An Introduction to physiology

Front matter

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Preface

I have written this hook with a distinct consciousness that physiology in a medical scliool is, in conjunction with anatomy, the introduction to medicine ami to surgery of Hwse wlw will be engaged in * general practice,^ atul I hope that the volume may be found to justify its title of * Human Physiology ' tvith reference to the position iliat the subject should occupy in medical education, as the junction to which anatomy, chemistry, and physics converge, and from which the principles of medicine and of surgery diverge.

Physiology does not consist in a knowledge of recondite phenomena, of difficult names, and of complicated instruments. It should fundamentally consist in the living mental jncture of what the great organs below a man^s skin are like, what they are doing, how they can be examined, wliat happens when they are not ivorking properly, how their actions hang together, how they may he influenced for good and for evil. But physiology, as it is written, contains more than this, and, in sparing measure, it is well that tlie * Institutes of Medicine ' should not be restricted to the visibly * useful,* or to the obviously * utilisahle.*

A short course of practical physiology is of the utmost value to the student of medicine, not merely because it puts into his liands the ineth^s of everyday medical chemistry and physics, but because it helps to correct that credulous bias or primitive * suggestibility * which is a physiological property of the human brain, and only too apt to be fostered by unmitigated bookwork. Practical physiology is the itulispensable adjuvant and corrective of book-physiology, because it brings words to the touchstone of physical instruments

Tiii PREFACE

and of chemical teats, because the conversion of phrases into facts gives measure of their relative valu€, and is at the same time an exercise of patience and of judgment — in short, because it is a rational discipline, as well as a useful technique.

Nor is this all. An acquaintance with at least the existence of frontier interests, and even a participation de tactu with science at its grmving surface, cannot be excluded from the laboratories of a medical school without serious and immediate loss to the interests of medicine and of surgery.

With regard to the plan of construction of this book. The chapter headings are intended to serve a double purpose : as a summary or syllabus — being, in fact, the condensed lecture-syllabus that I have tised during tJie last nine years; and as a means of self-examination. A student having read certain paragraphs or chapters, sliauld return to the cha^Her heading, and find by its recapitulation whether it contains expressions that are meaningless to him, or whether it recalls a series of ideas tlutt he has understood and assimilated. If an unfamiliar technical word is met with, its meaning should be ascertained at some otiierpart of the book, through the i7idex.

Certain subjects are more diffictdt than others ; some are more suitably studied during the first year, others during the second year ; others, again, are difficult and of practical importajice, some arc diffiadt and of scientific importance ; one subject may deserve days or weeks of study and require tho7'augh analytic treatment, ar be adapted to experimental demonstration ; others may be more lightly passed over. Detailed guidance in such matters will be supplied by the discretion of the teacher, and by the traditions current among examinees ; but in order to give some general guidance to the private reader, occasional use has been made of an asterisk in the chapter headings. In Part I. the sign has been freely used to indicate portions upon which a first-year student should not spend time if he should find the subject difficult. In Part II. the sign lias been sparingly used, to indicate portions of undoubted difficulty, which can be omitted by a second-year student who is not reading foi* the higher examinations. Subjects of unmistakable difficulty in Part II., such as the brain, vision, dc, have not been so marked, because

PREFACE IX

their great practical importance demands early and patient study from every student of medicine.

The descriptions of figures are to he regarded as forming jyart of the text 9 inasmuch as they frequently contain statements of fact that are not inclxuled in the text. The A2)2)endix contains matter that was felt to interfere with continuity of description in the main account of physiological phenomena.

I have given a Bibliography after some hesitatiofi, feeling that references to original papers are of no use to junior students, and must he too imperfect to he satisfactory to more advanced students. But doing so has allowed the text to he lightened of names, while preserving for the student who may inquire further the authorities for the principal statements made. Moreover, the chief use of a bibliography in a general text-hook is to afford a few main startingpoints and indications, to he followed up in the year-hooks and archives of a welUequipped lihrary ; and even for junior students, it ought to he of some assistance to know whether doctrines and statements date from last year or from last century. The year of publication has been given in each case, leaving the particular page of a particxdar paper to he looked up in the index of the journal to which reference has heen made.

The preparation if a new edition has given me the opportunity of making several corrections ; I have also made some alterations and transpositions of text that seemed to me to he desirable. Attention has been paid to recent work, but I have felt that the gradually-formed dei^osit of accepted knowledge must be of greater intrinsic value than the latest ' discovery ' or the newest theory. An early mental diet in which these items are predominant is an unwholesome diet ; their function in elementary instruction is that of condiments, valuable only in conjunction with a foundation of solid food, sening above all to teach that the * Institutes of Medicine * are not a museum of dead dicta, hut a living knowledge, of which the verbal fonnuhc are unstable — least unstable in the older strata, most unstable at the growing surface. I have therefore dcliherately abstained from mentioning many matters that I have heard of or read of, and such recent investigations as are mentioned I have, for

X PREFACE

the most part, either worked at myself or seen worked at by others,

I am indebted to many friends and fellow-students for informor- Hon and for criticism; to Dr. Mott and to Professor Sherrington re the spinal cord, to Professor Delepine re the liver, to Professors Halliburton and Wright re nucleo-albumins and coagidation.

A. D. W.

September, 1893.

PAET I

THE PHENOMENA OF NUTRITION

Introduction

PAGK

Chapter II The Blood

FUNCTION AND COMPOSITION . . ... . ,9

PHYSICAL PROPERTIES . . . . . . 10

MICROSCOPIC STRUCTURE . .11

CHEMICAL COMPOSITION . . . . 13

PLASMA AND SERUM; FIBRINOGEN AND FIBRIN . . .14

PLASMA, LYMPH, CHYLE AND SEROUS FLUIDS . . . . . 16

COAGULATION — FACTS AND THEORIES . . . .18

METHODS OF SEPARATING THE BLOOD-PROTEIDS . . . . 20

INFLUENCE OF THE VESSELS AND OF THE TISSUES UPON COAGULATION . 22

THE LIFE-HISTORY OF THE BLOOD-CORPUSCLES . . . . 24

THE BLOOD-GASES ........ 27

KLUMOGLOBIN — ITS COMPOUNDS AND DERIVATIVES . . . . 29

ARTERIAL BLOOD AND VENOUS BLOODS . . .85

ALTERATIONS OF THE BLOOD IN DISEASE . . . . 87

QUANTITY OF BLOOD IN THE BODY . . .88

TESTS FOR BLOOD . . . . . .89

CHAPTER III CIBCUIiATION flKNKRAL PRINCIPLES

PHYSIOLOGICAL ANATOMY OF THE HEART

EXAMINATION OF THE HUMAN HEART

42 46

Xll

CONTEXTS

BLOOD- PRESSURE AND BLOOD-FLOW .....

FURTHER PHYSICAL CONSIDERATIONS ....

THE PULSE ........

ON THE PROPERTIES AND MODE OF CONTRACTION OF CARDIAC MUSCLE DRUGS BY WHICH THE ACTION AlfD PROPERTIES OF THE HEART CAN BE

MODIFIED .......

INFLUENCE OF THE NERVOUS SYSTEM UPON THE HEART AND UPON THE

BLOOD-VESSELS ......

THE VAGUS ........

VASOMOTOR NERVES ......

THE LYMPH CIRCULATION ......

TAUK

55 60 80

99 102 107 115

Chapter IV Re8pibati0n

INTERNAL AND EXTERNAL RESPIRATION .

THE LUNGS AND THORAX ....

INSPIRATION AND EXPIRATION

TIDAL AIR, ETC. .....

COMPOSITION OF EXPIRED AIR; VENTILATION FREQUENCY AND DEPTH OF RESPIRATORY MOVEMENTS VARIATIONS OF RESPIRATORY ACTIVITY RESPIRATION OF MUSCLE ....

PARTIAL PRESSURES ....

INFLUENCE OF RESPIRATION UPON CIRCULATION CONTROL OF RESPIRATION BY THE NERVOUS SYSTEM BRONCHO-MOTOR ACTION OF VAGUS THE LARYNX .....

• •

. 118

-

. 123

. 124

. 127

. 132

. 139

. 144

. 149

. 152

. 154

Chapter V Digestion

THE DIGESTIVE MOVEMENTS THE DIGESTIVE FLUIDS :

I. SALIVA ....

CHANGES OF STRUCTURE CONSEQUENT SALTV^ARY NERVES II. GASTRIC JUICE

PEPSIN AND HYDROCHLORIC ACID ALBUMOSE AND PEPTONE .

III. BILE AND PANCREATIC JUICE .

INTESTINAL ABSORPTION GLYCOGENESIS ....

UPON SECRETION .

Chapter VI Benal Excretion

PAOK

THE KIDNEY ....

• •

. 221

THE URINE ....

• •

1 •

. 224

MECHANISM OF ITS SECRETION

• •

. 226

• • 1

•

. 281

ABNORMAL CONSTITUENTS .

• •

•

. 288

EXCRETORY ACTION OF THE LIVER

•

. 241

DIABETES .....

• •

. 248

* INTERNAL SECRETION '

• • •

•

CUTANEOUS EXCRETION

• •

Chapter VII Food, Nutrition And Excretion

FROM PROTEID TO UREA .....

FROM FAT AND CARBOHYDRATE TO CARBON DIOXIDE . THE BALANCE OF NUTRITION ....

THE NORMAL DIET OF MAN ....

CONSTRUCTION AND CALCULATION OF DIETARIES .

251 254 262

ANIMAL HEAT

PHYSICAL DATA

THERMOTAXIS

THE NORMAL HEAT-PRODUCTION OF MAN

THERMOMETRY AND CALORIMETRY .

278 288 284

XIV

PAKT II

THE PHENOMENA OF EXCITATION

NERVE

CLASSIFICATION. STRUCTURE AND COMPOSITION FUNCTION. EFFECTS OF SECTION TROPHIC ACTION OF NERVE-CELLS .

STIMULI .....

EFFECTS OF THE CONSTANT CURRENT ELECTROTONUS .....

THE TRANSMISSION OF NERVOUS IMPULSES FATIGUE .....

Chapter XI Animal Electricity

OALVANI. VOLT A. DU BOIS-REYMOND. HERMANN

THE ELECTROMOTIVE PROPERTIES OF MUSCLE AND NERMC

THE * CURRENT OF ACTION' ....

384 886

XV

I'AOK ELECTRICAL CHANGES CONNECTED WITH THE HEABT'S ACTION . . 389 ELECTRICAL CHANGES CONNECTED WITH GLANDULAR SECRETION AND

WITH RETINAL STIMULATION ..... 898 ELECTRICAL FISHES . . . . . . . . 896

Chapter XII Light And Vision

LIGHT. OPTICAL PRINCIPLES

COLOUR. THEORIES

THE EYE

THE SCHEMATIC EYE .

ACCOMMODATION

THE OPHTHALMOSCOPE .

FIELD OF VISION .

CORRESPONDING POINTS

DOUBLE VISION

MOVEMENTS OF THE EYEBALL

MO\'EMENTS OF THE IRIS .

RETINAL SHADOWS AND PHOSPHENES

OBJECTIVE EFFECTS OF LIGHT UPON THE RETINA

AFTER-IMAGES, POSITIVE AND NEGATHIS

CONTRAST, SIMULTANEOUS AND SUCCESSIVE •

RETINAL OSCILLATIONS

ANIMAL LUMINOSITY

PHYSICAL DATA ANATOMICAL DATA THEORIES .

Chapter XIII Sound And Hearing

OTHER SENSES

TASTE. SMELL. TOUCH. CUTANEOUS SENSATION

. 458

. 461 . 466

. 469

Chapter XIV The Spinal Cord And Bulb

EXPERIMENTAL, PATHO-

PHYSIOLOGICAL ANATOMY .

THE SPINAL CORD AS A CONDUCTOR .

PATHS OF MOTOR AND OF SENSORY IMPULSES

LOGICAL AND EMBEYOLOGICAL DATA THE SPINAL CORD AS A CENTRE ....

SPECIAL CENTRES OF THE CORD AND BULB .

EQUILIBRATION. THE SEMICIRCULAR CANALS THE CRANIAL NERVES: THEIR BULBAR NUCLEI THE SYMPATHETIC SYSTEM: ITS CONNECTION WITH THE CORD

XVI

Chapter XV The Brain General Plan Of Structure

THE hemispheres; the pyramidal tract .

CEREBRAL DEVELOPMENT AND INTELLIGENCE

THE BASAL GANGLIA*, THE CEREBELLUM

THE CORTEX CEREBRI ....

THE BLOOD-SUPPLY OF THE BRAIN THE FUNCTIONS OF THE BRAIN CORTICAL LOCALISATION OF FUNCTION. EXPERIMENTAL EXCITABILITY OF THE CORTEX ....

THE MOTOR AREA ; SENSORY ARK.«

EPILEPSY ......

APSASIA ..••..

THE REACTION TIME, oR * PERSONAL Ei^UATION ' . STIMULUS AND SENSATION

weight-discrimination; the muscular sense . contrast. illusions ..... fatigue. sleep. hypnosis

TAIJE

I. THE ORIGIN AND NUTRITION OF THE EMBRYO . . . 569

II. CONSTITUTIONAL FORMUL-*: OF SOME OF THE CHIEF PROXIMATE PRINCIPLES.©* CLASSIFICATION AND IDENTIFICATION OF PRO- TEIDS ......... 582

III, UNITS OF MEASUREMENT ...... 594

INDEX .

. . 597

. 615

PHYSIOLOGY