pigments from the 
 feces ; resulting in clay colored stools, common to all 
 those diseases already enumerated as interfering 
 with flow of bile. 
 
 Excessive Bile, on the other hand, exhibits an ex- 
 cess of pigments in the feces, producing dark green 
 or very yellow stools, seen principally in excessive 
 proteid feeding and in gall stones following on ob- 
 struction of the duct and consequent accumulation 
 of bile. 
 
 ■I. -m 1. 
 
 Bile Acids. — These acids are organic and are two 
 in number, glychocholic and torocholic. They do 
 not occur as free acids but in combination with sod- 
 ium basis as acid salts. They are formed directly in 
 the liver cells, and are the elements in the bile which 
 assist the pancreatic secretion in the digestion of 
 fats. They are largely absorbed in the intestines and 
 resecreted by the Hver — probably because of their 
 value as a stimulus to bile secretion. 
 
 Biliousness, as commonly understood by the laity, 
 is due to the poverty of the bile in these acid salts. 
 In their comparative absence fats are very hard to 
 digest or to dispose of, hence the intolerance of the 
 patient to greasy foods ; and the stimulation of bile- 
 flow is weakened, causing a general diminution of 
 bile and bile-function. 
 
 Cholesterin and Lecithin are both of them true 
 excretory products, being secreted from the blood 
 
110 FUNCTIONAL DIAGNOSIS 
 
 by the liver cells. They both pass out unchanged in 
 the feces. 
 
 ■b 'm *m 
 
 Innervation. — The secretion of bile does not ap- 
 pear to be under the control of any special set of 
 nerves, but is a constant function, dependent for its 
 regulation only upon the vaso-motor influences of the 
 hepatic vessels, and probably also on the character of 
 the blood flowing through them. 
 
 Discharge of Bile. — Normally the bile is not con- 
 tinuously given by the liver directly to the duode- 
 num, but is stored in the gall-bladder, guarded by a 
 sphincter, and discharged at intervals during diges- 
 tion. The ejection of the chyme into the duodenum 
 acts as a stimulus for the reflex which relaxes the 
 sphincter, contracts the gall bladder, and throws the 
 bile into the duodenum. This reflex is mediated by 
 the vagus and splanchnic nerves. Bruhs asserts that 
 the stimulus depends on the character of the chyme ; 
 acids, alkalies, and starches being inert, proteids and 
 fats or their products effective. 
 
 Retention of Bile results from any condition which 
 (a) interferes with the proper performance of the 
 gall-bladder reflex, or (b) obstructs the passage of 
 the duct, in which case the bile pigments are ab- 
 sorbed and appear in the epithelial tissues as jaun- 
 dice. 
 
 Familiar examples of the first variety are malaria, 
 sepsis, icterus neonatorum, pernicious anemia. 
 
 Of the second class conspicuous instances are gall- 
 
FUNCTIONAL DIAGNOSIS 111 
 
 stones, cholecystitis, malignant growth, and cir- 
 rhosis. 
 
 •* V ^ 
 
 Function of Bile. — Bile performs a two-fold role, 
 (1) that of an excretory function, eliminating choles- 
 terin, lecithin, and bile pigments, and (2) that of a 
 digestive process, accelerating the emulsification and 
 hydrolysis of fats in the intestine. The antiseptic 
 properties formerly ascribed to the bile have been 
 greatly discounted by recent observations. 
 
 Glycogen is frequently called animal starch, as it 
 has the same general chemical formula as vegetable 
 starch, and is amenable to the action of ptyalin with 
 practically the same end-products. It is constantly 
 present in the normal liver, being stored up during 
 digestion and given out to the tissues gradually in 
 the fasting intervals. The quantity present varies, 
 therefore, in regard to the occurrence of meals ; the 
 mean quantity is about 2.5 per cent of the weight 
 of the liver. It is held by the liver cells in a loose 
 chemical combination much the same way as the 
 hemoglobin is held by the red corpuscles of the blood. 
 
 Formation of Glycogen. — Normally the great bulk 
 of glycogen is undoubtedly derived from the hydro 
 carbon of the diet. These reach the liver in the 
 form of dextrose, levulose, and saccharose, which are 
 dehydrated by the liver cells into glycogen, as fol- 
 lows: 
 
 C 6 H 12 6 — H 2 O=C 6 H 10 O B . 
 
 Experiment and observation make it clear that 
 
112 FUNCTIONAL DIAGNOSIS 
 
 glycogen may also be derived from the proteids of 
 the blood. Of the various end-products of pepsin 
 and trypsin digestion, those containing a nitrogen 
 atom are probably converted in the liver into urea, 
 the balance going to make sugar, which is subse- 
 quently converted into glycogen. 
 
 Pats increase the amount of glycogen in the liver, 
 but whether by direct conversion into this product 
 or by diminishing the consumption of glycogen by 
 the tissues is not certainly known. Von Noorden 
 asserts that glycogen is derived directly from fats. 
 
 An important factor in Diabetes is a deficient for- 
 mation of glycogen. The sugars which are normally 
 utilized for this purpose remain unchanged in the 
 blood and are secreted through the kidney. Recent 
 experience shows that this deficiency is a disability 
 of the pancreas digestion rather than of the liver, 
 although certain forms of liver disease are attended 
 with glycemia. 
 
 Uses of Grlycog'en. — The modern doctrine of glyco- 
 gen is that it represents the storage of the carbo- 
 hydrate nutriment of the body which the liver holds 
 in trust and gives out to the blood as required. 
 Reaching the liver in the form of glucose these 
 hydrocarbons are dehydrated, as explained, into 
 glycogen and stored in the liver cells. When needed 
 by the system they are inverted into glucose and 
 given to the blood. It is now known that in order 
 that the muscles and other tissues may take up and 
 utilize the glucose distributed by the liver there 
 
FUNCTIONAL DIAGNOSIS 113 
 
 must be added to it a product of the pancreas. Just 
 wliat this product is is not definitely known. Von 
 Noorden assumes it to be a polymerising agent which 
 enables the protoplasm to again invert the glucose 
 into glycogen. 
 
 Diabetes. — It seems pretty well established that 
 the prime factor in the glycocemia and glycosuria of 
 diabetes is the failure of this polymerization process, 
 so that the tissues, although flooded with sugar, are 
 quite unable to assimilate it; hence it accumulates 
 in the blood and is forced through the kidneys. This 
 agrees with the two chief somatic conditions found 
 in diabetes, namely, poverty of the organs and tis- 
 sues in glycogen, and an excess of sugar in the 
 blood; also with the clinical fact that increased 
 muscular exercise does not reduce the glycemia, 
 and points to the pancreas as the chief organ of of- 
 fending in diabetes. 
 
 Diabetes Masked by Obesity. — In cases where this 
 polymeric disability exists but there is no impair? 
 ment of fat synthesis, the excess of sugar is utilized 
 in making fat instead of passing into the urine. In 
 these cases there is obesity and no glycosuria ; it is a 
 case of diabetes masked by obesity. 
 
 ■W ■* 'm 
 
 Regulation of Glycogen Formation. — The forma- 
 tion of glycogen is a constant metabolic process, and 
 modified only by the quantity and quality of the 
 diet. Each hydrocarbon has a different limit to 
 
114 FUNCTIONAL DIAGNOSIS 
 
 which the liver is able to dispose of its sugar-product. 
 For starch, which forms so large a portion of our 
 diet, no limit is known, and of the sugars themselves 
 glucose has the highest limit, as much as 150 gms. 
 being taken care of at one dose. When these articles 
 are fed beyond their limit glycemia occurs, due to 
 the surplus sugar-products which the liver is unable 
 to store as glycogen. 
 
 Regulation of Glycogen Distribution. — That the 
 doling out of glycogen in the form of glucose by 
 the liver to the tissues is in some way under the con- 
 trol of the nervous system seems probable from the 
 fact that certain disturbances of the nervous equilib- 
 rium bring about a temporary glycemia and glyo- 
 curia, and also from Claude Bernard's famous "pi- 
 qure" experiment, in which he induced glycosuria 
 by a puncture of the fourth ventricle. The mechan- 
 ism of this control is obscure. It is apparently medi- 
 ated by a centre which receives its stimulus from the 
 condition of the tissues (especially the muscles) in 
 regard to sugar supply. An increased demand for 
 sugar, as in increased metabolism (muscular exer- 
 cise) brings about a reflex acceleration of its distri- 
 bution from the liver, and vice versa. It would ap- 
 pear, however, that the inhibition reflex is only ef- 
 fective to a certain limit, as after periods of muscu- 
 lar rest, glycogen is found stored in the muscles, 
 demonstrating that the supply is not absolutely reg- 
 ulated by the immediate demand. 
 
 In diabetic patients there is no doubt that this 
 
FUNCTIONAL DIAGNOSIS 115 
 
 stimulus continues to act upon the nervous center, 
 since the tissues, although bathed in sugar are un- 
 able to utilize it, and are therefore hungry for it. 
 Thus a vicious circle is effected of an organism al- 
 ready overburdened with useless sugar constantly 
 stimulating the distribution of more. 
 
 Neurogenous Glycosuria is a temporary excess of 
 sugar in the urine due to nervous shocks, neuras- 
 thenia, post-operative conditions, and other disturb- 
 ances of nervous functions, and must not be con- 
 founded with true diabetes. There is no pancreatic 
 disability in these neurogenic forms; they depend 
 entirely on an exaggerated distribution of sugar by 
 the liver — hence increased muscular metabolism will 
 reduce the glycosuria. 
 
 •y v ^i 
 The Spleen is an organ whose function or func- 
 tions are very obscure. It is supposed to (1) gener- 
 ate new corpuscles, (2) furnish a graveyard for red 
 blood corpuscles, and (3) assist in the formation of 
 uric acid. 
 
 Although a swollen spleen is the accompaniment 
 of many diseases, particularly typhoid fever, malaria, 
 leukemia, and secondary anemia, there is not suffi- 
 cient data as to its physiological function to estab- 
 lish any diagnostic relationship between it and the 
 disease in question. 
 
116 FUNCTIONAL DIAGNOSIS 
 
 ELIMINATION. 
 
 The Kidneys secrete urine. Inasmuch, however, 
 as the constituents of the urine are all existent in 
 the blood when it reaches the kidney, and are 
 simply separated by those organs, it would be more 
 correct to say that they excrete urine. 
 
 In the absence of one kidney, the other, if healthy, 
 will compensate by performing double duty in- 
 definitely. Complete suppression of renal function, 
 however, rapidly produces death. 
 
 Process of Excretion. — Two principal theories 
 hold the field as to the mechanism by which the kid- 
 neys excrete the urine: 
 
 1. The Ludwig or mechanical theory accounts 
 for the process by the purely mechanical agencies 
 of filtration and diffusion. In the glomeruli the 
 entire urine, in a dilute condition, is filtered from 
 the blood, the process being regulated by the pres- 
 sure in the blood vessels. In the tubules it loses 
 some of its water by diffusion and becomes more 
 concentrated. 
 
 2. The Bowman-Haidenhain theory holds that 
 the glomeruli separate water and inorganic salts 
 from the blood, and the tubules secrete the organic 
 constituents, urea, etc., both processes depending 
 primarily upon the vital activity of the epithelial 
 cells, although blood pressure necessarily plays a 
 quite important part. 
 
FUNCTIONAL DIAGNOSIS 117 
 
 The preponderance of evidence is in favor of the 
 latter theory, and it will be assumed here. 
 
 Albuminuria. — In their normal condition the 
 epithelial cells of the kidneys are only permeable 
 to those inorganic and organic constituents of the 
 blood which make up the normal constituency of 
 urine. In diseased conditions of the kidney which 
 disable these cells, however, other elements are let 
 through the glomeruli and tubules, chief among 
 which is albumin. This phenomenon is known as 
 albuminuria, and is common to all those diseases 
 which injure the epithelial tissue of the kidneys. 
 
 There are two varieties of albumin found in patho- 
 logical urine, Nucleo-Albumin and Serum Albumin. 
 Of these the former is derived from the disintegra- 
 tion of the epithelial cells themselves, and is there- 
 fore not diagnostic of renal disease, as the disin- 
 tegrated cells may come from other parts of the 
 urinary tract. Serum albumen, on the other hand, 
 is derived directly from the blood, and is evidence 
 of the disability and permeation of the renal tissues. 
 
 The gravest forms of albuminuria, of course, are 
 found in diseases of the kidney proper, i. e., in all 
 forms of nephritis, amyloid disease, tuberculosis, 
 cancer, abscess, calculus, etc. 
 
 The next severest occurrences of it are seen in 
 those circulatory diseases, and diseases affecting 
 circulation, which produce a secondary congestive 
 effect upon the renal tissues, as heart diseases, he- 
 patic cirrhosis, tumors, anemia, etc. 
 
118 FUNCTIONAL DIAGNOSIS 
 
 All infections and toxic conditions cause a transi- 
 tory albuminuria by the extension of their poisonous 
 action to the renal cells. 
 
 Hematuria (blood in the urine) — Is the result of 
 grosser lesions of the kidney tissue, allowing blood 
 en masse to enter the glomeruli and tubules. (This, 
 of course, assuming that the blood originates in the 
 kidney, and not in some other part of the urinary 
 tract) . 
 
 All of the causes above credited with the power 
 of causing albuminuria may also, by affecting gross- 
 er injury, give rise to hematuria. 
 
 Hemoglobinuria is, of course, always present when 
 hematuria is, but may occur independently in dis- 
 eases in which there is great destruction of red cor- 
 puscles, e. g., anemia, grave infectious diseases, etc. 
 
 Glycosuria. — Ordinarily, that is to say under the 
 pressure in which it normally exists in the blood, 
 the renal tissues are impermeable to sugar. But 
 when it reaches an abnormally high percentage it is 
 excreted in the urine. This occurs in diabtes mel- 
 litus and is pathognomonic of that disease. 
 
 Casts are nothing more or less than particles of 
 renal tissue which have acquired the mould of the 
 tubules in passing through them, and in many cases 
 gained a covering of epithelium. They are of nu- 
 merous variety, depending upon their composition, 
 or more often upon their appearance, such as hya- 
 line, granular, waxy, fatty, and blood casts. True 
 epithelial casts, composed entirely of epithelial cells, 
 
FUNCTIONAL DIAGNOSIS 119 
 
 are rare. Casts, of course, are found only in de- 
 structive processes in the renal tissues, and are 
 diagnostic, when found in numbers, of organic kid- 
 ney lesions. 
 
 Absolute anuria is rare, but may be caused by (a) 
 complete destruction or disability of renal tissue, 
 as in violent acute nephritis and in the last stages 
 of organic kidney diseases, or (b) by complete pelvic 
 obstruction, as in nephrosis, calculus, etc. 
 
 Oliguria (diminished secretion) results from any 
 conditions injuring or disabling the secreting area 
 and uncompensated by increased renal blood flow, 
 as in malignant diseases, amyloid degeneration, 
 acute nephritis, later stages of chronic nephritis 
 after compensation has failed. 
 
 Polyuria (increased secretion) comes from condi- 
 tions which while not completely disabling the se- 
 creting tissues, render them abnormally permeable 
 to fluids, as in interstitial nephritis, cirrhosis, dia- 
 betes, etc. 
 
 "V "m %i 
 
 Innervation. — The secretion of urine is a continu- 
 ous process, performed, as stated, by the epithelial 
 cells of the glomeruli and tubules, and is innervated 
 by the sympathetic fibres supplying the kidneys 
 from the renal plexus. The kidneys receive no 
 nerves from the cerebro-spinal system, and their 
 function is outside the province of voluntary ac- 
 celeration or inhibition. 
 
 In view of the fact, elsewhere stated, that the 
 
120 FUNCTIONAL DIAGNOSIS 
 
 renal function is essential to life, it is fortunate that 
 interruption of the motive power of urinary secre- 
 tion, whatever that motive power may be, is so 
 rare as to be practically unknown. 
 
 Increased and decreased secretion, however, may 
 and frequently does result from nervous and emo- 
 tional conditions, which must be explained by their 
 effect upon the renal function through the nerve 
 channels above described. It is worthy of note in 
 this connection that such influences seem to affect 
 only the gomerular portion of the function, since 
 nervous and psychic polyuria consists always in an 
 increase in the water and inorganic salts, with a 
 corresponding drop in density, while the same types 
 of oliguria exhibit simply a diminution in these 
 ingredients with a corresponding rise in density. 
 The organic secretions do not seem to be influenced 
 in such purely nervous cases. 
 
 Hysteria, migraine, neurasthenia, epilepsy, de- 
 lirium tremens are examples of nervous polyuria. 
 
 Post-operative shock, melancholia, cerebral disor- 
 ders, etc., frequently inhibit the renal function, and 
 may even cause death thereby. 
 
 •m *m ■*. 
 
 Vaso-Motor Regulation. — It has already been said 
 that even under the Bowman-Haidenhain theory the 
 secretion of urine is partially regulated by the blood- 
 pressure in the kidneys. This is brought about by 
 vaso-motor mechanism. The kidneys are supplied 
 
FUNCTIONAL DIAGNOSIS 121 
 
 very richly with vaso-constrictor fibres, stimulation 
 of which contrasts the renal vessels, raises pressure, 
 lessens the flow of blood through the organs, and 
 diminishes the secretion of urine. Inhibition of 
 these constrictors dilates the renal vessels, increases 
 the flow of blood, and accelerates secretion of urine. 
 
 Constriction of the arterioles at the skin, reflexly 
 dilates those of the kidneys, increasing renal elimi- 
 nation. 
 
 Blood Flow. — From the foregoing it will be seen 
 that the amount of secretion depends upon the quan- 
 tity of blood passing through the kidney in a given 
 time rather than upon blood pressure, and upon the 
 latter only as it determines the former. High arte- 
 rial pressure and low venous pressure, with no con- 
 striction of the renal vessels, will of course, drive 
 large quantities of blood through the kidney and 
 increase the urine. Low arterial pressure, even 
 though the renal vessels be dilated, will lessen the 
 flow of blood and diminish the urine. 
 
 Polyuria. — For the above reasons the quantity of 
 urine secreted is always increased in those condi- 
 tions which increase the flow of blood through the 
 kidneys, as in cardiac hypertrophy primary (i. e., 
 not due to contracted kidney) which induces high 
 pressure in the renal arteries, and in cystic degen- 
 eration of the kidney and hydronephrosis which di- 
 late the renal vessels. 
 
 Oliguria, or diminished flow of urine, is for like 
 
122 FUNCTIONAL DIAGNOSIS 
 
 reasons induced by all diseases which lessen the 
 blood flow through the kidneys, e. g., myocarditis, 
 valvular diseases (uncompensated), lung diseases, 
 hepatic cirrhosis, which reduce the blood force, and 
 in all diseases of the kidney itself which constrict 
 the renal vessels. 
 
 •m % "i. 
 
 The urine is normally a pale amber-colored fluid, 
 slightly acid in reaction when passed, and of about 
 1.020 specific gravity. Its acidity depends chiefly 
 upon the presence of acid phosphates, of which sodi- 
 um phosphate is the most important, which, again, 
 owe their preponderance to the proteids in the diet. 
 The specific gravity is of course largely determined 
 by the proportion of solids in solution, of which 
 urea is the chief. 
 
 The average composition of normal urine (which 
 of course varies under differing diets and physio- 
 logical conditions) is as follows: 
 
 Water (average daily amount) 1500 c.c. 
 
 Urea (approximately) 30 grams. 
 
 Uric acid 1 gram. 
 
 Creatin 1.5 grams. 
 
 Sulphuric acid 4 grams. 
 
 Phosphoric acid 3 grams. 
 
 Inorganic salts 10 grams. 
 
 Pigments Variable. 
 
 The specific gravity of the urine is, of course, in- 
 creased by any influence which (a) increases the 
 
FUNCTIONAL DIAGNOSIS 123 
 
 amount of solids, or (b) decreases the quantity of 
 water in the secretion. 
 
 Glycosuria (sugar in the urine) is by far the most 
 important of the first class of pathological condi- 
 tions. In diabetes milletus the percentage of sugar 
 ranges from 0.5 to 8 per cent, and the specific grav- 
 ity varies between 1.035 and 1.040. In fevers the 
 increase of urea raises the density. 
 
 Acute and chronic parenchymatous nephritis are 
 conspicuous examples of the latter variety. In these 
 diseases the glomeruli are congested and degener- 
 ated, hence the amount of water secreted is lessened 
 and the density of the urine correspondingly in- 
 creased. 
 
 Specific gravity is decreased, on the other hand, 
 by any condition which (a) reduces the amount of 
 solids, or (b) increases the quantity of water se- 
 creted. 
 
 Interstitial nephritis (atrophied or contracted kid- 
 ney) and amyloid kidney are instances of the 
 former variety. 
 
 Diabetes insipidus furnishes a typical example of 
 the latter class. In this disease the quantity of wa- 
 tery secretion is largely increased, but not the se- 
 cretion of organic solids. 
 
 Hyperacidity is found in gout, lithiosis, and acute 
 rheumatism, owing to the preponderance of uric 
 acid; in fevers owing to the abundance of urea; and 
 in diabetes because of the presence of acetons. 
 
 Alkalinity occurs in cystitis, prostatitis, malignant 
 
124 FUNCTIONAL DIAGNOSIS 
 
 diseases of urinary tract, paralyses, and any other 
 condition which causes long retention and conse- 
 quent fermentation of the urine. Profuse hematuria 
 renders the urine alkaline. 
 
 ^ ^n 1. 
 
 Urea is the most important ingredient of normal 
 urine, as it is also the most important of the nitro- 
 genous excreta, which are practically all excreted 
 in the urine. Urea is by far the largest of the end 
 products of proteid digestion, and the quantity 
 found in the urine practically determines the amount 
 of proteids broken down in the body in a given time, 
 the other forms of nitrogen found in the urine 
 (creatin, ammonia, salts, and purin bodies) and 
 those secreted by other channels (milk, sweat) being 
 a negligible quantity. The precise rationale of its 
 elaboration is unknown. It is assumed that the am- 
 monium compounds resulting from proteid cata- 
 bolism reach the liver through the portal system, 
 are there converted into urea, and the latter elimi- 
 nated by the kidneys. Suppression of liver function 
 results in accumulation of ammonium compounds in 
 the blood, and suppression of kidney function in ac- 
 cumulation of urea. There is evidence, however, 
 that urea is formed to a limited extent by other tis- 
 sues than the liver. 
 
 Increase of urea in the urine is the direct outcome 
 of increased metabolism. Hence it is found in fevers 
 and inflammatory diseases, in diabetes, malaria, and 
 pernicious anemia. 
 
FUNCTIONAL DIAGNOSIS 125 
 
 Decrease of urea on the other hand points to ab- 
 normal decrease of metabolism, and is seen in 
 chronic nephritis, gout, rheumatism, malignant and 
 constitutional diseases, not so much as a result of 
 these diseases, but as an accompaniment, due to the 
 same metabolic disturbance as is causing the dis- 
 ease. 
 
 Uremia is sooner or later the upshot of a suppres- 
 sion of urea in the urine. Formerly it was thought 
 to be due to the accumulation of urea in the blood 
 (hence the name), but latterly it is agreed that the 
 process of metabolism of which urea is normally the 
 end-product is diverted, and produces abnormal 
 toxins which are not eliminated by the kidneys, but 
 circulate in the blood and poison the nerve centres. 
 
 *m -» "^ 
 
 Ureteral Function. — The urine which is being con- 
 stantly formed in the kidney passes into the ureter, 
 down which it is carried by the combined forces of 
 gravity and peristalsis to the bladder, into which it 
 is forced intermittently. The peristaltic contrac- 
 tions occur automatically every ten to twenty sec- 
 onds, beginning at the pelvic opening and passing 
 downward in the form of a wave. The ureter is- 
 therefore normally always filled with urine, each 
 wave forcing out about 1-2 c.c. into the bladder. 
 
 Obstruction. — The ureter is not infrequently the 
 seat of obstruction due to impacted calculus, shreds 
 of malignant growth, stricture, spasm, or external 
 
126 FUNCTIONAL DIAGNOSIS 
 
 pressure from pelvic and abdominal tumors. The 
 obstruction, of course, prevents the normal on-flow 
 of urine and produces stasis in the renal pelvis 
 (hydronephrosis), and if bilateral, eventual suppres- 
 sion of urine. Fortunately bilateral troubles of this 
 kind are rare. 
 
 Infection to and from the bladder and kidney is 
 occasionally carried by the ureters, causing pyelitis 
 or cystitis as the case may be. Owing to the normal 
 downward peristalsis, ascending infection is for- 
 tunately rare, and descending infection has, of 
 course, not so prolific a starting place. 
 
 * ?w "W 
 
 Innervation. — The nervous mechanism of the ure- 
 ters is undetermined. Opinions waver between the 
 view that it is a reflex phenomenon stimulated by 
 the urine, and the theory of an automatic myo- 
 genesis similar to that of the heart muscle. Byron 
 Robinson has recently pointed out that all of those 
 functions which are under the domain of the sympa- 
 thetic plexuses ("the abdominal and pelvic brain" 
 of Robinson) exhibit a periodicity in the perform- 
 ance of their function, varying from once a month 
 in the case of the menses to many times a minute in 
 the case of the heart. 
 
 The bladder serves as a reservoir for the urine 
 until it is voided from the body by the act of urina- 
 tion, being retained by the tonic contraction of the 
 sphincter vescicae. It must be understood that the 
 bladder, like the stomach, is always distended pre- 
 
FUNCTIONAL DIAGNOSIS 127 
 
 cisely in proportion to the amount of its contents, 
 its muscular coat being in a constant state of tonic 
 contraction around these contents, so that the 
 bladder is really always "full." What is usually 
 spoken of as a full bladder is really a fully dis- 
 tended bladder. 
 
 The urine, during its sojourn in the bladder, is 
 practically a non-vital fluid and is liable to physical 
 and chemical changes arising either from reactions 
 within itself, or from pathological conditions of the 
 bladder walls. 
 
 Decomposition and bacterial fermentation occur 
 if from any cause the urine remains too long in 
 the bladder, in which case it becomes alkaline (am- 
 moniacal) and a source of toxic infection to the 
 urinary tract. Such a phenomenon occurs in any 
 condition which delays the voidance of urine, e. g., 
 enlarged prostate, vescical paralysis, malignancy, 
 chronic cystitis, and brain diseases. 
 
 Pyuria, pus in the urine, frequently results from 
 suppurative and infectious conditions of the blad- 
 der. Epithelium, blood, and even nucleo-albumin 
 may also be derived from broken-down conditions 
 of the bladder-wall as in malignancy, tuberculosis, 
 calculus, cystitis. 
 
 ■% "W *m 
 
 Mechanism of Micturition. — The distension of the 
 bladder by urine stimulates a reflex contraction of 
 the muscular coat, and relaxation of the sphincter 
 
128 FUNCTIONAL DIAGNOSIS 
 
 vescicle, which would immediately empty the blad- 
 der were it not opposed by a voluntary contraction 
 of the sphincter. As soon as the brain relinquishes 
 this voluntary opposition the sphincter relaxes and 
 the urine is voided by the vescical contraction, aided 
 toward the end of the act by abdominal muscles. 
 
 The inhibitory conrol of the brain can only be 
 maintained up to a certain point of stimulation, be- 
 yond which the spinal centre will act in spite of it. 
 If the bladder distension should force a few drops 
 of urine into the urethra the spinal stimulus be- 
 comes much more intense and proportionately diffi- 
 cult to inhibit, owing to the excessive sensitiveness 
 of the urethral nerves. For the same reason, after 
 urination has once begun, and urine is flowing 
 through the urethra, it is very difficult to stop the 
 act. 
 
 Inhibitory control of micturition is acquired; in 
 infancy the act is purely reflex and involuntary. 
 
 Abnormal desire for urination both as to urgency 
 and frequency, are seen in pathological conditions 
 of the bladder and urethra. 
 
 Excessive desire, urgent and frequent, results 
 from conditions which either (a) rapidly distend the 
 bladder to its physiological limit, or (b) render the 
 nerves so sensitive that an abnormally small dis- 
 tension stimulates the reflex. 
 
 The former class includes all those diseases which 
 increase the secretion of urine, notably diabetes, 
 nephritis, cardiac hypertrophy, and neuroses. 
 
FUNCTIONAL DIAGNOSIS 129 
 
 Of the latter class the chief conditions are those 
 of cystitis and urethritis, in which the inflamed state 
 of the membrane renders the nerves amenable to 
 very slight stimulus. In these conditions a small 
 degree of bladder distension excites the reflex con- 
 traction, squeezing a drop of urine into the highly 
 sensitive inflamed urethra, and producing an over- 
 whelming desire to micturate. Small quantities are 
 of course passed at each act. 
 
 Subnormal desire, on the other hand, results from 
 any conditions which (a) diminish urinary secre- 
 tions, or (b) dull the sensibilities of the bladder or 
 urethra. 
 
 In the first variety come all those diseases which 
 diminish renal activity, notably chronic nephritis, 
 myocarditis, nephrosis, and neuroses. 
 
 In the second list are classed malignant diseases 
 of bladder and urethra, tuberculosis, and chronic 
 cystitis and urethritis, in which the tissues are ren- 
 dered lax and dull ; and central nervous lesions which 
 depress the general nervous activity. In any of 
 these conditions an abnormally powerful distension 
 is necessary to stimulate the reflex. 
 
 Over-concentration of the urine, hyperacidity, and 
 other chemical conditions of the urine may also 
 cause increased desire by unduly irritating the af- 
 ferent nerves. This frequently occurs in fevers, 
 gout, rheumatism, etc. It is probable, however, that 
 these properly belong under the heading of cystitis 
 and urethritis. 
 
130 FUNCTIONAL DIAGNOSIS 
 
 Innervation of micturition is mediated through 
 the veseico spinal centre in the third lumbar seg- 
 ment, the afferent stimulus from the bladder being 
 conveyed by the sensory fibres of the first to the 
 fourth sacral spinal nerves, and the efferent im- 
 pulse by the motor fibres of the same nerves. The 
 sympathetic fibres passing out by the second to the 
 fifth lumbar vertebrae (doubtless from the same 
 centre) and reaching the bladder through the mes- 
 enteric ganglion, keep its muscular coat in a con- 
 stant state of tone ; and the hypogastric nerve plays 
 a feeble part in its innervation. 
 
 Paralysis of the nervous tracts concerned in mic- 
 turition, either by destruction of the spinal centre 
 (most frequent) or by interruption of the afferent 
 or efferent paths, produces paralysis of the act. In 
 such cases the urine is not voided until distension 
 become so great that it is forced out of the bladder 
 by sheer mechanical pressure, after which it drib- 
 bles away involuntarily. It is rather an uncommon 
 phenomenon, occurring chiefly in severe forms of 
 spinal disease, e. g., myelitis, sclerosis, late tabes 
 dorsalis, and injuries. It must be distinguished from 
 
 Involuntary micturition, which depends upon a 
 suspension or interruption of the inhibitory influence 
 of the brain. In this condition the urine is voided 
 involuntarily, as soon as distension is sufficient to 
 stimulate the bladder reflex, the bladder being com- 
 pletely and as a rule convulsively emptied at each 
 
FUNCTIONAL DIAGNOSIS 131 
 
 orgasm. This phenomenon occurs in cerebral dis- 
 eases, profound coma, and certain neuroses. Ab- 
 normally deep sleep occasionally induces it (enure- 
 sis). 
 
 Psychic conditions may, by direct operation 
 through the vesico-spinal centre, influence the act 
 of micturition, either by suspending inhibition and 
 precipitating the reflex (most frequent), or by in- 
 hibiting the reflex itself. Conspicuous instances of 
 both these phenomena are frequently met with in 
 cases of psychic shock, hysteria, and melancholia. 
 
 *m U % 
 
 The mechanism of defecation is similar to that of 
 micturition. The feces are kept in the rectum by 
 the contraction of the internal and external sphinc- 
 ters. When the rectum becomes sufficiently dis- 
 tended the distension stimulates a reflex contraction 
 of the rectal muscles and relaxation of the internal 
 sphincter by which the feces would be expelled but 
 for the voluntary opposition of the external sphinc- 
 ter. "When this opposition is inhibited by the brain, 
 the external sphincter relaxes, and defecation takes 
 place. In forced defecation (and it is usually more 
 or less forced) the abdominal muscles assist in ex- 
 pelling the feces. 
 
 As in micturition, the control of the brain is pos- 
 sible only up to a certain degree of stimulation ; be- 
 yond that point defecation occurs in spite of the 
 will, 
 ease. 
 
132 FUNCTIONAL DIAGNOSIS 
 
 Abnormal desire for stool, both as to frequency 
 and urgency, is seen in pathological conditions of 
 the rectum and anus. 
 
 Excessive desire results from any conditions 
 which (a) rapidly distend the bowel to stimulation 
 point, (b) render the rectum unduly irritable so 
 that an abnormally small distension (or even no dis- 
 tension at all) stimulates the reflex. 
 
 In diarrhea and dysentery both of these factors 
 are usually active in producing frequent and urgent 
 desire for stool. It must not be forgotten, also, that 
 the liquid character of the feces makes a much more 
 vigorous contraction of the sphincter necessary in 
 order to keep them inside the rectum. 
 
 In proctitis the inflamed condition renders the 
 yectum so sensitive to stimulus that the presence of 
 small quantities of feces induces the reflex act of 
 defecation with great urgency and pain (tenesmus) . 
 
 Subnormal desire arises from any conditions which 
 (a) reduce the quantity of feces reaching the rec- 
 tum in a given time, or (b) render the rectum ab- 
 normally irresponsive to stimuli. 
 
 Constipation (diminished peristalsis) from any 
 cause, of course, comes under the first head, while 
 under the second may be classed malignant diseases 
 off the rectum, tuberculosis, chronic proctitis, which 
 render the rectal walls lax and dull, and central 
 nervous lesions which depress general nervous 
 activity. In any of these conditions considerable 
 distension is necessary to stimulate the reflex, and in 
 
FUNCTIONAL DIAGNOSIS 
 
 133 
 
 many of them the pain attending defecation induces 
 
 a voluntary retention. 
 
 % > t 
 Innervation of defecation is mediated through an 
 anal centre in the lumbar cord, the afferent stimulus 
 being furnished by the sensory fibres and the effer- 
 ent by the motor and inhibitory fibres of the sympa- 
 thetica from the pelvic flexus and inferior mesen- 
 teric ganglia and the hypogastric nerve. That the 
 phenomenon is under the influence of the higher 
 centres is demonstrated by the effects of emotions 
 and the involuntary defecation of infants. 
 
 Involuntary defecation results from an interrup- 
 tion of the inhibiting influence of the higher cen- 
 tres upon the sphincter. As soon as the distension 
 of the rectum is sufficient to stimulate the reflex 
 the feces are involuntarily voided by a vigorous con- 
 traction of the muscles concerned. This symptom 
 occurs in cerebral diseases, profound coma, and cer- 
 tain neuroses, and very exceptionally in deep sleep. 
 It must be differentiated from 
 
 Rectal paralysis, depending upon destruction of 
 some part of the reflex tract concerned in the act 
 of defecation. In these cases there is no defecation 
 until the rectum becoms so full that the feces are 
 forced out by physical pressure, slowly and with 
 no effort. This is seen in severe forms of spinal dis- 
 ease as in myelitis, sclerosis, late tabes dorsalis, and 
 injuries involving the lumbar region, and rarely in 
 
134 FUNCTIONAL DIAGNOSIS 
 
 neuritis by implication of the peripheral neuron 
 concerned in the act. 
 
 Psychic influences may, by direct operation 
 through the anal centre, modify the act of defeca- 
 tion either by suspending inhibition of the sphincter 
 and inducing involuntary defecation (most fre- 
 quent), or by inhibiting the reflex itself and retain- 
 ing the feces. Psychic shock, hysteria, and neuras- 
 thenia furnish instances of both kinds. 
 ■ta > •* 
 
 Feces. — As already stated, under digestion, very 
 little absorption of anything but water takes place 
 in the large intestine, and the alkaline reaction in 
 this part of the tract favors bacterial putrefaction. 
 By the time, therefore, the material reaches the rec- 
 tum, under normal conditions, three consummations 
 are reached; (a) the substance remaining contains 
 only waste matter; (b), it has acquired a relatively 
 solid consistency, and (c) it is in an advanced state 
 of decomposition. It is then known as the feces, 
 and is voided per anum. 
 
 The quantity of feces varies with the amount and 
 nature of the food ingested, the average quantity 
 being from 140 to 200 grams in twenty-four hours. 
 
 Abnormal Consistency. — Aside from the variations 
 due to diet, the consistency of the feces varies di- 
 rectly with the length of time they remain in the 
 large bowel. Under vigorous peristalsis (diarrhea) 
 they pass very rapidly, there is no time for any 
 great absorption of water, and the stools are usually 
 
FUNCTIONAL DIAGNOSIS 135 
 
 liquid. In diminished peristalsis (constipation), on 
 the other hand, they remain in the bowel a long 
 time, are inordinately drained of fluid, and are 
 therefore dry and hard. 
 
 ■W "% "m 
 
 The temperature of the feces, owing to fermenta- 
 tion, is higher than the body temperature — hence in 
 taking rectal temperature care should be exercised 
 not to insert the thermometer in a mass of feces. 
 
 Composition. — The constituents of the feces, of 
 course, vary with the diet and other circumstances. 
 Generally speaking, however, they contain the fol- 
 lowing ingredients: 
 
 Undigested food stuffs (principally fats). 
 
 Products of intestinal secretions (nitrogen). 
 
 Products of bacterial putrefaction (principally 
 indol and skatol). 
 
 Bile salts and pigments (uro and starcobilin) . 
 
 Inorganic salts. 
 
 The characteristic color of the feces is due to the 
 bile-pigments ; their odor to the skatol. 
 
 Lienteria, i. e., an abnormal quantity of undi- 
 gested food in the feces, indicates, of course, that 
 the alimentary tract is not properly disposing of 
 the food ingested. It occurs in all digestive disor- 
 ders. The particular stage of indigestion which 
 these lienteria are found (chemically) may furnish 
 information as to the precise part of the alimentary 
 process at fault. 
 
 Mucus in the feces is indicative of catarrh when 
 found in large amounts. 
 
136 FUNCTIONAL DIAGNOSIS 
 
 Clay-colored stools signify a lack of bile pigments 
 and indicate a suppression or obstruction of the gall- 
 bladder or common duct, as in jaundice, cholecystitis, 
 gall-stones, hepatic cancer, etc. 
 
 Blood may come from any part of the intestinal 
 tract and from many causes. Hemorrhoids are the 
 commonest cause. Enteritis, ulceration, cancer, 
 tuberculosis, are less frequent causes. In these cases 
 the blood is usually comparatively bright red. Black 
 blood (altered blood) originates in the upper ali- 
 mentary tract, as from duodenal, or gastric ulcer, 
 swallowed blood, hepatic cirrhosis, etc., and is par- 
 tially digested during its passage. 
 
 Gall stones are often found in the feces. Their 
 significance is obvious. 
 
 Microscopical and Chemical Contents. — Latterly 
 Nothnagel, and still later Adolph Schmidt, have in- 
 augurated a more thorough functional diagnostic of 
 digestive and intestinal disorders by means of a 
 minute and systematic examination of the feces, 
 similar to the methods employed in gastric func- 
 tional diagnosis. The system is, however, as yet 
 rather too imperfect to enter into a practical text 
 book. 
 
 Increased fat in the stools indicates (a) a defi- 
 cient secretion or flow of bile, as in jaundice, cho- 
 lecystitis, hepatic cancer, etc., (b) disturbance of 
 pancreatic secretion, hindering fat digestion, as in 
 pancreatitis, or (c) intestinal abnormalities interfer- 
 ing with absorption, as in intestinal tuberculosis, 
 malignancy, amyloid disease, etc. 
 
FUNCTIONAL DIAGNOSIS 137 
 
 THE NERVOUS SYSTEM. 
 General. 
 
 The Neuron Doctrine. — The modern conception of 
 the structure of the nervous system regards it as 
 made up of a series of neurons. Each neuron con- 
 sists of a nerve cell from which project a varying 
 number of spoke-like processes, called dendrites; 
 one of these processes is much longer than the rest, 
 forming what was formerly known as the nerve 
 trunk, and is called the axis cylinder, or axon. 
 
 The theory is that the nervous impulse originates 
 in the metabolic changes produced by the stimulus 
 in the nerve cell, and is propagated along the axon 
 by a physico-electric current, always in the direc- 
 tion away from the cell. (This is known as the 
 polarity of the neurons.) Reaching the end of the 
 axon, the impulse is transmitted to the nerve cell 
 of another neuron (through the latter 's dendrites?) 
 which, in its turn, is stimulated to metabolic changes 
 and propagates a current along its axon. Thus the 
 impulse reaches its destination by a relay process 
 similar to that used in the long distance telephone. 
 
 Afferent and Efferent Neurons. — The neurons are 
 arranged in two classes with reference to the direc- 
 tion of their impulses. In one class the polarity of 
 the neuron is from the peripheries to the center of 
 the system ; these are called afferent or sensory neu- 
 rons. In the other class the polarity of the neuron 
 
138 FUNCTIONAL DIAGNOSIS 
 
 is from the centers to the peripheries; these are 
 called efferent, and usually motor, neurons. 
 
 Afferent and Efferent Impulses.— Afferent im- 
 pulses, traveling from the peripheries toward the 
 centers, include: 
 
 (1) Sensory Impulses. 
 
 (a) Touch. 
 
 (b) Pressure. 
 
 (c) Temperature (heat and cold). 
 
 (d) Muscle Sense (degree of muscle 
 
 contraction). 
 
 (2) Special Sense Impulses. 
 
 (a) Sight. 
 
 (b) Hearing. 
 
 (c) Taste. 
 
 (d) Smell. 
 
 Efferent impulses traveling from the centers 
 toward the peripheries, include: 
 
 (1) Motor Impulses. 
 
 (a) General Muscle Motor. 
 
 (b) Vaso-Motor (Muscles of Vessels). 
 
 (c) Accelerator (Special Muscles). 
 
 (2) Secretory Impulses. 
 
 (a) Gland Secretion. 
 
 (b) Nourishment (Trophic). 
 Trophic Influence of the Cell, Wallerian Degen- 
 eration. — The cell exerts a nutritive or trophic in- 
 fluence upon the rest of the neuron, which appears 
 to be in the nature of a current, for if the cell be 
 cut off from the axon the axon degenerates on the 
 
FUNCTIONAL DIAGNOSIS 139 
 
 distal side of the cut-off, the degeneration proceeds 
 along the fibre in the same direction as an impulse 
 travel, viz., toward the end of the axon. A small 
 amount of degeneration also occurs in the proximal 
 end of the divided axon, but only in the immediate 
 vicinity of the cut. "Within a few hours of such 
 division, histological changes also take place in the 
 cell, from which it appears that the cell is also de- 
 pendent in some measure on the axon for its in- 
 tegrity. Contrary to former views, we now know 
 that this degeneration invariably follows division of 
 a neuron and proceeds to completion before there is 
 a reunion; it never heals by first intention. 
 
 Within a few days after division, regeneration be- 
 gins, and proceeds in the same order as, and almost 
 simultaneously with, degeneration. At the same 
 time, restitution occurs in the elements of the cell. 
 Within four to six weeks the axon is as fully re- 
 generated as it is possible for it to be without con- 
 nection being re-established with the cell, but it is 
 never capable of functionating until this connection 
 is re-established, either by a natural or a surgical 
 uniting of the divided ends of the axon. 
 
 This process, after its investigator, Waller, is 
 called Wallerian degeneration and regeneration. 
 
 Effects of Drugs and Physiological Conditions.— 
 The irritability of both cells and axon is greatly 
 modified by the action of certain drugs, and by 
 physiological conditions. 
 
140 FUNCTIONAL DIAGNOSIS 
 
 The activity of the whole cerebro-spinal system 
 seems to depend in a general way upon the activity 
 of its highest part, the cerebrum. Physiological ex- 
 altations and depressions of the psychical faculties, 
 such as are found in labor and sleep, joy and sadness, 
 correspondingly exalt and depress the activity of the 
 neurons throughout the system, increasing or dimin- 
 ishing their reaction to stimuli. 
 
 Delayed Conduction. — Pathological conditions of 
 definite tracts and environs frequently increase the 
 time of the passage of an impulse (delayed conduc- 
 tion). A conspicuous example of this is seen in 
 peripheral neuritis, (inflammation of the lower sen- 
 sory axons). 
 
 Certain drugs increase the activity of the cord and 
 brain, chief among them being strychnia, ergot, nux 
 vomica, belladonna and phosphorus; others depress 
 these functions, notably opium, chloral, curare, bro- 
 mides, and Indian hemp. 
 
FUNCTIONAL DIAGNOSIS 141 
 
 The Spinal Cord. 
 
 The spinal cord performs a double function. (1) 
 That of a great conducting medium, its white mat- 
 ter consisting of long axons which pass upward to 
 or downward from, the brain, and (2) That of a mul- 
 tiple center, its gray matter containing root and 
 ganglion cells which play the part of subordinate 
 brain centers in each segment of the cord. 
 
 The probabilities are that the central function 
 of the cord is its oldest function, from the stand- 
 point of evolution, each segment being originally a 
 separate and independent center, and the joining 
 of the segments and their long fiber connection with 
 the brain a later development. The higher one goes 
 in the scale of life the less independent a structure 
 the cord becomes, the more important a part the 
 brain plays, and the more numerous the conducting 
 neurons between the two. 
 
 Afferent and Efferent Paths. — The cord receives 
 theaxoms of afferent neurons (originating in the skin, 
 limbs, trunk, etc.), which enter it at different levels, 
 and terminate in various manners. The impulses 
 from these axons are transmitted to fresh neuron 
 cells within the cord, whose axons either emerge 
 from the cord again and carry the impulse back as 
 an efferent impulse (reflex), or extend upward to- 
 ward the brain and continue the impulse as an affer- 
 ent one. 
 
142 FUNCTIONAL DIAGNOSIS 
 
 The cord receives the axons of efferent neurons 
 (originating in the brain cells), which extend down- 
 ward to various levels in the cord and terminate in 
 various manners. The impulses of these axons are 
 then transmitted to fresh axons within the cord, 
 whose axons leave the cord auteriorly and terminate 
 in muscles, etc. 
 
 Upper and Lower Neurons. — The afferent or effer- 
 ent neuron between the periphery and the cord is 
 called the lower neuron ; that between the cord and 
 the brain is called the upper neuron. 
 
 Posterior Spinal Nerves. — The axons of the lower 
 afferent neurons enter the cord posteriorly, in sym- 
 metrical pairs, from either side of the body, one pair 
 to each corded segment, and are called the spinal 
 sensory nerves. The points at which they enter are 
 called the posterior or sensory roots. There is a 
 ganglion on each sensory root which appears to con- 
 tain trophic cell elements of the lower neuron. 
 
 Sensory Paralysis, or Anesthesia, results from in- 
 terruption in the course of these lower sensory neu- 
 rons, or injury to the peripheral endings which par- 
 alysis is, of course, limited to the area supplied by 
 the neurons involved. Such anesthesias are due to 
 (1) traumatic injury to nerve-ends as from burns, 
 skin diseases, etc., (2) vaso-motor disturbances at 
 the peripheries, as anemia or congestion, and (3) 
 lesions along the course of the axons, from tumors, 
 inflammation, etc. Peripheral and multiple neuritis 
 are conspicuous examples of this latter class. 
 
FUNCTIONAL DIAGNOSIS 143 
 
 Anterior Spinal Nerves and Roots. — The axons of 
 the lower efferent neurons emerge from the cord 
 anteriorly, in pairs similar to the afferent, and are 
 called the spinal motor nerves. They terminate in 
 and innervate skeletal muscles. Their points of 
 emergence are called the anterior or motor root, and 
 in these roots are located the trophic cell elements 
 of the lower efferent neurons. 
 
 After emerging from the cord, and before leaving 
 the vertebrae, the efferent axon of each segment 
 coalesces with the afferent axon of the same segment, 
 and travels between the cord and the periphery in 
 the same sheath, both supplying the same peripheral 
 area. 
 
 Motor Paralysis results from interruption in the 
 course of these lower efferent neurons, or injury to 
 their peripheral endings, limited to the area supplied 
 by the interrupted neurons. Such paralyses are due 
 to (1) traumatic injury to nerve ends, as from 
 burns, skin diseases, etc. ; (2) lesions in the course of 
 the axons, as tumors, inflammations, etc. 
 
 Owing to the fact that the lower motor and sen- 
 sory neurons travel in the same sheath, lesions of 
 these lower neurons almost always involve both, and 
 hence produce motor and sensory paralysis. A 
 double paralysis of a limited area is therefore sug- 
 gestive of a lesion of the lower neuron. 
 
 Atrophy. — In diseases of the nerves where the le- 
 sion is situated between the root-cells and the peri- 
 
144 FUNCTIONAL DIAGNOSIS 
 
 phery, or in which the root cells themselves are in- 
 volved, there is rapid atrophy of the muscles con- 
 cerned in addition to paralysis. Conversely where 
 rapid atrophy is associated with paresis, the lesion 
 may be safely located in one of these positions. 
 
 In poliomyelitis there is atrophy because the an- 
 terior horns are themselves inflamed and later de- 
 generated. 
 
 In diffuse myelitis the same is true. 
 
 In progressive muscular atrophy, the degeneration 
 begins in the lower neuron, often in the muscle, 
 hence atrophy precedes paresis. 
 
 In lateral amyotrophic sclerosis, the degeneration 
 begins in the spinal tracts and later attacks the root 
 cells, hence paresis precedes atrophy. 
 
 In multiple neuritis the lower neurons are in- 
 flamed, hence there is atrophy if the inflammation 
 continues for any length of time. 
 
 In diseases of the cord which involve only the 
 tracts, and in purely cerebral diseases, there is 
 no such atrophy, because there is no interruption 
 of the course between the limb and the root-cell, 
 the lesion being above the root-cell. 
 
 *m -m 1. 
 
 Conducting Paths in the Cord. — The conducting 
 neurons of the cord have been demonstrated to pur- 
 sue more or less definitely marked paths or tracts, 
 according to the impulses they convey. These tracts 
 are more definite in the case of the descending (ef- 
 ferent) than of the ascending (afferent) neurons. 
 
FUNCTIONAL DIAGNOSIS 145 
 
 Ascending Tracts. — The most important ascend- 
 ing, or afferent, tracts and their location in the cord, 
 are: 
 
 (1) Tract of Goll, in the posterior median col- 
 umn. 
 
 (2) Tract of Burdoch, in the posterior intermed. 
 column. 
 
 (3) Plechsig's Tract (Direct Cerebellar), in the 
 lateral column. 
 
 (4) Gowers' Tract (Ventral Cerebellar), in the 
 lateral column anterior to Flechsig's Tract. 
 
 Course of Posterior Fibres. — Contrary to former 
 ideas, the sensory fibres which enter the cord at the 
 posterior roots (vide supra) do not all pass up the 
 posterior columns of the cord. Indeed very few do 
 so. The great majority of them penetrate the gray 
 matter of the cord and transmit their impulses to 
 tract cells, whose axons pass up the lateral tracts 
 (Flechsig and Gowers) , or simply pass over to other 
 parts of the cord, or communicate with an anterior 
 motor neuron, forming a reflex arc. 
 
 Of those fibres which do pass up the posterior col- 
 umns, some continue to the medulla; others often 
 passing upward for a short distance branch off and 
 terminate in the tract of Flechsig. At these respect- 
 ive terminations they transmit their impulse to new 
 neurons, which carry them to the brain. 
 
 Muscle Sense. — Experiment and observation show 
 that the posterior and lateral tracts do not play any 
 important part in the transmission of ordinary sen- 
 
146 FUNCTIONAL DIAGNOSIS 
 
 sory impulses (touch, pressure, etc.), but conduct 
 principally impulses of muscle sense, or those im- 
 pulses which acquaint us with the position and de- 
 gree of contraction of our muscles. The great bulk 
 of these impulses are conveyed to the cerebellum, 
 which is the chief functionating center for co-ordi- 
 nation. 
 
 Inco-ordination. — Anything which interrupts the 
 passage of these muscle sense impulses deprives the 
 the cerebellum of information which is essential to 
 the performances of its co-ordinating function, and 
 results in inco-ordination, manifested clinically by 
 inability to accomplish purposeful movements of the 
 parts involved, staggering gait, loss of balance, in- 
 ability to perform delicate tasks with hands, etc. 
 
 Conversely, these clinical symptoms always point 
 to interruption of muscle sense impulses. Whether 
 the interruption is in the lower or upper neuron 
 must be determined by other symptoms. 
 
 In myelitis the spinal tracts, and in neuritis the 
 peripheral sensory neurons, are inflamed, and cannot 
 transmit impulses ; hence ataxia results. 
 
 In Locomotor Ataxia the posterior columns (Goll 
 and Burdoch) are degenerated; hence the muscle 
 aense can no longer be transmitted along these tracts 
 and ataxia results. 
 
 Lateral Scleroses, by virtue of the degeneration of 
 the lateral tracts (Flechsig and Gowers) produce a 
 similar result. 
 
FUNCTIONAL DIAGNOSIS 147 
 
 Touch, Pressure, Temperature. — Of the tracts by 
 which impulses of touch, pressure, temperature, 
 etc., are conveyed, nothing is definitely known. Ex- 
 periment and observation demonstrate that the dif- 
 ferent impulses are conveyed by separate fibres (dis- 
 sociated sensations) and make it probable that there 
 are many different paths by which they travel. 
 
 True sensory paralysis is rare — complete anes- 
 thesia still rarer. When it does occur it is mostly 
 peripheral in origin as already described. 
 
 Given the integrity of the sensory peripheries, 
 however, it is rarely that the sensory impulses can- 
 not find some path or other by which to reach the 
 brain. Interruption of any of the ascending tracts 
 of the cord never produces more than partial par- 
 alysis, except in rare cases of growths or degenera- 
 tions which involve the whole section of the cord, in 
 which case, of course, both motor and sensory par- 
 alysis are complete. Spinal anesthesias are usually 
 bilateral. 
 
 Anesthesias due to cerebral lesions, hemorrhage, 
 tumors, softening, etc., are extremely rare, difficult 
 to demonstrate, and never intense. They are usually 
 unilateral. 
 
 Syringomyelia is the disease which affords the 
 most interesting manifestations of sensory conduc- 
 tion. The anatomic basis of this disease is the for- 
 mation of cavities in the substance of the cord, and 
 it is clinically attended by some very peculiar and 
 
148 FUNCTIONAL DIAGNOSIS 
 
 characteristic sensory phenomena, chief among 
 which is a discriminate insensibility to the various 
 stimuli of temperature, pressure and touch (dissocia- 
 tion of sensations). 
 
 A far more common sensory phenomenon is that 
 of irritation, due to primary inflammation of either 
 the lower or upper sensory neurons, and manifested 
 clinically by pains referred to the periphery of the 
 affected neuron. These pains are seen in locomotor 
 ataxia (degeneration of the posterior column) mul- 
 tiple neuritis (inflammation of lower neurons, myel- 
 itis (inflammation of the spinal tracts), and other 
 similar diseases, in their early stages; on superven- 
 tion of degeneration or compression they give way 
 
 to partial anesthesia. 
 
 ■i. -^ i. 
 
 Decussation of Ascending Tracts. — The sensory 
 neurons which traverse the tract of Gowers decus- 
 sate or cross at the medulla and go to opposite sides 
 of the brain. The other tracts are mostly continued 
 to the brain in a direct course. This, however, 
 only applies to decussation or directness en masse, 
 for there is partial crossing of sensory fibres all the 
 way up the cord. 
 
 Physiologically it is, of course, certain that the 
 sensory impulse from the body peripheries are re- 
 ceived on opposite sides of the brain, and inasmuch 
 as the brain is a higher type of reflex arc, this is in 
 accordance with what we know of the crossed loca- 
 tion of the motor centres. However, this crossing 
 
FUNCTIONAL DIAGNOSIS 149 
 
 of the sensory tracts has no clinical significance, 
 because the crossed reception of sensory impulses 
 is impossible to demonstrate, the sensorium of the 
 brain always referring them to the side on which 
 they originate. 
 
 Descending' Tracts. — The principal efferent or mo- 
 tor tracts in the cord, and their topography, are : 
 
 (1) Direct Pyramidal Tract (anterior motor) in 
 the anterior columns. 
 
 (2) Crossed Pyramidal Tract (lateral motor) in 
 the lateral columns. 
 
 Course of Descending Tracts. — The course of the 
 motor tracts is much more definitely traced and bet- 
 ter understood than that of the sensory tracts. The 
 exoms forming the motor paths are received from 
 the brain, through the medulla, and continue their 
 course to the various levels in the cord, where they 
 communicate their impulse to a tract cell whose 
 axon passes out of the cord by an anterior root, and 
 terminates in a group of skeletal muscles. 
 
 Motor Paralysis. — Any interruption in the course 
 of these tracts produces motor paralysis in the part 
 below the interruption. A careful examination of 
 the muscles involved in such paralysis should there- 
 fore enable the diagostician to locate the level of the 
 lesion ; and so it usually does to a certain extent, but 
 unfortunately not with anything like the defiinite- 
 ness that the data would lead one to expect. In 
 fact, actual spinal paralyses are not nearly so 
 sharply defined as hysterical paralyses. 
 
150 FUNCTIONAL DIAGNOSIS 
 
 Poliomyelitis (inflammation of the anterior horns), 
 progressive muscular atrophy, which later attacks 
 the anterior root cells, and amyotrophic lateral scler- 
 osis (involving the crossed pyramidal tracts) all pro- 
 duce motor paralysis by interrupting the motor 
 tracts of the cord. In multiple sclerosis there is sel- 
 dom true motor paralysis because in spite of the dif- 
 fuse nodules the neuraxons usually persist and func- 
 tionate. 
 
 Myelitis, which inflames all the tracts, produces 
 motor paresis. 
 
 Decussation of Descending Tracts. — The lateral 
 motor tracts decussate in the medulla and supply op- 
 posite sides of the body. The anterior motor tracts 
 continue their course directly down the same side 
 of the cord, but eventually their fibres cross at vari- 
 ous levels in the cord. 
 
 Crossed Paralysis. — Injury to a motor tract above 
 the point of discussation will produce a crossed 
 paralysis, i. e., a paralysis of the opposite side of the 
 body to the lesion, but on the same side of the head 
 and neck, as the cranial nerves are given off before 
 decussation takes place. In case the cranial nerves 
 are not injured (a rare combination), there is no 
 way of diagnosing the crossed nature of the paraly- 
 sis. 
 
 Injury to a motor tract in the lateral column of 
 the cord will produce a paralysis on the same side 
 below the seat of the lesion. 
 
FUNCTIONAL DIAGNOSIS 151 
 
 Injury to the direct motor tract will give paralysis 
 on both sides. This class of paralysis is frequently 
 associated with lesions of the lateral sensory tract, 
 involving ataxia. 
 
 As a matter of practice, however, paralysis due 
 to lesions in the spinal tracts are almost invariably 
 bilateral (paraplegia) because the pathological proc- 
 ess usually involves both sides of the cord. 
 
 "i. "W % 
 
 The Cord as a Center. — The principal function of 
 the cord as a multiple center is that of producing 
 true reflexes, each segment of the cord functionating 
 as an arc for reflexes produced by its own sensory 
 nerve. The sensory impulse is usually communi- 
 cated to several motor neurons, and sent back as a 
 multiple efferent impulse, innervating a group of 
 muscles in a purposeful manner (co-ordinated re- 
 flex). : ^1£i#l 
 
 Overflow Reflex. — Sometimes the stimulus is so 
 vigoruous that the sensory impulse, reaching the 
 cord, is communicated to motor neurons quite out- 
 side the purposeful group and produces motion in 
 an unnecessary group of muscles. This is called a 
 reflex overflow. 
 
 Special Reflexes. — In the accompanying table will 
 be found a list of the more important spinal reflexes, 
 the afferent and efferent paths, and the location of 
 the centres concerned in them. 
 
152 
 
 FUNCTIONAL DIAGNOSIS 
 
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FUNCTIONAL DIAGNOSIS 153 
 
 Absence of a reflex may indicate an interruption 
 in either of the lower neurons in the afferent or ef- 
 ferent, or a destruction of the spinal are in the cord. 
 The former cause may be excluded by absence of 
 other indication, such as flabbiness and atrophy of 
 muscles. Far the greater proportion of reflex fail- 
 ures are due to injury to the spinal arc. 
 
 Naturally the reflexes whose arcs are lowest down 
 in the cord are the most commonly utilized in diag- 
 nosis, as they indicate the condition of the cord 
 above the arc. Of these low-down reflexes the knee- 
 jerk (patellar) and tendon Achilles are the most 
 easily elicited and constant. 
 
 The normal knee-jerk indicates integrity of both 
 afferent and efferent (lower) neuron of the third 
 lumbar nerve, of the commisural arc at the third 
 lumbar segment, and of the tracts from the third 
 lumbar segment up to the brain. Thus a normal 
 knee-jerk practically assures integrity of the entire 
 spinal tract. 
 
 Exaggeration of the knee-jerk indicates an inter- 
 ruption in one or more of the descending spinal 
 tracts between the third lumbar segment and the 
 brain, cutting off the inhibitory influence of the 
 brain. For the same reason an exaggerated reflex 
 is associated with hypertonus of the muscles. This 
 condition is seen in multiple sclerosis, where the 
 tracts are studded with nodules, amytrophic lat- 
 eral sclerosis, in which the lateral motor tracts are 
 
154 FUNCTIONAL DIAGNOSIS 
 
 degenerated (very marked), in cerebellar disease, 
 where the co-ordinating influence upon the tendons 
 is cut off, and in all cerebral lesions. Central mye- 
 litis gives this symptom, because it involves the up- 
 per and not the lower neurons. 
 
 Absence of Diminution of the knee-jerk indicate 
 interruption in the afferent or efferent neuron of the 
 third lumbar nerve, or injury to the commissural arc, 
 or disease of the posterior tract of the cord which 
 includes destruction of the arc. The knee-jerk is 
 abolished or lessened in neuritis and progressive 
 muscular atrophy because of the inflammation of the 
 lower neurons; in locomotor ataxia because of de- 
 generation in the posterior tract and consequent 
 destruction of the spinal arc. In the latter disease 
 a careful examination of the various reflexes whose 
 arcs are at different levels will indicate the upward 
 limit to which the degenerative process extends. In 
 diffuse myelitis the same occurs because the roots of 
 the lower neurons are involved. 
 
 Both exaggeration and diminution of reflexes may 
 be due to exalted or depressed conditions of the 
 cord, caused by drugs or mental emotions, but these 
 indications are as a rule easily recognized or ex- 
 cluded. 
 
 The tendo Achillis and plantar reflexes of course 
 give information concerning the spinal tracts, from 
 a still lower level, and these and other reflexes ex- 
 hibit certain peculiarities and give information con- 
 cerning their own specific neurons. 
 
FUNCTIONAL DIAGNOSIS 155 
 
 Tonic Functions of Cord. — Another central func- 
 tion of the cord is the furnishing of tonicity to the 
 muscles. The cord is continually sending out a 
 steady stream of nerve energy to the muscles which 
 keeps them in a constant condition of partial con- 
 traction, or "tone," so that when they are needed, 
 voluntary innervation will not have to overcome 
 complete inertia before they can be moved. 
 
 This outflow of tonic energy is controlled and 
 modified in an important manner by the brain, by 
 means of inhibitory currents. 
 
 Differentiation of Spinal and Cerebral Paralysis. 
 — Interruption of the course between the brain and 
 the spinal neuron, in other words, injury to or divi- 
 sion of the upper neuron, interferes with the inhib- 
 itory influence of the brain upon the tonic function 
 of the cord, and an excess of tonic energy is poured 
 out by the latter into the muscles. This is mani- 
 fested clinically by a spastic condition of the muscles 
 involved, and an exaggeration of reflex. 
 
 Interruption of the course between cord and 
 periphery, i. e., injury to or division of the lower 
 neuron, results in a cutting off of the tonic current, 
 manifested clinically by a flaccid atonic condition of 
 muscles involved and absence of reflex. 
 
 Conversely, therefore spastic paralyses and exag- 
 gerated reflex indicate injury to the upper neuron 
 or brain. Flaccid paralyses and absence of reflex 
 point to injury to the lower neuron. This should be 
 
156 FUNCTIONAL DIAGNOSIS 
 
 one of the first diagnostic points to be determined 
 in the investigation of a paralytic condition. 
 
 In peripheral neuritis (inflammation of the lower 
 neuraxon), poliomyelitis (inflammation of anterior 
 roots), and progressive muscular atrophy (degener- 
 ation of the lower neuron), the tonal path is inter- 
 rupted, and these diseases are characterized by flac- 
 cidity of the muscles involved, and diminished re- 
 flexes. 
 
 In lateral amyotrophic sclerosis, there is first spas. 
 ticity and exaggerated reflexes, as long as the proc- 
 ess is confined to the lateral tracts, followed by flac- 
 cidity and diminished reflexes when the root cells 
 are attacked. 
 
 In multiple sclerosis, involving only the spinal 
 tracts, and in all cerebral paralyses, the muscles are 
 spastic and the reflexes are exaggerated. In central 
 myelitis there is spasticity, because the upper neu- 
 rons only are involved; in diffuse myelitis the re- 
 verse, because the roots of the lower neurons are 
 inflamed. 
 
 Spasticity manifests itself in completely paralyzed 
 limbs by resistance to passive motion. In partially 
 paralyzed limbs it is shown by the jerky character 
 of the movements ; in the legs by a peculiar dragging 
 walk (spastic gait). 
 
FUNCTIONAL DIAGNOSIS 157 
 
 THE MEDULLA OBLONGATA. 
 
 The medulla oblongata occupies, both anatomic- 
 ally and physiologically, a midway position between 
 the cord and the brain. Like the cord, it performs 
 the double role of a conducting medium for axons 
 and a center for the governance of certain functions. 
 
 The direct fibres of the posterior column terminate 
 in the medulla and their impulses are here trans- 
 mitted to fresh neuron cells whose axons pass up- 
 ward to the cerebrum and cerebellum. The lateral 
 afferent fibres diseussate in the medulla to pass to 
 opposite sides of the brain. 
 
 The efferent or motor fibres, descending from the 
 brain pass through the anterior portion of the me- 
 dulla (pyramid) and pass downward into the cord, 
 a portion of them decussating and some continuing 
 in a direct course. 
 
 The Medulla as a Center. — The central canal of 
 the cord widens out in the medulla and forms the 
 floor of the fourth ventricle, the roof of which is 
 formed by the base of the brain. Prom this cham- 
 ber originate all the cranial nerves but the olfactory 
 and the optic. All of these nerves but one (the 
 pneumogastric) innervate the region of the head and 
 neck. 
 
 Bulbar Centres. — In addition to the cranial nerve 
 origins, the medulla contains certain important cen- 
 tres which, while they are not usually regarded as 
 reflex centres, undoubtedly functionate as true co- 
 
158 FUNCTIONAL DIAGNOSIS 
 
 ordinate reflex arcs, the afferent stimulation being 
 automatically furnished by the organs which they 
 innervate. In many of these bulbar reflexes the 
 cranial nerves take part. 
 
 These bulbar centres and their functions are as 
 follows : 
 
 (1) Eespiratory. (4) Deglutition. 
 
 (2) Vaso-Motor, (5) Vomiting. 
 
 (3) Cardio-Inhibitory. (6) Heat Regulation. 
 The Respiratory Center controls the muscular 
 
 function of respiration by means of neurons which 
 pass down the cord terminating at various levels 
 and communicating their impulses to the lower 
 motor neurons which supply the muscles of respira- 
 tion, notably to the phrenic nerves at the fourth and 
 fifth cervical segments, special accessory, and the 
 intercostals. 
 
 Automacy of Respiration. — Many authors ascribe 
 to the respiratory center an automatic character 
 similar to that usually ascribed to the heart muscles, 
 and many ingenious experiments have been per- 
 formed to demonstrate the hypothesis. However, 
 the point must be regarded for the present as unset- 
 tled. Prom a deductive standpoint the writer is 
 inclined to the reflex explanation in spite of the 
 apparent predominance of contrary evidence. 
 
 Bulbar Paralysis. — Injury to or disease of the me- 
 dulla, if it involves, as it usually does, the respira- 
 tory center, of course paralyzes respiration and 
 
FUNCTIONAL DIAGNOSIS 159 
 
 causes death. Dislocation of the atlas as a rule pro- 
 duces instant death by sudden trauma and compres- 
 sion of the medulla. 
 
 In amyotrophic lateral sclerosis the atrophy even- 
 tually reaches the medulla and ends the scene of 
 paralyzing either respiration or deglutition. Mul- 
 tiple neuritis frequently has the same outcome from 
 inflammatory investment of the lower neurons con- 
 cerned in respiration. 
 
 ■V -V *m 
 
 Vaso-Motor Center, Vaso-Constrictor Nerves. — 
 The vaso-motor center controls the constriction and 
 dilatation of the vessel by means of the vaso-motor 
 nerves, whose lower neurons pass out of the cord at 
 the anterior roots. These neurons are called vaso- 
 constrictor nerves; this stimulation causes contrac- 
 tion of the muscles of the vessels, and a consequent 
 rise in blood pressure. The center performs for 
 these muscles the same tonic function that the cord 
 centers perform for the skeletal muscles, and main- 
 tains the level of blood pressure necessary to life. 
 Interruption of any of the neurons causes dilation 
 and a fall in blood pressure in the vessel supplied; 
 destruction of the center causes a general dilatation 
 and fall of pressure, resulting in death. 
 
 Vaso-Dilator Nerves. — It is an experimental fact 
 that neurons exist whose stimulation causes dilata- 
 tion of the vessels, and it is usual, therefore, to speak 
 of these as vaso-dilator nerves. Inasmuch, however, 
 as these neurons are shown to have no reflex center, 
 
160 FUNCTIONAL DIAGNOSIS 
 
 as the constrictors have, and considering further, 
 that physiology furnishes no precedent for the as- 
 sumption of a nerve-current which relaxes a muscle, 
 it would seem far more reasonable that the so-called 
 vaso-dilator nerves are afferent neurons which set 
 in motion an inhibitory reflex, restraining the func- 
 tion of the constrictors, in the same way that muscle 
 sense impulses inhibit the innervation of antagonis- 
 tic muscles and relax one or the other. 
 
 •m *m V 
 
 THE PONS VAROLII. 
 The Pons Varolii. — The pons, as its name implies, 
 is a connecting link between the various parts of 
 the brain, i. e., between the two cerebral hemis- 
 pheres, between them and the cerebrum, and be- 
 tween all three and the medulla. Its function, so 
 far as is known, is entirely that of conducting im- 
 pulse from one to the other, and furnishing passage 
 to the great sensory and motor tracts. 
 
 ■V *m -V 
 
 THE CEREBELLUM. 
 The Cerebellum. — The function of the cerebellum 
 is at the present time a subject of much discussion: 
 The preponderance of opinion, however, ascribes to 
 it the office of co-ordinating motor impulses, i. e., 
 directing them to a purposeful and economic end. 
 This is, of course, stating its function in terms of its 
 net result, for in order to accomplish this end it must 
 also take cognizance of sensory impulses. It would 
 
FUNCTIONAL DIAGNOSIS 161 
 
 therefore be better to say that the function of the 
 cerebellum is to strike a balance between the nervous 
 income and expenditure, to the most purposeful and 
 economical utilization of nervous capital. 
 
 Information of the Cerebellum. — It is necessary 
 that the cerebellum be kept constantly informed of 
 every item of nervous income and expenditure. Of 
 the income it receives information by way of the 
 sensory tracts, principally from the muscles (muscle 
 sense) but partly also from all other peripheries. 
 Of the expenditure it receives advice by means of 
 commissural fibres from the cerebrum, by fibres from 
 the motor tract as the latter passes through the pons, 
 and possibly by the recurrent fibres which re-enter 
 the cord from the lower motor neurons just after 
 they leave the roots. 
 
 The paramount sources from which the cerebellum 
 receives afferent impulses are : 
 
 (1) The skin, 
 
 (2) The muscles, 
 
 (3) The semi-circular canals of the ear. These 
 canals are constructed on three planes, at .right 
 angles to each other; they communicate freely, and 
 are filled with endolymph, which by its outward 
 pressure on the hair follicles lining the canals trans- 
 mits sensations to the cerebrum and cerebellum. 
 The least deviation of the head in any plane disturbs 
 the center of gravity in the canals, a sense of which 
 is immediately transmitted to the cerebellum. In 
 this way the canals exercise an important influence 
 in the maintenance of static, and probably also of 
 dynamic equilibrium. 
 
162 FUNCTIONAL DIAGNOSIS 
 
 Inco-ordination. — Interruption of the passage of 
 sensory impulses from any of these sources to the 
 cerebellum, or incapacity on the part of the cerebel- 
 lum to receive them, produces inco-ordination, man- 
 ifested clinically by impairment of purposeful move- 
 ments of the parts involved. The interruption may 
 occur either in the lower or upper neuron, or the 
 cerebellum itself may be the seat of the lesion. Its 
 location must be determined by considering accom- 
 panying symptoms. 
 
 Peripheral neuritis produces ataxia by interrupt- 
 ing the transmission of impulses from the skin and 
 muscles at the periphery. 
 
 Locotomor Ataxy manifests ataxia because of in- 
 jury to the posterior columns of the cord — one of 
 the paths of the upper sensory neurons (vide supra). 
 
 In multiple sclerosis the nodules are scattered 
 through the tracts, effecting a partial and diffuse 
 interruption of sensory impulses, the result being a 
 partial form of ataxaia which is now understood to 
 be the explanation of intention tremor. 
 
 In lateral amyotrophic sclerosis, on the contrary, 
 the process is always sharply limited and the cere- 
 bellar tract left intact; hence, amid all the havoc 
 wrought by this formidable disease, co-ordination is 
 
 Myelitis, in which all the tracts are involved, gives 
 ataxia, but the motor paralysis masks it. 
 
 In a hereditary form of locomotor ataxia, known 
 as Friedreich's Disease, the inco-ordination extends 
 to the muscles of speech, anfl the muscles of the 
 
FUNCTIONAL DIAGNOSIS 163 
 
 trunk are involved, making it difficult to maintain 
 static as well as dynamic equilibrium. 
 
 That the sense of vision plays an important part 
 in co-ordination is proved by the fact that in all 
 the ataxia diseases referred to the inco-ordination 
 becomes more marked when the eyes are closed 
 (Komberg's symptom). 
 
 "V •m -m 
 
 Mechanism of Co-ordination. — By just what means 
 the cerebellum exerts its co-ordinating influence on 
 the motor impulses is not known. Possibly by im- 
 pulses sent to the motor area of the cerebrum which 
 instruct the latter in the distribution of its motor 
 currents; possibly by inhibitory impulses given to 
 the motor fibres on their way down through the 
 pons; possibly by direct neurons of its own to the 
 muscles concerned (comma tract?). 
 
 Degeneration or atrophy of the cerebellum pro- 
 duces complete ataxia, including the facial muscles. 
 This condition is seen in a rare disease known as 
 hereditary cerebellar ataxia. Motor power is intact. 
 Muscular sense and general sensibility are unim- 
 paired, as are also the cutaneous reflexes; but the 
 tendon reflexes are exaggerated because the ten- 
 dons are under the influence of the cerebellum. The 
 facial movements are noticeably purposeless and ab- 
 surd. 
 
 Relation of Cerebrum to Cerebellum.— It may be 
 said that in removal or injury of the cerebellum, al- 
 though it produces temporary ataxia and inco-ordi- 
 
164 FUNCTIONAL DIAGNOSIS 
 
 nation, without any impairment of motor power, the 
 ataxia and inco-ordination in man, are largely re- 
 gained after a time, provided the cerebrum is in- 
 tact. This physiological fact coincides with the ana- 
 tomical fact that a goodly proportion of neurons 
 which convey muscle-sense are distributed to the 
 cerebrum, and affords another instance of the domi- 
 nant capacity of the cerebrum, which is able to as- 
 sume a great many functions in the absence of their 
 customary centres. 
 
 A notable exception to this is found in the case of 
 the disease just mentioned, hereditary cerebellar 
 ataxia. In this trouble the cerebrum does not com- 
 pensate for the cerebellum, doubtless because there 
 has been no conscious education in co-ordination, 
 and the cerebrum therefore has no experience to fall 
 back upon. 
 
FUNCTIONAL DIAGNOSIS 165 
 
 THE CEREBRUM. 
 
 The cerebrum is, both topographically and func- 
 tionally, the highest part of the nervous system. Its 
 function is but little understood, its activity being 
 dependent upon consciousness — that unknown and 
 unknowable factor in the physiologic equation. "We 
 are only able to state, in a general way, that it is the 
 seat of intelligent and voluntary function. More- 
 over, it seems that it only becomes so after repeated 
 impressions and experiments, for the brain of an in- 
 fant can hardly be regarded as a seat of intelligence 
 or volition; and this trial and error process (even 
 the passive part of it) is only possible in the pres- 
 ence of consciousness, for no impression can be made 
 on the cerebrum during unconsciousness. 
 
 Psychical Functions. — Of the higher operations of 
 the brain, commonly called psychical, including the 
 phenomenon of consciousness, nothing can be predi- 
 cated by physiology. They are generally supposed 
 to be functionated in the outermost layer of the 
 cortex (molecular layer), the axoms of whose neu- 
 rons do not pass out of that layer, but communicate 
 freely and completely with each other. This, how- 
 ever, is a purely histological hypothesis. 
 
 Cortical Region. — The pyramidal and polymor- 
 phous layers of the cerebrum, consisting chiefly of 
 gray matter (non-medullated), send axons both up- 
 ward into the molecular layer and downward into 
 the medulla of the brain. 
 
166 FUNCTIONAL DIAGNOSIS 
 
 The Cerebral Medulla.— The medulla of the brain 
 consists almost entirely of white matter (medullat- 
 ed), representing axons from neuron-cells in the 
 upper layers and in the spinal cord. The fibers com- 
 posing the medulla are classified according to their 
 anatomy and function. 
 
 (1) Association Fibers, connecting one part of 
 the cortex with another. 
 
 (2) Commissural Fibers, connecting the two 
 hemispheres, cerebellum, and pons. 
 
 (3) Projection Fibers, which come from or go to 
 the medulla oblongata and cord, and from the great 
 sensory and motor tracts. These fibers, after leav- 
 ing the cortex, sweep backward, in the form of an 
 arc (corona radiata), getting closer together the 
 lower they are traced, and pass in a very compact 
 bundle on each side, through the capsule (the mo- 
 tor fiber through the auterior and for part of the 
 posterior limb, the sensory through the back part of 
 the posterior limb) down to the medulla oblongata, 
 where they decussate, and into the cord. 
 
 Cerebral Motor Paralysis. — Trauma or disease of 
 the great sensory and motor tracts during their pas- 
 sage through the capsule and pons, where the fibers 
 are compressed into a very small sectional area, nat- 
 urally includes all of the neurons in the injury, and 
 produces a paralysis of all the parts supplied by the 
 tract — partial or complete according to the extent of 
 the injury or compression. If the lesion is above the 
 
FUNCTIONAL DIAGNOSIS 167 
 
 cranial nerve roots (as it usually is), the result is a 
 crossed paralysis involving the same side of the head 
 and neck and the opposite side of the body. If it is 
 below the cranial nerve nuclei, the paralysis in- 
 volves the opposite side of the body. 
 
 Hemorrhages into the capsule are very common, 
 as are also embolisms of the middle cerebral artery, 
 tumors, gummata and abscesses involving the cap- 
 sule. The first two lesions usually cause a sudden 
 and complete paralysis ; the other three lesions usu- 
 ally produce gradually progressive hemiplegia. 
 *. si "y 
 
 Cerebral Localization. — Experiment and observa- 
 tion have demonstrated that certain areas of the cor- 
 tex, being stimulated, functionate various parts of 
 the body ; one area, for example, always moving the 
 leg, another the arm; and still smaller points are 
 found in these areas which influence detailed sec- 
 tions of the parts in question, as the foot and toes, 
 hands and fingers. The same is true of special func- 
 tions, such as speech, hearing, etc. Hence we con- 
 clude that every part of the body is represented, 
 afferently and efferently, by a certain definite area 
 in the cortex, although the sensory areas, naturally, 
 cannot be mapped out with the definiteness of the 
 motor areas. 
 
 Monoplegias. — Inasmuch as the motor centres of 
 the cortex are separated from each other by a more 
 or less measurable distance, traumata and degener- 
 
168 FUNCTIONAL DIAGNOSIS 
 
 ative processes of the cortex, unless extraordinarily 
 extensive, do not involve more than one or two of 
 these centres. Hence the paralyses produced by cor- 
 tical lesions do not as a rule involve more than one 
 group of muscles, and are known as monoplegias. 
 Conversely a monoplegia may as a rule be diagnosed 
 as due to a cortical lesion, for in no other part of 
 the cerebro-spinal course are peripheral groups rep- 
 resented by neurons sufficiently isolated to incur 
 separate injury. 
 
 In certain types of cortical epilepsy the central 
 irritation starts in one of these cortical centres, and 
 the fit begins with a corresponding disturbance in 
 the group of muscles controlled by that centre ( Jack- 
 sonian Epilepsy). 
 
 •*• *k -m 
 
 Location of Motor Areas. — The motor areas are 
 for the most part situated along the fissures of Ro- 
 lando and sylvius, and a description of the probable 
 location of the centres for the most important parts 
 of the body will be found in the accompanying ta- 
 ble. The location of special senses centres will be 
 indicated in discussing those senses : 
 
 It will be readily seen from the table and illustra- 
 tion that the arrangement of the centres facilitates 
 the occurrence of monoplegias. These are quite fre- 
 quent in practice and it is usually a simple matter 
 to diagnose the exact spot in the brain at which the 
 lesion exists. Frequently, too, the lesion will include 
 two adjoining centres, such as those of the face and 
 
FUNCTIONAL DIAGNOSIS 
 
 169 
 
170 FUNCTIONAL DIAGNOSIS 
 
 arm, or of the arm and leg, and a paralysis of these 
 two regions is then produced which is called an as- 
 sociated plegia. But it is apparent that an associ- 
 ated cortical paralysis of the leg and face, without 
 paralysis of the arm cannot occur as the result of a 
 single cortical lesion. 
 
 The greatest care must be exercised in differen- 
 tiating between the various centres concerned in the 
 functions of speech, hearing, and writing, and the 
 effects of injury to these foci. Each of these func- 
 tions is made up of two distinct operations of the 
 brain, performed by two distinct and separate cen- 
 tres, which may be classified as follows : 
 
 Hearing. — (1) Perception of sound; (2) Storing 
 of Sounds (auditory memory). 
 
 Sight. — (1) Perception of images; (2) Storing of 
 Images (visual memory). 
 
 Speech. — (1) Recognition of stored sounds 
 (spoken words) ; (2) Motor Speech. 
 
 Writing. — (1) Recognition of Stored Images 
 (written words) ; (2) Motor Writing. 
 
 It will be readily apparent that the function of 
 speech depends upon that of hearing since sounds 
 cannot be reproduced which have not first been per- 
 ceived and memorized. In like manner the function 
 of writing depends upon that of sight, since the 
 images cannot be reproduced which have not been 
 first perceived and memorized. Psychologically the 
 acts of storing and reproducing an impression are 
 
FUNCTIONAL DIAGNOSIS 171 
 
 identical ("there can be no impression apart from 
 expression"). 
 
 It will be further seen that the centres for these 
 intradependent functions are situated immediately 
 above each other in the brain as follows : 
 
 Motor Speech, 
 
 Memory of Spoken Words, 
 
 Hearing, 
 
 Arm and Hand, 
 
 Memory of Written Words, 
 
 Vision. 
 
 Pure Deafness. — A lesion of the auditory cen- 
 tre, or centre of pure hearing, produces inability to 
 perceive sound. The current conveyed by the audi- 
 tory nerve produces no effect upon it. This lesion 
 is not necessarily fatal to speech, in these days of 
 modern resource and patience, as the patient may 
 be taught by sight, and, in the absence of sight, even 
 by thought, to recognize and reproduce motions of 
 the mouth and tongue. This form of deafness is 
 called pure deafness. 
 
 Word Deafness. — A lesion of the centre of sound 
 memory produces inability to store sounds, and 
 therefore to recall them. This form of deafness is 
 called word deafness, and is fatal to intelligent 
 speech, because the word desired to be spoken can- 
 not be thought of. In regard to speech this is 
 known as amnesic aphasia. 
 
 Pur© Blindness. — A lesion of the visual centre 
 
172 FUNCTIONAL DIAGNOSIS 
 
 produces inability to perceive an image. The cur- 
 rent conveyed by the optic nerve makes no impres- 
 sion upon it. This form of blindness is called pure 
 blindness and can be overcome by patient education 
 so far as the ability to write is concerned. 
 
 Word Blindness. — A lesion of the visual memory 
 centre produces inability to store and hence to recall 
 images. This form of blindness is called word blind- 
 ness and is fatal to intelligent writing because the 
 word desired to be written cannot be recalled. In 
 regard to writing this is called amnesic agraphia. 
 
 Aphasia. — The form of aphasia dependent upon 
 injury to the sound memory centre (amnesic apha- 
 sia) has already been described. The other form of 
 aphasia is that which results from injury to the mo- 
 tor mechanism of speech and is called motor or pure 
 aphasia. 
 
 Agraphia. — The form of agraphia resulting from 
 injury to the centre of visual memory (amnesic 
 agraphia), has been described. That form which 
 comes of injury to the motor mechanism of the arm 
 and hand is called motor or pure agraphia. 
 
 Soul Blindness and Deafness. — There is still an- 
 other form of word blindness and deafness in which 
 sounds are heard and images seen, and both are 
 stored and reproduced, but no connection is per- 
 ceived between the sound or the image and any con- 
 ception of the mind. This is known as soul blindness 
 and deafness. It depends on no special centre, but 
 upon a general dissociation of the cerebral areas. 
 
FUNCTIONAL DIAGNOSIS 173 
 
 REACTION OF DEGENERATION. 
 
 Reaction of Degeneration. — A similar process of 
 degeneration occurs in a neuron which is cut off 
 from its cell by pathological lesions in the interven- 
 ing axon, such as new growths, sclerosis, inflamma- 
 tory congestions, etc. The process is then known as 
 secondary degeneration, ascending or descending as 
 the case may be, and is clinically detected and meas- 
 ured by certain abnormal ways in which the neuron 
 and the muscles it supplies react to electrical cur- 
 rents. This is known as the Reaction of Degenera- 
 tion and may be briefly stated as follows : 
 
 In health, both nerve and muscle react to the fara- 
 dic current by contracting sharply upon application 
 of the needle, and to the galvanic current by a con- 
 traction at the closing and opening of the circuit, 
 but not during the passage of the current, the Ka- 
 thode contraction being more vigorous than the 
 anode. 
 
 In complete reaction of degeneration neither nerve 
 nor muscle reacts to faradic current ; the nerve does 
 not react to galvanic; the muscle contracts slowly 
 and undulatingly to the galvanic, and exhibits as 
 good a reaction to the kathode as to the anode. 
 
 In incomplete reaction of degeneration the reac- 
 tions exhibit intermediate between normal and com- 
 plete degeneration. 
 
 Reaction of degeneration enables us to locate the 
 lesion in the lower neuron or in the root-cells, i. e., 
 
174 FUNCTIONAL DIAGNOSIS 
 
 between the periphery and the trophic ganglia ; and 
 the persistence or improvement of the abnormal re- 
 action indicates a grave or favorable prognosis of the 
 restitution of the integrity of the neuron. 
 
 Reaction of degeneration is generally associated 
 with muscular atrophy, because the trophic influence 
 of the ganglion is also exerted upon the nutrition of 
 the muscle. 
 
 It does not occur in diseases involving only the 
 cord tracts or upper neurons, or in cerebral lesion. 
 Multiple neuritis, involving inflammation of the 
 lower neuraxons ; poliomyelitis, inflammation of the 
 anterior horns; and Progressive muscular atrophy, 
 involving both lower neuraxons and anterior roots; 
 all give reaction of degeneration. Amyotrophic la- 
 teral sclerosis gives reaction of degeneration in its 
 later stages, when it attacks the motor roots. 
 
FUNCTIONAL DIAGNOSIS 175 
 
 SPECIAL FUNCTIONS. 
 Vision. 
 
 Ocular Movements are performed by means of the 
 extrinsic muscles of the eye, the movements exe- 
 cuted by each pair being as follows : Superior Bec- 
 tus, upward and inward ; Inferior Eectus, downward 
 and inward; External Eectus, outward on vertical 
 axis ; Internal Eectus, inward on vertical axis ;. Su- 
 perior Oblique, outward on antero-posterior axis; 
 Inferior Oblique, correcting the inward deviation of 
 the recti. 
 
 These muscles are in a constant condition of to- 
 nicity and oppose each other. 
 
 Muscular Imbalance is the result of inadequacy 
 on the part of one of the extrinsic muscles, causing 
 a deviation of the eyeball in the direction of the 
 opposing muscle or muscles. This condition may be 
 overcome for a time by excessive innervation of the 
 faulty muscles, but eventually this gives way, and 
 strabismus ensues. The inadequate muscle is com- 
 monly one of the recti, since these bear the brunt of 
 the work. Inadequacy of the external rectus causes 
 convergent strabismus; internal rectus causes di- 
 vergent strabismus. 
 
 ■b "m 'm 
 
 Muscular Innervation. — All the extrinsic muscles 
 are innervated by the third cranial nerve, except 
 two, namely, the external rectus supplied by the 
 sixth, and the superior oblique by the fourth cranial. 
 
176 FUNCTIONAL DIAGNOSIS 
 
 Muscular Imbalance. — It is due to the fact that the 
 external and internal recti are supplied by separate 
 nerves that imbalance occurs between these two 
 muscles. The inadequacy of one of them, due to op- 
 tical defects, is compensated for a time by excessive 
 innervation of the other, until the overworked nerve 
 gives way and becomes paralyzed. The sound nerve 
 continues to innervate the opposite muscle which 
 pulls the eye in its own direction. 
 
 Paralysis of the third nerve causes divergent, of 
 the sixth convergent, strabismus. 
 
 Paralysis of the fourth nerve causes inability to 
 turn the eye downward and outward. 
 
 Lucitas. — When the third nerve is paralyzed, not 
 only dies it produce divergent squint, but inasmuch 
 as all other muscles which might move the eyeball 
 are controlled by the same nerve complete immo- 
 bility of the eyeball results. This is known as 
 lucitas. 
 
 ■v 'm n. 
 Accommodation is the faculty of increasing the 
 convexity of the lens. It is accomplished by contrac- 
 tion of the ciliary muscle, which draws the choroid 
 forward, thus releasing the suspensory ligaments 
 and allowing the lens by its elasticity to assume a 
 more convex form. Accommodation takes place for 
 the purpose of focussing divergent rays, i. e., for 
 sighting near objects, and is relaxed to focus parallel 
 rays, i. e., for sighting distant objects. The exercise 
 of this faculty belongs to the province of optics, and 
 will not be further discussed here. 
 
FUNCTIONAL DIAGNOSIS 177 
 
 Presbyopia. — In persons over forty-five and in 
 younger persons under certain pathological condi- 
 tions, the lens becomes hard and inelastic, and ac- 
 commodation is greatly limited. 
 
 ■V *m *m 
 
 Innervation of Accommodation. — The faculty of 
 accommodation is innervated by the third nerve, 
 through its branches to the ciliary muscle, known as 
 the ciliary nerve. 
 
 Paralysis of Accommodation results from (a) cen- 
 tral lesion of the fourth ventrical, as from brain, tu- 
 mor, cerebral sclerosis, toxins (diphtheria), consti- 
 tutional diseases, (b) interruptions of the course of 
 the third or ciliary nerve, as in cerebral tumors, neu- 
 romata, etc., or (c) peripheral paralysis of the ciliary 
 nerves, as in the action of certain drugs, notably 
 atropin. The location of the lesion may be diagnosed 
 by the involvement or otherwise of other muscles. 
 
 Spasm of Accommodation results from over-use of 
 the ciliary nerves, and is a common accompaniment 
 of errors of refraction. 
 
 ^i 1. *m 
 
 Convergence is the faculty of directing the yel- 
 low spots of both eyes toward a point for the recep- 
 tion of divergent rays, i. e., toward a near point, and 
 is accomplished by means of the internal recti. 
 
 Innervation is mediated by the third cranial nerve. 
 
 Convergence and accommodation are closely asso- 
 ciated, and in the normal eye are performed in direct 
 
178 FUNCTIONAL DIAGNOSIS 
 
 ratio, but they are quite independent faculties and 
 may be exercised independently. 
 
 Anomalies of Convergence have already been dis- 
 cussed under the heading of ocular movements. 
 
 ■"W fm •k 
 
 The Iris serves as a cut-off to the light that enters 
 the eye, much the same as the shutter of a camera, 
 so that the image upon the retina may be clear. Its 
 circular muscle (sphincter), contracting, contracts 
 the pupil; its longitudinal muscles, by contracting, 
 dilate the pupil. 
 
 Sluggish or Immobile Pupil results from adhesion 
 of the iris, to the lens in iritis with exudation. 
 
 Photophobia and Disordered Vision are seen in 
 iritis because of interference with the regulation of 
 light entering the eye. 
 
 The Pain of iritis is spasmodic because it increases 
 with contraction of the longitudinal muscles, and 
 worse at night because these muscles are then in 
 steady contraction. 
 
 •W V V 
 
 Innervation of the Iris is a reflex phenomenon. The 
 afferent stimulus is furnished by light falling upon 
 the retina, the impulse being carried by fibres which 
 accompany the optic nerve as far as the corpora 
 quadrigemina, where they branch off to the centre 
 in the fourth ventricle. The efferent (motor) im- 
 pulse is conveyed to the sphincter by means of the 
 third cranial nerve through the ciliary ganglion. 
 The longitudinal muscles are innervated by the sym- 
 
FUNCTIONAL DIAGNOSIS 
 
 179 
 
 pathetics. It is an involuntary phenomenon, which 
 may be inhibited, but not consciously, by the brain, 
 as in case of emotions, nervous conditions, etc. 
 
 Mydriasis (dilation of the pupil) is caused by any 
 condition which (a) paralyzes either the central or 
 peripheral end of the third nerve, (b) inhibits its 
 functionation through the brain, or (c) stimulates 
 the sympathetic. 
 
 Tumors of the brain, and of the third nerve, and 
 the action of certain drugs, notably atropin, are ex- 
 amples of the first class. 
 
 Fevers, comatose conditions, hemasthenia, tubercu- 
 losis, and nervous depression are instances of the 
 second class. 
 
 Pain, sensory irritation, and visceral diseases fur- 
 nish illustrations of the third variety. 
 
 Myosis (contraction of the pupils) on the other 
 hand, results from influences which (a) irritate the 
 third nerve, or (b) depress the sympathetic. 
 
 Photophobia, from any cause, brain tumors, men- 
 ingitis and certain drugs, as eserin, are instances of 
 the former; spinal sclerosis, aneurisms (by pressure)' 
 and opium of the latter. 
 
 Argyll-Robertson Pupil, in which the pupil reflex 
 is wanting, is seen in tabes dorsalis and dementia 
 paralytica, supposed to be due to involvement of 
 Minert's fibres. 
 
 Wernicke Pupillary Reaction is a test for deter- 
 mining the location of an injury to the optic tract, 
 (usually employed in cases of hemianopsia). If the 
 
180 FUNCTIONAL DIAGNOSIS 
 
 reflex is present, in the half of the eye that is af- 
 fected, then the lesion is back of the corpora quad- 
 rigemnia; if not, it is in front of these ganglia; be- 
 cause at that point the reflex path leaves the optic 
 tract to go to the ventricle. 
 
 Hippos, a periodic contraction and dilatation of 
 the pupil, due to alternate excitation and inhibition, 
 is seen in disorders affecting the emotions, as in 
 mania, hysteria, etc. 
 
 "b ^. «W 
 
 The Humors of the eye, consisting of the aqueous, 
 the vitreous, and the lens, serve as a refracting me- 
 dium for rays of light, their resultant index of re- 
 fraction, together with that of the surfaces of the 
 cornea, lens, and vitreous, being just sufficient in a 
 normal eye to focus parallel rays on the retina. 
 
 Inter-Ocular Tension results from a disturbance 
 between the secretion and absorption of the humors. 
 This condition is known as Glaucoma. 
 
 The steady increase of internal pressure in this dis- 
 ease produces a characteristic train of symptoms, 
 such as steady pain, cupping of the disc, vascular 
 stasis, dimness of vision, and, if not relieved, even- 
 tual blindness due to destruction of the eye. 
 
 Scotoma (blind spot) is frequently due to opaci- 
 ties in the humor, especially the vitreous, in which 
 case they are seen by the patient as spots before the 
 eyes (muscae volitantes). 
 
 Cataract, an opacity of the lens, produces, of 
 course, diminished acuteness of vision, most marked 
 
FUNCTIONAL DIAGNOSIS 181 
 
 when it is central, least marked when it is peripheral 
 in location. Vision is better in dim light, because the 
 pupil is then dilated and more rays (relatively) en- 
 ter the eye. 
 
 Increase in index of refraction, due to increased 
 density of the lens, occurs in cataract producing my- 
 opia (short sight). 
 
 1i •!» % 
 
 Stimulation of the Retina. — The light, falling on 
 the retina, stimulates the rods and cones, which in 
 turn, transmit the vibrations to the fibrils of the op- 
 tic nerve. Inasmuch as the image on the retina is 
 a crossed one, the halves of the retina receive stimuli 
 from the opposite field of vision, i. e., the nasal half 
 receives light from the temporal field and the tem- 
 poral half from the nasal field. The character of the 
 impulse generated by the light is not clear, some 
 holding it to be thermic, some electric, some chem- 
 ical. Certain it is, however, that the rods and cones 
 transform the light vibrations into another type of 
 impulse, for light falling directly on the optic nerve 
 makes no impression (blind spot). 
 
 In the ordinary use of the eye, the visional percep- 
 tion is concentrated entirely upon those stimulations 
 which fall upon the central portion of the retinal 
 field; those which fall upon the peripheral areas 
 make no conscious effect upon the brain unless spe- 
 cial conscious effort is made to perceive them. 
 
 Hemianopsia (blindness of one-half of the retina) 
 must be subjectively diagnosed with a view to the 
 
182 FUNCTIONAL DIAGNOSIS 
 
 crossed rays — paralysis of the nasal half producing 
 blindness to objects in the temporal field of vision, 
 and vice versa. 
 
 Flashes of light are seen in retinitis, due to the 
 sensitive condition of the retina to stimulation, but 
 steady over-stimulation is almost unknown, because 
 the inflammation quickly renders the rods and cones 
 impermeable to stimulus. 
 
 Diminution of Vision is far the commoner symp- 
 tom in all forms of retinitis, also in degeneration of 
 the retina, glioma (tumor of the retina), anemia, 
 due to poor circulation. 
 
 Sudden Blindness results from embolism of the 
 central retinal artery, cutting off its entire blood 
 supply and gradual blindness from retinal throm- 
 bosis. 
 
 Scotoma (blind spot) results from a defect in the 
 retina. If the defect is in the peripheral field the 
 spot is not perceived by the patient; but when it is 
 in the central field the patient perceives it as a fixed 
 defect of vision. 
 
 •m •. •. 
 
 The Optic Nerve serves to conduct the light im- 
 pulses from the retina to the chiasm, each optic nerve 
 conveying impulses from its respective retina alone. 
 
 Lesions of the Optic Nerve alone, naturally affect 
 only that eye supplied by the pathologic nerve. In- 
 asmuch, however, as optic neuritis (practically the 
 only known pathologic condition) is usually due 
 either to brain lesions or to infectious diseases, it is 
 
FUNCTIONAL DIAGNOSIS 183 
 
 usually bilateral. It is, of course, always attended 
 with diminution of vision, and eventually, if not 
 cured, by blindness. 
 
 Complete Blindness of one eye always indicates 
 injury to the optic nerve for reasons explained under 
 The Optic Tracts. 
 
 -» > "W 
 
 The Optic Tract. — At the chiasm the impulses 
 decussate, those from the right half of each ret- 
 ina proceeding to the right occipital lobe, and those 
 from the left half to the left. Impulses from the 
 macula lutea, however, go to both lobes. Hence, re- 
 membering the crossed image on the retina, visual 
 impulses excited by objects in the left visual field 
 are represented in the right occipital hemisphere, 
 and vice versa. 
 
 Hemianopsia. — This arrangement makes possible 
 that frequent form of visual disturbance known as 
 hemianopsia or hemianopia, paralysis of one lateral 
 half of the retinal field, manifested, of course, by 
 blindness to the opposite visual field. 
 
 Temporal Hemianopsia, i. e., blindness to both tem- 
 poral fields, must necessarily be due to an interrup- 
 tion involving the inner half of the optic tracts, viz., 
 either one lesion in the center of the chiasm, or two 
 separate lesions, one in each occipital lobe. 
 
 Nasal Hemianopsia, i. e., blindness to both nasal 
 fields, is due to interruption of the outer halves of 
 the tract, and must be two separate lesions, one each 
 side of the chiasm, or one in each occipital lobe. 
 
184 FUNCTIONAL DIAGNOSIS 
 
 Homogeneous Hemianopsia, i. e., blindness to the 
 nasal field in one eye, and to the temporal field in 
 the other, is due to an interruption of one whole 
 tract, or destruction of one whole occipital lobe. 
 
 Scintillating Scotoma, temporary hemianopsia, due 
 to circulatory disturbances in one of the occipital 
 lobes is seen in migraine. 
 
 Complete Blindness of One Eye, as will readily be 
 seen, must be due in every case to a lesion in front 
 of the chiasm, as only there are both fields of one 
 eye alone represented. 
 
 1. •m "W 
 
 Visual Centre. — From both the occipital lobes the 
 impulses are conveyed to the visual centre in the left 
 frontal convolution of the cerebral cortex, where all 
 the areas of both eyes have central representation. 
 
 Functional Disturbances of the centre have al- 
 ready been fully discussed under the Nervous Sys- 
 tem, q. v. 
 
 Congenital Amblyopia, a defect of vision, not rem- 
 ediable by glasses, and usually associated with high 
 degrees of refractional error, is due to the fact that 
 a distinct image never having been thrown upon the 
 retina, the brain has never learned to interpret the 
 stimulus aright. 
 
 ■fc "W *m 
 
 Theories of Color Perception. — Two theories pre- 
 vail to account for color perception. 
 
 The Young-Helmholz Theory holds that there are 
 present in the normal retina three photo-chemical 
 
FUNCTIONAL DIAGNOSIS 185 
 
 substances, whose decomposition imparts to the optic 
 nerve three distinct sensations. The maximum stim- 
 ulation of these separate substances is produced re- 
 spectively by red, green and violet waves, but every 
 spectrum wave stimulates all three to a greater or 
 less degree, and the relative degrees of stimulation 
 thus produced in the three substances determine 
 the color sensation perceived by the brain. 
 
 The Hexing Theory also assumes the existence of 
 three photo-chemical substances in the retina, but at- 
 tributes to each a double stimulative faculty, certain 
 spectrum waves causing assimilation of the substance 
 and other waves disassimilation, these two effects in 
 their turn producing correspondingly different color 
 sensations. The double capacity and stimulation ef- 
 fect of these substances may be thus expressed. 
 
 Assimilation. Disassimilation. 
 Red-Green Red Green 
 
 Yellow-Blue Yellow Blue 
 
 White-Black White Black 
 
 Varying degrees of assimilation and disassimila- 
 tion in the various substances, of course, produce 
 corresponding combined color sensations. 
 
 Color Blindness. — Frequently a patient is met 
 with who is unable to perceive certain colors, and is 
 therefore said to be color blind to that particular 
 color and its combinations. The commonest colors 
 to which color blindness is found are red and green. 
 This condition may be (a) retinal, i. e., due to a de- 
 
186 FUNCTIONAL DIAGNOSIS 
 
 ~~'3E 
 
 feet in the retina, by far the most common variety, 
 or (b) central, i. e., due to a defect in the visual 
 center. Whichever of the two theories above out- 
 lined be accepted, the retinal defect must consist in 
 an absence of the photo-chemical substance whose 
 maximum modification is brought about by the spec- 
 trum wave corresponding to the color to which sen- 
 sation is lacking. 
 
 Because of its investigation by Dalton, this con- 
 dition is sometimes known as Daltonism. 
 
FUNCTIONAL DIAGNOSIS 187 
 
 HEARING. 
 
 The Muscular Movements of the ear are limited to 
 the action of the tensor tympani and stapedius, both 
 of which render the tympanic membrane more re- 
 ceptive to sound, the former by direct tension of the 
 membrane, the latter by traction on the stapes. 
 
 Innervation of these muscles is mediated by the 
 fifth cranial nerve. 
 
 In Facial Paralysis (of the fifth nerve) the fac- 
 ulty of rendering the ear drum tense is lost, and the 
 hearing is impaired to that extent. 
 
 *m ^ «U 
 
 The Tympanic Membrane is set in motion by the 
 air waves, and by virtue of its funnel-like structure, 
 transmits them in diminished amplitude and in- 
 creased intensity to the ossicles. 
 
 Imperfect Vibration of the tympanic membrane 
 occurs in any condition which (1) interferes with 
 the diaphragmatic adjustment of the membrane, as 
 in myringitis (inflammation of the drum), chalk de- 
 posits on the drum, catarrh, and impaction of ceru- 
 men, all of which thicken the membrane, and in 
 perforation, which destroys its tension and integrity; 
 and (2) bars the meatus leading to the drum, as in 
 catarrh, impacted cerumen, and growths of the 
 meatus. 
 
 ■k ?W "m 
 
 The Eustachean Tube admits air to the tympanic 
 chamber, thus maintaining equal atmospheric pres- 
 
188 FUNCTIONAL DIAGNOSIS 
 
 sure on both sides of the membrane and enhancing 
 its delicacy of vibration. 
 
 Bulging of the Membrane, and consequent impair- 
 ment of its vibrations, result from blocking of the 
 tube, as in exudative inflammation, catarrh, and ab- 
 scess. 
 
 •m Tm "1« 
 
 The Ossicles, comprising the malleus, incus and 
 stapes, receive the vibrations of the tympanic mem- 
 brane and transmit them to the membrane of the 
 fenestra ovalis. By virtue of their arrangement they 
 also diminish the amplitude of the vibrations (Helm- 
 holz estimates by one-third) and increase their in- 
 tensity (according to the same authority, by one- 
 half). 
 
 Impaired Hearing results from any influence 
 which either changes the relative sizes and relations 
 of the ossicles as hypertrophy due to catarrh, caries, 
 etc., or interferes with their free motion, as anky- 
 losis. 
 
 *k V •* 
 
 The Perilymph, filling the internal ear, receives 
 the vibrations from the fenestra ovalis, and trans- 
 mits them to the rods of Corti in the cochlea. 
 
 Rhine's Test for determining the location of a 
 lesion causing deafness depends upon the fact that 
 if the course from the external meatus to the fenes- 
 tra ovalis is interrupted while the internal ear and 
 auditory nerve are intact, vibrations will be com- 
 
FUNCTIONAL DIAGNOSIS 189 
 
 municated to the perilymp more readily by way of 
 the bones of the head than by the meatus (Rhine +), 
 the lesion is located in the external or middle ear; 
 but if the contrary (Rinne — ) the lesion is in the 
 internal ear. 
 
 Weber's Test shows that in affections of the mid- 
 dle ear and integrity of the nervous mechanism, a 
 tuning fork held up the vertex is heard better in the 
 •deafer ear (Weber +) and vice versa (Weber — ). 
 This depends upon the fact that where the middle 
 ear is blocked the vibrations received through the 
 head bones find no outlet through the meatus and 
 are confined to the perilymph, being thereby intensi- 
 fied. 
 
 ^i •m •* 
 
 The Rods of Corti, comprising the organ of Corti, 
 perform the essential part of the function of hear- 
 ing. They are from 16,000 to 20,000 in number, and 
 are stimulated by sound waves in much the same 
 way that the rods and cones of Jacob's are stimu- 
 lated by light waves. 
 
 The Piano Theory of Hearing assumes that each 
 rod of Corti is a resonator, responding to a distinct 
 pitch or wave-length, and that simple and com- 
 pound sensation of sound depend upon the stimula- 
 tion of one or more of these resonators, recording 
 a specific reaction in the brain for each rod. 
 
 The Telephone Theory holds that the compound 
 sound wave stimulates the organ of Corti as a unit, 
 and that the analysis of the sensation is performed 
 in the brain centre. 
 
190 FUNCTIONAL DIAGNOSIS 
 
 In Disease of the Labyrinth extending from the 
 middle ear, the hearing for high pitched notes ia 
 greatly impaired, because the few short rods at the 
 commencement of Corti's organ, hear the vestibule 
 resonate to high pitched sound waves. 
 
 ■b ?W "in 
 
 Auditory Limits. — The range of perceptible sound 
 waves varies in different individuals, but the aver- 
 age audible gamut is from 30 vibrations per second 
 (low pitch) to 40,000 per second (high pitch). 
 Slower vibrations than the former, if perceived at 
 all, are usually only perceived as stimulations of the 
 sensory nerve of the tympanum — the auditory nerve 
 does not react to them ; or else the auditory nerve re- 
 sponds to their overtones, for particulars of which a 
 work on acoustics must be consulted. 
 
 Pathological Limitations of Fitch are caused by 
 ankylosis of the ossicles which prevents those bones 
 
 from vibrating rapidly. 
 
 ■w "1. «w 
 
 The Auditory Nerve collects the vibrations from 
 the rods of Corti and transmits them to the auditory 
 centre in the temporal lobe, each ear being separate- 
 ly represented in each corresponding temporal lobe. 
 
 Sudden Deafness is a prominent symptom of Men- 
 iere's disease, caused by a hemorrhage into the audi- 
 tory nerve or labyrinth. 
 
 Timitus is a symptom of all ear disorders which 
 increase tension in or shut off egress from the in- 
 ternal ear, because the physiological noises, such as 
 
FUNCTIONAL DIAGNOSIS 191 
 
 circulation, muscle tonus, etc., which under ordinary 
 conditions are too diffused to be heard, are confined 
 to the labyrinth and become audible. 
 
 Vertigo and Dizziness accompany all such condi- 
 tions because of the interference with the integrity 
 of the semi-circular canals and consequent disturb- 
 ance of co-ordination. (See Nervous System.) 
 
 *> *i % 
 Auditory Centre. — The auditory centres in the 
 
 temporal lobes transmit the sensation of sound to 
 
 the auditory centre in the left frontal. 
 
 Affections of the Auditory Centre are fully dealt 
 
 with under Cerebrum. 
 
192 FUNCTIONAL DIAGNOSIS 
 
 SMELL. 
 
 The Olfactory Mechanism consists in the contact 
 of chemical particles of the odoriferous substance, 
 usually but not necessarily in gaseous forms, with 
 the upper roof of the nasal chamber where they stim- 
 ulate the outspread filaments of the olfactory nerve. 
 This contact may be effected either by way of the 
 anterior or the posterior nares. In the latter case 
 it enters largely into what is commonly regarded as 
 taste. 
 
 The olfactory faculty is probably the most acute 
 and delicate of the senses, no adequate measure- 
 ment of the threshold stimulus having yet been 
 found. 
 
 Anosmia (loss of smell) is, of course, seen in all 
 disorders which (a) impair or destroy the mucous 
 membrane in which the filaments are spread, as in 
 rhinitis, especially the chronic hypertrophic and 
 atrophic forms, catarrh, etc., or (b) obstruct the 
 nares, as in adenoids, polypi, hypertrophy of the 
 turbinate, new growths and allied troubles. 
 
 Hyperosmia (increase sensitiveness to smell) and 
 Parosmia (perverted sense of smell) are usually 
 nervous disorders (vide infra). 
 
 -W -W -b 
 
 The Innervation of Smell, so far as we know it, 
 is a simple matter. The stimulation of the filaments 
 promulgates a nerve current along the olfactory 
 nerve, which reaches the olfactory centre in the 
 
FUNCTIONAL DIAGNOSIS 193 
 
 frontal lobe and registers itself there as a sensation. 
 It is held, that the various qualities of odor are due 
 to stimulation of different fibres of the nerve. 
 
 Anosmia results from any condition which (a) de- 
 stroys or impairs the path of innervation, or (b) 
 renders the nerve or centre irresponsive to stimuli- 
 Brain tumors and cerebral softening are the most 
 conspicuous examples of the first; hysteria, melan- 
 cholia and nervous depression of the second. 
 
 Hyperosmia is usually an accompaniment of hys- 
 teria, which renders the olfactory center unusually 
 acute. 
 
 Parosmia is also the result of such functional 
 psychic aberrations as hysteria, neurasthenia, and 
 melancholia, but may be due to congenital absence 
 of certain specific fibres in the nerve. 
 
194 FUNCTIONAL DIAGNOSIS 
 
 TASTE. 
 
 The Mechanism of Taste consists in the contact of 
 the sapid substance, in solution, with the surface of 
 the tongue, where it stimulates the filaments of the 
 nerves of taste. It is absolutely essential' that the 
 substance be in solution ; taste is impossible on a dry 
 tongue. 
 
 Absence or Diminution of Taste results from any 
 condition which destroys or impairs the mucous 
 membrane in which the nerve filaments or taste buds 
 lie, as cancer, ulceration, tuberculosis, and severe 
 forms of glossitis. 
 
 N. B. Absence of taste, so called, in catarrh, is 
 due to impairment of retronasal olfaction. 
 
 Perversion of Taste (far more frequent than di- 
 minution) may arise from conditions of the tongue 
 and palate which alter the sapid substance, as sali- 
 vary disorders (mumps), digestive troubles (from 
 food coating), fevers and sore throat (from epithe- 
 lial coating), etc. The anomaly is therefore not 
 really a perversion of the sense, but of the sapid sub- 
 stance. 
 
 ■V *m ~m 
 
 Classification and Distribution of Taste Sensations. 
 
 — There are but four fundamental taste sensations, 
 of which all others are combinations and modifica- 
 tions, and while these are distributed over the tongue 
 and palate differently in different individuals, yet 
 
FUNCTIONAL DIAGNOSIS 195 
 
 the general average preponderance of the various 
 sensations is as follows: 
 
 Sweet. — Tip and forepart of tongue. 
 
 Bitter. — Back of tongue. 
 
 Acid. 
 
 Salty. 
 
 Dissociated Taste Sensations are diagnostic of dis- 
 orders of the tongue occurring in patches, which can 
 be located (but not with exactness) by the dominant 
 sensations. 
 
 •m *m "h. 
 
 Innervation of Taste is mediated by the lingual (a 
 branch of the inferior maxillary division of the 
 fifth) nerve, supplying the anterior two-thirds of the 
 tongue; and the glossopharyngeal, supplying the 
 posterior third. Recent observations by Cushing of 
 Baltimore demonstrate that that the former fibres do 
 not accompany the fifth nerve through the Gasserian 
 ganglion, but pass to the Petrosal ganglion and 
 thence to the fourth ventricle. The same evidence 
 indicates that the latter fibres pass directly to the 
 gessiculate ganglion and enter the brain with the 
 seventh nerve. 
 
 The Sensation does not depend upon any specific 
 character of peripheral stimulation but upon the spe- 
 cific reaction of the cerebral termini. 
 
 Absence of Taste results from any condition which 
 interrupts the course of the nerve currents con- 
 
196 FUNCTIONAL DIAGNOSIS 
 
 cerned, or the recording of those impulses in the 
 brain, as brain tumors, neuromata, neuritis, etc. 
 
 Hypersensitive Taste is seen in conditions which 
 exalt the nervous functions, as hysteria, and the in- 
 influence of certain drugs, strychnia, etc. 
 
 Perversion of Taste is almost always due to per- 
 version of psychic function, as in melancholia, hys- 
 teria, neurasthenia, hypochondria, etc. 
 
FUNCTIONAL DIAGNOSIS 197 
 
 REPRODUCTION. 
 OVULATION. 
 
 The Testicle is the essential organ of ovulation in 
 the male. In the seminiferous tubules of these 
 glands the spermatogenie cells (a very elementary 
 variety of epithelial cells), by a process of Karyo- 
 kinesis, evolve the spermatozoa. These are produced 
 in enormous numbers, from twenty-five to a hundred 
 million of them being contained in every cubic centi- 
 meter of ejaculated semen. The secretion of these 
 cells begins at the age of puberty, and continues 
 indefinitely, doubtless under the nervous influences 
 of the sympathetics. 
 
 Azoospermatism, an absence of spermatozoa in the 
 semen, results from secretory disablement of the tes- 
 ticles. Absolute azoosperma is a rare condition, re- 
 quiring complete disablement of both testes, but 
 comparative azoosperma is not infrequent, consist- 
 ing of a diminution in number or activity of sperma- 
 tozoa. It is seen in malignancy of the testicle, 
 orchitis, syphilis, tuberculosis, and sexual exhaustion 
 from excessive coitus. Its effect is of course total or 
 relative sterility. 
 
 The Vas Deferens carries the spermatozoa from 
 the testicles as fast as they are produced, to the 
 seminal vescicles. 
 
 Azoospermatism is sometimes seen in conditions 
 which impair the potulency of the vasa deferentia, 
 
198 FUNCTIONAL DIAGNOSIS 
 
 preventing the passage of the spermatozoa into the 
 
 vescicles. 
 
 V *U *m 
 
 The Seminal Vescicles fulfill two offices. They 
 serve as reservoirs for the spermatozoa, and their 
 mucous lining secretes a fluid which is mixed with 
 the spermatozoa. The specific influence of this se- 
 cretion is unknown, but it serves at all events to in- 
 crease the motility of the spermatozoa. 
 
 The Prostate and Cowper's Gland also contribute 
 to the constituency of the semen. The secretion of 
 the former, which consists chiefly of sodium chlorid, 
 dilutes the semen and decreases its consistency, thus 
 rendering it very motile. 
 
 In Seminal Vesciculitis, especially of the chronic 
 type, the walls of the vescicles frequently become 
 adherent, and the spermatozoa are unable to pass 
 out into the semen. Such a condition of course pro- 
 duces asperma and sterility. 
 
 Prostatitis, especially when chronic, often results 
 in sterility, due to the absence of prostate fluid, and 
 consequent immotility of the spermatozoa. This 
 condition of the semen is known as colloid semen. 
 
 ■U *m "1« 
 
 The Semen is a mixed product, consisting of se- 
 cretions of the testes, vasa defer entia, vesiciculae, 
 seminates, prostate, and Cowper's gland. It is a 
 whitish viscid fluid, alkaline in reaction, specific 
 
 gravity of about , and having a characteristic 
 
 odor. It contains water and sodium chlorid (the 
 
FUNCTIONAL DIAGNOSIS 199 
 
 greater bulk) nuclein, protanin, proteid, lecithin, 
 cholesterin, fat, and inorganic salts. 
 
 The Ovary is the essential female organ of ovula- 
 tion. In it the ovum is developed, from the Graafian 
 follicle. As the ovum grows the follicle is forced to 
 the surface and the circulation at the point of ten- 
 sion is cut off, producing necrotic changes, until the 
 follicle finally bursts and liberates the ovum. The 
 cavity thus left is filled with a yellow filtration 
 liquid and is known as the corpus luteum. The life of 
 the corpus luteum is about three weeks, except 
 when the liberated ovum is fertilized, under which 
 circumstance it is not absorbed for several months 
 (corpus luteum of pregnancy). 
 
 Like the ovulation of the male, ovarian activity 
 begins with puberty and lasts until forty or forty- 
 five years of age, at which time the sexual life of the 
 female ends. 
 
 Absolute Sterility, such as occurs in the male in 
 the absence of the testical secretion, occurs in the 
 female in total disability of both ovaries. Fortun- 
 ately such a condition is exceedingly rare, and is 
 only found in such uncommon cases as bilateral 
 ovarian cysts, ovarian atrophy and profound consti- 
 tutional diseases in which the ovarian vascularity 
 suffers in common with the other organs. 
 
 As in the case of the male, however, sterility from 
 complete suppression of ovulation is extremely rare. 
 
 Excessive Ovulation results from a hyperemic 
 
200 FUNCTIONAL DIAGNOSIS 
 
 state of the ovary, such as is induced by frequent 
 coitus, ovaritis, and any form of pelvic congestion. 
 In such cases the vitality of the rapidly matured 
 ovum is below par, so that the net result of such 
 conditions is diminished fertility, or relative sterility. 
 Premature Menopause is induced by those condi- 
 tions which unduly increase ovulation, owing to the 
 
 rapid exhaustion of ovarian vitality. 
 
 ■w i» ^ 
 
 The Fallopian Tubes receive the discharged ovum 
 from the ovary, and convey it by ciliary motion, in 
 a varying length of time, to the uterus. Evidence 
 tends to show that the ovum is not necessarily dis- 
 charged into the tube on the same side as the func- 
 tionating ovary, but is discharged into the pelvic 
 cavity and caught by the fimbriated extremities of 
 either tube, or may never reach the tube at all but be 
 disintegrated and absorbed in the abdominal cavity. 
 
 Sterility is more frequently due to disease of the 
 tubes than to all other causes combined. Any condi- 
 tion which impairs the integrity of the tubes nat- 
 urally hinders the passage of the ovum and prevents 
 its meeting with the male element. Conspicuous ex- 
 amples are seen in salpingitis, hydro- and pyo-sal- 
 pinx, and tubercular infiltrations of the tubes. 
 
 Ectopic Gestation of the abdominal type occa- 
 sionally occurs as the result of the failure of the 
 ovum to reach the tube, and the migration of a male 
 sperm-cell into the abdominal cavity, where the two 
 meet and fuse. 
 
FUNCTIONAL DIAGNOSIS 201 
 
 Menstruation is a periodic phenomenon in the fe- 
 male process of ovulation, in which the ovaries, fal- 
 lopian tubes, and uterus take an active part. There 
 can be little doubt that menstruation bears a sequen- 
 tial relation to the liberation of the ovum, the gen- 
 eral idea being that the growth of the Graafian fol- 
 licle furnishes in some way, a stimulus to increased 
 uterive metabolism. 
 
 The Process of Menstruation is divided by Howell 
 into four stages, as follows: (1) Period of growth, 
 five days, characterized by a rapid increase in the 
 uterine stroma, blood vessels, epithelium, etc. ; (2) 
 period of degeneration, four days, during which cap- 
 illary hemorrhage takes place and the epithelium is 
 degenerated and cast off; (3) period of regeneration, 
 seven days, during which the mucous membrane re- 
 turns to its normal condition; (4) period of rest, 
 twelve days, during which the endometrumi remains 
 quiescent. 
 
 The Rationale of Menstruation is undoubtedly that 
 of a preparation of the uterus for the reception of 
 the ovum, whether we adopt the view that the con- 
 gestion of the membrane constitutes the preparation 
 or the raw surface left by degeneration. 
 
 Amenorrhea is commonly understood to signify 
 simply a failure of the visible flow in the second pe- 
 riod of menstruation, and as such may result from 
 obstructive and anatomic causes. True functional 
 amenorrhea, however, is a failure of the whole proc- 
 
202 FUNCTIONAL DIAGNOSIS 
 
 ess, and usually depends upon (a) some constitu- 
 tional dyscrasia by which vascularity of the genera- 
 tive organs suffers with that of the other organs, or 
 (b) some local vaso-motor disturbance in the genera- 
 tive tract. 
 
 Of the former variety, anemia, tuberculosis, and 
 neurasthenia are frequent examples; of the latter 
 type, trauma, surgical shock, cold, etc. 
 
 Menorrhagia (excessive flow), on the other hand, 
 results from those conditions which increase uterine 
 congestion and metabolism, either systematically, as 
 in fevers, or locally, as in metritis, local malignancy, 
 and all forms of pelvic inflammation. 
 
 Dysmenorrhea, outside of those cases due to ana- 
 tomic anomalies, is comparatively rare. True func- 
 tional dysmenorrhea is usually due to a neurosis of 
 some kind, as neuralgia, neurasthenia, or hysteria. 
 
 Suspended Menstruation With No Other Signs of 
 Disturbed Health, especially in a woman who has 
 heretofore been regular, is almost infallibly indica- 
 tive of pregnancy. 
 
 Vicarious Menstruation. — Sometimes the mucous 
 membrane of the uterus fails to undergo degenera- 
 tion, and under the increased vascular tension the 
 capillaries in other parts of the body, such as the 
 breasts, stomach, lungs, nose, etc., breaks down in 
 hemorrhage. 
 
 Supplementary Menstruation occurs when the cap- 
 illaries of other organs break down in addition to 
 uterine disintegration. 
 
FUNCTIONAL DIAGNOSIS 203 
 
 FERTILIZATION. 
 
 Erection is an important, though not absolutely 
 essential, factor in fertilization because it facilitates 
 the entrance of the penis into the female vagina, and 
 the depositing there of the spermatozoa. It is ac- 
 complished by means of engorgement of the vessels 
 of the cavernous spaces of the erectile tissue, where- 
 by the penis is enlarged and rendered hard and 
 erect. 
 
 Innervation of Erection is mediated by the nervi 
 erigentes, composed of sympathetic fibres from the 
 sacral segments of the cord by way of the pelvic 
 plexus. The act is a reflex one, whose stimulus may 
 arise from the brain, as in the ease of erotic thoughts, 
 or from irritation of the sensory nerves of the testes, 
 urethra, or glans penis, and is effected through a 
 centre in the lumbar cord. Experiment shows that 
 the nature of the efferent impulse is a vaso-dilator 
 influence, but its precise rationale is obscure. 
 
 Impotence, as to erection, results from any condi- 
 tion which (a) interrupts the course of the reflex, or 
 (b) inhibits it from the higher centres. 
 
 The former conditions are found in all of those 
 spinal diseases which impair the integrity of the 
 lumbar centre, as tabes dorsalis, sclerosis myelitis, 
 and in all of those nervous diseases in which the 
 general reaction to stimulus is lowered, as neuras- 
 thenia, tuberculosis, diabetes, etc. 
 
204 FUNCTIONAL DIAGNOSIS 
 
 The latter type of impotence is generally known 
 as psychical impotence, and is seen in hysteria, mel- 
 ancholia, and neuroses of all kinds. 
 
 Priapism, on the other hand, arises from any state 
 which (a) renders the reflex abnormally sensitive, or 
 (b) stimulates the cerebral end of the tract. In the 
 former class are inflammatory spinal diseases, as 
 early myelitis, meningitis, spinal and cerebral hy- 
 peremia, and growths. In the latter class are manias, 
 epilepsies, hysteria, etc. 
 
 V •* V 
 
 Ejaculation is accomplished by a vigorous and 
 sudden contraction of the muscles of the vaso def- 
 erentia, seminal vescicles, perineum, and urethra, in 
 the sequence indicated, throwing the semen into the 
 female vagina. It is the last part played by the male 
 in the process of reproduction. 
 
 Innervation of Ejaculation is similar to that of 
 erection, is effected through the same spinal centre, 
 and stimulated by an intensification of the same pe- 
 ripheral stimuli. It is, however, rarely precipitated 
 by direct cerebral stimulation, as erection is. 
 
 Impotence, as to ejaculation, depends in a general 
 way, upon essentially the same functional disturb- 
 ances as failure of erection, and the classification 
 under that head may be accepted as applying to this 
 process. It may be said, however, that this faculty 
 fails earlier than that of erection; and to other 
 causes must of course be added those conditions in 
 which no semen is secreted. The latter, however, do 
 
FUNCTIONAL DIAGNOSIS 205 
 
 not of themselves really influence the functional per- 
 formance of ejaculation, as the reflex takes place 
 even though no fluid is ejaculated. 
 
 Premature Ejaculation and Emissions occur under 
 the same conditions as those enumerated under pri- 
 apism, q. v. 
 
 ■W "W V 
 
 Impregnation of the ovum by the spermatozoon 
 takes place usually in the Fallopian tube. The prob- 
 ability is that the ovum exerts a chemotaxic attrac- 
 tion for the spermatozoon within certain limits of 
 distance. The minute nature of the impregnating 
 process belongs to the science of embryology, and 
 will not be discussed here. 
 
 Infecundity, due to impaired integrity of the 
 tubes, is, as already stated, far more frequent than 
 from any cause. Any condition which renders the 
 tube impassable and prevents the passage of the 
 male spermatozoon is fatal of course to impregna- 
 tion. Such • conditions are found in the plastic ad- 
 hesions caused by salpingitis (especially gonorrheal), 
 tubal tuberculosis, and in pyo-, hydro-, and hemato- 
 salpinx. 
 
 Tubal Pregnancy. — In some instances the impair- 
 ment of the tubes, although not sufficient to hinder 
 the passage of the spermatozoon, is enough to pre- 
 vent the fertilized ovum from passing down into the 
 uterus, in which case it remains in the tube and 
 there develops into a fetus. This is known as tubal 
 ectopic pregnancy. 
 
206 FUNCTIONAL DIAGNOSIS 
 
 GESTATION. 
 
 The Uterus is the essential organ of gestation. 
 The fertilized ovum attaches itself to the decidual 
 membrane furnished by the menstrual process, and 
 develops into the fetus. Thereafter the menstrual 
 cycle is suspended until gestation is completed and 
 the uterus emptied of its contents. 
 
 The uterus enlarges with the growth of the fetus, 
 and at about four months of pregnancy, becoming 
 too large for continence by the pelvis, it rises into 
 the abdominal cavity. 
 
 Incapacity for Gestation may arise from any con- 
 dition of the uterus which renders it unfit for the 
 attachment of the placenta. Such incapacity usually 
 results from either an anemic and poorly nourished 
 state of the uterus, or in constitutional diseases, ma- 
 lignancy, anemia, or from the opposite condition of 
 hyperemia, as in metritis, endometritis, pelvic con- 
 gestion, tumors, etc. 
 
 Abortion due to the premature severing of the 
 ovum from the uterine wall often results from the 
 same causes as those just enumerated and for the 
 same reason. 
 
 -. ••• -m 
 
 The Placenta constitutes the vascular medium 
 through which nutritive material passes from the 
 maternal blood to the fetal, and waste products from 
 the fetal to the maternal, by the agency partly of 
 
FUNCTIONAL DIAGNOSIS 207 
 
 osmosis and diffusion, but chiefly, no doubt, of the 
 epithelial cells of the villi, of the placenta. The ma- 
 ternal and fetal blood do not come into actual con- 
 tact. 
 
 The metabolic exchanges thus effected include 
 practically the same as those of the independent or- 
 ganism, namely, proteids, carbohydrates, and oxy- 
 gen on the one hand, and nitrogenous wastes and 
 carbon dioxid on the other. 
 
 Vomiting of Pregnancy. — In the early weeks of 
 gestation the volume of maternal blood has not yet 
 adjusted itself to the increased demands upon it. 
 The consequence is an impoverished and toxic condi- 
 tion of the maternal blood which poisons and irri- 
 tates the nerve centres and causes nausea and vomit- 
 ing. "Morning Sickness" is the expression of a 
 cerebral anemia due to assuming the vertical posture 
 after sleep. 
 
 Death of the Fetus of course follows interruption 
 of the communication between the maternal and the 
 fetal organism — in other words, any impairment of 
 the integrity of the placenta. 
 
 Abortion, in the sense of premature termination 
 of gestation, occurs more frequently from placental 
 impairment than from any other cause outside of me- 
 chanical trauma. 
 
 Placental Impairment. — As the placenta is essen- 
 tially a vascular organ it is subject to all of the dis- 
 orders that affect other vascular organs. Such dis- 
 
208 FUNCTIONAL DIAGNOSIS 
 
 orders may be (a) of a constitutional nature, affect- 
 ing the placenta in common with the rest of the or- 
 ganism, or (b) local in character, peculiar to the 
 placenta. Of the former syphilis is by far the most 
 common offender; tuberculosis, malignancy, dia- 
 betes, nephritis, toxemia (of any kind), all of which 
 degenerate the placental tissues ; in the latter variety 
 are included embolism, thrombosis, and apoplexy, of 
 the placenta, hydatid pregnancy, infarctions, calca- 
 reous and fatty degenerations^ etc. 
 
 Infection may pass in either direction, from 
 mother to fetus or from fetus to mother, through the 
 placental medium. In this way syphilis, tuberculosis 
 and other infectious diseases are frequently trans- 
 mitted. 
 
 Malnutrition. — Those placental conditions cited as 
 causes of fetal death commonly are not sufficient to 
 kill the fetus but result in its insufficient or vitiated 
 nutrition. 
 
 •m "W "fa 
 
 The Mammary Glands during gestation exhibit 
 considerable growth and activity in their true gland- 
 ular structure, and in the latter part of pregnancy 
 secrete a scanty fluid known as colostrum. 
 
FUNCTIONAL DIAGNOSIS 209 
 
 PARTURITION. 
 
 Muscular Contractions of the uterus occur spon- 
 taneously about 280 days after conception, and con- 
 tinue periodically at varying intervals of twenty 
 minutes at the beginning to one minute at the last, 
 until the fetus is expelled. The contractions are 
 confined to the upper part of the uterus, the lower 
 walls offering no resistance to the expulsive disten- 
 sion ; a detailed account of the process of parturition 
 belongs to a study of obstetrics, and will not be con- 
 sidered here. 
 
 Protracted and Precipitated Labor are the two op- 
 posite deflections from the normal process, depend- 
 ing upon a disturbance of the normal balance be- 
 tween the uterine forces and the dimensions of the 
 fetus. 
 
 Protracted Labor is due either to a subnormal 
 character of uterine contractions, or to a super-nor- 
 mal size of the fetus. The former is known as uter- 
 ine inertia, and is seen in all conditions of poor con- 
 stitutional health, and in myoma of the uterine 
 walls, due to tumors, fatty degeneration, anemia, 
 tuberculosis, etc. 
 
 Precipitate Labor results from either abnormally 
 powerful uterine contractions or an abnormally 
 small fetus, usually the latter. 
 
 Obstructive and anatomic causes of dystocia are 
 
2 K) FUNCTIONAL DIAGNOSIS 
 
 not functional in their nature and will not be dis- 
 cussed here. 
 
 1. Si -U 
 
 Innervation of Parturition is a matter of some ob- 
 scurity. Undoubtedly it is a reflex phenomenon 
 whose afferent stimulus is furnished in some way by 
 the resultant conditions attendant upon a matured 
 fetus, but the precise modus operandi of this stimu- 
 lus is unknown. Experiment shows that the reflex 
 is independent of the cerebro-spinal centres, al- 
 though it is well known that the process is influ- 
 enced, and may even be inaugurated, through these 
 centres. 
 
 Premature Parturition (Abortion) results, outside 
 of trauma and physical accidents, from any condi- 
 tion which sets in motion the stimulus above referred 
 to before the fetus is matured. Until more is defi- 
 nitely known of the nature of that stimulus, little 
 can be predicated about its premature excitation. 
 
 Accepting the theory that the normally matured 
 fetus acts as an independent foreign body in the 
 uterus, then any condition which renders the fetus 
 an independent foreign body — in other words, any- 
 thing which terminates the physiological union of 
 mother and fetus causes expulsion. Among such con- 
 ditions are constitutional disease, causing placental 
 degeneration, hyperemia of the pelvis from exercise 
 or coitus, placental apoplexy. 
 
 Mental Shock may also start premature contrac- 
 tions through the cerebro-spinal tract. 
 
FUNCTIONAL DIAGNOSIS '211 
 
 LACTATION. 
 
 The Breasts, immediately after delivery, secrete 
 an abundant supply of milk, and continue to do so, 
 under normal conditions and within certain limits, 
 as long as the child is kept at the breast. 
 
 Innervation of Lactation, like that of parturition, 
 is obscure. The breasts are physiologically connect- 
 ed with the uterus and ovaries, and undoubtedly re- 
 ceive specific nerve stimuli both from the process of 
 ovulation and parturition, but the precise mechanism 
 of these stimuli is at present unknown. Like the 
 process of parturition, lactation is directly influ- 
 enced through the cerebro-spinal centres. 
 
 Agalactia, absence of milk, in its complete form, 
 is extremely rare, but relative agalactia is not un- 
 common, depending, of course, on either a disability 
 of the glands themselves, as in malignancy, anemia 
 (lack of vascular nourishment), diabetes, tubercu- 
 losis, syphilis (lack of cellular nutriment) and mas- 
 titis; or to impairment of the nervous mechanism, as 
 in anomalies of the uterus and ovaries (perverted 
 stimulus), and more frequently in mental disturb- 
 ances such as melancholia, neurasthenia, hysteria, 
 shock. 
 
 Polylactia, an excess of milk, is very common, 
 and results from any condition which (a) increases 
 the flow of blood to the breasts, or (b) overstimu- 
 lates the nervous mechanism. In the former class 
 
212 FUNCTIONAL DIAGNOSIS 
 
 are mastitis, vaso-motor disturbances, etc., in the 
 latter metritis, ovaritis and psychic influences. 
 
 Premature Lactation is precipitated by a prema- 
 ture consummation of the physiological conditions 
 which normally mature at parturition. It usually 
 indicates premature separation of the fetus from 
 physiological dependence upon the mother, hence 
 fetal death. 
 
 v "W ^ 
 
 The Milk has an average composition as follows : 
 Proteids, 1 to 2 per cent ; fats, 3 to 4 per cent ; sugar, 
 6 to 7 per cent ; salts, .01 to .02 per cent. There are 
 also negligible quantities of nitrogen, urea, creatin, 
 lecithin, cholesterin, etc. The bulk of the proteids 
 are in the form of casein. This and the milk sugar 
 are true secretory products of the mammary glands, 
 as neither preexists in the maternal blood. 
 
 Infant Feeding must be based upon the normal 
 composition of human milk, as that must be regard- 
 ed as the ideal supply of the infant's nutritional 
 needs. 
 
 Abnormal Proportions of the constituents of the 
 milk occurs in cases where the maternal metabolism 
 exhibits corresponding inequalities. Thus when pro- 
 teid metabloism predominates the proteids in the 
 milk are high, and vice versa. 
 
 Abnormal Proportions of the constituents of the 
 milk are seen in cases where the maternal metabolic 
 balance exhibits corresponding inequalities. Thus, 
 
INDEX 
 
 Accommodation, 176. 
 Acidosis, 97. 
 Albuminuria, 117. 
 Anemia, 43. 
 Auditory center, 191. 
 
 — nerve, The, 190. 
 
 Bile, The, 107. 
 
 — acids, 109. 
 
 — function of the, 111. 
 
 — innervation of, 110. 
 
 — pigments, 109. 
 Biliousness, 109. 
 Blood, The, 41. 
 
 — coagulation of, 49. 
 
 — metabolism of, 45. 
 
 — pressure, 52. 
 
 — pressure, high, 56. 
 
 — pressure, low, 56. 
 
 — pressure, systemic, 74. 
 
 — pressure, varieties in, 54. 
 
 — red corpuscles of the, 41. 
 
 — transfusion of, 44. 
 
 — velocity of the, 49. 
 
 — velocity, variations in, 54. 
 
 — white corpuscles of the, 
 47. 
 
 Breasts, The, 211. 
 Breathing, bronchial, 10. 
 
 — Cheyne-Stokes, 58. 
 
 — rapid in fevers, 23. 
 
 — rapid, shallow, 19. 
 
 — stridulous, 11. 
 
 — types of, 18. 
 
 — vescicular, 11. 
 
 — sounds, suppressed, 12. 
 Bulbar centers, 157. 
 
 Cardiac cycle, The, 71. 
 Cerebellum, The, 161. 
 
 — sensory, information of 
 the," 161. 
 
 Cerebral localization, 167. 
 
 — paralysis, 167. 
 Cerebrum, functions of the, 
 
 165. 
 Circulation, The, 40. 
 Color-perception, 184. 
 Co-ordination, mechanism 
 
 of,, 163. 
 Coughing, 27. 
 
 Decarbonization, insufficient, 
 
 33. 
 Defecation, innervation of, 
 
 132. 
 
 — mechanism of, 131. 
 Degeneration, Wallerian, 
 
 138. 
 Deglutition, 83. 
 
 — innervation of, 86. 
 Digestion, lipase, 105. 
 
 — pancreatic diastase, 105. 
 
 — pepsin, etc., 96, 
 
 — rennin, 96. 
 
 — trypsin, 104. 
 
 Ejaculation, 204. 
 
 — innervation of, 204. 
 
 Emphysema, 25. 
 
 Eustachian tube, The, 187. 
 
 Erection, 203. 
 
 Expiration, 14. 
 
 — • delayed, 14. 
 
 Eye, humors of the, 180. 
 
 Fallopian tubes, The, 200. 
 Feces, The, 134. 
 
 Gestation, 206. 
 
 Glycogen, formation of, 111. 
 
 — regulation of distribution 
 of, 114. 
 
 — regulation of formation 
 of, 113. 
 
INDEX 
 
 — of lower neurons, 142-3. 
 
 — special, 170. 
 
 — spinal, 147. 
 Parturition, 209. 
 
 — innervation of, 210. 
 Percussion, 13. 
 Placenta, The, 206. 
 Pneumothorax, 9. 
 Pons Varolii, The, 160. 
 Pressure C0 2 in respiration, 
 
 32. 
 
 — intrapulmonic, 25. 
 
 — intrathoracic, 25. 
 
 — nitrogen, in respiration, 
 33. 
 
 — oxygen, in respiration, 29. 
 
 — suction negative, 27. 
 Pupil, The, 178. 
 Pupillary reflex, 179. 
 Pulse, The, 58. 
 
 — abnormal, 58. 
 
 — velocity of the, 60. 
 
 — waves catacrotic, 61. 
 Reaction of degeneration, 
 
 173. 
 
 Respiration, internal, 33. 
 
 — variations in amplitude 
 of, 39. 
 
 — variations in frequency 
 of, 34. 
 
 — variations in rhythm of, 
 38. 
 
 Respiratory sounds, 9. 
 Retina, innervation of the, 
 181. 
 
 Saliva, The, 78. 
 
 — function of the, 83. 
 
 — innervation of, 80. 
 
 Salivary glands, 78- 
 Salivation, imperfect, 83. 
 Secretory impulses, 138. 
 Sensory impulses, 138. 
 Semen, The, 198. 
 Seminal vesicles, 198. 
 Smell, innervation of, 192. 
 
 — mechanism of, 192. 
 Spinal cord, The, 141. 
 
 — nerves, 143. 
 
 — reflexes, 151. 
 
 — roots, 143. 
 
 — tracts, 144. 
 
 Stomach, innervation of se- 
 cretions of the, 93. 
 
 — juice, 91. 
 
 — movements of the, 87. 
 
 — muscular innervation of 
 the, 90. 
 
 Taste, classification of, 195. 
 
 — innervation of, 195. 
 
 — mechanism of, 194. 
 Testicles, 197. 
 
 Urea, 124. 
 Uremia, 125. 
 
 Ureters, function of the, 
 125. 
 
 — innervation of the, 126. 
 Uterus, The, 206. 
 
 — muscular contractions of 
 the, 209. 
 
 Urine, The, 122. 
 
INDEX 
 
 — uses of, 112. 
 Glycosuria, 118. 
 Haemic murmurs, 70. 
 Hearing, innervation of, 187. 
 
 — muscular mechanism of, 
 187. 
 
 — tests for, 189. 
 
 Heart, changes in position 
 of the, 66. 
 
 — in pulmonary lesions, 69. 
 
 — inhibition of the, 76. 
 
 — nervous control of the, 
 76. 
 
 — beat, The, 63. 
 
 — beats, accentuation of 
 the, 70. 
 
 — beats, reduplication of 
 the, 71. 
 
 — block, 64. 
 
 — sounds, 67. 
 Hematuria, 118. 
 Hemoglobin, 42. 
 Hemolysis, 44. 
 Hemorrhage, repair of, 46. 
 Hiccough, 11. 
 
 Impregnation, 205. 
 Inco-ordination, 146. 
 Infant feeding, 212. 
 Inspiration, 14. 
 
 — forced, 15. 
 
 — mechanism of, 15. 
 
 — prolonged, 14. 
 
 — reflex, 19. 
 Intestinal absorption, 102. 
 
 — innervation, 99. 
 
 — movements, 98. 
 Iris, The, 178. 
 
 — innervation of the, 178. 
 
 Kidneys, innervation of the, 
 119. 
 
 — theories of secretion of 
 the, 116. 
 
 — vaso-motor regulation of 
 the, 120. 
 
 Lactation, 211. 
 
 — innervation of, 211. 
 Lens, crystalline, 180. 
 Leucocytosis, 48. 
 Litten's phenomenon, 17. 
 Lung sacs, 9. 
 
 Lungs, retractions in, 9. 
 
 — unequal of expansion of, 
 16. 
 
 Mastication, 78. 
 Medulla oblongata, The, 157. 
 Menstruation, 201. 
 Micturition, innervation of, 
 130. 
 
 — mechanism of, 127. 
 Milk, The, 212. 
 Motor impulses, 138. 
 Muscle sense, 145. 
 
 Narcosis COz, 34. 
 
 Nerve impulses, afferent and 
 
 efferent, 138. 
 Neuron doctrine, The, 137. 
 
 — afferent and efferent, 137. 
 
 — upper and lower, 142. 
 
 Ocular accommodation, 176. 
 
 — accommodation, innerva- 
 tion of, 177. 
 
 — convergence, 177. 
 
 — convergence, innervation 
 of, 177. 
 
 — movements, 175. 
 
 — muscle innervation, 175. 
 Ossicles, The, 188. 
 Optic Nerve, The, 183. 
 
 — tract, The, 183. 
 Ovary, The, 199. 
 Oxidation, insufficient, 31. 
 
 Pancreas, function of the, 
 103. 
 
 — innervation of the, 104. 
 Paralysis, cerebral, 166. 
 
 — differentiation of, 155. 
 
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