Animal Physiology: The Structure And Functions Of The Human Body | by John Cleland
The principal object of this book is to supply to readers previously unacquainted with anatomical details as complete an account as possible of the functions of the body. In doing this, the author has kept constantly in view the desire of the Publishers to supply the information required for the Advanced Course of the Directory of the Science and Art Department; and at the same time has sought to furnish to the junior student of medicine a compendium of physiology which may assist him in obtaining a clear idea of the principles of the science, and prepare him for the perusal of works of more elaborate character.
| Title | Animal Physiology: The Structure And Functions Of The Human Body |
| Author | John Cleland |
| Publisher | William Collins Sons, & Company |
| Year | 1874 |
| Copyright | 1874, William Collins Sons, & Company |
| Amazon | Animal Physiology, the Structure and Functions of the Human Body |
By John Cleland, M. D., F.R.S., Professor of anatomy and physiology in Queen's College, Galway.
Preface- Necessarily such a book is, to some extent, a compilation; but it is hoped that, in grouping of facts, and in directing the reader's mind to just conceptions and conclusions, this manual may be found ...
- Chapter I. Introduction. Functions Of Animals. Nucleated Corpuscles. 1. The World Around Us
- The World Around Us is divisible into the organic and inorganics worlds; the organic world including all bodies which either are or have been alive, and the inorganic comprising all others. Physiol...
- 4. The Organic World
- The Organic World is divisible into two kingdoms, the animal and the vegetable. The power of building up the complex molecules of organic matter from the separate elements, or such simple combinations...
- 5. The Functions Of Animals
- The Functions Of Animals may be enumerated as nutrition, reproduction, sensory functions, and movement. The first two of these, being equally characteristic of animals and vegetables, are sometimes te...
- 6. The Expression Living Parts Of Living Beings
- The Expression Living Parts Of Living Beings, has been already twice used, and will attract the student's attention to the fact that every part of the texture of the body does not equally exhibit the ...
- 7. Amoeba
- Amoeba is the name of a family of animals which are microscopically minute, and inhabit both salt and fresh water. They consist of a mass of protoplasm unlimited by any envelope, containing granules, ...
- 8. The Nucleated Corpuscles
- The Nucleated Corpuscles found in the textures of the higher animals present many varieties of appearance, but in their young and active condition they have this much resemblance to amoeba, that they ...
- 9. The Most Widely Distributed Texture In The Body
- The Most Widely Distributed Texture In The Body is that which is termed connective tissue. It is the substance which connects the integument everywhere with the deeper structures, and it makes partiti...
- 10. White Fibrous Tissue
- The term connective tissue is a very general one, and the varieties to which we have already referred are the homogeneous and areolar; but there are others which are more markedly fibrous, and constit...
- 11. Elastic Tissue
- Elastic Tissue occurs both in the form of fibres and thin homogeneous membranes. It gets its name from being highly extensible and resilient, and is most widely distributed in the fibrous form. In the...
- 12. Adipose Tissue
- Adipose Tissue is the term technically used for the fat of the body, because fat in its proper acceptation means a solid oil, such as tallow. Adipose tissue consists of a number of minute vesicles, va...
- Chapter III. The Skeleton
- 13. By the skeleton is meant the hard framework of the body. It consists of bones, cartilages, and ligaments. What is called the backbone, or, more properly, the vertebral or spinal column, may be ...
- 15. The Fifth Or Lowest Lumbar Vertebra
- The Fifth Or Lowest Lumbar Vertebra rests on the broad upper end of a curved wedge, the sacrum, which consists of five other vertebræ fused together in one bone; and at the lower and narrow end of thi...
- 16. The Thigh Bone Or Femur
- The Thigh Bone Or Femur corresponds with the humerus of the upper limb; in front of the knee is the patella or kneecap, which is a sesamoid bone or ossification within a tendon, and not at all corres...
- 17. The First And Second Cervical Vertebræ
- The First And Second Cervical Vertebræ are termed the atlas and axis, and are specially modified to facilitate movements of the head, which rests on them. The atlas, instead of presenting a body in fr...
- 18. The Skull
- The Skull consists of cranium and face. The cranium, or part enclosing the brain, is counted as having eight bones. But it is right that even a tyro should understand that various of these bones consi...
- 20. Peculiarities Of The Human Skeleton
- The most remarkable peculiarities of the skeleton of man, as compared with other animals, are connected with the maintenance of the erect posture. The foot has a broad sole, and is arched both from...
- 21. Skeletal Textures
- The textures found in the skeleton are bone, cartilage, and the fibrous tissues. The fibrous tissues have been already considered. Bone, which is the prevalent texture in the adult skeleton, makes its...
- 22. Bone
- Bone is a more complex tissue than cartilage; its complexity depending on the impermeability of its matrix to fluids, and the consequent necessity of canals for nutrition. The matrix consists two-thir...
- Bone. Continued
- 24. While cartilage is capable of rapid growth, as has been already stated, by multiplication of its corpuscles and expansion of its matrix, bony tissue is capable of very little expansion, and increa...
- 26. Mechanics Of The Skeleton
- By the contraction of muscles passing over joints and attached to bones, the parts of the skeleton are thrown into different positions, so that we are enabled to support ourselves in different attitud...
- Chapter IV. Muscles
- 29. The active element in which the force resides by which not only the bones and joints are set in motion, but likewise all the movements of the organs are accomplished, is called muscular fibre. ...
- 30. Striped Muscular Tissue
- Striped Muscular Tissue consists of very long fibres which, in their best developed varieties, approach of an inch in diameter. In most instances each fibre exhibits a delicate sheath or sarcolemma, w...
- 31. Unstriped Muscular Tissue
- Unstriped Muscular Tissue is often arranged in bands of indefinite length like the striped fibres; but even when this is the case, it consists of a series of elongated fusiform corpuscles varying usua...
- 32. New Muscular Fibres
- New Muscular Fibres of both the striped and unstriped variety, would appear to be capable of being developed from connective-tissue-corpuscles. In both varieties the connection with the nervous system...
- 33. Muscular Substance
- Muscular Substance consists in greater part of muscle-fibrin, a description of albuminoid material which, in the form in which it is found after death, is termed syntonin, and is distinguished from ot...
- 37. Unstriped Muscle
- Unstriped Muscle is, for the most part, found diffused among the other tissues of organs, into the formation of which it enters, or lying in strata. Striped muscle, for the most part, is gathered into...
- Chapter V. Free Surfaces, Epithelium, Secretion, And Integument
- 38. The free surfaces to be noted in the study of the body are of three descriptions :— First, the external surface of the body is covered with integument. Secondly, the surfaces of hollows and ...
- 39. Epithelium
- All the free surfaces now alluded to agree in one point, namely, that they are clothed with one or more strata of nucleated corpuscles. Such investments are termed epithelium, and the corpuscles which...
- 40. Secretion
- It has been pointed out that epithelial cells are in some instances devoted to secretion, and it will be convenient in this place to explain the nature of that function. Secretion is the preparation a...
- 41. The Integument
- The integument combines the functions of protection, sensation, and secretion, and consists of two parts, the epidermis and the cutis vera. Fig. 37. Integument or Hand, vertical section magni...
- 42. The Cutis Vera, Derma, Corium, Or True Skin
- The Cutis Vera, Derma, Corium, Or True Skin, has a white fibrous basis. Its surface is thrown into papillae or finger-like prominences, the largest of which are about 1/100 of an inch in length. In th...
- 43. The Sensibility Of The Skin
- The Sensibility Of The Skin is due to the presence of nerve terminations, which are of different descriptions and at different depths. The largest of these are termed Pacinian bodies, and are especial...
- 44. The Glands Of The Skin
- The Glands Of The Skin are of two descriptions, the sudoriparous and the sebaceous. The sudoriparous, or sweat glands, are in great numbers all over the body. In the palm of the hand there are as m...
- 45. The Perspiration
- The Perspiration is the combined product of both sets of glands, but principally is derived from the sudoriparous. The sebaceous glands secrete nothing but oil, and they are not the exclusive source o...
- 46. Epidermal Appendages
- For purposes of protection there occur in different animals a variety of special growths from the cuticle; and those which occur in the human subject are nails and hairs. Fig. 39. Nail ah=nd ...
- 47. A Hair
- A Hair consists of a bulb or root imbedded in a follicle, and a shaft or stem ascending therefrom. The follicle is an invagination of the integument lined with a thin prolongation of the cuticle, divi...
- 48. The Shaft Of The Hair
- The Shaft Of The Hair is in some instances cylindrical, and in others flattened, and the tendency to curling is connected with the form. Thus the straight hair of the North American Indian is cylindri...
- Chapter VI. Alimentation
- 49. It has been already mentioned that the tissues of the body are constantly parting with particles which enter into their composition, and are receiving new materials to replace what is lost. We hav...
- Chapter VII. Digestion
- 52. The food is received into the digestive or alimentary tube; there it is subjected to a series of agencies by which it is in greater or less part digested or reduced to a condition in which it can ...
- 53. The Teeth
- Under this term, in its widest signification, may be included all hard structures for the trituration of the food; and these are of many different kinds, and found in different positions. In certain m...
- 64. Dentine
- Dentine has a matrix yielding gelatin, and impregnated with mineral matter in slightly greater proportion than bone; but, instead of lacunæ, it contains a multitude of closely set tubes, which radiate...
- 56. The Milk Teeth
- The Milk Teeth are twenty in number, namely, two incisors, a canine or eye tooth, and two molars, on each side in the upper and the lower jaw. The permanent teeth are thirty-two in number, namely:—inc...
- 58. Course Of The Ingesta
- The mouth, or buccal cavity, as it is technically called to distinguish it from the opening of the lips, is walled in by voluntary muscles of the face; within the arches of teeth it has the tongue in ...
- 60. The Lower End Of The Aesophagus
- The Lower End Of The Aesophagus, a little to the left of the middle line, pierces the diaphragm, as the arched muscular partition is called which separates the thoracic from the abdominal cavity, and ...
- 61. The Stomach
- The Stomach is succeeded by the small intestine, a tube about twenty feet long, and having a breadth of about an inch and a half at the commencement, and an inch at its termination. For about the firs...
- 62. The Large Intestine
- The Large Intestine is about five or six feet long. It begins in a short cul-de-sac, the caecum (caput caecum coli), below the entrance of the ileum; and into the extremity of this there opens a small...
- 64. The Form Of Digestive Tube
- The Form Of Digestive Tube, which has been briefly described, is that which is found in the human subject, but there is great variety in different animals. In certain fishes, the pipe fishes and other...
- 65. Digestive Fluids
- The first substance added to the food is the saliva, which is furnished by three pairs of compound sacculated or lobulated glands—the parotid, the submaxillary, and the sublingual. The parotid gland i...
- 67. The Mucous Membrane Of The Stomach
- The Mucous Membrane Of The Stomach, by which the gastric juice is secreted, is thick, soft, and smooth. Looked at under the microscope, the surface is seen to be thrown into shallow pits, into each of...
- 69. The Pancreas
- The Pancreas is a large lobulated gland, about eight inches long and one inch and a half broad, not unlike the salivary glands in appearance, and sometimes called by the Germans the abdominal salivary...
- 70. The Action Of The Fluid Secreted By The Lieberkuhnian Follicles
- The Action Of The Fluid Secreted By The Lieberkuhnian Follicles (succus intestinalis), has been examined by gathering it from the intestines of animals experimented on, and by other means. Like the pa...
- 72. The Great Intestine
- The Great Intestine has a smooth mucous membrane, with tubular follicles like those of the small intestine, but apparently having a different secretion. The details of the processes which take place i...
- Chapter VIII. The Blood
- 74. Having traced the process of digestion, it would be natural to pursue the history of the new supplies of nourishment after their entrance into the economy from the alimentary tube. It will be foun...
- 75. When Blood Flows From A Wound
- When Blood Flows From A Wound it speedily coagulates or runs into a clot. This depends on the presence of a spontaneously coagulable albuminoid substance, called fibrin, which, being diffused through ...
- 76. When Blood Is Examined Microscopically
- When Blood Is Examined Microscopically it is seen to contain two kinds of corpuscles, the coloured kind already alluded to, and a less numerous set of white corpuscles. The coloured or red corpuscl...
- 77. The White Or Colourless Corpuscles
- The White Or Colourless Corpuscles, also termed leucocytes, are spherical in form, larger than the red, being, in man, about 1/3000 inch in diameter, or more than that. They have a turbid or mottled a...
- 79. The Small Amount Of Fibrin In The Liquor Sanguinis
- The Small Amount Of Fibrin In The Liquor Sanguinis, compared with the quantity of albumen, will attract the student's attention. The proportion of fibrin present varies in different parts of the circu...
- 80. The Red Corpuscles
- The Red Corpuscles consist of a firm stroma with a substance in solution, which is partly composed of the paraglobulin already mentioned, but principally of a coloured substance, haemoglobin, which is...
- Chapter IX. Circulation
- 84. We have already had occasion to mention that the blood circulates through the body in a system of close vessels. It is propelled by the heart through the arteries to a fine capillary network, when...
- 85. The Heart In Mammals
- The Heart In Mammals, as will be seen from what has been said, is divisible into a right and a left part, each of which is comparable with a fish heart, consisting, as it does, of an auricle and a ven...
- 87. The Arterial Valves
- The Arterial Valves guarding the entrances into the pulmonary artery and aorta are named semilunar, because they consist each of three delicate pouches, with semilunar attachments to the wall of the a...
- 89. The Frequency Of The Heart's Pulsations
- The Frequency Of The Heart's Pulsations varies in health with different circumstances, but principally according to age. In infancy the beats are 120 or more per minute; in early life they quickly dim...
- 90. The Arteries
- The Arteries, into which the blood is sent by the heart, are a series of branching, elastic, and contractile tubes. They have a smooth internal lining, and externally have a tough felted coat of areol...
- 91. The Pulse In The Arteries
- The Pulse In The Arteries is caused by their distension and elongation under the pressure exerted by the rush of blood with each beat of the heart, but can only be felt in those positions in which an ...
- 92. The Capillaries
- The Capillaries are the smallest blood-vessels, those through the walls of which materials pass to and from the tissues, and so delicate that, as has already been pointed out, even blood corpuscles ar...
- 93. The Veins
- The Veins begin by radicles from the capillaries, in like manner as the arteries end in these vessels. The blood moves in them from the capillaries towards the heart, and their course on that account ...
- 94. The Pressure Or Force With Which The Blood Is Urged
- The Pressure Or Force With Which The Blood Is Urged on its course by the heart must not be confused with its velocity. The velocity is at its minimum in the capillaries; the pressure diminishes from q...
- 95. The Time Required For A Portion Of The Blood To Be Carried Through The Whole Circulation
- The Time Required For A Portion Of The Blood To Be Carried Through The Whole Circulation, has been made the subject of most interesting experiments. An easily detected substance, such as ferrocyanide ...
- 96. Portal System
- Before leaving the subject of the circulation, it remains to be pointed out that there are exceptions to the rule that the arteries continually divide till they reach the capillaries, and that the vei...
- 97. The Object Of Respiration
- The Object Of Respiration is to liberate the carbonic acid accumulated in the blood returning from the tissues, and to take in a fresh supply of oxygen, which, passing to the tissues, is used in chemi...
- 98. The Main Air Tube, The Trachea Or Windpipe
- The Main Air Tube, The Trachea Or Windpipe, is about four and a half inches long, and is surmounted by the larynx, the part in which the glottis is placed, and which constitutes the organ of voice. Th...
- 100. The Expansion And Diminution Of The Chest In Respiration
- The Expansion And Diminution Of The Chest In Respiration affects the whole thoracic cavity, containing the heart and great blood-vessels as well as the lungs. It may, therefore, rise and fall are comp...
- 102. The Muscles By Which The Ribs Are Moved
- The Muscles By Which The Ribs Are Movedare placed between them, forming two layers, sloped in opposite directions, and named the external and internal intercostal muscles.* In full inspiration muscles...
- 103. The Acts Of Inspiration
- The Acts Of Inspiration take place at a rate usually varying from fifteen to twenty per minute; but, like the pulsations of the heart, they are much more frequent in childhood, being above forty per m...
- 104. The Vital Capacity
- The Vital Capacity indicates the mobility of the walls of the chest, but by no means varies according to the dimensions of the cavity; for differences in the dimensions occur, irrespective of height, ...
- 105. The Atmosphere
- The Atmosphere which we breathe consists of 79 volumes of nitrogen with 21 of oxygen, containing in every 10,000 volumes four or five of carbonic acid. It further contains minute quantities of acciden...
- 106. The Volume Of Carbonic Acid
- The Volume Of Carbonic Acid contained in the expired air forms usually about 4 1/2 per cent of its bulk. The proportion is, however, variable. When respiration is rapid, the percentage of carbonic aci...
- 107. The Amount Of Oxygen Taken Into The Blood In Respiration
- The Amount Of Oxygen Taken Into The Blood In Respiration does not bear any constant proportion to the amount of carbonic acid given off; but it is generally somewhat greater, and is always so when the...
- 108. Gases Brought Into Contact
- Gases Brought Into Contact one with another tend to diffuse till they form a uniform mixture; and when two gases are separated by a membrane, they pass in opposite directions through it in definite pr...
- 111. Ventilation
- Ventilation has for its object the preservation, within buildings, of an atmosphere as free as possible from accumulation of carbonic acid, or any other impurity, by affording ingress to fresh air and...
- Chapter XI. Absorption
- 113. We have now to take into consideration the means by which the substance of the blood is replenished. This is effected by absorption, or the sucking up of material into vessels, partly from the al...
- 114. The Lymphatics
- The Lymphatics commence in very fine networks, and in interstitial spaces in the tissues; in some instances lined with exceedingly delicate epithelium, like the capillary blood-vessels, and in others ...
- 115. The Absorbents
- The Absorbents which come from the small intestine, although they in no way differ from the lymphatics of the rest of the body, are distinguished as lacteals. The distinction is unscientific, inasmuc...
- 118. The Passage Of Liquids Through Membranes
- The Passage Of Liquids Through Membranes is regulated by physical laws of diffusion, which are closely connected with capillary attraction. Just as gases diffuse according to definite laws, so also do...
- 119. The Difference In The Absorbing Power Of The Lacteals And The Blood Vessels
- The Difference In The Absorbing Power Of The Lacteals And The Blood Vessels has probably a considerable importance, dependent on the different courses taken by the two sets of vessels. The lacteals, w...
- Chapter XII. The Ductless Glands, The Liver, And The Kidneys
- In the preceding chapters we have so far traced the history of the blood, that we have seen how it is vitiated in the tissues and oxygenated in the lungs, and how it is replenished with material both ...
- 121. The Spleen
- The Spleen (figs. 57 and 78) is an organ engaged beyond all question in the elaboration of the blood, and however obscure the particulars of its function may be, there is at least more known about it ...
- 122. The Liver (Figs. 57 And 78)
- The liver is much the largest gland in the body, between 3 and 4 lbs. in weight, and of remarkable complexity, both of structure and function. Its most obvious function is to secrete bile; but the bil...
- Chapter XIII. The Nervous System
- 133. In the working of a nervous system in any animal, there are three sets of parts involved; namely, the nervous centre, the terminal organ, and the link of communication between the two, namely, th...
- 144. Structure Of The Encephalon
- The brain or encephalon, the portion of the cerebro-spinal axis contained within the cranium, consists of various parts to which different names are given. The part in continuity with the spinal cord,...
- 145. The Whole Of The Brain Above The Level Of The Tentorium
- The Whole Of The Brain Above The Level Of The Tentorium is included under the name of cerebrum, and is connected with the parts below by a neck or isthmus, in thickness about the size of a florin, whi...
- The Whole Of The Brain Above The Level Of The Tentorium. Continued
- 147. On the under surface, or base of the brain, the crura cerebri are crossed by two bands of fibres, which can be traced round the crura to the back parts of the optic thalami, and to the corpora qu...
- 150. Cranial Nerves (Fig 99)
- From the under surface of the brain, a number of nerves emerge which are termed cranial. They differ greatly among themselves, both in size and function, and are variously numbered by different anatom...
- 151. Functions Of The Encephalon
- The medulla oblongata is principally remarkable for its connection with respiration. Respiration is a reflex act in which a stimulus is apparently furnished by the unaerated blood, an impression is co...
- 153. The Cerebral Hemispheres
- The Cerebral Hemispheres are the parts of the brain connected with the higher operations of intelligence. The experiment just alluded to, as performed on fowls, can bo performed less easily on mammals...
- 156. The Most Moderate Exercise Of The Mental Faculties
- The Most Moderate Exercise Of The Mental Faculties, the mere continuance of consciousness, appears to involve exhaustion of the brain, and necessitates restoration of its vigour by sleep. Of the physi...
- 157. The Sympt Thetic System
- This is the portion of the nervous system by which the viscera are principally supplied. The primary part consists of two chains of ganglia, one on each side, in front of the vertebral column, called ...
- 158. The Vaso Motor Nerves, Or Nerves To The Arterioles
- The Vaso Motor Nerves, Or Nerves To The Arterioles, form an important part of the sympathetic system. When in action, they contract the muscular coats of the vessels, and limit the amount of blood to ...
- Chapter XV. The Senses
- The senses are five in number, namely, common sensation and the four special senses; and the special senses are naturally arranged in two pairs, taste and smell giving sensations of a simple kind, whi...
- 160. An Important Element In Delicacy Of Touch
- An Important Element In Delicacy Of Touch consists in the localization of the feeling excited by contact; and an attempt has been made to measure the degree of sensitiveness of different parts of the ...
- 162. Smell
- Smell, the sense by which we distinguish odours, is located within the nasal cavities, and depends on a simpler mechanism than any other of the special senses. The nasal cavities or fossæ extend fr...
- 164. The Olfactory Nerves
- The Olfactory Nerves consist each of a brush of filamerits of the soft and nucleated variety, and ramify beneath the mucous membrane of the upper and middle turbinated bones and the ethmoidal part of ...
- 165. Taste
- Taste is a sense which is closely allied to both common sensation and smell, and as it is less definite in its nature than the other special senses, so also it is dependent on a less definitely distin...
- 166. The Sensory Nerves Of The Tongue
- The Sensory Nerves Of The Tongue end in a variety of ways. End-bulbs (p. 68) are found in the papilla? close to their extremities. Also, on the frog's tongue, nerves have been traced into elongated ce...
- 168. Vision
- If by means of the eye we merely had a sensation varying in intensity according to the amount, and in character according to the colours of the light before us, vision would be a sense completely comp...
- 169. The Eyeball
- The Eyeball is a nearly spherical structure, about an inch in diameter, pierced at the back, at a point about a tenth of an inch internal to the centre, by the optic nerve, which, being in its sheath ...
- The Eyeball. Continued
- 171. In the course of dissection, let the choroid coat be gently torn open and raised from the subjacent structures. If this be done with due care, there will be seen laid over a globe of transparent ...
- 174. The Eye
- The Eye may be likened to a camera obscura, such as that which is used in photography. In front are the refractive media by which the inverted image is produced, while, behind, the retina receives tha...
- The Eye. Part 2
- It being clear that the layer of nerve fibres is not the part of the retina in which the rays of light produce nervous impression, it is curious to observe that the rays have to pierce these fibres an...
- The Eye. Part 3
- Another change which takes place in adjustment to short distances is lessening of the pupil; and it has been suggested that the contraction of the circular fibres of the iris presses on the sides of t...
- 181. Distance
- Distance, however, is a thing which the eye certainly learns to appreciate by experience. A child, from its entrance into the world, no doubt sees objects as things outside itself; but it learns only ...
- 182. The Appearances Of Solidity And Hollowness
- The Appearances Of Solidity And Hollowness depend partly on the apparent diminution of receding objects, partly on the way in which the light falls, and partly on the pictures presented to the two eye...
- 184. Colour Blindness
- Colour Blindness is of three sorts. Some persons have been found unable to appreciate any difference of colour at all, to whom the world was like an engraving. A number of persons have an inability to...
- 185. The Laws Which Regulate The Colours Of The Ocular Spectra
- The Laws Which Regulate The Colours Of The Ocular Spectra, above alluded to, are curious, and not so easily explained as we are often asked to believe. If a brightly-coloured object on a white ground ...
- 186. The Effects Of Pressure On Coloured Spectra
- The Effects Of Pressure On Coloured Spectra afford an interesting illustration of the fact that mechanical irritation of the retina produces a sense of light, and not of pain. I gaze on the flame of t...
- 187. Lachrymal Apparatus
- The secretion of tears is primarily useful for keeping the surface of the cornea clear, and, in connection with this object, there are channels provided by which they may be removed without unduly acc...
- 188. Hearing
- The simplest form of ear may be studied with advantage in the cuttlefishes, in which animals the organs of hearing are imbedded in a cartilaginous collar in the neck, and consist each of a sac supplie...
- 189. The External Ear
- The External Ear consists of two parts, the pinna and the canal. The pinna, or that part which is understood when the ear is spoken of as a feature, presents various named inequalities of surface. The...
- 190. The Middle Ear
- The Middle Ear, called also the cavity of the tympanum or drum, is a space of greater vertical height than the canal, and still more extensive from before backwards, but narrow transversely. At its fo...
- 191. The Tympanic Ossicles
- The Tympanic Ossicles, three in number, the malleus, incus, and stapes, make a communication between the membrana tympani and the internal ear. The ossicles termed malleus and incus, from a fancied re...
- 193. The Internal Ear
- The Internal Ear is imbedded in osseous tissue; and the cavity which it occupies, the osseous labyrinth, can be well studied in a macerated temporal bone. The petrous portion of the temporal bone is a...
- 194. The Cochlea
- The Cochlea is, in its early development, an outgrowth from the vestibule, and as it elongates it becomes spirally coiled, taking two complete turns and a half, tapering to its extremity, and acquirin...
- Chapter XVI. Voice And Speech
- 196. Voice The organ of voice is the larynx, a modification of the upper part of the trachea, consisting of a framework of cartilages, lined with mucous membrane, and moved on one another by ...
- 198. Speech
- Speech is to be carefully distinguished from voice. Voice without speech is an inarticulate sound; speech without voice is a whisper. Speech is accomplished by the modifying action of various organs o...
- 199. The Simplest Method Of Multiplication
- The Simplest Method Of Multiplication observed in any set of living bodies is by splitting up into different parts, each of which becomes a distinct individual. This is called multiplication by fissip...
- 202. The Ovum Or Egg
- The Ovum Or Egg, in birds and various other animals, is enlarged by the incorporation with it of a great amount of matter which does not undergo fertilization, useful only as material for the nourishm...
- 203. The Uterus Or Womb
- The Uterus Or Womb is a muscular organ placed, in ordinary circumstances, within the pelvis. It is a pear-shaped body about three inches long, flattened from before backwards, and connected with the a...
- 204. The Ovaries Of Persons Who Have Died In The Prime Of Life Present
- The Ovaries Of Persons Who Have Died In The Prime Of Life Present, scattered through their tough fibrous structure, and more or less distinctly seen from the surface, a variable number of clear vesicl...
- 207. The Embryo
- We have seen that after impregnation the contents of the ovum are converted, by the disappearance of the spermatozoa and germinal vesicle, and the cleavage of the yelk, into a mass of nucleated corpus...
- The Embryo. Continued
- 210. On each side of the chorda dorsalis, in the early embryo, the middle layer, except in the head, is divided into a part near the middle line called the dorsal plate, and a part beyond termed the ...
- 212. The Process Of Separation Of The Embryo From The Rest Of The Ovum
- The Process Of Separation Of The Embryo From The Rest Of The Ovum, so as to complete its visceral walls, is effected by the folding-in of the layers at the sides, by the prolongation backwards of the ...
- 214. The Heart
- The Heart is at first a straight tube which runs forwards towards the head, from the point where the omphalomesenteric veins unite. But it soon elongates so much that it is thrown into a loop, the pro...
- 217. The Period Of Gestation In The Human Species
- The Period Of Gestation In The Human Species is about two hundred and seventy days, but is undoubtedly liable to a certain amount of variation. Toward the end of that time, a great relaxation of parts...
- 219. Growth After Birth
- The proportions of the body of the new born infant are very different from those of the adult. The umbilicus is about the middle, the lower limbs and the chest are small, and the head, as compared wit...
- 220. Death
- The precise causes of diminished vitality in old age are not known; but it is worthy of note that the corpuscular elements of the tissues have each, apparently, a life of only limited duration, and th...
