1 I 1 1 I 1 I THE LIBRARIES COLUMBIA UNIVERSITY HEALTH SCIENCES LIBRARY BHuafiggnuiiinjiifrtfgiiugnugniiiii 1 Digitized by tine Internet Arciiive in 2010 witii funding from Columbia University Libraries http://www.archive.org/details/textbookofanatomOObund ANATOMY AND PHYSIOLOGY FOR NURSES B U N D Y TEXT-BOOK OF ANATOMY AND PHYSIOLOGY FOR NURSES BY ELIZABETH R. BUNDY, M. D. MEMBER OP THE MEDICAL STAFF OP THE WOMAN's HOSPITAL OF PHILADELPHIA; GYNECOLOGIST NEW JERSEY TRAINING SCHOOL, VINELAND; FORMERLY ADJUNCT PROFESSOR OF ANATOMY, AND DEMONSTRATOR OF ANATOMY IN THE WOMAN's MEDICAL COLLEGE OF PENNSYLVANIA; FORMERLY SUPERINTENDENT OF CONNECTICUT TRAINING SCHOOL FOR NURSES NEW HAVEN, ETC. SECOND EDITION REVISED AND ENLARGED WITH A GLOSSARY AND 215 ILLUSTRATIONS 42 OF WHICH ARE PRINTED IN COLORS PHILADELPHIA P. BLAKISTON'S SON & CO 1012 WALNUT STREET 1913 PREFACE AND DEDICATION TO FIRST EDITION. The pupil-nurse in a training-school has very few hours at com- mand for the study of text-books, but it is hoped that she may find in this "Anatomy for Nurses" an aid to the acquirement of that knowledge of the human body which is essential to the full understanding of her important duties. In preparing a book of this kind, the inevitable difficulty of selection, when dealing with a subject of such magnitude, is at once manifest. What appears from one point of view to be of minor interest, is from another paramount in importance; while in truth, no detail is of itself insignificant. The author trusts that in the present work such matters as are not available for immediate use in the hospital ward may still be of value, to meet the growing need of the graduate-nurse as she finds herself developing with the practice of her profession. It was, in part, to meet this frequently expressed need that the work was undertaken. The old plan of systematic anatomy is followed, but the usual order of subjects is not strictly observed. For example, the descrip- tion of the blood-vessels is deferred until the student shall have become familiar with many of the organs from which a large number of vessels derive their names. The chapter entitled "Foods and Digestion" is introduced in response to a request. Concerning the use of anatomic terms, indications point to the general adoption of the nomenclature accepted by the German Anatomical Society at the meeting of 1895, ^^ Basle, Switzerland. The B. N. A., as it is called, will soon be in use among the younger physicians at least; therefore, many of the terms belonging to it are here introduced, and several tables are given which include names not found in the text. The author gratefully acknowledges her indebtedness to Dr. Marie L. Bauer for valuable aid in the preparation of the book, vii Vlll PREFACE AND DEDICATION TO FIRST EDITION. and to Drs. Frances C. Van Gasken and J. William McConnell for assistance in the reading of proofs and for helpful suggestions. The original illustrations, most of which are printed in colors, are drawn by Chas. F. Bauer. To the members of the nursing profession, with cherished recol- lections of labors and responsibilities shared, this Text-book of Anatomy is dedicated. Elizabeth R. Bundy. CONTENTS INTRODUCTORY. Page. Plan of study, anatomic terms; muscle, nerve, and connective tissues; epithelial tissues; serous and mucous membranes; processes included in metabolism of the body i CHAPTER I. BONE TISSUE AND BONE CLASSIFICATION. ARTICULATIONS. Chemical composition of bone; structure of osseous tissue; marrow; medullary and nutrient canals; shapes and surfaces; periosteum; ossification; divisions of the skeleton; joint movements; remarks 8 CHAPTER II. BONES AND ARTICULATIONS OF THE SKULL. Bones of the cranium; sutures and fontanelles; bones of the face; the mandibular joint; the skull as a whole; four larger fossae of the skull; the teeth; dentition; care of the teeth; clinical and obstetric notes i6 CHAPTER III. BONES AND ARTICULATIONS OF THE SPINAL COLUMN AND TRUNK The vertebra;; Hgamenta flava; ligamentum nucha; movements of spinal column; spinal curves; bones and articulations of the thorax; the pelvic girdle; sacra- sciatic ligaments; dorsal and ventral, or neural and visceral cavities; clinical and obstetric notes 35 CliAPTER IV. BONES AND ARTICULATIONS OF THE EXTREMITIES. Bones of the upper extremity; pronation and supination; bones of the lower extremity; patella; Y-ligament, crucial ligaments; arches of the foot; com- parison of extremities; articular nerves; clinical and surgical notes; special notes 50 CHAPTER V. COMPLETION, REPAIR AND PHYSIOLOGY OF BONES. Completion of long bones; the skeleton at different ages; bones in infancy; green- stick fracture; rachitis; spina bifida; process of repair; functions of bone tissues; surgical and special notes 70 ix X CONTENTS CHAPTER VI. THE CONNECTIVE TISSUE FRAMEWORK AND SKELETAL MUSCLE SYSTEM. Page. Fascia, deep and superficial; inguinal ligament; bursae; structure of muscles; tendon and aponeurosis; origin and insertion; muscles of expression, of neck and thorax; abdominal muscles and linea alba; sheath of rectus, semilunar and transverse lines. Diaphxagm.; surgical a.nd clinical notes; special points ... 75 CHAPTER VII. MUSCLES OF THE EXTREMITIES. Structure and action of muscles of upper extremity; axillary space; pronators and supinators; vaginal synovial membranes; annular ligaments; palmar fascia; muscles of lower extremity; popliteal space; annular ligaments; Physi- ology of muscle tissue; muscle tissue a source of heat and electricity; tetanus; cramp; fatigue; clinical notes; special points; classification by actions . 94 CHAPTER VIII. THE ORGANS OF DIGESTION. Alimentary tract or canal; glands of digestive apparatus; enzymes; saliva, alkaline; the stomach; gastric juice, acid; the intestine; intestinal fluids, alkaline; viUi; ileo-colic valve; cecum and appendix; rectum and anal sphincters; peristalsis; liver and gall bladder; bile; the porta; notes, clinical and surgical . 12a CHAPTER DC. FOODS AND DIGESTION. Four classes of foods in dietary; air as food; food combination; reasons for cooking food; Digestion, mechanical and chemical; mastication, insalivation ; gastric digestion (acid), chyme; intestinal digestion chyle; peristalsis; absorption; clinical notes 141 CHAPTER X. THE BLOOD AND CIRCULATORY ORGANS. Blood-corpuscles or cells. Erythrocytes and leucocytes; ameboid n;ovements, diapedesis;. plasma (alkaline); normal saline solution; coagulation; arteries, capillaries; veins; the heart; chambers and valves of heart; endocardium; systole and diastole; the pulse; pericardium; course of blood through the heart; surgical and clinical notes; important notes 152 CHAPTER XI. THE CIRCULATION AND PHYSIOLOGY OF THE BLOOD. Pulmonary vessels; aorta and branches; arteries of the head, of the upper extremity; palmar arches; thoracic, abdominal and pelvic arteries; arteries of the lower extremity; veins, deep and superficial; jugular veins; azygos veins; superior vena cava; inferior vena cava; portal circulation; fetal circulation; Physiology of blood; phagocytes; opsonic index; collateral circulation; clinical and surgical notes j5y CONTENTS XI CHAPTER XII. THE LYMPHATIC SYSTEM. Page, Lymph spaces, capillaries and vessels; lymph, origin; lymph glands or nodes; edema, effusion; thoracic duct; right lymphatic duct; principal nodes; the lymph stream; metastasis; summary of functions; c/jwica/ Mo/ej 194 CHAPTER XIII. THE RESPIRATORY ORGANS AND RESPIRATION. The respiratory tract; the nose, nares and choanse; the larynx; trachea, bronchi and bronchial tubes; ciliated epithelium; air cells; the lungs; the pleura; respiratory movements; respiration and heat production; modifications of breathing; clinical notes 202 CHAPTER XIV. THE KIDNEYS. THE SKIN. ELIMINATION. Structure of the kidney; the ureter; composition of urine; suppression of urine; retention of urine; structure of the skin; elasticity; glands; hair and nails; composition of perspiration; regulation of body temperature; clinical notes . 211 CH.\PTER XV. MAMMARY GLANDS. DUCTLESS GLANDS. GENERAL METABOLISM. Structure of mammary gland; milk; colostrum; mammary abscess; ductless glands and internal secretion; the spleen, structure and blood supply; leukemia; the pancreas, structure and blood supply; adrenals, adrenalin; thyroid body; cretinism; thymus body an infantile structure; secretion and secreting organs; excretion and excreting organs; animal heat, variations and regulation of tempeTa.tuie; clinical and practical notes 219 CHAPTER XVI. THE NERVE SYSTEM. Two divisions of the nerve system; the neuron, cell body and nerve fiber; cerebro- spinal division; gray and white nerve tissues; nerve centers; spinal cord and membranes; structure of spinal nerves; 5Mr^Jca/ and c/zwfca/ Mo/es 229 CHAPTER XVII. THE SPINAL NERVES. Anterior and posterior divisions; the cauda equina; cervical plexus, phrenic nerve; brachial plexus, radial, ulnar and median nerves; lumbar plexus, femoral nerve; sacral plexus, sciatic nerve; Physiology of spinal cord and sjiinal nerves; reflex action; co-ordination; electrical stimulus; points 0/ interest . . 235 XU CONTENTS CHAPTER XVIII. THE BRAIN AND CRANIAL NERVES. Page. Structure of brain, cortex and fibers; fissures; ganglia; internal capsule; cerebellum; medulla oblongata; pons; crura; ventricles of brain; membranes of brain; cranial nerves; Physiology of brain and cranial nerves; cerebral localization , surgical and clinical notes 249 CHAPTER XIX. THE SYMPATHETIC DIVISION OF THE NERVE SYSTEM. Vertebral ganglia; cardiac and splanchnic nerves; cardiac and celiac (solar) plexuses; semilunar ganglia; functions of sympathetic nerves; vasomotor and reflex, presiding over visceral action; Physiology of nerve system as a whole; important notes 262 CHAPTER XX. THE SPECIAL SENSES AND THE VOICE. General and special sensation; the sense of smell, olfactory region; the sense of touch, touch corpuscles; the sense of taste, taste buds; the sense of hearing, external ear and auditory canal; middle ear or tympanum and auditory tube; internal ear or labyrinth; the sense of sight; structure of eyeball; lacrimal gland; the voice; organs of the voice; organs of speech; vocal glands; clinical notes . 270 CHAPTER XXI. THE PELVIC ORGANS. The rectum; bladder; urethra; urethral caruncle; the prostate gland; the uterus; uterine or Fallopian tubes; the ovaries, ovulation; corpus luteum; menstrua- tion; the menopause; the vagina and infra-vaginal portion of cervix uteri; the pudendum; the perineum; the testes and spermatic cord; clinical and surgical notes ^ . . . , 283 CHAPTER XXII. A BRIEF STUDY OF IMPORTANT REGIONS. The head; the neck; thorax and thoracic viscera; abdomen, abdominal viscera and peritoneum; the ischio-rectal fossa; the axillary space; the ante-cubital space; Scarpa's triangle or the femoral trigone; Hunter's canal or the ad- ductor canal; the popliteal space; the inguinal rings and inguinal canal; the femoral rings and femoral canal; hernia; the extremities compared; review notes; points for compression of larger arteries of the body .; ... 292 CHAPTER XXIII. REFERENCE TABLES. The systemic arteries; names of systemic arteries and veins according to the B. N. A 311 Glossary 321 Index 331 ANATOMY AND PHYSIOLOGY FOR NURSES. INTRODUCTORY. Anatomy deals with the structure of the body in its different parts; physiology teaches the uses or ftmctions of those parts. Plan of Study. We shall study first the framework of the body — the bones which give support to all other structures, with the joints by which they are held together, either loosely or firmly; and the muscles by which they are moved and still further connected. Afterw^ard will be presented the organs or viscera (which are enclosed in the two general cavities formed by the bones and muscles) with their nerve supply, and the system of vessels by which the entire body receives its nutriment. We shall see that all these parts are wrapped in delicate connective tissue, and held in place by bands and sheaths of the same substance. The muscles are stretched upon the bones, the firm layers and partitions of deep fascia bind them in place, the wrapping of superficial fascia keeps them warm and flexible, and the skin or integument makes an elastic and sufficient covering for the whole. The study of the nerves by which these structures receive their stimulus, and the action and interaction of the various parts, will follow. The organs of the special senses receive attention, and the last section is devoted to a review of the several regions of the body which, it is hoped, will prove interesting and profitable. Anatomic Use of Terms. The anatomic position is that with the face toward the ob- server and the palms turned forward, and the terms anterior, posterior, I 2 ANATOMY AND PHYSIOLOGY FOR NURSES. right, left, etc., are to be understood with this position in mind. Thus, the anterior surface of the hand is always the palm; and, if we speak of any part as situated to the right we mean that it is nearer to the right side of the body which we are studying (which for convenience we will call the "subject"), but it has no relation whatever to the right side of the student. Of course the words superior and inferior are easily understood, but the use of the words medial and lateral (formerly internal and external) requires special mention. Imagine a line drawn through the middle of the head and trunk and striking the floor between the feet, thus dividing the body into right and left halves. This is called the median line. Any part or surface of one-half of the body is said to be medial to another part if it is nearer the median line while in the anatomic position, or lateral to another part if it is farther from the median line. All of these terms once applied to a part of the body belong to it always. For example, the little finger is always medial to the others and the great toe is likewise medial, because these relations are established once for all while the subject is in the anatomic position. Likewise, the palm is the anterior surface of the hand even if it be temporarily turned backward. The words exterior and interior are applied to the parts of the body which are on the surface or within, respectively. Proximal, means nearer to the head; distal, farther from the head. Thus we may speak of the proximal end of the finger, or the distal end of a toe, or the proximal end and distal end of an arm or a leg. TISSUES AND MEMBRANES OF THE BODY. The simplest form of living matter is protoplasm. A living cell may be nothing more than a definite quantity of protoplasm (called cytoplasm or bioplasm) or it may be more complex, having a nucleus^ when it is said to be nucleated, and it may have a nucleolus within the nucleus. A nucleated cell is capable of forming new cells by the division of its substance, the division always beginning in the nucleus. Sometimes the cell is enveloped by a thin membrane called the cell wall. TISSUES OF THE BODY 3 Tissue. — Any collection of cells held together by intercellular substance is a tissue. The various tissues of the body are composed of cells (and intercellular substance) which are developed in special ways; for example: Muscle tissue is composed largely of cells which are highly developed in the power to contract. Nerve tissue, of cells which are particularly sensitive to special kinds of stimulus. Connective tissue is the fibrous soft framework of the entire body— the connecting structure by means of which all of its parts are held together. (Fig. i.) Fig. I. — Connective-tissue Bundles of Various Thick- nesses OF THE Intermuscular Connective Tissue of Man. X 240. — (Stohr.) In super- posed layers Fig. 2. — ^Adipose Tissue. — (Stohr.) Under this heading are included the following varieties: Fibrmis tissue, a form of connective tissue containing slender white fibers, closely packed together. Areolar tissue, containing the same kind of fiber cells loosely woven into a network (often called cellular tissue). Adipose tissue, a variety of areolar tissue with cells containing fat. (Fig. 2.) Elastic tissue, a form of connective tissue containing many elastic fibers, pale yellow in color. (Fig. 3.) Osseous tissue, composed largely of cells having the power to utilize mineral substances of the blood in the formation ANATOMY AND PHYSIOLOGY FOR NURSES. of bone. (The intercellular substance is filled with min- eral matter.) (Figs. 6 and 7.) Cartilage, a form of connective tissue with firm white elastic substance (intercellular substance) between its cells. Fig. 3. /'x -Elastic Fibers. X 560. Very thick elastic fibers /, from ligamentum nuchse of ox; b, connective-tissue bundles. — (Stohr.) Many cartilages are covered with a thin membrane called perichondrium, similar to the periosteum of bones (see page 10). . The principal varieties are: Hyaline cartilage which has few cells and much intercellular substance. (Fig. 4.) WJtite fibro-cartilage which contains many white S- — fibers, giving to it additional strength. Yellow or elastic fibro-cartilage which contains elastic fibers giving additional elasticity. '^ Note. — Most bones are formed in cartilage. (See ^ _ Ossification page 11.) Fig. 4.^Hyaline t^.ii-i. Cartilage. Epithelial tissue forms the surface layers of the body both within and without. It is com- posed of layers of cells resting upon a base of the simplest possible substance, which holds the cells together and which bears vessels and nerves for their use. The form of epithelial cells varies with their location and use or function. (Fig. 5.) The epithelium of the exterior of the body is formed by flattened cdls, arranged in few or many layers according to the degree of EPITHELIAL TISSUES. ^ friction or pressure to which the skin of the part may be exposed. The covering thus formed varies therefore in thickness, from that of the deKcate covering of the lips to the tough sole of the foot. The epithelium of interior surfaces is quite different. Its cells may be flattened, spherical, cuboid or columnar in shape and it is always moist. Fig. 5. — Epithelial Cells of Rabbit, Isolated. X 560. i. Squamous cells (mucous membrane of mouth). 2. Columnar cells (corneal epithelium). 3. Columnar cells, with cuticular border 5, (intestinal epithelium). 4. Ciliated cells; h, cilia (bronchial epithelium). — (Stohr.) In the lining of the air passages the epithelial cells are ciliated, that is, they bear tiny hair-like projections of their substance called cilia, which are in con- stant waving motion, always in the same direction, sometimes slow, sometimes rapid. In the digestive organs the epithelial layer plays an important part in the formation of digestive fluids, and also in the absorption of digested food. In the lining of closed cavities it assists in the formation of the fluids which they contain (example, the pleura). Included under this heading are: Gland tissue, where a layer of cells has the power to form a special substance from the blood. {Adenoid tissue resembles gland tissue.) Mucous membranes, which line all interior surfaces to which air has access. Their special cells produce a clear thick fluid called mucus which keeps the surfaces moist. Serous membranes , which line the closed cavities of the body. They are themselves closed sacs containing a clear thin fluid called serum which prevents the surfaces from rubbing together. Synovial membranes, which line the interior of movable joints; they contain a thick fluid called synovia which like serum prevents friction. 6 ANATOMY AND PHYSIOLOGY FOR NURSES. The epithelial lining of the heart and blood-vessels, serous membranes, and lymph vessels, is called endothelium. Clinical notes. — Mucous membranes are w^ell supplied with blood-vessels and bleed freely when wounded, as seen in operations upon the nose and throat. An accumulation of serum in the large serous membrane of the abdomen causes the condition called ascites (a variety of dropsy). The processes of secretion and excretion are carried on through epitheHal cells. Secretion is the process of separating substances from the blood (generally in fluid form). Such substances if useful to the body are called secretions ; if they are waste matters to be thrown off or eliminated, they are called excretions. Secreting organs — mucous and serous membranes, all glands. Excreting organs— -hing^^ kidneys, liver, cutaneous glands. To summarize the functions of epithelial tissues — they are pro- tective, secretory, excretory, absorptive. An organic substance is a substance formed by living cells, whether they are single or arranged together in organs. Organic substances disappear in burning. An organ is any part of the body designed for a special function or use; it may be composed of several kinds of tissue. An organ in the interior of the body (internal organ) is called a viscus (pleural, viscera). Examples, heart, lungs. A system is composed of a number of organs of similar structure. Examples, the muscular system, the nervous system. An apparatus is composed of a number of organs of like or different structures, so arranged and associated that their action together will serve a special purpose. Example, the digestive apparatus. Metabolism. — ^This term is used to express in one word the related processes of building up and breaking down which are con- stantly going on in all living cells. The cell appropriates materials and combines them to perfect itself; in the exercise of its function it uses up some portion of its substance and so must be again built up, to be again pulled apart • — in endless repetition. Cell action in some tissues results principally in liberating heat and in hody movement, as in muscles. In others it forms new compounds for other cells to use — for example, the liver cells form glycogen; the gastric glands secrete METABOLISM. 7 gastric juice, etc. Again, certain cells combine waste matters to get them into shape for other organs to excrete, for example, the formation of iirea in the liver. In this way food materials are used for different purposes and worked over in different tissues until waste alone remains. These examples (and many more which might be given) illustrate the metabolism which is constantly taking place in the body. CHAPTER I. BONE TISSUE AND BONE CLASSIFICATION, ARTICULATIONS. 0) 2 His Bone tissue is conspicuously a hard tissue. This hardness is due to the mineral or inorganic substances which it contains. They are. mostly phosphate and car- bonate of lime and form two-thirds of the weight of an adult bone. The remaining one-third is composed of organic or animal substances, con- sisting of vessels, marrow, hone corpuscles, and gelatinous matter. The mineral portion alone may be seen in a bone which has been burned, thus destroying the organic substances. This leaves the bone still hard, but very brittle and easily crushed. The pale grayish color of a burned bone is noticeable, the result of the loss of all the marrow and blood which it contained before, and which gave it a pinkish tinge. The organic portion of a bone may be shown by immersing it in dilute hydrochloric acid for a few days. The mineral salts will be thus dis- solved out, leaving the flexible and elastic organic portion which still retains the shape of the bone. A long bone after the lime salts are removed in this way, is said to be decalcified, and may be bent and twisted, or even tied in a knot. By these experiments it i? seen that the mineral matter gives hardness to a bone, while the animal matter gives flexibility and elasticity. The proportions of the two kinds of substance vary at different ages. The bones of a child SectJon^ OT^A^ToNG ^^^ ^^^^ bccausc they have not enough mineral Bone.— (Testut.) matter to make them hard, while the bones of 0%^^i BONE TISSUE AND BONE CLASSIFICATION. 9 an aged person are brittle, because they no longer contain sufficient animal matter to keep them elastic. The hardest part of any bone is at its surface; it is white in color like ivory, and is called compact bone tissue. The deeper part is porous, and is therefore called spongy tissue (also named cancellous tissue, because its appearance suggests lattice work). (See Fig. 6.) Compact tissue is most abundant on the shafts of the long bones, which by their situation in the extremities are exposed to external violence, and therefore need especial strength for resistance. Since it is important that the bones be slender as well as strong, these two results are gained by packing the bone tissue as closely as possible. Cancellous tissue is more abundant in the parts of bones where extent of surface is desirable. For example, the enlarged extremities of long bones are composed of cancellous tissue covered with a thin Periosteum Outer ground lamellae Haversian canals Haversian lamellae Interstitial lamellas Inner ground lamellas Marrow Fig. 7. — From a Cross-Section of a ^SIetacarp of Man. X 50. The Haversian canals contain a little marrow (fat-cells). — (Stohr.; compact layer; thus they can give attachment to many tendons and ligaments, v/hile the spongy character of the bone prevents increase in weight. The marrow of bones is contained in the spaces of cancellous tissue, where it is thin and red, and in little canals running through the bone substance. Under the microscope may be seen small channels in the compact tissue called Haversian canals, which con- tain minute vessels and a little marrow. A large canal called the medullary canal runs in the shaft of each long bone, containing firm yellow marrow and larger vessels. lO ANATOMY AND PHYSIOLOGY FOR NURSES. Articular surface of bone is that portion which enters into the formation of a movable joint. It consists of a very compact tissue called the articular layer or articular lamella. Surface Markings of Bone. Any inequality of the surface of a bone, whether it be an elevation or depression, or an opening, is called a "marking." The most prominent elevations often occur where the muscles are attached to the periosteum (owing partly to the calcification of these attachments); and the greatest enlargements of bones are at their extremities, where they form important joints. A process is a decided projection; the larger processes are called tuberosities, small ones, tubercles. A spine is usually a long or a sharp projection. A crest is a prominent border; it may be rather broad. A condyle is a rounded articular eminence. A fossa is a depression or concavity. A foramen is a hole through a bone. Periosteum. There is no such thing as bare bone in the normal state; all bones are closely covered more or less completely with a strong fibrous membrane called periosteum. This membrane is essential to the life of the bone, because many blood-vessels which nourish it lie in the periosteum until they become divided into minute branches which then enter the bone tissue. The articular surface of bone is the only portion which is not covered with periosteum. A bruise of sufficient violence will so injure the periosteum that it no longer serves for the purpose of nutrition, and that area of bone immediately underneath the injured membrane dies from want of food, and becomes "dead bone" (the process is called necrosis). The sensation imparted by a probe which touches dead bone is that of roughness, and is distinctly different from the feeling of sound bone with its smooth covering of periosteum. A similar membrane called endosteum lines the canal in the shaft of long bones. It bears the "nutrient" artery which, in the cavity OSSIFICATION. II of the shaft, divides into two branches running in the endosteum toward the two extremities. The deep layers of the periosteum contain bone-forming cells. (See Ossification.) Classification of Bones According to Shape. According to differences of shape and arrangement of their tissue, bones are classified as long, short, flat, and irregular. A long bone has always a shaft of compact tissue, and two enlarged extremities of cancellous tissue with a thin compact covering. The shaft is hollow, containing yellow marrow, this cavity being called the medullary canal. A short bone has neither shaft nor extremity; it is composed of cancellous tissue with a thin com- pact covering. Aflat bone is arranged in layers, two of compact tissue with one of spongy or cancellous tissue be- tween them. An irregular bone conforms to no special defi- nition. Remarks. — In no part of anatomy is it more important that the student should learn the structures from the actual specimens than in the division called osteology. The bodies are to be studied, not the book. It is supposed that with the bone in the hand the student will use the book as a key, by means of which she will become acquainted with the names of its parts and their uses. The- habit of studying the human body itself rather than the description of it, cannot be too soon nor too firmly established. OSSIFICATION. Fig. 8. — Right Femur, Anterior, SHOWING Extremi- ties OR Epiphyses, AND Shaft or Di- APHYSis. — (Morris.) Ossification is the formation of bone from cartilage or membrane by the deposit of mineral substances, mostly salts of lime. Flat bones de- velop in membrane; others in cartilage. The deposit of mineral matter begins in small spots, forming centers of ossification which gradually increase in size until the entire bone is completed. Long bones have always three centers at first — one for the shaft, and one for each extremity — others appear- 12 ANATOMY AND PHYSIOLOGY FOR NURSES. ing later, at different dates. (The extremities are named epiphyses, the shaft being the diaphysis) (see Fig. 8). The principal parts of a bone are ossified separately, uniting wth each other after all are developed. Ossification begins before birth in all bones except the coccyx, those of the carpus, and four in the tarsus; but many bones remain in two or more pieces during childhood and youth. The periosteum of bone has an inner layer in which, also, the process of ossification goes on. Consequently, when it becomes necessary to remove a portion of bone, if it can be done without taking the periosteum away the bone will re-form. This has occurred many times, particularly in the case of the mandible. The nutrition of bone.— Bones have a free blood supply from a network of small arteries in the periosteum. One special artery, larger than the others, enters the nutrient canal which leads to the interior of the shaft (this vessel is called the nutrient artery). THE HUMAN SKELETON. The skeleton of the body comprises 200 bones, as follows: In the cranium 8 In the face 14 In the spinal column ■. . . 24 In the pelvis 4 In the upper extremities 64 In the lower extremities. 60 Ribs 24 Os hyoides i Sternum i These are joined together or articulated to form the hard, strong framework of the body — the natural skeleton. In addition to these, there are four bones in each ear called ossicles, or "little bones." According to their location in the body they are classified as follows : Bones of the Head and Neck, Trunk, Extremities. The bones of the head form the skull, which supports the face and the organs of special sense, and securely encloses the brain within its cavity. The bones of the neck connect the head with the trunk, and support the tongue and various other structures. THE HUMAN SKELETON. 13 The bones of the trunk assist to form a cavity, divisible into three portions — the thorax, the abdomen, and the pelvis. Tarsus Metatarsus 'halanges Fig. 9. — Bony Skeleton. — (Gould's Illustrated Dictionary.) The bones of the four extremities contribute the solidity and strength which are necessary for their uses in various positions of the body. 14 ANATOMY AND PHYSIOLOGY FOR NURSES. ARTICULATIONS (ARTHROSES). Articulations are formed when two or more bones are con- nected together, or when bone and cartilage are joined. They may be immovable, or movable. Immovable Joints (Synarthroses). In these the bones are held together firmly by fibrous tissue, sometimes by a thin layer of cartilage which becomes calcified in later life. The best examples of immovable joints are found in the skull, t . where the flat bones are joined at their edges, forming sutures. (See page i6, Fig. II.) Movable Joints (Diarthroses). In these the bones are not closely joined, but are loosely connected by ligaments which allow freedom of move- ment between the surfaces. They are best studied in the extremities, where all varieties of movable joints are found. The essential structures in a mova- ble joint are four in number: Articular hone, articular cartilage, ligaments, syno- vial membrane with synovia. The surfaces of bone which are to be connected together (articular surfaces) are made of a specially hard compact tissue called articular bone. It is smoother than other portions of the bone and easily recognized by the eye. It has no periosteum, but is covered by firm white hyaline cartilage — the articular cartilage. To hold the bones together, bands or cords of white fibrous tissue are provided, strong and flexible, but not elastic. They are called ligaments. The ligaments pass from one bone to the other on every side of the joint, like a capsule, completely enclosing it, and the capsule thus formed is lined by synovial membrane, so named because Fig. io. — Illustration Showing Essential S t r u c - TURES IN A Movable Joint (Diagrammatic.) ARTICULATIONS. I5 it secretes a fluid called synovia (the lubricating fluid or "joint- oil") which resembles in appearance the white of egg and prevents friction. The synovial membrane not only lines the capsule but is attached to the margins of the articular cartilages. Seven varieties of movement are allowed by these joints. They are: Flexion, or bending. Extension, or straightening. Rotation, or rolling. Circumduction, a free sweeping movement in a circle. Abduction, or moving away from a middle line. Adduction, or moving toward a middle line, Gliding (which explains itself). Movable joints are classified according to the movements of individual joints, or by peculiarities of structure. The most im- portant are the following: Class. Motions. Example. Hinge (ginglymus) Flexion and extension. . . . Elbow, Knee. Ball and socket (Enar- throsis). In all directions Shoulder, Hip. Pivot (Trochoides) Rotation within a ring. . . . Head of Radius. Rotation of ring around a pivot . . Atlas and axis. Arthrodia Gliding Carpal joints. There are other joints in which motion is so slight that they are not classed as movable, nor do they possess a cavity containing synovia. They have been well described by the term yielding. In these the bones are usually connected by fibro-cartflage discs. Examples are found in the joints of the pelvis (page 46) and in the spinal column (page 38). CHAPTER II. BONES AND ARTICULATIONS OF THE SKULL. The skull includes the cranium and face. BONES OF THE CRANIUM, 8. Frontal i Occipital I Temporal 2 Parietal 2 Ethmoid i Sphenoid i Frontal bone {os frontale). — In the anterior part of the skull, shaped like a cockle-shell, and consisting of the frontal part, or forehead, the two orbital parts, and the nasal part. The frontal GLABELLA, ANTERIOR NASAL SPINE PROSTHIO Fig. II. — The Skull. — (Gerrish.) part {squama frontalis) is flat in structure, and unites above with the parietal bones. This part is bounded below by a prominent border forming the two supraorbital margins. At the medial 16 BONES OF THE CRANIUM. 17 third of each margin is a supraorbital notch (sometimes foramen) for the supraorbital nerve, artery, and vein. Just above the margins are the superciliary arches, which bear the eyebrows and mark the position of spaces in the frontal bone called the fro^ital sinuses. These sinuses begin to develop at the age of seven years and grow larger as time advances. They communicate with the nose, and contain air. The smooth space between the eyebrows is the glabella. The nasal part is just below the glabella. The orbital parts (or plates) of the frontal bone are so called because they are in the roof of the orbits, or eye-sockets; the space between these parts is occupied by the ethmoid bone and is called the ethmoid notch. Just underneath the lateral part of the superior margin of the orbit is a small fossa (the lacrimal fossa), containing the lacrimal gland, where the tears are formed. At birth the frontal bone is in halves — right and left — which become united in early life. Occipital bone (os occipi- tale).— At the back of the skull and consisting of two portions: squamous (scale-shaped) and basal (Figs. II and 20). The squamous portion {squama occipitalis) is flat in structure, triangular in shape, and joined to the parietal bones. The most prominent point on the back of the skull is on this portion, and is called the occipital protuberance or inion. The basal portion bends forward, extending far enough toward the front to form the roof of the throat. This portion presents a large opening called the foramen magnum (or great foramen), which transmits the spinal cord. At the sides of the foramen magnum are two smooth prominences, called the occipital condyles, which rest upon the first bone of the spinal column, whereby the nodding movement of the head is permitted. The inner surface of this bone has broad grooves for the transverse sinuses (lateral sinuses); also one for the sagittal sinus (superior longitudinal sinus). 2 Fig. 12. — Frontal Boxe, showing that IT Originates in Halves. — (Alorris.) i8 ANATOMY AND PHYSIOLOGY FOR NURSES. Temporal bones (ossa temporales). — Right and left; situated at the sides and base of the skull. (See Figs, ii and 13.) Each temporal bone consists of four portions — the squamous, the mastoid, the petrous, and the tympanic. The squamous portion {squama temporalis) is fiat, and presents the zygomatic process in the form of a ridge running forward in front of the ear to the cheek. Below the beginning of this process is the canal leading into the ear and called the external auditory meatus \ just in front of that is the mandibular fossa, where the lower jaw- bone, or mandible, is joined to the temporal bone (Fig. 11). Fig. 13. — Pasietal, Temporal, and Sphenoid Bones; Posterior Aspect. I, Body of sphenoid bone; 2,2, greater wing and squamous portion of sphenoid bone; 3, 3, parietal bones; 4, 4, mastoid process of temporal bones. — (Gould's Dictionary.) The occipital bone occupies the space included between these bones. The mastoid portion forms the prominence behind the ear and terminates in the mastoid process, which contains a number of small cavities, the mastoid cells. They all communicate with the middle ear, and mastoid disease may therefore follow an infection of the middle ear. The inner surface of this portion shows the sigmoid groove for the transverse sinus. The petrous portion is exceedingly hard, like stone, hence its name. A slender point of bone, called the styloid process, is seen BONES OF THE CRANIUM. I9 on its lower surface, and the carotid artery, on its way to the brain, passes through the carotid canal, which is in this portion. The petrous bone contains the greater part of the ear, and the internal auditory canal for the auditory nerve, or nerve of hearing, is on its posterior surface (seen within the skull). The tympanic portion forms the greater part of the external auditory meatus, or canal. Parietal bones {ossa parietales). — Right and left, situated at the top and sides of the head, and so named because they form the sides or ivalls of the skull. They are fiat in structure, and nearly square in shape, and the four borders are called sagittal, squamous, frontal, and occipital (Figs, ii and 13). At the extremities of the borders are the angles — the frontal and occipital angles above, and the sphenoid and mastoid angles below. The most prominent point on the side of the skull is near the center of the parietal bone and is called the parietal eminence. On the inner surface of this bone well-marked grooves are seen for the middle meningeal artery, and depressions for the con- volutions of the brain. Ethmoid bone {os ethmoidale). — Situated between the orbits and, therefore, in the upper part of the nose. (For illustration see pages 29, 30.) It consists principally of two lateral portions formed of spongy bone, and containing the ethmoid cells or sinuses. These portions are called ethmoid labyrinths. They are in the walls of the nasal cavity, and the cells open into it, therefore they contain air. The labyrinths are attached to the borders of the horizontal plate, situated in the roof of the nose and perforated for the passage of the nerves of smell. The upper part of the nasal septum, which .divides the nasal cavity into two parts, is formed by the vertical plate of the ethmoid, which hangs from the horizontal plate, and is, therefore, between the two labyrinths (Fig. 25). Two of the turbinated boner, (superior and middle) are seen projecting from the medial surface of the labyrinths (Fig. 24). (For description of in- ferior turbinated see page 22.) Sphenoid bone ios sphenoidale). — Immediately behind the ethmoid, to which it is joined. Its shape resembles a bat with 20 ANATOMY AND PHYSIOLOGY FOR NURSES. the wings spread (Figs, ii and 13). It consist of a body, wings, and two pterygoid processes. The body is joined to the ethmoid in front, and to the occipital behind. It is hollow, and its two cavities (called the sphenoid sinuses) communicate with the nose. The wings, two pairs — greater and lesser — extend outward from the body at about the level of the orbits. The optic foramen, for the optic nerve, is in the lesser wing. The processes extend downward from the body, completing the back part of the sides of the nose. Note. — The lateral extremities of the greater wings may be seen at the sides of the skull, between the frontal and temporal bones; the sphenoid is thus wedged in behind the face, between it and the other cranial bones. (The name sphenoid signifies wedge-like.) ARTICULATIONS OF THE CRANIUM. The joints of the cranium are called sutures. Most of them are formed by the interlocking of irregular edges of the bones held firmly together by fibrous tissue between them. Sometimes the edges resemble saw-teeth in form, and then the suture is dentated or serrated. Sometimes the edges are smooth and overlap each other, and sometimes one fits between two others; but they are always immovable. (For illustration, see Fig. 11.) The sutures which are most important for the nurse to recognize are those formed with three borders of the parietal bones. The two sagittal (or superior) borders, uniting with each other, form the sagittal suture; the frontal borders, uniting with the frontal bone, form the coronal suture, while the occipital borders, uniting with the occipital bone, form the lambdoid suture. BONES OF THE FACE, 14. Nasal ' 2 Palate. . 2 Lacrimal 2 Inferior turbinated. ... 2 Zygomatic. 2 Vomer i Superior maxillary. . . 2 Inferior maxillary, or united, form the maxilla. mandible i Nasal bones {os nasale, sing.). — Right and left. (Fig. 11.) They are fiat in structure and form the bridge of the nose, being joined to each other in the median line of the face and to the frontal bone above. BONES OF THE FACE. 21 Lacrimal bones (os lacrimale, sing.). — Right and left; small and thin, situated in the walls of the orbits, just under the ex- tremity of the supraorbital margin (Figs, ii and 23). In this bone is the beginning of the canal in which the lacrimal duct runs con- veying the tears into the nose, thus preventing them from over- flowing the eyelids and running down the cheek. Zygomatic bones {os zygomaticum, sing.). — ^Forming the promi- nences of the cheek (Fig. 11). They are especially noticeable in certain races, as the Chinese, for example, who have high "cheek bones." Maxilla (or upper jaw-bone). — Situated in the front of the face, and composed of the two superior maxillary bones joined Infraorbital foramen Articulates with zygo- matic bone Posterior dental canals Canine eminence '^jff Tuberosity Fig. 14. — Tile Maxilla. — (Alorris.) together below the nostrils. It supports the cheeks, helps to form the nose and also the floor of the orbits. It consists of a body and several processes. The body is hollow, the space being called the maxillary sinus or antrum of Highmore which opens into the side of the nasal cavity. In the lower border of the body the teeth are imbedded, the sockets of the large teeth being in the floor of the antrum, which explains how a diseased tooth may lead to antrum trouble. The foramen on the surface of the body just below the orbit is called the infraorbital foramen. It is on a line with the supraorbital foramen of the frontal bone already mentioned. Processes. — The frontal process extends upward along the side of the nasal bone to join the frontal. The palate process 22 ANATOMY AND PHYSIOLOGY FOR NURSES. is in the roof of the mouth, the bony part of the roof being called the hard palate. The alveolar process (or alveolus) is the thick border of bone in which the upper teeth are fixed. This process is very spongy and is sometimes broken in extracting a tooth. The zygomatic process joins the zygomatic bone to form the prominence of the cheek. Foramina and in- cisive suture - Palate process 1 Palatine foramina J in a palate bone . Fig. 15. — The Hard Palate, or Roof or the Mouth. — (Morris.) Palate bones {os palatinum, sing.). — Right and left; shaped like the capital letter L, and placed behind the maxilla. The upright portion is in the side of the nose at the back; the horizontal portion lies in the floor of the nose, being at the same time in the roof of the mouth, and thus completing the hard palate (Figs. 20 and 24). Inferior turbinated bones {concha nasalis inferior, sing.). — Right and left; situated in the right and left walls of the nasal cavity below the superior and middle turbinated bones which belong to the ethmoid (Fig, 24) . Each is composed of a thin plate of spongy tissue, having one edge rolled under like a shell {concha); they extend from front to back on the lateral wall of the cavity. Clinical note. — Hypertrophy (or overgrowth) of the inferior turbinated bone is a frequent cause of obstruction to proper breathing. Vomer. — A thin bone resembling a plowshare in shape, joined above with the vertical plate of the ethmoid, and below with the maxilla, thus forming the lower part of the septum of the nose. It BONES OF THE FACE. 23 is this part of the septum which is sometimes bent to one side, or "deflected," and it often presents a ''spur" on one of its surfaces. (The vertical plate of the ethmoid and the vomer together form the bany septum Fig. 25.) Articulates with ethmoid Groove for nerve Articulates with hard palate Ala Posterior border Fig. 16. — The Vomer. — (Morris.) Mandible (inferior maxillary, or lower jaw-bone, mandibula). — The only movable bone in the skull. It consists of a body having on either side a ramus (or branch) which is attached by ligaments to the temporal bone. The body is the lower portion, shaped much like a horseshoe, with a thickened border (the alveolus) which bears the lower teeth. Fig. 17. — The Mandible. I, Body of bone; 2, ramus; 3, symphysis; 4, incisive fossa; 5, mental foramen; 7, depression for passage of facial artery; 8, angle of jaw; 10, coronoid process; 11, con- dyle; 12, sigmoid notch; 13, alveolar border; a, incisors; b, bicuspids; c, canines; m, molars. — (Gould's Dictionary.) On each side is an opening called the mental foramen, which is in a line with the infraorbital and supraorbital foramina, already mentioned. Each of these three openings transmits an important nerve, artery, and vein, bearing the same name as the foramen. See Surgical note, p. 258. The ramus extends upward from the body, and ends in two processes, one of which is the condyle; it is this condyle which articulates with the temporal bone to form the temporo-maxillary joint. H ANATOMY AND PHYSIOLOGY FOR NURSES. Clinical note. — Dislocation of this joint easily occurs if the mouth is opened too widely. The angle of the jaw or mandible, is the posterior extremity of the lower border. The prominence of the angle differs in different people and at different ages. ARTICULATIONS OF THE FACE. The bones of the face are all irregular, and many of them are very frail. They are fixed by sutures with one exception — that of the mandible which moves freely. (For description of a movable joint, see page 14.) The Mandibular Joint. The mandibular joint is a hinge-joint, and the only movable joint in the skull. The action may be felt in front of the ear. The bony surfaces are the condyle of the mandible and the mandibular fossa of the temporal bone. They are covered with Capsule Fig. 18. — Mandibular Joint. — (After Morris.) cartilage and connected by ligaments forming a capsule, which is sufficiently loose to allow the condyle to glide freely in the fossa, back and forth or sidewise, as in opening and closing the mouth and masticating the food. Surgical notes. — If the mouth be suddenly opened very widely, as in hearty laughing, dislocation easily results — that is, the condyles glide too far forward and slip in front of the fossa. THE SKULL AS A WHOLE. 25 making it impossible to close the mouth. To correct this condition (or "reduce the dislocation") press the jaw forcibly downivard and backward with the thumbs placed upon the molar teeth. (First wrap the thumbs with a napkin to protect them, as the mouth will close suddenly.) POINTS OF INTEREST IN CONNECTION WITH THE SKULL AS A WHOLE. The Cranium. The cranium is a firm, strong case for the brain, composed largely of flat bones, the layers of these fiat bones being called the tables of the skull. The innermost table is very brittle and may be fractured by a blow which does not break the outer one, and owing to this brittleness it is called the vitreous, or glassy layer. GLABELLA, ANTERIOR NASAL; SPINE PROSTHIO Fig. 19. — The Vertex and Side of the Skull. — (Gerrish.) Observing the illustrations, or better, with the skull in the hand, the student may trace the frontal, two parietal, and occipital bones forming the vault of the skull, or the vertex; and at the sides the squamous and mastoid portions of the temporal bones and the tip of the great wing of the sphenoid. 26 ANATOMY AND PHYSIOLOGY FOR NURSES. Turning the skull upside down, observe the base. In the median line at the back is the basal part of the occipital bone, with the foramen magnum and the condyles on either side of it. In front of that are the &o(/;y and /»foce55e5 o///^e sphenoid, and the roof of the mouth (or hard palate) bounded by the upper teeth. Tracing forward from the lateral part of the occipital bone is the 20 F"i,-as».- Fig. 20. — Base of Skull. I, 2, 3, Foramina and sutures in hard palate; 4, post-nasal spine; 5, nasal septum; 6, 7? ^; 9) 1°) iij 12, pterygoid processes, and markings on sphenoid bone; 13, zygomatic arch; 14, spheno-occipital suture; 15, 16, 17, 18, 19, 20, markings on temporal bone; 21, 21, condyles of occipital bone; 22, basal portion of occipital bone; 23, foramen magnum; 24, 25, crest and lines of occipital bone. — (Gould's Dictionary.) petrous portion of the temporal, with its sharp styloid process and round opening of the carotid canal; and in front of the temporal is the great wing of the sphenoid. The ethmoid may be seen through the posterior nares where the turbinated bones (better, shell-hones) are all visible. Numerous openings or foramina pierce the base of the skull, for vessels and nerves. The jugular foramen is just back of the THE FACE. 27 carotid canal; through it the jugular vein leaves the skull to pass downward in the neck. The interior surfaces of all cranial bones show depressions for the convolutions of the brain. The Face. (See Figs. 19, 23.) Beginning with the forehead, note the two frontal eminences, and below these the superciliary arches with the glabella between them. Still lower, the supraorbital arches, with the nasal notch between them, to which the nasal bones are attached. Observe the lacrimal canal at the medial side of the orbit leading to the nasal Fig. 21. — Skull of New-born Child, showing Frontal Fontanelle. — (Edgar.) Fig. 22. — Occipital Fontanelle. Both cuts show moulding of the head. —(Edgar.) cavity. Below the orbit, locate the infraorbital foramen on the surface of the maxilla and the mental foramen on the body of the mandible. Remember that these three foramina transmit three very sensitive nerves, as follows: The supraorbital nerve for the forehead, the infraorbital nerve for the cheek, and the menial nerve for the lower lip and chin. (Blood-vessels bearing the same names accompany these nerves.) The prominences at the sides of the cheeks are made by the zygomatic bones. The openings of the nasal cavity are the anterior nares, within which may be seen the septum, and the middle and inferior turbinated bones (shell bones). 28 ANATOMY AND PHYSIOLOGY FOR NURSES. The Skull at Birth. The bones are only partially developed, a considerable space between them being occupied by membrane (in some places, carti- lage), and the frontal bone is in two pieces. Fontanelles. — The parietal and frmital bones are incomplete at the angles where their sutures meet, leaving a diamond-shaped space above the forehead where there is only membrane, and which is called the anterior or frontal fontanelle. The parietal and occipital bones are also lacking where their sutures meet, leaving a triangular soft spot called the posterior or occipital fontanelle, which is much smaller. These fontanelles are closed as the bones develop; the occipital in a few months, the frontal before the end of the second year. Obstetric note. — Owing to the fact that the bones are not firmly jointed, they can be made to overlap and thus adapt the shape of the child's head to the passage which it must traverse during birth. This is called the moulding of the head (Figs. 21 and 22). Superciliary ridge Glabella Fig. 23. — The Orbit. — (After Morris.) FOSS.^ OF THE SKULL. The four large fossae of the exterior of the skull are the temporal, infratemporal, orbital, and nasal. The temporal fossa (fossa temporalis). — The thinnest part of the skull (Fig. 19). It is bounded by the temporal ridge and the zygomatic arch, occupied by the temporal muscle, and covered FOSSiE OF THE SKULL. 29 by a strong membrane, called the temporal fascia, through which the motion of the muscle may be felt. Infratemporal (or zygomatic) fossa. — At the side of the skull below the temporal fossa, from which it is separated by the zygo- matic arch (Fig. 19). It is covered by the ramus of the mandible, and occupied by two of the muscles of viastication, and also by a number of important arteries, veins, and nerves. Concha superior Sphtnoidxl binus Superior J meatus I ^ Inferior meatus — Probe in nasal canal Fig. 24. — Lateral Wall of Nasal Fossa or Cavity. — (Morris.) Orbital fossa (or orbit). — Containing the eye. It is shaped like a pyramid, the apex being at the back of the fossa. The large opening on the face is bounded by the margins of the orbit, having the frontal bone above, the maxilla below, and the zygo- matic bone on the lateral side. The orbital plate of tlie frontal bone is in the roof of the orbit, and the orbital plate of the maxilla in the Jloor. The lacrimal and ethmoid bones are in the medial wall , the sphenoid and zygomatic bones in the lateral wall. 3° ANATOMY AND PHYSIOLOGY FOR NURSES. The lacrimal canal begins in the lacrimal bone and runs down into the nose. The optic foramen, for the optic nerve, is at the apex of the fossa. Nasal fossa. — i?oo/ formed by nasal and ethmoid hones; Jio or by maxillary and palate bones; lateral wall by nasal, ethmoid, maxillary, and palate bones; septum by ethmoid and vomer (Fig. 24). The openings on the face, or anterior nares, are bounded by the maxillary and nasal bones, and separated by the vomer. The posterior nares are bounded by the sphenoid and palate bones, separated by the vomer, and open into the throat. Turbinated bones are seen on the lateral walls of the fossae. Fig. 25. — The Bony Septum. Body of sphenoid immediately behind it. — (Morris.) Fig. 26. — Hyoid Bone, Anterior Aspect. 1,1, Anterior or convex surface of body; 2, 2, greater cornua; 3, 3, junc- tion of greater cornua with body; 4, lesser cornua. — (Gould's Dictionary.) Each nasal fossa communicates with four sinuses: the sphenoid, ethmoid, frontal, and maxillary. The sphenoid sinus opens into the upper and back part; the ethmoid, frontal, and maxillary (or antrum of Highmore) open at the side, lower down. The lacrimal canal also opens at the side near the floor. The nasal fossae are lined with mucous membrane (the Schneiderian membrane) which is continued into all of the sinuses and the pharynx. Clinical note. — Inflammation of this membrane may extend into any of the sinuses, causing sinusitis. If this occurs in the frontal region, a dull pain is felt over the eyes; if in the ethmoid region, a pain at the side of the nose and a change in the sound of the voice BONES OF THE NECK. 3I {nasal tone) are noted. The inflammation frequently extends into the antrum of Highmore. The sense of smell resides in the upper part of the nose, the olfactory nerves coming down through the sieve-Hke plate of the ethmoid bone in the roof of the fossa. BONES OF THE NECK. Hyoid, {os hyoides); seven cervical vertebrcE. The hyoid bone, or os hyoides. — Shaped like the letter U, situated in front of neck, about on a level with the chin, and sus- pended by ligaments and muscles from the styloid process of the temporal bone. The hyoid is not articulated to any other bone. It consists of a body and four cornua (or horns), and is designed to give attachment to the muscles of the tongue, and to others which connect it to the mandible above and sternum and clavicle below. Seven cervical vertebrae. — The seven cervical vertebrae and their articulations will be described with the spinal column. THE TEETH. A tooth is composed of dentine or tooth-bone, and consists briefly of a crown, a neck, and a root. The crown is the exposed portion and is covered with hard white enamel. The root (connected with the crown by the neck) Neck Cingulum Fig. 27. — A Molar Tooth in Section and a Canine Tooth. — (Morris.) is concealed in the socket of the jaw and is covered with cement. The shape of the tooth varies from that of the flat incisor or cutting tooth, to the broad one for crushing and grinding. The incisors are the front teeth, four in number in each jaw. They arc used for biting and cutting the food. The cuspids (pointed) or canine teeth are situated next to the incisors; they also bite. 32 ANATOMY AND PHYSIOLOGY FOR NURSES. The bicuspids (two-pointed) or pre-molars, and the molars are for purposes of mastication. The shapes of all are shown in the illustrations. The teeth are hollow and contain tooth-pulp. This consists of a delicate meshwork of vessels and nerves entering at the point of the root. The upper teeth are imbedded in the alveolus of the maxilla, or upper jaw; the lower teeth in the alveolus of the mandible, or lower jaw. Dentition : the Eruption of the Teeth. The teeth make their appearance in two sets, called temporary and permanent. k ilk \§ 1 MJlT^ «« f Fig. 28. — The Tempoeary Teeth. The rudiments of the permanent teeth are seen enclosed in the bones. — (Gorgas.) The temporary teeth are twenty in number; their eruption or "cutting" usually begins at about the seventh month and proceeds in following order: Two lower central incisors at 7 months. Two upper central incisors at 8 to 10 months. Two upper lateral incisors at 9 to 12 months. Two lower lateral incisors at 12 to 15 months. Four first molars, i right, i left in each jaw at 12 to 15 months. Four canines, i right, i left in each jaw at 16 to 22 months. Four second molars, i right, i left in each jaw . . at 24 to 30 months. Twenty teeth in the temporary set at two and one-half years of age. THE TEETH. 33 Thus, at one year of age the average child will have six teeth; at two years, sixteen; and the full number before it is three years old. Many exceptions occur, for example: the dentition of artifici- ally fed children may be delayed; and it is oftenest late in children affected by rachitis or "rickets." The upper canines are known in the nursery as "eye-teeth"; the lower canines as "stomach teeth." Clinical points. — "Teething" or "cutting" of the temporary set occurs while the digestive tract is still in process of develop- ment and very easily disturbed; therefore special care should be Premolar Molars Wisdom tooth Fig. 29. — The Tp:eth of an Adult. — (Morris' Anatomy.) given to the child's diet both as to quality and c^uantity. Likewise, the always delicate nervous system is at this time most easily irritated and excitement and fatigue should be avoided. These two points are equally important. Meanwhile the permanent teeth arc forming (Fig. 29). They gradually push toward the surface, cutting ofi the blood supply to the temporary teeth which become loose and fall out. The permanent teeth are thirty-two in number. At the age of six years the first permanent molar ("six-year molar") should appear; the others follow in order somewhat like the following: 3 34 ANATOMY AND PHYSIOLOGY FOR NURSES. Four first molars, i right, i left, in each jaw at 6 years. Eight incisors, 2 central, 2 lateral, in each jaw ... at 7 to 8 years. Eight bicuspids, 2 right, 2 left, in each jaw at 8 to 10 years. Four canines, i right, i left, in each jaw at 12' to 14 years. Four second molars, i right, i left, in each jaw .. .at 12 to 15 years. ■ Four third molars, i right, i left, in each jaw at 17 to 25 years. (The third molars are called "wisdom teeth.") Thirty-two teeth in permanent set at twenty-five years of age. Clinical notes. — Caries, or decay of teeth, is due to bacterial action. This is favored by accumulation of particles of food, the warmth and moisture of the mouth furnishing perfect conditions for the development of bacteria. Careful cleansing with brush or dental floss, or both, will prevent this and thus aid in preserving the teeth. Care is important in the use of brush or floss or toothpick, not only that the removal of injurious particles may be well done but in order to avoid wounding the mucous membrane which covers the gums, thus exposing them to bacterial irritation. Recession of the Gums. — Any irritation (as by bacteria) of the gums may be followed by their recession, which exposes the dentine where it is not protected by enamel. Sudden changes of temperature, as from hot to cold liquids, is injurious to the enamel. Acids as ordinarily taken in food, have no special action upon the teeth but sweets may do harm by their fermentation in a mouth where teeth are not kept clean. CHAPTER III. BONES AND ARTICULATIONS OF THE SPINAL COLUMN AND TRUNK. The bones • of the spinal column are twenty-six in number. They are irregular and are arranged as follows, from above downward : 24 separate vertebras I sacrum. I coccyx. r 7 cervical in the neck. I 12 thoracic in the back. [ 5 lumbar in the loins. 1 \ in the pelvis. J A vertebra consists of a body and an arch, joined together to form a ring of bone with a space enclosed called the vertebral foramen, which is occupied by the spinal cord. The bodies are composed of spongy bone, placed one above the other and held together by discs of fibrocartilage be- tween them. In this way the solid and flexible portion of the spine is constructed. The arch consists of two roots next to the body, and two lamince which meet at the back. There are seven processes on the arch of each vertebra, — four articular (two to form joints with the bone above, two for the bone below); two transverse (pro- jecting from the sides), and one spinous which projects backward. The row of spinous processes is felt by passing the fmger down the back in the median line; that of the seventh vertebra is easily seen, and this bone is called the vertebra prominens. 35 Fig. 30. — Vertebral Column, Lateral Aspect. 1-7, Cervical vertebrae; 8-19, dorsal vertebrae; 20- 24, lumbar vertebrae; A, A, spinous processes; B, B, articular facets of trans- verse processes of first ten dorsal vertebrae; C, auricu- lar surface of sacrum; D, I), foramina in transverse processes of cervical verte- brae.— (Gould's Illus. Dic- tionary.) 36 anatomy and physiology for nurses. Points of Special Interest, The cervical vertebras present a foramen at the base of the transverse process, the transverse foramen, through which an artery runs to the brain, entering the skull through the foramen magnum. (There are no transverse foramina in the dorsal or lumbar regions.) Their spinous processes are cleft, or bifid. Transverse foramen Transverse process Articular process Lamina Spinous process Pedicle Fig. 31. — Cervical Vertebea, Showing Bifid Spinous Process. — (Morris.) Fig. 32. — Atlas, Superior Surface. I, Tubercle of anterior arch; 2, articular facet for odontoid process of axis; 3, posterior arch and posterior tubercle; 4, groove for vertebral artery and first cervical nerve; 5, transverse process; 6, transverse foramen; 7, superior articular process; 8, tubercle for attachment of transverse ligament. — (Gould's Dictionary.) Fig. t,t,. — Axis, Posterosu- perior View. I, Posterior surface of body; 2, odontoid process; 3, 3, superior articular proc- esses; 4, 4, inferior articular processes; 5, 5, transverse processes; 6, spinous process. — (Gould's Dictionary.) The first is called the atlas. It is a mere ring but has the usual number of processes (Fig. 32). The atlas is so named because it bears the weight of the skull (as Atlas, the fabled giant, bore the globe upon his shoulders). The second is the axis. A strong process projects upward from its body forming a pivot for the ring-like atlas to revolve around. The pivot is called the tooth (or odontoid process) and is held in its place in the front part of the ring of BONES OF THE SPINAL COLUMN. 37 the atlas (Fig. 32) by a strong ligament, which prevents it from pressing upon the spinal cord. The thoracic vertebrae are peculiar, in that their bodies present marks for the head of ribs; also, they have long transverse and spinous processes. Fig. 34. — A Thoracic Vertebra, showing marks for Head of Rib. — (Morris.) The lumbar vertebrae are the largest and strongest in the column, the bodies being conspicuously thicker than in the other regions, especially in the case of the fifth. There are various other modifications of bones in the three regions — cervical, dorsal, and lumbar — which need not be mentioned here. Fig. 35. — A Lumbar Vertebra in Section to show the Pressure Curves. — (Morris.) Sacrum. — An irregular bone formed by the consolidation of five incomplete vertebrae, and joined to the last lumbar. Its general shape is that of a curved wedge; it is placed with the base upward, and the concavity forward, forming the ^^ hollow of the sac- rum." A canal extends from the base to the apex, called the sacral canal, which is a continuation of the spinal (or neural) canal. There are two sets of short canals, running from front to back through the sacrum. Seen from the front they present the an- 38 ANATOMY AND PHYSIOLOGY FOR NURSES. ierior sacral foramina; seen from the back, the posterior sacral for- amina (for the passage of nerves). The angle formed by the sacrum and the fifth lumbar vertebra projects sharply forward and is called the promontory. Coccyx. — The terminal bone of the spinal column, and formed of four very rudimentary vertebrae. The base is joined to the sacrum; the apex is directed downward and forward. Fig. 36. — Sacrum, Anterior Aspect. I, I, I, I, Bodies of sacral vertebrae with trans- verse lines of union; 2, 2, 2, 2, anterior sacral fora- mina; 3, base; 4, auricular surface of lateral aspect; 5, its inferior portion; 6, articular surface of base; 7, notch for formation of last lumbar intervertebral foramen, 8, superior articular process of first sacral vertebra; 9, apex of sacrum; 10, cornu; 11, notch for transmission of fifth sacral nerve. — (Gould's Illus- trated Dictionary.) Fig. 37. — Coccyx, Ante- rior Aspect. I, Base; 2, 2, cornua; 3 second coccygeal vertebra; 4, third coccygeal vertebra; 5, fourth coccygeal vertebra; 6, fifth coccygeal vertebra. — (Gould's Illustrated Dic- tionary.) THE ARTICULATIONS OF THE SPINAL COLUMN. The bodies of the vertebrae are connected by discs of fihro- cartilage which are placed between them. They serve not only to connect the vertebrae but to give flexibility to the column, so that it may bend in any direction, and they also make it elastic. The bodies are further connected by fibrous bands on their anterior and posterior surfaces. (Slightly movable or yielding joints.) The arches are connected by broad thin ligaments between the laminae, thus completing the spinal or neural canal, which contains the spinal cord. (These ligaments are an exception to the rule, in that they are elastic; they are called the ligamenta Jiava.) The articular processes are covered with cartilage and enclosed by capsules which are lined with synovial membrane, forming true movable joints. These are gliding joints. (Arthrodia.) ARTICULATIONS OF THE SPINAL COLUMN. 39 K The only independent movements of the head are provided for by the arrangement of the atlas and axis. The cup-like articular processes of the atlas receive the condyles of the occipital bone to allow the nodding motion of the head. The occipital bone is held to the atlas by ligaments, and rotation of the atlas around the tooth of the axis turns the head also, from side to side. The ligamentum nuchae is a name given to a thick elastic band (not a true ligament) which stretches from the occipital protuberance to the seventh spinous process. It helps to sustain the weight of the head while bending forward, and is particularly well developed in the larger grazing animals. From the seventh cervical down to the sacrum a supraspinous ligament is stretched, attached to all the spinous processes. The movements of the spinal column are flexion, extension, lateral flexion, and rotation. Motion is freest in the cervical region, and most restricted in the dorsal. Clinical note. — The limited motion be- tween neighboring bones becomes a wide range in the column as a whole and may be increased by frequent and judicious exercises. THE SPINE AND THE SPINAL CURVES. The length of the spine is about 27 inches. The solid portion is a flexible and elastic column which bears the weight of the head and its delicate organs without giving them the full force of the jar caused by walking, running, etc. The flexibility of the column allows the whole body to move with freedom and grace, while the strength of the spine makes it suitable for the attachment of the extremities. The arches, connected by their ligaments, enclose the spinal or neural canal, which extends Fig. 38. — Spine and Spinal Curves. 40 ANATOMY AND PHYSIOLOGY FOR NURSES. through the sacrum to the base of the coccyx. Since the spinal canal contains the spinal cord there must be places of exit for the spinal nerves; these are found in the intervertebral foramina between the roots of the arches. The spine has four curves: cervical, thoracic, lumbar, and sacral. ■ The cervical and lumbar curves are concave posteriorly, as is seen to a slight degree in the back of the neck, and more plainly in the so-called ''small of the back"; while the thoracic and sacral curves are concave anteriorly, to accommodate the organs in the thorax and pelvis. These curves are caused by variations in the thickness of the bodies and cartilage discs. For example, the thoracic bodies are slightly thicker at the back, while the lumbar bodies are thicker in front. A lateral curve usually exists in the upper thoracic region, but this may be called accidental, as it is explained by the excessive use of one or the other arm. THE TRUNK. Includes the Thorax, Abdomen and Pelvis. BONES OF THE THORAX. Sternum i Ribs (costae) , 24 Thoracic vertebrae .....' 12 Sternum or breast-bone. — Placed in the front of the thorax. It is about 6 inches long, flat in shape and structure, and its two surfaces are called anterior and posterior. It has three divisions, the manubrium, the body, and the xiphoid appendix (Fig. 39). The upper border of the sternum is notched — the sternal (or jugular) notch; the lateral borders give attachment from above downward to the clavicle and the cartilages of the first seven ribs. The xiphoid appendix is the lowest portion of the bone and gives attachment to some of the muscles of the abdomen. It remains cartilaginous until middle life. Ribs (costae). — Twelve in each side of the thorax, forming a series of movable elastic arches. They consist of a bony portion BONES OF THE THORAX. 41 (the costal hmie) and a flexible portion (the costal cartilage). They are flat in structure, curved in shape. The posterior or vertebral extremity is the head, next to the head is the iieck, and the remaining bony portion is the shaft. The inner surface of the shaft is marked by a groove at its lower border (the costal groove) in which the intercostal nerves and vessels run, being thus protected from external injury. Fig. 39. — The Thorax. I, 2, Manubrium and body of sternum; 3, xiphoid appendix; 4, circumference of apex of thorax; 5, circumference of base; 6, fiirst rib; 7, second rib; 8, 8, third, fourth, fifth, sixth, and seventh ribs; 9, eighth, ninth and tenth ribs, 10, eleventh and twelfth ribs; 11, 11, costal cartilages. — (Gould's Dictionary.) The first seven are called '■'■true ribs/^ being connected in front with the sternum by their cartilages. The remaining five are "false ribs"; the eighth, ninth and tenth arc connected in front, each to the one above; the eleventh and twelfth, arc not connected with anything in front, and arc called "floating ribs." Thoracic vertebrae. — Twelve in number; described with the bones of the spinal column. 42 ANATOMY AND PHYSIOLOGY FOR NURSES. Tubercle The seventh rib of the left side, inferior surface. The costal groove is seen, to the borders of which the intercostal muscles are at- tached, thus completing a channel for in- tercostal vessels and nerve. The tubercle is at the beginning of the shaft; the articular surface marked a, is a part of the tubercle. Fig. 40. — The Seventh Rib. a, articular surface for transverse process; b, neck.— (Morris.) ARTICULATIONS OF THE THORAX. ARTICULATIONS OF THE THORAX. 43 Sternum. — The three pieces {manubrium, body, and xiphoid ap- pendix) are connected together by fibro-cartilages and anterior and posterior ligaments. After middle life they become united in one bone. Ribs (costse). — The costal cartilages are connected in front to the sternum, or to each other, as already mentioned. The heads arti- culate with the bodies of two thoracic vertebrae. (Exceptions: the first, eleventh, and twelfth are each connected to one body.) Where the neck of the rib joins the shaft (marked by a tubercle) it rests against the tip of the transverse process of a vertebra behind Head of rib Articular surface of transverse process Intcr-articular liga- ment Fig. 41. — Heads of Ribs Articulating with two Vertebra. — (After Alorris.) it, which thus forms a brace for it. All of these joints are enclosed by capsules and lined with synovial membrane, providing for the movements of the ribs in breathing, talking, etc. (Figs. 39, 41). Vertebrae. — Their joints have been described. By the articulation of the ribs with the spine at the back and sternum in the front, the bony thorax is completed. It is shaped like a cone, flattened before and behind, and shortest in front (the sternum reaching only as low as the ninth dorsal vertebra). The intervals between the ribs are called the intercostal spaces. The elasticity of the ribs and cartilages and their gliding joints, give a yielding character to the thoracic walls to accommodate the movements of the lungs within. 44 ANATOMY AND PHYSIOLOGY FOR NURSES. BONES OF THE ABDOMEN. The five lumbar vertebrae, already described. BONES OF THE PELVIC GIRDLE. I Hip bones 2 The bones are \ Sacrum i [ Coccyx I- Hip-bone (os coxae). — Consisting of three parts which are entirely separate in the child. They are the os ilium, the os ischii, and the os pubis; they unite in forming a cup-shaped cavity called the acetabulum, seen on the lateral surface of the bone. The acetabulum is the socket of the hip-joint (Fig. 42). Fig. 42. — Hip-bone, Exterior. — (Morris.) The OS ilium is the highest part of the hip-bone and has a broad expanded portion called the wing (or ala). The medial surface of the wing is the iliac fossa, which is filled with the iliac muscle; the lateral surface is crossed by three curved lines (called the posterior gluteal, the anterior gluteal, and the inferior ghiteal lines). BONES OF THE PELVIS. 45 The superior border is called the crest. It can be easily felt, and the anterior extremity is known as the anterior superior iliac spine, more often called the spine of the ilium. The OS pubis is the anterior division of the hip-bone. It has a body and two branches, or rami. The body joins the ilium, the superior ramus has a short projection called the spine of the pubes, and the inferior ramus extends downward and backward to join the ischium, thus forming the upper part of the pubic arch. The two pubic bones join each other in the median line, forming the pubic symphysis (symphysis pubis). Os ilium Os pubis Fig. 43. — Hip-BOXE, Interior, before Union of Parts. — (Morris.) The OS ischii (or the ischium), the lowest part of the hip-bone, — has a sharp spine projecting backward, a tuberosity upon which the trunk rests in the sitting position, and a ramus which joins the pubic ramus to complete the pubic arch. The ilium, ischium, and pubes united form the hip-bone (os coxae). Two large notches are seen on the posterior border of the completed bone, separated by the spine of the ischium and called the sciatic notches. The upper one is the greater and the lower one is the lesser sciatic notch. In front of the acetabulum is the 46 ANATOMY AND PHYSIOLOGY FOR NURSES. obturator foramen, the largest foramen in the skeleton. It is almost entirely closed by the obturator membrane, which is composed of white fibrous tissue. THE ARTICULATIONS OF THE PELVIS. The two hip-bones unite with each other in front at the pubic symphysis, but the sacrum is between them in the back, having the coccyx attached to its apex, and thus the pelvic girdle is formed, usually called the pelvis (or basin). These joints have no cavity, and are only slightly movable, or yielding. There is a distinct disc of fibro-cartilage at the pubic symphysis. Greater sacro- sciatic ligament Lesser sacro-sci- atic ligament Tendon of biceps muscle Fig. 44. — Greater and Lesser Sacro-sciatic Ligaments and Foramina. — (Morris.) Obstetric note. — The pubic symphysis and the sacro-iliac symphysis probably soften slightly during pregnancy. The sacro-coccygeal joint has limited motion until middle life advances, when it may become fixed. Sacro-sciatic ligaments (Fig. 44).— Two strong bands are stretched between the sacrum and the ischium. They have no connection with any joints but are called the greater and the lesser sacro-sciatic ligaments. The greater THE PELVIC GIRDLE. 47 (ligamentum sacro-tuberosum) extends from the borders of the sacrum and coccyx to the tuberosity of the ischium; the lesser (ligamentum sacro-spinosum) is placed immediately in front of it, extending from the sacrum and coccyx to the spine of the ischium. Thus are formed two foramina with the lesser liga- ment between them, the one above being called the greater sciatic foramen, and the one below the lesser sciatic foramen. (The sciatic nerves pass through the greater foramen.) Fig. 45. — The Pelvis. — (Morris.) Pouparfs ligament, or the inguinal ligament, may be felt like a tight cord stretched between the spine of the ilium and the spine of the pubis — "from spine to spine." The Pelvis or Pelvic-Girdle. False pelvis. — The upper part, between the wings of the ilia. It is broad and shallow. True pelvis. — The lower part, bounded by the puhes in front, the ischia at the sides, and the sacrum and coccyx at the back. It is deeper and narrower. The female pelvis has lighter bones, a wider pubic arch, and greater capacity than the male pelvis; the sacrum is less curved and the sacral promontory less projecting. The limiting line or boundary between the false and the true pelvis is a curved line called the brim, and the space included 48 ANATOMY AND PHYSIOLOGY FOR NURSES. is the inlet; the lower openmg is the outlet. The inlet and the outlet are also known as the superior and inferior straits. The measurements or diameters of these straits in the female pelvis are as follows: 16 V_7 7 P lAC ft E SAL Fig. 46. — The Pelvis. Inlet, or Superior Strait. — (Gould's Dictionary.) I, Iliac fossa; 2, crest of ilium; 3, anterior-superior spine of ilium; 4, anterior-infe- rior spine of ilium; 5, ilio-pectineal joint; 6, 7, body an^ symphysis of pubes; 8, acetabu- lum; 9, tuber of ischium; 10, 11, pubic arch; 12, spines of ischia; 13, coccyx; 14, sacro- iliac joint; 15, is placed just above the promontory. Inlet (Edgar's Obstetrics). Antero-posterior 11 cm. (Symphysis to promontory.) Oblique. 12^ cm. (Ilio-pectineal joint to sacro-iliac joint.) Transverse 13 J cm. (Widest part of brim.) Outlet. Antero-posterior 92^12 cm. (Symphysis to tip of coccyx.) Transverse 11 cm. (Between tuberosities.) THE DORSAL AND VENTRAL CAVITIES OF THE BODY. By articulation of the bones of the head and trunk a framework is formed for two cavities, within which are situated the internal organs or viscera. (These delicate and important parts must be provided with surrounding structures which insure both their safety and efficiency.) The cavities are called dorsal and ventral, or neural and visceral. Briefly speaking, they may be described as situated THE DORSAL AND VENTRAL CAVITIES. 49 posteriorly and anteriorly to the solid part of the spinal column or bodies of the vertebrae. The spinal canal is a part of the dorsal or neural cavity which extends into the interior of the skull, the bones of the cranium being modified vertebrae, and the ca\dty within them representing the uppermost part of the neural canal. The dorsal or neural cavity contains the brain and spinal cord, well protected within iirm, unyielding walls. The mouth, neck, thorax, abdomen and pelvis inclose the ventral or visceral cavity, which is in front of the spinal column. The bony walls are very incomplete, especially in the abdomen. They are finished out by muscles; this arrangement allows the walls to be flexible and yielding in character, thus securing to the organs con- tained, that freedom of movement which is necessary to their perfect action. The diaphragm (page 91) divides the ventral cavity into two portions, upper and lower; the pelvic floor (page 103) completes the boundary below. The ventral cavity contains the organs of respiration, circulation, digestion and reproduction; also the kidneys and bladder, which are organs of elimination. Having studied the bones of the dorsal and ventral cavities or those of the head and trunk, we will proceed in Chapter IV to those of the extremities. CHAPTER IV. BONES AND ARTICULATIONS OF THE EXTREMITIES. BONES OF THE UPPER EXTREMITY. The upper extremity, as the artist sees it, begins with the arm. The anatomist includes the shoulder as a part of the extremity. The bones are therefore as follows: In the shoulder. In the arm In the forearm. . In the wrist or carpus^ In the hand. I clavicula I scapula humerus , / radius [ ulna scaphoid semilunar cuneiform pisiform 1 • I 1 ist row. . . 2d row. .8 trapezium trapezoid OS magnum unciform J J palm or metacarpus (metacarpal bones) 5 [ fingers or digits (phalanges) 14 32 * The names of carpal bones are given as follows in Spalteholz's Hand Atlas: ist row— OS naviculare manus. 2nd row — os multangulum majus. OS lunatum. os multangulum minus. OS triquetrum. os capitatum. OS pisiforme. os hamatum. Note. — The end of a bone which is nearest to the trunk is called the proximal extremity; the other end is the distal extremity. The same terms are applied to surfaces The Shoulder or Shoulder-girdle. Scapula, or shoulder-blade (Fig. 47).— Placed a<- the upper part of the chest, behind the ribs (from the second to the eighth). It is fiat and irregular in structure, and triangular in shape. SO BONES OF THE UPPER EXTREMITY. SI The margins are called the superior, the vertebral, and iheaxillary; the angles, lateral, medial, and inferior. The inferior angle and vertebral border or margin usually project a little backward, sometimes very notably, making the so-called "winged scapula." The anterior surface (costal surface) is called the subscapular fossa, and is filled with the subscapular muscle. The posterior or dorsal surface is crossed by a rough ridge called the spine of the scapula which terminates in an important process, the acromion, overhanging the shoulder-joint. Below and in front of the acromion is the coracoid process. Fig. 47. — Scapula, Posteroex- TEioiAL Aspect. I, Supraspinous fossa; 2, infra- spinous fossa; 3, superior or coracoid border; 4, coracoid or suprascapular notch; 5, axillary or lateral border; 6, anterior angle and glenoid cavity; 7, inferior angle; 8, rough impression for long head of triceps; 9, medial or spinal or vertebral border; 10, spine; ir, smooth surface over which tra- pezius muscle glides; 12, acromion; 13 base of spine; 14, coracoid process. — (Gould's Dictionary.) Fig. 48. — Clavicle, Inferior Aspect. I, Longitudinal depression for insertion of subclavius muscle; 2, rough impression for attachment of costoclavicular ligament; 3, 3, for attachment of coraco-clavicular ligaments; 4, 4, posterior border; 5, 5, an- terior border; 6, facet for articulation with sternum; 7, facet for articulation with acro- mion.— (Gould's Dictionar}'.) The lateral angle presents a shallow depression called the glenoid cavity. This cavity forms the socket of the shoulder-joint. Clavicula (or collar-bone, Fig. 48.) — Long in shape, but having no medullary canal. It is curved like an italic letter /and placed horizontally across the front of the upper ribs. The inner extremity articulates with the sternum and is therefore called the sternal extremity. The outer extremity articulates with the acromion process of the scapula, and is called the acromial extremity. Clinical note. — The weight and curves are increased by exercise, and both bones are usually more developed in men than in women. 52 ANATOMY AND PHYSIOLOGY FOR NURSES. The clavicula Is easily broken, especially in children, being frequently the seat of "green-stick" fracture. The clavicula and scapula together form the shoulder-girdle, which is open at the back, but closed in front by the sternum placed between the two claviculas. \ ii Fig. 49. — Left Humerus, An- terior Aspect. I , Shaft or body; 2, head; 3, anatomic neck; 4, greater tubercle; 5, lesser tubercle; 6, 7, 8, 9, mark- ings for muscles; 10, orifice for nutrient artery; 11, capitulum; 12, trochlea; 13, 14, lateral and medial epicon- dyles; 15, 16, lateral and me- dial borders; 17, coronoid fossa. — (Gould's Diet.) The Arm or Brachium. Humerus. — Long in structure and shape, hav- ing a shaft with a medullary canal and two extremi- ties (Fig. 49). The upper extremity (proximal extremity) in- cludes the head, neck and tubercles. The head articulates with the glenoid cavity of the scapula to form the shoulder-joint; the short, thick, anatomic neck joins the head to the shaft; and just below the neck are the greater and lesser tubercles for the attachment of muscles to rotate the arm. The lower extremity curves slightly forward and presents two projections at the sides called the medial and lateral epicondyles; the medial is the longer and consequently it is more frequently broken off. Between the epicondyles are the articular surfaces for the elbow-joint, the trochlea for the ulna and the capitulum for the radius. The shaft has three borders and three surfaces (like all long bones). The anterior and medial borders run from the greater and lesser tubercles. In the upper part they are called the crests of the tubercles and the groove for the long tendon of the biceps muscle is between them (formerly called bicipital groove). The broad, shallow groove containing the radial nerve winds across the posterior surface. Note. — The slender portion of the shaft just below the tubercles is called the surgical neck, be- cause it is so often fractured. Forearm, or Antebrachium (Fig, 50). Ulna. — A long bone in structure and form, situated in the medial side of the forearm (the ulnar side). The upper extremity presents BONES OF THE UPPER EXTREMITY. 53 two strongly marked processes, — the olecrancni, projecting upward from the back and curving forward, and the coronoid, projecting forward from the front and curving upward. Thus these processes curve toward each other, and the cavity between them is the semilunar notch. It receives the trochlea of the humerus to form the elbow-joint. On the lateral side of the coronoid process is the „ , radial notch, where the head of the radius lies. \\ \ The lower extremity is the head of the ulna, which lies in the ulnar notch of the radius. There is a well-marked projection on this head called the styloid process. The posterior border of the shaft is subcutaneous and may be traced down from the point of the elbow. The space between the radius and the ulna is called the interosseous space, and is occupied by an interosseous membrane. Radius. — A long bone in structure and in form, situated on the lateral side of the forearm (the radial side). The upper (or proximal) extremity is the head, which is depressed at the top to fit the capitulum of the humerus. Below the head is the neck, and below that, in front, is the tuber- osity of the radius for the attachment of the biceps muscle of the arm. The lower (or distal) extremity of the radius is broad and t];iick, and is the largest bone in the formation of the wrist-joint. On its lateral border is the styloid process. Running across the upper half of its anterior surface is the oblique line, which is a part of the anterior border. Special notes. — The head of the humerus is proximal and articulates with the glenoid cavity 'of the scapula. The head of the radius is proximal and articulates with the humerus. The head of Ike ulna is distal. ' The upper end of the ulna is its largest part, and an important bone in the elbow-joint. The lower end of the radius is the largest part, and important in the wrist-joint. Observe that in the long bones of the upper extremity the nutrient foramina are in the shafts and are directed toward the elbow-joint. They transmit nutrient arteries to nourish the bones. Fig. 50. — Left Ulna and Radius, Anterior Surfaces. —(Gould.) I, Shaft or body of ulna; 2, semilunar notch; 3, radial notch occupied by radial head; 4, olecranon; 5, coronoifl process; 6, orifice for nutrient artery; 7, interosse- ous borders with in- terosseous space be- tween; 8, head of ulna; 9, styloid proc- ess of ulna; 10, shaft or body of radius; 1 1, 12, head and neck of radius; 13, tuberosity of radius; 14, mark- ing for muscle; 15, 16, lower extremity and styloid jjrocess. 54 anatomy and physiology for nurses. Carpus. Fig. 51. — Bones of Car- pus, Dorsal Surface. • — (Gould's Dictionary.) The carpal bones (ossa carpi) are eight in number, and are typical short bones, They are arranged in two slightly curved rows — the first and second — with the convexity of the curves turned upward toward the radius, the first row articulating with it. First Row. Navicular (os naviculare). — On the radial side of the wrist, named from its shape which resembles a boat, and marked by a tubercle. Semilunar (os lunatum). — Well named from its half-moon shape. Cuneiform (os triquetrum). — Very slightly resembling a wedge. Pisiform (os pisiforme). — Resembling the half of a split pea, and placed in front of the cuneiform. Second Row. Trapezitmi (os multangulum majus). — On the radial side, marked by a ridge. Trapezoid (os multangulum minus). — The smallest of the carpal bones. Os magnum (os capitatum). — The largest, having head, neck, and body. Unciform (os hamatum). — Named for its unciform or hook- shaped process. When the carpus is seen from the front, four prominent points are to be noted, namely — the tubercle of the navicular and ridge of the trapezium, on the radial side; the pisiform bone and hook of the unciform on the ulnar side. These mark the boundaries of a deep groove where the long tendons of the fingers glide. The Metacarpus or Palm (Fig. 52). The five metacarpal bones (ossa metacarpalia) are lon^ in shape but have no medullary canal. Each has a base, a shaft, and a head, the head being distal. The bases are articulated with the BONES OF THE H.A.ND. 55 second row of the carpus, and the heads with the first row of the phalanges. The first corresponds to the thumb; the second to the index finger; the third to the middle finger, the fourth to the ring finger, and \ht fifth to the little finger. The spaces between them are inter- osseous spaces and are occupied by inter- osseous muscles. Note. — The third metacarpal bone (of the middle finger) is the longest, and its head is the most prominent when the hand is clenched, as in making a "fist." Phalanges. These are the bones of the fingers and thumb (digits). A finger has three, first, second and third; the thumb has two, first and second. They are long in shape, but without a medullary canal. Each has a base, a shaft, and a head, the head being distal. The first row of phalanges in- cludes those which are next to the meta- carpal bones. The terminal phalanges Fig. 52. — Right Hand, Palmar or Volar Surface. 1-9, Carpus, and grooves for tendons; 10-10, meta carpus; 11 11, phalanges; 12, 12, 2d phalanges; 13, 13, 3d phalanges; 14, 15, ist and 2d phalanges of thumb. — ■ (Gould's Dictionary.) (those of the third row) have each a horse- shoe-shaped border on the anterior surface for the support of the sensitive finger tip; because these bones bear the nails, they are called the ungual phalanges.^ Resume. — With the limb in the anatomic position, observe the groove for the biceps muscles on the front of the humerus, beginning between the greater and lesser tubercles. In the forearm, note that the ulna is the bone of the elbow-joint, while the radius makes the wrist-joint; that their shafts are parallel and the palm is turned forward, and the carpus curved to help in forming the hollow of the hand (or the "cup of Diogenes"), and that the thumb is on the radial side, and free. ' This description of the metacarpal bones and phalanges follows that of stand- ard text-books. It would seem, however, more in accordance with the facts to consider the palm as composed oi four metacarpal bones — one for each finger — and to give to the thumb three phalanges, since the bone commonly called the first metacarj)al (or the metacarpal of the thumb) resembles those of the first row of the phalanges in both form and development. 56 ANATOMY AND PHYSIOLOGY FOR NURSES. ARTICULATIONS OF THE UPPER EXTREMITY. Sterno-clavicular, a gliding joint {arthrodia). — This is the one joint by which the upper extremity articulates with the trunk. Articular surfaces; on the upper angle of the manubrium and the sternal end of the clavicula. Anterior and posterior ligaments connect the bones, forming a capsule. (The joint is divided by a disc of fibro-cartilage into two cavities and there are two synovial membranes.) mm -Sterno-clavicular Joint, — The inter-articular cartilage is shown in the joint of the ri< the left side. (Morris. ht side; capsules shown on Motions. — Gliding, by which the shoulder moves upward^ downward, backward and forward. Ligaments not connected with the joint but useful in preventing dislocation: — The costo-clavicular, holding the clavicle to the first rib, and the conoid and trapezoid connecting it with the coracoid process of the scapula. Acromio-clavicular. — A small gliding joint between the acromion process of the scapula and the acromial end of the clavicula. It is enclosed by a capsule. Shoulder- joint. — A ball-and-socket joint {enthrosis). Artic- ular surfaces : the head of the humerus and the glenoid fossa of the scapula. The fossa is deepened by a rim of fibro-cartilage called the glenoid margin. The capsule is attached to the scapula around the margin of the glenoid fossa, and to the humerus around the anatomic neck. It is so loose that the head of the humerus will ARTICULATIONS OF THE UPPER EXTREMITY. 57 fall an inch away from the glenoid fossa by its own weight if the surrounding muscles be removed; it contains a synovial membrane which covers the glenoid margin and folds like a sheath around the long tendon of the biceps muscle (Fig. 54). Motions. — In every possible direction, as flexion, exiensioUy abduction, adduction, rotation, and circumduction, with greater freedom than any other joint of the body, because the socket is so shallow and the capsule is so loose. Elbow- joint. — A hinge-joint {gingly- mus) (Fig. 55). Articular surfaces: the trochlea of the humerus in the semilunar notch of theidna, and the capitidum of the humerus in the depressed head of the radius. The ligaments — anterior, posterior, me- dial, and lateral — together compose a large capsule. (They are attached to the humerus above the olecranon fossa at the back, and above the coronoid and radial fossae in front.) The synovial membrane is extensive. Motions. — The elbow-joint proper is capable of flexiofi and extension only, like all hinge-joints. -Left Acromio CLAVICULAR AND ShOULDER- JOINTS. I, Acromio-clavicular joint; 2,3, conoid and trapezoid liga- ments; 4, transverse ligament, across suprascapular notch; 5, 6, capsule; 7, groove for biceps tendon. — (Potter's Anatomy.) The radius and ulna are connected together at their extremities, making roiling joints (see p. 15); their shafts give attachment to an interosseous membrane of white fibrous tissue which almost fills the space between the bones. Wrist-joint. — Between the forearm and the carpus, having a variety of gliding motions, but used principally as a hinge-joint. Articular surfaces : Above — the lower end of the radius and the tri- angular cartilage (or articular disc) ; below — the first row of carpal bones (not including the pisiform). The ligaments — anterior, posterior, medial, and lateral — enclose the joint like a capsule. Motions. — Flexion, extension, and slight lateral bending (or from side to side) making abduction and adduction. (If the hand is bent far backward or over-extended, this is dorsal flexion.) Surgical note. — The anterior ligament of the wrist-ioint is eg ANATOMY AND PHYSIOLOGY FOR NURSES. remarkably strong and seldom torn; the lower end of the radius breaks instead, under sudden great force, as in Colles' fracture. Carpal. — Eight bones arranged in two rows, bound firmly toc^ether by short ligaments. Motions — Gliding only. Metacarpal. — ^Five bones, articulated by their bases to the carpios, and by their heads to the digits. Head of first, belonging to thumb, is free; heads of others connected together by a transverse band. Motions— Slight gliding, except in case of the thumb, which may be flexed or bent upon the palm; extended or straightened; abducted from hand; adducted toward hand. Surgical note. — In the normal hand, a dis- location of the thumb is most difficult of reduc- tion, because the metacarpal head and the base of the first phalanx are interlocked in such a manner as to form what is called a joint by reciprocal reception^ or "saddle joint." Phalangeal. — Three bones in each finger, two in the thumb. Anterior, posterior, and lateral ligaments. Motions. — Flexion and exten- sion. Note. — In the completed hand, the fingers and the thumb can be moved from side to side, independently; that is, they can be spread apart {abduction) and drawn together {adduction) (p. 102). Fig. 55. — Left Elbow-joint, Lat- eral Aspect. I, Humerus; 2, 3, ulna and radius; 4, lateral ligament; 5, orbicular or ring liga- ment; 6, lateral por- tion of capsule; 7, anterior portion of capsule; 8, lateral epicondyle. — (Pot- ter'sAnatomy.) Supination and Pronation. These are terms applied to certain movements of the extremities. They are best seen in the forearm where they change the position of the hand. The head of the radius rests in the radial notch of the ulna, held there by a circular band called the ring ligament (orbicular) , and it can be rolled forward or backward, within the ring (a form of pivot joint). Of course, the shaft moves at the same time, the lower end turning forward or backward around the head of the ulna, and the BONES OF THE LOWER EXTREMITY. 59 wrist and hand must accompany it. When the radius and the ulna are placed in the anatomic position, their shafts are parallel and the hand lies upon its back; this is supination. If the radius rolls forward, the shafts become crossed, and the hand lies upon its face; this is pronation. Surgical notes. — Supination and pronation are very important movements. If they are prevented the hand loses much of its useful- ness, therefore fractures of the shafts would not be set in the position of pronation, lest adhesions should form between the crossed shafts, preventing supination. BONES OF THE LOWER EXTREMITY. In the Thigh . Femur i In the Leg. Tibia Fibula Talus Calcaneus Cuboid. In the Tarsus^ . | Navicular bone. ist cuneiform. . 2d cuneiform. ... I 3d cuneiform. ... J Metatarsus — 5 metatarsal bones 5 Toes and Digits — 14 phalanges 14 Patella — i sensamoid bone i ist row. 2d row. ^As given by Spalteholtz — Talus \ Calcaneus (os calcis) J ist row Os cuboideum Os naviculare pedis Os cuneiforme I Os cuneiforme II Os cuneiforme III 30 2d row. The Thigh. Femur. — The largest bone in the body. Its upper extremity presents a nearly spherical head joined by a neck to the shaft, and resting in the acetabulum. At the junction of the neck and shaft are the two trochanters, — the tro- chanter major on the lateral side, and the trochanter minor on the medial and posterior side. The lower extremity presents two 6o ANATOMY AND PHYSIOLOGY FOR NURSES. condyles projecting downward, the medial and the lateral. The medial is slightly longer and the lateral slightly broader of the two; and the deep notch between them is called the intercondyloid notch or fossa. There is a projection from the side of each condyle called the medial and the lateral epicondyle. Fig. 56. -The Femur, Left Poste- rior Aspect. I, I, Linea aspera; 2, 2, 3, divisions of linea' aspera; 4, 4, divisions of linea aspera; 5, 6, head, and mark for liga- mentum teres; 7, neck; 8, 9, trochanter major; 10, trochanter minor; 11, 12, lat- eral and medial condyles; 13, intercon- dyloid notch; 14, 15, lateral and medial epicondyles, — (Gould's Dictionary.) Fig. 57. — Left Tibia and Fibula, Anterior Aspect. I, Shaft or body of tibia; 2, 3, me- dial and lateral condyles; 4, spine or intercondyloid eminence; 5, tubercle of tibia; 6, crest or shin; 7, 8, lower ex- tremity, and medial malleolus; 9, shaft or body of fibula; 10, upper extremity or head of fibula; 11, lower extremity and lateral malleolus. — (Gould'sDictionary.) The shaft has a prominent posterior border called the linear aspera. This divides lower down into two lines running to the con- dyles and enclosing a smooth triangular space called the popliteal space, or plane of the femur. The other borders are not plainly seen. boxes of the lower extremity, 6l The Leg (Fig. 57). Tibia. — A long bone in the medial side of the leg. Its upper extremity is the head, which is composed of two cmidyles, medial and lateral, having shallow depressions on the top to bear the condyles of the femur. Between these depressions is the inter- condyloid eminence, or spine of the tibia. The tuberosity of the tibia is a large elevation in front, just below the head. The lower extremity has a projection downward from its medial surface called the medial malleolus, which helps to form the ankle-joint. The shaft has a prominent anterior border called the cresi or shin, which is plainly felt under the skin. This border and the medial surface are both called subcutaneous because no muscles cover them. Fibula. — A long bone, in the lateral side of the leg, slender and easily broken. Its upper extremity is the head, which has a short styloid process pointing upward. The lower extremity is the lateral malleolus, which helps to form the ankle-joint. Note. — The space between the tibia and fibula is called the interosseous space, and is occupied by interosseous membrane. The lower extremities of these two bones form the prominences at the side of the ankle known as the ankle-bones; they are the medial and the lateral melleoli, which, being subcutaneous, are especially exposed to blows. Special notes. — Observe that the heads of all three bones are proximal; that (he fibula does not form any part of the knee-joint; that ih.& nutrient foramina all run from the knee. The Tarsus (Fig. 58). There are seven tarsal bones arranged in two irregular rows to form the arches of the foot, or instep. First Row. Talus (astragalus). — On the tibial side. Has a head, a neck, and a body; the body is received between the two malleoli to form the afikle-joint, and the head is turned forward toward the toes. It rests upon the calcaneus. 62 ANATOMY AND PHYSIOLOGY FOR NURSES. Calcaneus (os calcis) or bone of the heel. — The largest tarsal bone. It is under the talus (astragalus), and bears the weight of the entire body in the erect position. The tuberosity of the cal- caneus projects backward beyond the ankle, and gives attachment to the largest tendon in the body, the tendon of Achilles (tendo A chillis). Calcaneus Talus Scaphoid, or navicular First cuneiform Tarsus Metatarsus Phalanges Fig. 58. — Bones of Left Foot. — (Morris.) Second Row. Navicular (os naviculare). — On the tibial side, in front of the talus, articulating with its head. Cuneiform bones (or wedge-shaped bones). — In front of the navicular. They are three in number, first, second, and tliird. Cuboid (os cuboideum). — It lies in front of the calcaneus. articulations of the lower extremity. The Metatarsus. 63 The five metatarsal bones in the foot resemble the metacarpal bones of the hand in their general characteristics, with some special developments; the interosseous spaces between them are occupied by interosseous muscles. Phalanges. Fourteen in number, as in the hand, and arranged in a similar manner — two for the great toe, and three for each of the other toes. Note. — The great toe is in the medial border of the foot. A. B. Fig. 59. — Left Patella. A , Anterior Surface, B, Posterior Surface.— (Morris.) Patella. The patella is the largest sesamoid bone. It is triangular in shape, placed in front of the "knee-joint, and held to the tuber- osity of the tibia by a strong band about three inches long — the so-called ligament of the patella. Its location while the body is erect is in front of the condyles of the femur, but in the sitting position it is in front of the lower ends of the condyles, and in kneeling it is beneath them, ARTICULATIONS OF THE LOWER EXTREMITY. Hip-joint (ball-and-socket joint {Enar thro sis), Fig. 60).^ Articular surfaces: head of the femur, and the acetahdum deepened by the glenoid rim of the acetabulum (a rim of fibro-cartilage). The bones are directly connected by the ligamentum teres (or round ligament) within the joint, which is attached by one extremity near 64 ANATOMY AND PHYSIOLOGY FOR NURSES. Tendon of biceps musde Capsule Fig. 6o. — Hip-joint. — (Morris.) ■■Capsule Glenoid run Fig. 6i. — Ligamentum Teres. — (Morris.) ARTICULATIONS OF THE LOWER EXTREMITY. 65 the middle of the head, and by the other to the bottom of the acetabulum (Fig. 61). A capsule encloses the joint (Fig. 60). It is strengthened by special bands of fibers extending to surrounding bones, — one, the ilio-femoral from the ilium to the great trochanter, resembles an inverted letter Y, and was formerly called the Y-ligament; also the ligament of Bigelow. The synovial membrane not only lines the capsule but invests the ligamentum teres. ratty tissue Synovial membrane re- flected off crucial liga- ments Cut end of anterior cru- cial ligament Posterior crucial liga- ment Extension of synovial sac of knae upon femur Tendon of quadriceps extensor, forming flbrous capstile of Joint PATELU Pre-patellar bursa CONDYLE OF FEMUR (INNER) Ligamentum mucosum Patty tissue between ligamentum patellae and synovial aac Bursa beneath ligamentum patellae Fig. 62. — Lnterior of Knee-joint. — (Morris.) Motions. — Free motion in every direction, like that of the shoulder. Knee-joint (hinge or ginglymus joint) (Fig. 62). — Articular surfaces: the condyles of the femur, the head of the tibia, and the posterior surface of the patella. The two surfaces on the top of the tibia are shallow, but their depth is increased by semilunar fibro-cartilages attached around the borders, thus forming shallow cups for the condyles. 5 66 ANATOMY AND PHYSIOLOGY FOR NURSES. The femur and tibia are directly connected by two ligaments within the joint, which cross each other and are therefore called the crucial ligaments. (One passes from the front of the spine to the lateral condyle, the other passes from behind the spine to the medial condyle.) The patella lies in front of the condyles, being imbedded in a thick tendinous band about three inches long which continues to the tuberosity of the tibia. This band is really the tendon of insertion for some thigh muscles, and is improperly called the ligament of the patella. It serves as the anterior liga- Plantar ligaments Fig. 63. — Ligaments of the Ankle-joint and Plantar Region. — (Morris.) ment of the joint but is at the same time the quadriceps extensor tendon, sometimes called the patellar tendon. There are distinct medial and lateral ligaments, and some strong oblique bands at the back; and all are connected by a capsule which encloses the joint cavity. The synovial membrane is very extensive (Fig. 62); it covers the crucial ligaments and semilunar cartilages. Motions. — Flexion, extension, and very limited rotation of the leg. Note. — The patella cannot be drawn upward under any circumstances. When the knee is flexed, it lies against the lower ends of the condyles, and in ARTICULATIONS OF THE LOWER EXTREMITY. 67 kneeling the condyles rest upon it. The elasticity of the great muscles to which the patellar tendon belongs, allows very free motion and at the same time keeps the patella always in place close to the condyles. Bursae. — There are several small cavities called bursae, the use of which is to prevent friction in the tissue outside the knee-joint. They usually com- municate with the joint. The largest one is, however, subcutaneous, being in front of the patella between it and the skin. (Fig. 62 and page 77.) Surgical note. — This prepatellar bursa is subject to frequent pressure and easily becomes inflamed and enlarged, making the so-called "housemaid's knee." Ankle-joint, (hinge-joint). — Articular surfaces on the medial and lateral malleoli and the body of the talus. They are connected by anterior, posterior, medial, and lateral ligaments. Tendo Achillis Talus Vessels and nerve Scaphoid First cuneiform First metatarial Calcaneus Muscles of plantar region Fig. 64. — Medial Border of Right Foot, Showing Bones in Position. — (Morris.) The medial is often called the deltoid ligament, from its shape i like the Greek letter delta, and the lateral ligament is in three distinct bands, the anterior, middle, and posterior. Motions. — Flexion, extension, and slight abduction and adduction; also lifting the medial border, or eversion, and lifting the lateral border, or inversion. Notes. — The transverse ligament is a special band behind the talus, connecting the two malleoli, to prevent backward dislocation of foot in jumping, running, etc. There is no motion of the lower extremity which corresponds to supination 68 ANATOMY AND PHYSIOLOGY FOR NURSES. in the upper, the whole extremity being in the permanently pronated position, which brings the great toe toward the median line of the body, or on the medial border of the foot. (The thumb is on the lateral border of the hand.) Tarsal. — An interosseous ligament connects the talus to the calcaneus; it is the strongest one in the body. Short fibrous bands connect the various tarsal bones to each other to complete the instep, and there is one elastic ligament upon which the head of the talus rests. It assists to prevent excessive jarring as the foot strikes the ground. (This is the only ligament containing elastic tissue in the extremities.) Metatarsal. — Like the metacarpal, except that the heads are all joined together by a transverse band; the great toe is not free. Phalangeal. — Like those of the hand. Arches of the foot. — The principal arch is from the heel to the ball of the foot; a second one, the transverse, is equally impor- tant. The arteries and nerves in the sole of the foot are protected from pressure by these arches, which are preserved not only by the ligaments and the shape of the bones, but by the tendons of certain muscles. Practical points. — In walking the weight is transmitted principally through the talus, the navicular, and three cuneiform bones to the three medial toes, giving the "springy" step to the well-arched foot. In standing, it falls more upon the calcaneus, and is distributed through the cuboid to the two lateral toes as well. Resume. Comparing the joints in the upper and lower extremities, note that both the shoulder and hip are ball-and-socket joints; that the elbow and knee are hinge-joints, as are also the wrist and ankle; but whereas in the wrist extension is limited, in the ankle it is so free as to bend the top of the foot almost against the leg, becoming dorsal Jlexion, and is actually csdltd Jlexion of the ankle-joint, the term extension being used to signify the act of straightening the foot in a line with the leg. The back of the hand and the top of the foot are both called the dorsum; the face of the hand is the palm or volar surface, and the sole of the foot is the plantar surface. The thumb is free; the great toe is bound with the others. ARTICULAR NERVES. 69 The following table of articular nerves is inserted in this place for convenient reference, when, in the care of painful joint affec- tions, the nurse may be interested to know the names of the par- ticular nerves involved. NERVE SUPPLY TO THE PRINCIPAL JOINTS. Temporo-mandibular. . Fifth cranial or trifacial. Shoulder Suprascapular, subscapular, axillary. Elbow. Musclo-cutaneous (principally). Wrist and hand. Ulnar, median, deep branch of radial. Joints of spinal column. Spinal nerves. Hip Femoral, obturators, sciatic. Knee Femoral, obturator, tibial, peroneal. Ankle and foot Deep branch of peroneal, two plantar nerves. CHAPTER V. COMPLETION, REPAIR AND FUNCTIONS OF BONES. Notes Concerning the Completion of Long Bones. In the humerus, radius, and ulna, the nutrient canals lead toward the elbow and the bones are completed here at an earlier date than at the wrist or shoulder. In the femur, tibia, and fibula, the nutrient canals lead away from the knee; and the bones are completed first at the hip and the ankle. Surgical notes. — The time of union of the extremities and shafts of long bones is important from a surgical viewpoint. Thus, in the ends of bones at the elbow-joint the extremities join the shafts at about the seventeenth or eighteenth year; therefore, injuries near the elbow-joint before this age may cause a separa- tion of the parts, called an epiphyseal fracture. The upper end of the humerus and lower ends of the radius Sindulna unite with their shafts at about the twentieth year; therefore, in the case of an injury of the shoulder or wrist before this age the same possibility is borne in mind. In the lower extremity certain differences are noted, since the nutrient arteries run differently. The bones are completed first at the upper end of the thigh, at about nineteen, and at the lower end of the leg at about eighteen or twenty years^ while the knee is completed last, at between twenty and twenty-five. It is important for the nurse to understand something of the nature of the baby's skeleton. The general condition at certain ^ periods of life is also of interest. » Brief Survey of the Skeleton at Different Ages. At birth : Head .' . . .Skull-hone?, have unossified borders and angles, therefore, the membrane is soft at the fontanelles; the base of the skull is largely in cartilage, and the bones are slightly movable. Face-hone?, small and very incomplete. Spinal column Bodies of vertebrae partially ossified, with much cartilage between them. Arches, each in two separate pieces or halves. Pelvic-girdle Hip-bones (ossa coxae) in two pieces, well separated by cartilage. Sacrum partially ossified. Coccyx not at all ossified. Ribs Shafts only are bony. 70 DEVELOPMENT OF BONES. 7I Sternum Presents a number of small centers, imbedded in carti- lage. Upper extremity Shmdder-girdle ossified at acromial end of clavicula and in body of scapula; other parts are cartilage. Long bones — Shafts partially ossified. Carpus — all bones entirely cartilaginous. Lower extremity Long bones — Shafts partially ossified; at the knee the ends of the femur and the tibia have begun to ossify. Tarsus — three bones (talus, calcaneus, and cuboideum) have begun to ossify. The metacarpal, metatarsal and phalangeal bones have thin lines of osseous tissue before birth. At age of 20 years : Head 1 Hands [ All completed. Feet J Long bones All completed except tibia and fibula whose upper ends are not yet united with the shafts. Ribs 1 A • . • u } Are m two pieces each. Sternum J Shoulder-girdle Clavicula, sternal end still separate. Scapula soft at borders and processes. Pelvic-girdle Hip-bones (ossa coxae) completed. Sacrum and coccyx still in two or more pieces. Spinal column All parts ossified. At age of 25 years :. . .The skeleton is practically completed. The bones are strong, and the proper proportions of animal and mineral matter are preserved during adult life. The coccyx may unite with the sacrum in middle life, thus modifying one of the diameters of the pelvic outlet. In old age : There is no more growth. The supply of animal matter decreases, and the bones become brittle so that they may be easily broken. P01NT.S OF Practical Interest Concerning the Bones in Infancy. First, the baby's bones are soft, and are still largely composed of cartilage. Second, since the process of ossification is going on continually, the proper shape of the cartilage should be preserved in order that the shape of the future bone may be normal. In infancy the skull bones are movable as well as soft, and the shape of the baby's head may be altered by pressure. Witness the Flat- head Indians, who bind a board across the top of the infant's skull. 72,, ANATOMY AND PHYSIOLOGY FOR NURSES. The spine and the vertebral extremities of the ribs are com- posed largely of cartilage; it is therefore evident that not only should a baby's back be supported, but the child should rest in a horizontal position, the spine being so soft that it cannot easily be held upright, even if the little muscles were strong enough to do this without fatigue. The pelvis and hip. — During the first year or two both the sacrum and the coccyx are still in separate pieces, while the centers in the three portions of the hip-hones are well separated by carti- lage, leaving the acetabulum unossified; the head of the femur is also soft. Consequently, a thought only is needed to explain why the clothing about a baby's hips should leave them free from pressure. Note. — An advantage is derived from the softness of the skeleton during childhood, as the many jarrings and tumbles incident to the child's experience are far less injurious to the jelly-like frame than they would be to a harder one. Green-stick fracture. — Up to the age of four years the bones are sufficiently soft to hend rather than break, as an older bone would do under similar circumstances. Usually some of the fibers do break, but not the whole bone; this is called a green- stick fracture, because the bone behaves like a bough of green wood when forcibly bent. Rachitis or rickets. — In this disease ossification is delayed, and the bones are more soft and yielding than usual until completely ossified. The extremities grow larger and the shafts are often bent. When the mineral salts are finally deposited the bone is permanently misshapen. Spina bifida. — In the formation of the vertebrae, the com- pletion of the arches and spinous processes occurs latest in the lower lumbar and upper sacral region. Sometimes it is not perfect, and the spinal canal is then left open. This condition is known as spina bifida and the membranes and fluid of the spinal cord protrude, forming a tumor upon the child's back. Spina bifida occurs rarely in other regions. Repair of Bone. When a bone is broken nature repairs it in her own way. First, more blood flows to the part; then a certain amount of animal matter like cartilage, appears about the fracture, forming REPAIR AND PHYSIOLOGY OF BONES. 73 a callus. This is soon hardened by deposit of mineral matter and the callus becomes bone, but the mark of fracture and repair will always remain. The callus will form and unite the ends of bone even if they are not well matched, but in this case deformity will result. Surgical note. — "Setting" a fractured bone consists in placing the ends in proper position, or "apposition." This, nature cannot do, because the muscles above and below are pulling them out of place, therefore the skill of the surgeon is required for its accomplishment. Practical point. — The nursing care of a fracture is directed to the end of keeping the bone supported in position, and as far as may be, perfectly quiet until the callus is hardened, so that the least possible deformity will remain. To accomplish this the nurse must not only have a knowledge of anatomy, but must exercise skill and judgment to an unusual degree. PHYSIOLOGY OF BONE AND THE SKELETON. At first thought it would appear that not much could be said concerning the physiology of bone tissue, which is a finished product, the changes which it undergoes being directed solely to its own pres- ervation. The ability of bone to repair injuries by utilizing ma- terial from the blood is, however, a physiological process; and the membranes which cover bony surfaces (periosteum outside, endos- teum within medullary canals) have a well-defined function in the formation of bone tissues, already referred to. One of the most important functions of the body, namely: — providing an origin for cells (or corpuscles) of the blood, belongs to the marrow of bones. Cancellous bone contains in its spaces thin red marrow (the "red bone marrow" of clinic use) in which red cells have their origin, while the medullary canals of long bones contain a firmer fatty maiTow where many of the white cells of the blood have their beginning. Taking a broad view, we find many points of interest in the bones and the skeleton which they comprise, some of which have already been touched upon. It is their mechanical physiology which is con- spicuous and of great importance — they afford attachment to mus- cles; they enclose cavities; they sustain pressure. 74 ANATOMY AND PHYSIOLOGY FOR NURSES. Their usefulness is due to their physical characteristics — for instance, the hardness of bones enables the framework which they compose to support the soft parts of the body, and in certain localities enables them to protect internal organs. An important example is the neural canal with its contents — the brain and spinal cord. Again, it is this same quality of hardness which enables the skel- eton to bear direct pressure and the body weight. Osseous tissue in certain bones — notably the femur and the os coxae — is especially arranged in lines of pressure for this purpose; namely, that super- imposed weight may be borne with the least strain upon the bone. The relation between the shapes of bones and the arrangement of their two tissues has a direct bearing upon their usefulness and the convenience with which it is exercised. Examples are seen in the long bones — their (comparatively) large extremities enter into the formation of joints; they also give attachment to many muscles which move the joints. Here, extent of surface is needed and cancellous bone is used with but a thin covering of . compact, thus securing the necessary surface without undue weight. Their shafts give attachment to fewer muscles, but their position in the extremity exposes them to violence (applied transversely) and calls for endurance of strain. Hence, for these two reasons — first, that extent of surface is unnecessary; and second, that strength and endurance are demanded — the compact tissue is appropriate. It also secures a convenient slenderness of bone where the bulk of muscle tissue is greatest. By far the greatest variety of functions is seen in the articulated skeleton, whereby the movements necessary to the well-being of the individual are made possible by the character of the joints. The movements of the trunk are limited, but sufficient for the needs of the organs which it contains; while those of the extremities are many and free. They may resist external force; they may themselves overcome opposing forces. They may be used as weapons of offense or defense. Facilities for tansporting the body from place to place, or locomotion, are provided by the articulated bones of the lower extremities; and the power of the upper ex- tremities to perform a thousand necessary acts would not exist without a similar framework. These points have been mentioned already, and will be dwelt upon later in connection with the study of the muscular system. CHAPTER VI. THE CONNECTIVE TISSUE FRAMEWORK AND THE SKELETAL MUSCLE SYSTEM. THE FASCI.E OF THE BODY AND MUSCLES OF THE HEAD AND TRUNK. Although present In every part of the body, the connective tissue is so conspicuously associated with the muscle system that a few facts of interest concerning this universal tissue are here reviewed, before commencing the study of the muscles. For muscles it is a veritable framework, as will be seen. In fibrmis form it is conspicuous on their surfaces as sheaths, or as separating one from another; and in tendons. As delicate areolar tissue it invades them, bearing tiny vessels and nerves and forming tissue-spaces. This it does in all organs — wrapping them, supporting their cells, and invading them to convey vessels and nerves. It fills in spaces between organs, and accompanies large vessels to and from them. It connects organs to each other; and everywhere it forms a network of tissue-spaces containing nutritive fluid obtained from the blood-vessels for the cells of the body. If one could imagine that everything in the human body except connective tissue could be destroyed, the remaining portion would bear the same relation to the body that had been, as a skeleton leaf bears to a fresh green one. THE FASCLE OF THE BODY. The word fascia is applied to the connective tissue which sur- rounds various organs or lines cavities. Fascia is found in every part of the body, and we shall study here two varieties, which are associated with the muscles and skin. They are called the deep and the superficial fascia. The deep fascia. — This is a firm layer of connective tissue with but small spaces between its fibers, therefore it is dense and 75 76 ANATOMY AND PHYSIOLOGY FOR NURSES. tough. It is white and smooth, and seldom contains any fat. The deep fascia covers the muscles and binds them down, and also separates them into groups, thus forming intermus- cular septa. (Many muscle fibers arise from intermuscular septa.) (Fig. 65.) Special points. — The inguinal liga- ment (Fig. 74) is a band of the deep fascia between the spine of the ilium and the tubercle of the pubes. It feels like a cord from one bone to the other. The fascia lata {broad fascia) is the deep Fig. 65. — Deep Fascia of Thigh (Partial). 6, 7, 8, 10, 14, indicate portions of fascia lata. — (Gould's Dictionary.) Fig. 66. — Showing Oval Fossa. The superficial fascia has been dis- sected away, leaving cutaneous veins lying upon deep fascia. fascia of the thigh; it is thicker and stronger than any other fascia of the body. It is attached to the hip-bones above and the leg-bones below. A ■portion which is especially tense and strong may be felt on the lateral side of FASCIA OF THE BODY. 77 the thigh, above the tuberosity of the femur, like a tight band attached to the tibia; it is called the ilio-tibial band. See page 105, tensor fascia lata. The oval fossa or saphenous opening in the fascia lata is an inch and a half below the medial portion of the inguinal ligament. It allows the long saphena vein to pass through to the femoral vein (Fig. 66 ). The lumbar fascia is not a part of the general deep fascia of the body, but belongs to the transversus muscle described on p. 90. It is attached behind to the lumbar vertebrce, above to the last tivo ribs, and below to the crest of the ilium. The superficial fascia covers the deep fascia. It lies immedi- ately beneath the skin in its whole extent and consists of loose- meshed connective tissue, arranged somewhat in layers, and con- taining the subcutaneous fat. It also imbeds the superficial or cutaneous arteries, veins, and nerves between its layers. In places where the fascia is thin, as on the back of the hand, the veins are easily seen. This fascia is closely connected with the skin, and they glide together over the deeper structures. A bursa is a sac in the fascia which contains smooth fluid resem- bling syno\da. Bursce are found where much pressure or friction occurs between different structures. They act like water-cushions, thus saving the tissues from bruising or rubbing. The largest sub- cutaneous bursa is in the superficial fascia in front of the patella. It is called the prepatellar bursa (Fig. 62). Surgical note. — When the prepatellar bursa becomes inflamed and enlarged, it forms "housemaid's knee." Sometimes bursas are placed underneath tendons or between muscles, and these deep ones may communicate with joints. There is a large one between the gluteus maximus and the tuberosity of the ischium, and another between the same muscle and the great trochanter. Note. — The transversalis and pelvic fasciae are described on pages 93 and 103. MUSCLES, THEIR IMPORTANCE. The growth of bone and fashioning of joints has but prepared the way for more important ends to be accomplished. The head and trunk protect and support the vital organs, but the food and the air upon which their life depends come only through 78 ANATOMY AND PHYSIOLOGY FOR NURSES, the aid of those constant workers, the muscles. All motion of any sort in the body, whether conscious or unconscious, is due to their action. If the motion is voluntary it is due to muscles which are controlled by the will, or voluntary muscles. Muscles which cannot be controlled by the will are involuntary; they are found in the inter- nal organs of the body, or the viscera, and in the coats of the vessels. All other muscles are volun- tary, and since they are at- tached to bones they are called skeletal muscles. Note.— The general appear- ance of muscle tissue may be learned from specimens obtained in markets, and almost all of the various shapes may be studied in the domestic fowl. STRUCTURE OF MUSCLES. Muscles consist chiefly of collections of red fibers, each fiber composed of little bun- dles of muscle-cells. All of these are wrapped in connec- tive tissue, bound together and enclosed in a sheath. Examining a muscle with care, we can strip off the sheath of con- nective tissue (epi-mysium) , and we shall find that it sends layers down into the muscle to form septa or partitions (peri-mysium) enclosing the bundles (or fasciculi) of which the muscle is made up. With the aid of the microscope the fiber cells which compose the bundles are revealed, surrounded by still more delicate connective tissue (endo-mysium). Also, under the microscope the fiber cells of voluntary muscle tissue appear striped, consequently voluntary muscle is said to be striped or striated. In- voluntary fiber cells are plain — involuntary muscle is unstriped or non-striated. This sort of muscle is found in internal organs, whose work must go on con- tinually without our conscious supervision. Exception. — The heart: which acts whether we will or not, although its muscle is striated. Fig. 67. Muscles. (Holden.) -Showing Lxtremities of Tendon. 5, Aponeurosis. — STRUCTURE OF MUSCLES. 79 In most cases the connective tissue is prolonged beyond the mus- cle into a white cord or band called a tendon, if the muscle is long and thick; or into a broad thin layer called an aponeurosis if the muscle is flat; and by these tendons and aponeuroses the muscles are attached to bones and other organs. Sometimes the red fibers are attached directly to the parts which they move, but in by far the greater num- ber the tendons are conspicuous (Fig. 67). Muscles are described as consisting of a body and two ex- tremities; the body or belly being the red contracting part which swells in action, while tendons (which are possessed by most of the muscles) are simply strong white fibrous bands having no power to contract and no elas- ticity. This is equally true of the aponeuroses. The attachments of the ex- tremities are spoken of as the origin and the insertion. The extremity which is stationary while the other end moves, is the origin; the end which moves with the organ attached to it, is the insertion. The insertion is always pulled toward the origin when the muscle contracts. THE MUSCLES OF THE TRUNK. ^ Intercostal muscles. — In two sets, the internal and the external, which occupy the in- tercostal spaces. The fibers run obliquely from rib to rib, the in- ternal fibers running upward and forward, the external fibers running downward and forward. Action. — They move the ribs up and down in breathing and the various acts associated with it. ' Many skeletal muscles have their origin partly from the deep fascia covering them. The bony origins only are given here, as a rule. Fig. 68. — Intercostal Muscles. — (Morris.) 8o ANATOMY AND PHYSIOLOGY FOR NURSES. Principal Muscles of the Back. In the skeleton a broad groove exists on either side of the spinous processes, which is filled in its whole extent with many vertical muscles of different lengths, the use of which is to hold the spine in the erect position; also they assist to move it in various directions. The erector spinae is the name given to this large group, which is bound down in its place by a thin layer of fibrous tissue called the vertebral aponeurosis. This muscle group extends from the skull to the lower part of the sacrum (Fig. 69). The action is most easily seen in the lumbar and dorsal regions, where it is not deeply covered with other muscles. Nerves. — Posterior spinal. The latissimus dorsi (broadest of the back, Fig. 70). — This muscle covers most of the erector spinae and a great portion of the back of the trunk. Origin. — The spinous processes, from the sixth thoracic down to the end of the column. Also the crest of the ilium and a few fibers from the inferior angle of the scapula. Insertion. — The crest of the lesser tubercle of the humerus. Action, — ^Principally to pull the arm backward and keep the scapula or shoulder- blade close to the chest; brought prominently into use in rowing a boat or when the body is suspended by the hands and an effort is made to draw it up. Nerves. — Posterior spinal and long subscapular. Muscles of the Back of the Neck. These muscles move the head and neck. Only the most im- portant are here described. The splenius. — This muscle is in two portions, the splenius of the head (capitis) and the splenius of the neck (cervicis) (Fig. 69). -The Figures Refer to the Spinal Group AND the QuADRATUS LuM- BORUM. — (Potter's Anatomy.) MUSCLES OF THE NECK. 8r Origin. — The spinous processes of the last cervical and first six thoracic vertebras. Insertion. — Partly upon occipital and mastoid bones {splenius cap- itis) and partly upon the transverse processes of the upper vertebrae {splenius cervicis) . Fig. 70. — Superficial amp Middle Muscular Layers of the Posterior Aspect OF THE Trunk. — Holden.) I, Trapezius; 2, latissimus dorsi; 3, aponeurosis; 4, 5, 6, 8, 19, 20, different portions of latissimus dorsi; 9-12, deep muscles; 13, stemo-mastoid; 14, splenius; 15, elevator of scapula; 16, infraspinatus; 17, teres minor; 7, 18, teres major; 21, portion of anterior serratus; 22, 23, abdominal muscles; 24, 25, gluteus maximus; 26-30, deep muscles; 31, deltoid; 32, triceps. Action. — The muscle of one side alone will rotate the head, tw^isting the neck. The muscles of both sides acting together simply pull the head backward or extend it and the neck. Nerves. — Posterior cervical. 6 82 ANATOMY AND PHYSIOLOGY FOR NURSES. The trapezius covers the other muscles of the back of the neck, and also the upper portion of the latissimus dorsi. It is one of the largest muscles in the body (Fig. 70). The two muscles, right and left together make a large diamond-shaped sheet. Origin. — The occipital bone, the ligamentum nuchae, and the spinous processes of the thoracic vertebrae. Insertion. — ^The spine of the scapula and lateral third of the clavicula. Action. — With the shoulders stationary the trapezius acts upon the head to pull it backward or sideways. With the head stationary it can elevate the shoulder-girdle and the whole upper extremity with it. Both muscles together can draw the shoulders back. If the hands grasp a bar above the head these muscles will assist to draw the body up. The largest two of the "climbing muscles" are the latissimus dorsi and the trapezius. Nerves. — Cervical, and spinal accessory. Note. — Observe in the illustration its tendinous area, which remains flat during action of the muscle. Clinical Note. — Spasmodic action of the trapezius is often the cause of wry-neck, or torticollis, and this may be increased by spasm of the splenius. Muscles or Head, and Front and Side of the Neck (Fig. 71). The muscles of expression are those of the scalp and face. They are closely connected with the under surface of the skin, or with each other; they have no deep fascia over them, and therefore their slightest contraction is shown on the face, thus varying the movements and lines of expression. Epicranial muscle.— On the forehead and the top and back of the head — a broad thin muscle made up of two distinct parts with an aponeurosis between them. The posterior part is the occipitalis, taking origin from the curved line of the occipital bone and ending in the aponeurosis on the top of the head. The anterior part is the frontalis, having origin in the aponeurosis, and passing down over the forehead to the insertion in the tissues of the eyebrows. Action. — ^Principally to lift the eyebrows, producing the trans- verse wrinkles across the forehead which express surprise. The skin is closely connected with this double muscle in its whole length, THE EPICR.A.NL\L MUSCLE. 83 SO that contraction causes movement of the scalp. (Some people can move the scalp backward and forward by contracting the two portions alternately). Epicranial aponeurosis Frontalis Fig. 71. — Muscles of tiie Head and Neck. — (Morris.) The aponeurosis extends in a thin layer at the side over the temporal region, giving origin to certain small muscles which move the ear. The scalp and ear usually move together. Nerve. — Seventh cranial {or facial). §4 ANATOMY AND PHYSIOLOGY FOR NURSES, Orbicularis oculi. — The ring-like muscle of the eyelid. It is attached to the medial border of the orbit. Some of its fibers are in tjjg \{^ — the palpebral portion — while others surround the lids like a broad flat ribbon, forming the circular or orbilal portion, and bearing the eyebrows (Fig. 71). Action. — When the palpebral fibers contract the lids cover the eyeballs lightly; when the circular fibers contract the lids are pressed against the ball. Nerve. — Seventh cranial. Levator palpebrag (elevator of the eyelid). — Within the orbit. Origin. — At the apex of the orbit. Insertion. — In the upper lid. Action. — It lifts the lid and opens the eye. Nerve. — Seventh cranial. Corrugator. — The muscle which wrinkles the eyebrow. Origin. — The frontal bone. Insertion. — The under surface of eyebrow. Action. — It draws the brows downward and inward toward each other; it is the frowning muscle. Nerve. — Seventh cranial. Orbicularis oris (ring muscle of the mouth). — Surrounds the opening of the mouth, constituting the larger portion of the lips. The fibers have only one bony attachment — below the septum of the nose. Action. — It closes the mouth. The lips themselves are moved in various ways by muscles above and below them — the elevators and depressors of the lips (all supplied by the seventh cranial nerve). Special points. — Most of the changes in the expression of the face are caused by the action of the ring imiscles and of those which are attached to them. For example, the lifting of the eyelids by the frontalis expresses surprise. The wrinkling of the brows by the corrugators speaks disapproval or bewilderment. The risorius, or laughing muscle, draws the corners of the mouth outward. The sneering muscle lifts the nostril, and lip together. Pleasure is expressed by the lifting of the angles of the lips upward and outward, while grief depresses them. (There are but three of the depressors, or grieving muscles, on each side, and six for the manifestation of happier feelings.) Muscles of Mastication, Five in Number The temporal muscle. — Occupying the entire temporal fossa. Origin. — The floor of the fossa, and the temporal fascia covering it. Insertion. — The coronoid process of the mandible. MUSCLES OF MASTICATION. 85 Action. — It closes the mouth and draws the mandible or lower jaw-bone backward. Nerve. — Fifth cranial (or tri-facial). The masseter. — At the side of the face (Fig. 73). Origin. — The zygomatic arch. Insertion. — The lateral surface of the ramus of the mandible. Action. — It closes the mouth and moves the jaw forward slightly. Nerve. — Fifth cranial. Temporal Buccinator Fig. 72. — The Temporal Muscle. — (Morris.) The internal pterygoid. — In the infra-temporal fossa covered by the ramus of the mandible on which it is inserted. Action. — It closes the mouth and moves the ']a.w forward and sideways. External pterygoid. — Also in the infra-temporal fossa and inserted on the mandible. Action. — It moves the jaw forward and sideways. Nerve. — Fifth cranial. Buccinator. — Origin, from both the maxilla and the mandible on the alveolar borders. The fibers approach each other, interlacing and running forward, and some of them join the lip muscles, constituting the insertion (Fig. 72). 86 ANATOMY AND PHYSIOLOGY FOR NURSES. Action. — It helps to close the mouth, and keeps the food between the teeth during the act of mastication. Nerves. — Fifth and seventh cranial. By the action of the first four muscles the food is divided and crushed, and also ground; the external pterygoid is especially a grinding muscle. The function or use of these four would be some- what limited without the aid of the buccinator. Muscles in the Front of the Neck. The ribbon muscles, thin and fiat, connecting the larynx and hyoid bone above, with the sternum, rib, and clavicula below. Fig. 73. — Muscles in Front or the Neck. I, 2, 3, Digastric muscle; 4, stylo-hyoid; 5, mylo-hyoid; 6, hyo-glossus; 7, 8, 9, sterno-mastoid; 10, 11, 12, 13, 14, ribbon muscles; 15, pharynx; 16, occipitalis; 17, ear muscles; 18, trapezius; 19, 20, splenius; 21, levator scapulae; 22, 23, scalene; 24, deltoid; 25, pectoralis major; 26, right platysma; 27, 28, lip muscles; 29, masseter; 30, buccina- tor.— (From Holden.) They are the stemo-hyoid, the stemo-thyroid, and the otno-hyoid (a double-bellied muscle, with an intervening tendon, the inferior belly being attached to the upper border of the scapula, the superior belly to the hyoid bone, while the tendon between them glides through a loop of fascia attached to the clavicula). MUSCLES OF THE NECK. 87 Action of the three muscles. — They draw the hyoid bone and the larynx downward, and steady them. Nerves. — Ninth cranial, or hypoglossal. The digastric is another double-bellied muscle (Fig. 73). The posterior belly is attached to the mastoid process (medial surface) ; the anterior belly to the under surface of the mandible close to the symphysis. The intervening tendon glides through a loop of fascia connected with the hyoid bone. Action. — It draws the mandible downward, and opens the mouth. It is assisted by some other short muscles connecting the mandible to the hyoid bone. Nerves. — Sei'enth cranial and fifth cranial. The mylo-hyoid (Fig. 73) is a flat muscle which forms the floor of the mouth, being attached by one border to the inner surface of the body of the mandible, and by the other to the hyoid bone, which, it will be remembered, is on a level with the mandible. Action. — It can draw the hyoid bone forward in the act of swallowing, thus keeping the larynx out of the way of the food. Nerves. — Seventh cranial {and cervical). The platysma. — As the muscles of the back and side of the neck are covered by the trapezius, so those of the front and side are covered by the platysma, which is a broad thin sheet of muscular fibers attached above to the mandible and the fascia of the side of the face, and below to the deep fascia on the front of the shoulder (Fig. 71). Like the face muscles, it is not covered by deep fascia, and since it moves the skin, it is like them a muscle of expression. It draws the angle of the mouth downward, and strong contractions of the muscle assist in causing an appearance as of one in a "great rage." The action of this muscle in grazing animals is displayed when used to shake off insects which alight upon the skin of the neck. The sterno-cleido-mastoid (Figs. 71, 73) is the most conspicu- ous muscle in the side of the neck. Origin. — By two divisions, one on the sternum (sternal, or medial origin), the other on the clavicula (clavicular, or lateral origin). Insertion. — The mastoid process and upper curved line of the occipital bone. Action.— Principally to pull the mastoid process toward the sternum and clavicula. If the righl muscle contracts the right mastoid process comes downward and forward and the chin turns upward to the left. If the left muscle contracts the left mastoid is pulled downward and forward and the chin goes upward to the right. Both muscles together simply bend the head forward, or flex it. Nerves. — Spinal accessory {and cervical). S8 ANATOMY AND PHYSIOLOGY FOR NURSES. Clinical note. — The sterno-mastoid is another muscle which is sometimes the seat of spasmodic contractions, causing wry-neck, or torticollis. Levator scapulae. — The elevator of the scapula is an important muscle in the side of the neck. Origin. — The upper three or four transverse processes. Insertion. — The medial angle of the scapula. Nerves. — Cervical. Fig. 74. — Anterior Surface of the Abdominal Wall. I) 2, 3, 7, Pectoralis major; 4, external oblique; 5, serratus anterior; 6, latissimus- dorsi; 8, xiphoid appendix; 9, 9, 15, aponeurosis of ext. oblique; 10, 14, linea alba; 11, umbilicus; 12, transverse lines of aponeurosis; 13, 13, subcutaneous abdominal ring; 16, 17, 18, 19, refer to muscles of neck; 20, deltoid. — (Gould's Dictionary.) Lower border of aponeurosis is inguinal ligament. THE ABDOMINAL WALL. The abdominal wall has no bones except the lumbar vertebrae, being mostly muscular and aponeurotic. Each lateral half is com- posed of one vertical muscle in front, next to the median line;^ ABDOMINAL MUSCLES. 89 another in the back, next to the spinal column; and three well- developed layers having fibers of different directions, at the sides. Rectus abdominis (Fig. 75). — This is the vertical muscle in front. Origin. — The body of the pubes. Insertion.— The ensi- form appendix and the cartilages of the fifth, sixth, and seventh ribs. It is therefore narrow below and broad above, and its outer border is curved from the seventh rib down to the pubes. This is indicated in the fascia over the muscle by a distinct line called the linea semilunaris {semilunar line). Fig. 75. — Internal Oblique and Transverse Muscles. I, Rectus abdominis; 2, 2, 3, 3, internal oblique and cut edge of its aponeurosis; 4, 4, cut edge external oblique; 5, 5, spermatic cords; 6, aponeurosis ext. oblique turned down; 7, rectus, upper part removed; 8, 8, 9, transversus muscle; 10, umbilicus; 11, 12, linea alba; 13, serratus anterior; 14, 15, cut edge latissimus dorsi; 17, 17, external inter- costal; 19, cut edge external oblique. — (Gould's Dictionary.) Action. — It compresses the abdominal organs. Nerves. — Lower thoracic. Quadratus lumborum. — This is the vertical muscle at the back (Fig. 69). Origin. — The crest of the ilium. Insertion.— The lowest rib and transverse processes of the lumbar vertebrae. It occupies the space at the back of the trunk between the thorax and pelvis, being covered by the erector spinge and latissimus dorsi. 90 ANATOMY AND PHYSIOLOGY FOR NURSES. Action. — It draws the rib down and the spine to one side — lateral flexion of the trunk. Nerves. — Lower thoracic. The three layers at the side and front consist of the obliquus externus or external oblique; the obliquus internus, or internal oblique; and the transversus muscles. They occupy the space between the eight lower ribs above, and the ilium and pubes below. Being broad and fiat they do not possess tendons of the usual kind, but many of their muscle fibers terminate in layers of white fibrous tissue called aponeuroses, which continue to the median line, there blending with the layers from the opposite side. This produces a firm interlacing of white fibers called the linea alba or white line, stretched between the ensiform appendix above and the body of the pubes below. It is a very strong and important line, through which, a little below the middle, the umbilical cord passes in the fetus. This point in the linea alba is indicated by the umbilicus, or navel. The external oblique (Fig. 74) is the outermost of the three layers. Origin. — The lower eight ribs. Direction of fibers, down- ward and forv/ard. Insertion. — Some fibers on the crest of the ilium; others in an aponeurosis which passes to the linea alba. Nerves. — Lower thoracic. Special point. — The lower border of the aponeurosis of this muscle between the spine of the iUum and the spine of the pubes is firm and unyielding, easily felt, and important to be recognized; it is called the inguinal ligament (or Pouparfs ligament) . The internal oblique (Fig. 75) lies underneath the external oblique. Origin. — The lumbar fascia, crest of the ilium, and lateral half of the inguinal ligament. Direction of fibers, upward and for- ward. Insertion. — Some fibers on the lower four ribs, others in the linea alba, and the lowest ones on the crest of the pubes. Nerves. — Lower thoracic and ilio-inguinal. The transversus (Fig. 75) is the innermost of the three layers. Origin. — The lower six ribs, the lumbar fascia, crest of the ilium, and lateral half of the inguinal ligament. Direction of fibers, trans- versely across the side of the abdomen, toward the front. Inser- tion.— In the linea alba, and the crest of the pubes. On the pubes it is blended with that part of the internal oblique which is attached to the same bone, making the conjoined tendon. Nerve. — Lower thoracic. SHEATH OF RECTUS ABDOMINIS. DIAPHRAGM. 91 Action, of the three broad muscles. — They compress the ab- dominal viscera and expel the contents of those which are hollow. The fibers from the inguinal ligament, of both internal oblique and transversus muscles, arch downward to the pubes. Sheath of the Rectus Abdominis (Figs. 74, 75). In the lower fourth of the linea semilunaris, the entire thickness is continued forward as one layer in front of the muscles. In the upper three-fourths the linea semilunaris divides into two layers which meet again in the linea alba; thus a compartment is formed to be occupied by the rectus muscle. This is called the sheath of the rectus, with its anterior and posterior layers, the anterior layer being thickest and strongest in the lower part where the greatest strain would be brought upon it. Lineae transversse (transverse lines). — At three different levels above the umbilicus the anterior layer of the sheath is held down to the rectus muscle by fibers forming three transverse lines. Note. — The location of all these markings — the semilunar line, the white line, and the three transverse — may be seen on the surface of the body during the action of the muscles; and in a piece of statuary representing the trunk they should be plainly indicated (Fig. 74). Roof of the Abdomen. The roof of the abdomen is the diaphragm; it has no floor of its own, the pelvic floor serving for both cavities (page 103). The diaphragm. — This is a broad, thin, dome-shaped muscle separating the abdom- inal and thoracic cavities. The central portion is apo- neurotic, serving for the in- sertion of the remaining or muscular portion. Origin. — a. By two vertical bundles at the sides of the lumbar vertebrce. These vertical portions are the crura of the diaphragm. Their fibers turn forward, crossing and interlacing before they end Fig. 76. — The Diaphragm. Dotted lines indicate descent in contraction. — (Holden.) 92 ANATOMY AND PHYSIOLOGY FOR NURSES. in the central tendon, b. From arches of lumbar fascia and the lower boundary of the thorax (seventh to twelfth ribs and xiphoid appendix). Insertion. — In a fiat central tendon, shaped like a clover leaf, near the center of the dome. The lateral portion arches higher than the central, forming a cupola on each side. Action. — When the diaphragm contracts it becomes flattened, pressing upon the abdominal organs; when it relaxes, it springs back to its 'dome-shape, as high as the fourth or fifth rib, pushing gently against the lungs. Nerve. — Phrenic. Fig. 77. — The Diaphragm, Inferior Surface. I, 2, 3, Tendinous leaflets; 4, muscle fibers; 5, 6, 7, tendinous arches; 8, 10, fibers arising from vertebrae; 11, aorta — a large artery; 12, esophagus, leading to stomach; 13, opening for vena cava. — (Potter's Compend of Anatomy.) Special points. — This muscle forms the floor of the thorax, and at the same time the roof of the abdomen (convex floor, concave roof). There are three openings in it at the back part for the passage of a large artery and vein, — the aorta and vena cava, and the esophagus. With the muscles thus far described the walls of the cavities of the trunk— dorsal and ventral — are completed (see page 48). Interior Abdominal Muscles. The psoas major and iliacus. — These are two muscles within. the abdomen (on the posterior wall) which pass out over the brim of the pelvis into the thigh. ILIO-PSOAS. 93 Psoas major. Origin. — The sides of the lumbar vertebrae. Insertion. — Trochanter minor of the femur. Iliacus. Origin. — The iliac fossa. Insertion. — With the psoas on the trochanter minor of the femur. Action. — -They act together as one muscle, the ilio-psoas, to flex the thigh, at the same time rotating it, so that the foot turns outward. Nerves. — Lumbar and femoral. Fig. 78. — Abdominal Muscles, Interior. 1-5, Psoas minor and major; 6, attachment of psoas major to trochanter minor, 7, 7, 8, 8, iliacus; 9, 9, cut tendon rectus femoris; 10, 10, obturator externus; 11-13 quadratus lumborum; 14, 14, transversus. — (Gould's Dictionary.) Surgical note. — Disease of the lumbar vertebrs resulting in pus forms psoas abscess. The pus often follows the muscle fibers downward and appears below the inguinal ligament. (The psoas minor is a small muscle in front of the major.) The transversalis fascia is a layer of loose connective tissue which completely lines the abdomen; it is continuous with the iliac fascia on the iliacus muscle and with the pelvic fascia below. CHAPTER VII. MUSCLES OF THE EXTREMITIES. The muscles of the extremities are frequently named for their use, and they may all be grouped according to their action; as flexors, to bend the joints over which they pass, and extensors to straighten them; pronators and supinators; abductors smd adductors; and rotators, inward or outward. Their origins are not only from bones, but from fascia, and the fibrous septa between them. This is true of most muscles to some extent, but particularly so in the extremities. The bony attachments only are given here. MUSCLES OF THE UPPER EXTREMITY. Shoulder Muscles. Supraspinatus. — On the dorsal surface of the scapula. Origin. — The supraspinous fossa, the tendon passing over the head of the humerus to the insertion on the top of the greater tubercle. Action. — It lifts the arm away from body (abduction). Infraspinatus. — Also on the dorsal surface of the scapula. Origin. — ^The infraspinous fossa. Insertion. — The greater tu- bercle of the humerus (below the supraspinatus). Action. — It rotates humerus outward (the palm turns forward). Nerve, both muscles. — Suprascapular. Teres minor. Origin. — The axillary border of the scapula. Insertion. — The greater tubercle, just below the infraspinatus. Action. — It rotates humerus outward {palm turns forward). Nerve. — Axillary. Teres major. Origin. — Near the inferior angle of the scapula (on axillary border). Insertion. — The shaft of the humerus (crest of lesser tubercle), joining the tendon of the latissimus dorsi and acting with it (Fig. 79) . Action. — It draws the arm backward, and rotates it inward (the- palm turns backward). Nerve. — Subscapular {lower) . 94 MUSCLES OF THE SHOULDER. 95 Subscapularis (Fig. 8i). Origin. — The subscapular fossa. Insertion. — The lesser tubercle of the humerus. Action. — It holds head of humerus in place and rotates it in- ward (the palm turns backward). The deltoid (Fig. 80).— Is triangular in shape and forms a sort of cap over the shoulder- joint. Origin. — The spine and acromion of the scapula, and the lateral portion of the clavicula. Insertion. — The lateral surface of the humerus at the middle of the shaft, on the deltoid tuberosity. Action. — Principally to elevate the humerus to a hori- zontal position (acting with the supraspinatus, an abductor of the arm). Nerve. — Axillary. The serratus anterior (Figs. 70, 80). — A large flat and important muscle which lies between the scapula and the thorax. Origin. — By separate slips from eight ribs, on the front and side of the thorax. Insertion. — The vertebral border of the scapula. It lies close to the side of the thorax, covering a considera- ble portion of the ribs and intercostal muscles. Three actions. — It holds the scapula firmly in place and pulls it forward, thus pushing the arm ahead. If the shoulders are held firmly it can elevate the ribs, assisting inspiration. It sustains the weight of the body when resting upon hands and knees, as in creeping. Nerve. — Long thoracic or external respiratory. Fig. 79. — Muscles of the Shoulder. I, 2, 3, 4, 5, Triceps; 6, attachment to olecranon; 7, anconeus; 8, 8, g, deltoid (por- tion removed); 10, supraspinatus; 11, infra- spinatus; 12, 13, two extremities of teres minor (intervening portion removed); 14, teres major; 15, latissimus dorsi; 16, 17, 18, 1 9, musclesof forearm. — (Gould's Dictionary.) c)6 anatomy and physiology for nurses. Breast Muscles. Pectoralis major. Origin. — Clavicular portion, on the sternal end of the clavicula; sternal portion, on the surface of the sternum and on six upper ribs. Insertion. — By a broad strong tendon on the shaft of the humerus, on the crest of the greater tubercle. Figs. 74, 80. iff 9-1 —13 4-i^' I as 10 n Fig. 80. — Muscles of Anterior Aspect of Thorax. 1-5, Pectoralis major; 6, 9, pectoralis minor; 7, subclavius; 8, deltoid; 10, anterior portion of anterior serratus; 11, external oblique; 12, 13, latissimus dorsi; 14, teres major. — (Gould's Dictionary.) Action. — It draws the arm to the front of the thorax, opposing the latissimus dorsi; thus it also is a "rowing '"muscle. The pectoralis minor is entirely covered by the major. Origin. — Three upper ribs. Insertion. — The coracoid process of the scapula. Action. — It pulls the shoulder downward. It may pull ribs upward in labored breathing or forced inspiration. Nerves of both muscles. — Anterior thoracic. Note. — When the whole body is drawn upward by the hands, as when hanging from a trapeze, the two pectorals, the trapezius and the latissimus are acting together. The subclavius is a small muscle lying in the subclavian groove between the clavicle and first rib. It may elevate the ribs or depress the clavicle. Arm Muscles. Anterior. Biceps brachii (a two-headed muscle). Origin. — The scapula: the long head above the glenoid fossa, and the short head on the MUSCLES OF THE ARM. 97 coracoid process. Insertion. — By one tendon on the tuberosity of the radius (Fig. 8i). Action. — It flexes the forearm on the arm. Nerve. — Musculo-cutaneous. Note. — If the biceps hrachii begins to contract while the hand is pronated, the first effect would be to pull the radial tuberosity around and place the hand in the supinated position, then flexion would follow; in other words, the biceps may act as both a supinator and flexor. The coraco-brachialis. — A smaller muscle, close to the biceps. Origin. — The tip of the coracoid process. In- sertion.— The shaft of humerus, medial side, opposite the deltoid. Action. — It lifts the humerus for- ward. Nerve. — Musculo-cutaneous. The brachialis. — Is underneath the biceps. Origin. — The anterior surface of the humerus. Insertion. — The tuber- cle of the ulna, just below the coronoid process. Action, — With the biceps it flexes the forearm. Note. — This is a broad muscle and covers the front of the elbow-joint. Nerve. — Musculo-cutaneous and radial. Arm Muscles (Fig. 79). Posterior. The triceps brachii (a three- headed muscle). Origin. — The long head, on the scapula, just below the glenoid fossa,; the medial and lateral heads on the posterior surface of the humerus, separated by the groove for the radial nerve. Insertion. — The (top of the) olecranon process of the ulna. Action. — It extends the forearm Nerve. — Radial. 7 E.SALLE S. Fig. 81. — Muscles of the Arm. I, 2, 3, 5, Biceps and bicipital fascia; 4, attachment of biceps to tuberosity of radius; 6, coracobrachialis; 7, 8, inser- tion of pectoralis major; 9, latissimus dorsi (insertion) ; 10, teres major; 11, subsca pularis; 12, brachialis; i^, 14, two heads of triceps. — (Holden.) (opposing the biceps). gS ANATOMY AND PHYSIOLOGY FOR NURSES. Note. — The back of the triceps is covered at its lower portion by a fibrous layer (aponeurosis) which receives many of the muscular fibers. In action, the three heads swell while this fibrous layer remains flat. Muscles of the Forearm. Anterior. The superficial flexors. — The medial epicondyle of the humerus gives origin to a group of superficial muscles which flex the wrist and fingers (Fig. 82). Flexor carpi radialis, or radial Jiexor of the wrist. Origin. — The medial epicondyle. Insertion. — The base of the second metacarpal bone (that of the index-finger). Nerve. — Median. Flexor carpi ulnaris, or ulnar jiexor of the wrist. Origin. — The medial epicondyle and dorsal border of the ulna. Insertion. — • The base of the fifth metacarpal bone. Action of the two. — To flex the wrist. Nerve. — Ulnar. Flexor digitoriun sublimis, or superficial jiexor of the fingers. Origin. — The medial epicondyle, the upper extremity of the ulna, and the shaft of the radius (the three long bones). Insertion. — By four tendons, one for each finger, on the second row of the phalanges. Action. — It flexes the second joints of the fingers, but not the finger-tips. Nerve. — Med 'an. Deep flexors. — The shafts of the bones give origin to the deep flexors of the fingers and thumb, which act upon the third row of the phalanges. Flexor digitorum profundus, or deep flexor of the -fingers. — Is underneath the superficial flexor. Origin. — The shaft of the ulna. Insertion. — By four tendons, on the third or last row of phalanges. Action. — It flexes the finger-tips. Note. — Since the tendons of the superficial flexor stop at the second phalanges, while those of the deep flexor pass to the third phalanges, there is a fissure in each superficial tendon just before it ends, through which the deep tendon passes forward to the bone of the finger-tip (Fig. 82) . Nerves. — Median and ulnar. Flexor poUicis longus, or long flexor of the thumb. — Origin. — The shaft of the radius (under flexor sublimis). Insertion. — The last phalanx of the thumb. MUSCLES OF THE FOREARM. 99 Fig. 82. — Muscles of the Forearm. I, 2, 4, 4, Muscles of arm; 3, tendon of insertion of oiceps; 6, round pronator; 7, radial flexor of wrist; 8, 9, palmaris longus; 10, II, ulnar flexor of wrist; 12, 13, brachio-radialLs; 14-18, muscles and ten- dons belonging to posterior of forearm; iQ, 19, superficial flexor of fingers; 20, 20, 21, 21, tendons of the same, showing fissure; 22, 22, tendons of deep flexor coming through fissure to reach the third row of phalangc-s. — (Holden.) Fig. 83. -Muscles of the Forearm, Dorsal Aspect. I, Aponeurosis of triceps; 2, upper end of brachio-radialis; 3, 4, long radial exten- sor of wrist; 5, 6, short radial extensor of wrist; 7, 8, 8, 9, 9, extensors of thumb; 10, 10, annular ligaments; 11, 12, 12, com- mon extensors of fingers; 13, 14, special extensors for index and little fijigers; 15, 16, ulnar extensor of wrist; 18, ulnar flexor of wrist; ig, posterior border of ulna; 20, olecranon process of ulna; 21, medial epicondyle. — (Holden.) lOO ANATOMY AND PHYSIOLOGY FOR NURSES. Action. — It flexes the tip of the thumb. Nerve.— Ulnar. Note. — These tendons for the fingers and thumb lie in the deep groove on the front of the carpus. Friction between them is prevented by sheaths of synovial membrane. — vaginal synovial membranes. The Two Pronators, the Round and the Square. Pronator teres, or round pronator (Fig. 82). Origin. — The medial epicondyle, and a small slip from the ulna (coronoid process). It passes across to the lateral side of the radius, to the insertion at the middle of the shaft. Nerve. — Median. Pronator quadratus, or square pronator. Origin. — The shaft of the ulna. Insertion. — The shaft of the radius. It lies just above the wrist and underneath the long muscles (close to the bones). Nerve. — Ulnar. Action of the two pronators. — They rotate the radius so as to turn the palm downward (or backward). One slender muscle, which is superficial to all, is the palmaris longus. It arises on the medial epicondyle and is attached below to the palmar fascia to keep it tense — a tensor of the palmar fascia. Nerve. — Median. Note. — It is understood that the muscles arising from the epicondyle have a common tendon of origin. Practical point. — Observe, by experimenting, that flexion and moderate pronation are naturally performed together, and are associated in the majority of the motions which are required of the upper extremity. Muscles of the Forearm (Fig. 83). Posterior. The lateral epicondyle of the humerus and the ridges above it give origin to the muscles which extend the wrist and fingers. Extensor carpi radialis longus, or long radial extensor of the wrist. Origin. — Lateral border and epicondyle of humerus. Insertion. — The base of the second metacarpal bone. Nerve. — Radial. THE SUPINATOR MUSCLES. lOI Extensor carpi radialis brevis, or short radial extensor. Ori- gin.— The lateral epicondyle. Insertion. — The base of the third metacarpal bone. Nerve. — Deep branch of radial. Extensor carpi ulnaris, or ulnar extensor of the wrist. — Origin. ^The lateral epicondyle and dorsal border of the ulna. Inser- tion.— The base of the fifth metacarpal bone. Action of the three. — They extend the wrist. Nerve.— Deep branch of radial. Extensor digitorum communis, or common extensor of the fingers. Origin. — The lateral epicondyle. Insertion. — By four tendons, on the second and third rows of phalanges, in such a way that it can extend the bones of either row separately or both at the same time. The little finger has a special extensor for its tip (e.xiensor minimi digiti). The index finger also has a special extensor {extensor indicis), and the thumb has three — two for its phalanges, and one for its metacarpal bone. By forcibly extending the thumb these three tendons are brought into view, the one for the tip of the thumb being at a little distance from the other two; thus they bound a little hollow which has been called the "anatomic snuff box." Nerves of all. — Deep branch of radial. The Two Supinators. The supinator. Origin. — The lateral epicondyle and upper end of the shaft of the ulna. It winds around the head and neck of the radius to the insertion on upper part of the shaft. This is the chief supinator; it is entirely covered by other muscles. Action. — It rotates the radius and turns the dorsum of the hand downward or backward. Nerve. — Deep branch of radial. The brachio-radialis (Fig. 82). Origin. — The lateral border of the humerus. Insertion. — The styloid process of the radius. Action. — It assists in both flexion and supination of the forearm. (This muscle was formerly called the long supinator.) Nerve. — Radial. Annular Ligaments. These are special bands of deep fascia h(jld!ng in place those tendons which pass the wrist-joint. They include the tendons in I02 ' ANATOMY AND PHYSIOLOGY FOR NURSES. canals through which they glide freely. Friction is prevented by synovial sheaths within the canals. The fascia which binds down the extensor tendons is the dorsal ligament of the wrist; that which conlmes ih.e Jiexor tendons is the transverse ligament of the wrist. Muscles of the Palm (Fig. 82). There is a group of muscles in the palm of the hand which move the thumb in various directions (flexion, abduction, adduction, and so on). They form the elevation called the thenar eminence, or the "ball of the thumb." A similar group for the little finger forms the hypothenar eminence. They arise mostly on carpal bones and deep fascia and are inserted on first phalanges. In the hollow of the hand between these two eminences lie the long tendons, already described, on their way to the fingers; also some small muscles between them and beneath them. The interosseous muscles fill the interosseous spaces. The action of the dorsal group is to spread the fingers apart (abduction) while that of the palmar group is to bring them together {adduction) . Note. — A line drawn from the middle of the wrist to the tip of the middle finger is called the median line of the hand. To abduct the fingers and thumb is to draw them away from this line,^n other words, from the middle finger. To adduct them is to draw them toward the middle finger. Nerves. — To the hypothenar muscles. — Ulnar- To thenar muscles.- — Median and ulnar. The muscles in the palm are covered by particularly dense, deep fascia called the pahnar fascia, or palmar aponeurosis. MUSCLES OF THE LOWER EXTREMITY. The Pelvis — Interior. False pelvis. — The iliacus is the only muscle in the false pelvis; it is already described with the psoas major, page 93. True pelvis. — The piriformis. Origin. — The front of the sacrum; it passes out through the great sciatic notch to the inser- tion on the top of the great trochanter. Action. — External rotation of the femur. Nerve. — From sacral plexus. Obturator internus (also within the true pelvis, Fig. 87). Origin. — The surface of obturator membrane, and a portion MUSCLES OF THE PELVIC FLOOR. 103 of bone around it; it passes out through the small sciatic notch to the insertion on the great trochanter. Action. — External rotation of the femur. Nerve. — From sacral plexus. The floor of the pelvis consists of two flat muscles on either side, the levator ani and the coccygeus. Their origin is on the interior of the pelvic wall, — that is, on the pubic bone and the spine of the ischium, and a line of fascia Sacrum piriformis Coccyx Levator ani (di- vided below the "white line") Space for obtu- rator internus Rectum Prostate Symphysis Fig. Passage for glu- teal vessels and nerve Piriformis Passage for sci- atic and pu- dic vessels and nerve Ischial spine Coccygeus Cellular interval Levator ani Capsule of pros- tate, and pu- bo- prostatic ligaments — Interior and Floor of the True Pelvis. — (Morris.) between these two points. Insertion. — The muscles meet each other in the median line, being also attached to certain pelvic organs (bladder and rectum in the male; bladder, rectum, and vagina in the female) and to the coccyx. Their action supports the pelvic organs, especially the rectum, and lifts them in various motions of the body, as in respiration. Xerve. — From sacral nerves. Special notes. — These two muscles form a concave floor like an inverted dome, which is the pelvic diaphragm. When this dome contracts it rises. There are two openings in the pelvic iioor for the bladder and rectum, and a third opening in the female pelvis for the vagina. The pelvic fascia is a continuation of the transversalis fascia which lines the abdomen and of the iliac fascia which covers the I04 ANATOMY AND PHYSIOLOGY FOR NURSES. iliacus muscle. It covers the obturator muscle and its fascia and the muscles of the floor, and forms ligaments for the pelvic viscera. The Pelvis — Exterior. Three gluteal muscles. — From the three gluteal lines of the os coxas and the spaces above them, arise three gluteal muscles. Gluteus minimus. Origin. — The in- ferior line and space above it. Insertion. — The front of great trochanter. Action. — It abducts the thigh and ro- tates the femur slightly inward (so that the foot turns in). Gluteus medius. Origin. — The ante- iior or middle line and space above it up lo the crest. Insertion. — The outer sur- I ice of great trochanter. Action. — Abduction of the femur and -ome rotation outward. Nerve of both. — Superior gluteal. Gluteus maximus. Origin. — The posterior line and space behind It to the crest (also from the back of ^dcrum). Insertion. — The back of great trochanter and the shaft below it, also the deep fascia, or fascia lata. Action. — External rotation of femur; it is also a powerful extensor of the hip-joint when one rises from the sitting position, or in mounting steps. Nerve. — Inferior gluteal. Fig. 85. — The Gluteal Region. I, 2, 3, 4, 5, 5, Gluteus maximus; 6, 7,8, 10, fascia lata; 9, lower end of tensor fasciae latae; 11, upper portion of biceps femoris; 12, upper portion of semitendinosus; 13, upper portion of semimembranosus; 14, gracilis. — (Gould's Dictionary.) It also abducts the thigh. Obturator extemus. Origin. — The obturator membrane and bone around it. Insertion. — The fossa of great trochanter. Action. — External rotation of femur. (Fig. 78.) Nerve. — Obturator. Practical point. — Observe the number of muscles for external rotation and note that the usual position of the foot is with the toes turned out. THE QUADRICEPS FEMORIS, 105 Muscles of tee Thigh. . Anterior. On the front and the sides of the femur are the muscles which extend the leg — four in number — which blend at their insertion, therefore constituting a four- headed mus- cle, the quadriceps femoris. They are the rectus femoris, the vastus lateralis, vastus medialis and the vastus intermedius. Rectus femoris. Origin. — The an- terior inferior spine of the ilium, and the upper border of the acetabulum. The three vasti. Origin. — On the linea aspera and the three surfaces of the femur. Insertion of the four. — By one tendon passing in front of the knee-joint to the tubercle of the tibia. (It encloses the patella and has been improperly called the ligamentum patellae.) Action. — They extend the leg as in walking, or with great force in kicking; these muscles also keep the patella in place during various positions of the knee. Nerve. — Femoral. The sartorius. — The longest muscle in the body; it passes across the front of the quadriceps. Origin. — The anterior superior spine of the ilium. Insertion. — The inner surface of the tibia, just below the head. Action. — Since it passes across to the medial side of the thigh, and behind the medial epicondyle, it flexes the leg and at the same time lifts it in such a way that when both legs are acted upon together, they Sive flexed and crossed, hence the name, signifying "tailor" muscle. Nerve. — Femoral. The tensor fasciae latae. — Is attached to the anterior part of the crest of the ilium between two layers of the fascia lata; it makes tense the outer portion Fig. 86. — Muscles of the Thigh. I, 2, Iliacus and psoas; 3, 4, tensor fasciie latiE; 5, sar- torius; 6, rectus femoris; 7, vastus lateralis; 8, vastus me- dialis; 9, gracilis; 10, adduc- tor longus; II, pectineus. — (Holden.) io6 ANATOMY AND PHYSIOLOGY FOR NURSES. of the fascia which is connected with the tibia, or the ilio-tibial hand. (This is felt like a strong cord above the lateral epicon- dyles.) It also rotates the thigh inward (Fig. 86). Nerve. — Superior gluteal. Muscles of the Thigh. Posterior. The muscles are three in num- ber— the biceps femoris, semiten- dinosus, and semimembranosus (Figs. 87, d>d>). The biceps femoris. Origin. — Long head on the tuber of the ischium, short head the linea aspera (lateral Hp). Insertion. — ^The head of the fibula. The semitendinosus and the semimembranosus also arise on the tuber of the ischium, and are inserted on the tibia, medial surf ace and back of head. (Their names indicate their shape, one being tendinous in half its length, and the other aponeurotic, or mem- branous.) Action. — These three muscles act together to flex the knee. Nerve to the three. — Sciatic. LE.E Lu^ J., Fig. 87. — Medial Aspect of the Thigh and Pelvis. I, 2, 3, 4, Iliacus, psoas, obturator, piriformis; 5, gluteus maximus; 6, sartorius; 7, gracilis; 8, semitendinosus; 9, semimembraDosus 10, 11, 12, ten- dons of sartorias, gracilis, and semi- tendinosus; 14, tendon of semimem- branosus.— (Gould's Dictionary.) Notes. — They also assist the gluteus maximus to extend the thigh, as in rising from a chair. The biceps tendon may be felt behind the lateral epicondyle; the two others, behind the medial epicondyle, making the borders of a deep space — the popliteal space, or ham. They are called "ham- string" tendons. MUSCLES OF THE LOWER EXTREMITY. 107 Fascial insertion of gluteus maximus Biceps Vastus lateralis Plan tans Gastrocnemius Solcus Peroneus longus S emi-membranosus Semi-tendinosus G racilis Tendon of semi-membranosus — Sartorius I'lexor digitorum longus Tcndo Achillis Fig. 88.— Posterior of Thigh and Leg and Hamstring Tendons (Morris). io8 ANATOMY AND PHYSIOLOGY FOR NURSES. Hamstring tendons. I Lateral side, biceps femoris. semitendinosus. Medial side, , semimembranosus, sartorius. gracilis. The popliteus is a flat muscle behind the knee-joint, forming part of the floor of the popliteal space. The most important muscles in the medial side of the thigh are the four adductors (Fig. 89). The adductor longus. Origin. — From the superior ramus of the pubes. Insertion. — The middle of the linea aspera. The adductor brevis. Origin. — Upper part of the pubic arch. Insertion. — The linea aspera behind and above the longus. The adductor minimus. Origin. — The lower part of the pubic arch. Insertion. — The linea aspera, behind the brevis (upper part). The adductor magnus. Origin. — Pubic arch and tuber of the ischium. Insertion. — Linea aspera (behind the others), and medial epicondyle. Action of the four. — They all adduct the femur (rotating it outward) and draw the thighs together as in horseback riding. Nerve to the four.-^^Obturator. Note. — The magnus makes a broad sheet of muscle between the quadriceps which extends the knee, and the muscles on the back which flex it. The longest and strongest fibers of the magnus rotate the femur inward. They run between the tuber of the ischium and the medial epicondyle. Muscles of the Leg. Anterior. These muscles flex the ankle and extend the toes.^ The muscles in the front of the leg are between the tibia and the fibula; the medial surface of the tibia, having no muscles upon it, is called subcutaneous. The tibialis anterior. Origin. — The shaft and head of the tibia (lateral surface) and the interosseous membrane. ' Note. — This movement of the toes is dorsal flexion. Fig. 89. — Adductors. I, 2, 3, Femur, ilium, pubes; 4, external obtura- tor muscle; 5, 6, 7, 8, 9, 10, adductor muscles; 11, 12, openings for vessels passing to back part of thigh. — (Gould's Diction- ary). MUSCLES OF THE LEG. 109 Insertion. — The first cuneiform and first Nerve. — Deep peroneal. The peroneus tertius. Origin. — The (lower part). Insertion. — The fifth metatar- sal bone. Action of the two. — To flex the ankle. The tibialis acting alone lifts the medial border of the foot; the peroneus lifts the lateral border. Nerve. — Deep peroneal. The extensor hallucis longus, or long extensor of the great toe. Origin. — The shaft of the fibula and the interosseous membrane. Insertion. — The last phalanx of the great toe. Action. — To extend the great toe. Nerve. — Deep peroneal. The extensor digitonim longus, or long extensor of the toes. Origin. — The shaft of the fibula and interosseous membrane (a few fibers from head of tibia). Insertion. — By- four tendons on the second and third phalanges of the four lateral toes, like the similar extensor of the fingers. Action. — To extend the toes. Nerve. — Deep peroneal. Note. — These two muscles, since they pass in front of the ankle- joint, flex it. On the dorsum of the foot the extensor digitorum brevis has four slender tendons for the /oMrwze^fza/ toes. Nerve. — Deep peroneal. Muscles of the Leg. Posterior. metatarsal bones, shaft of the fibula Fig. 90. — Muscles of THE Leg, Anterior. I, Rectus femoris; 2, tibia; 3, tibialis an- terior; 4, long extensor of toes; 5, long extensor of great toe; 6, peroneus tertius; 7, 8, peroneus longus, p. brevis; 9, 10, lateral and medial heads, gastrocnemius; 11, short extensor of toes; 12, an- nular ligament (Gould's Dictionary) These muscles extend the ankle and flex the toes; they all pass behind the medial malleolus. They are covered by the calf muscles. The tibialis posterior. Origin. — Shaft of both tibia and fibula and the interosseous membrane. Insertion. — Navicular and first cuneiform bones. Action. — Extension of the ankle. Nerve. — Tibial. no ANATOMY AND PHYSIOLOGY FOR NURSES. The long flexor of the great toe, or flexor hallucis longus. Origin. — Shaft of fibula. Insertion. — Last phalanx of the great toe (Fig. 91). Nerve. — Tibial. Long flexor of the toes, or flexor digitorum longus. Origin. — Shaft of fibula. Insertion. — By four tendons on the last phalanges of the four lateral toes (Fig. 91). Action of these two muscles. — Flexion of the tips of the toes. Nerve. — Tibial. Leg — Lateral Side (Fig. 92). Peroneus longus. Origin. — Shaft of fibula. Insertion. — In the sole of the foot, first meta- tarsal bone. The tendon passes behind the lateral malleolus and crosses in the sole to the medial border of the foot. Peroneus brevis. Origin. — Shaft of fibula. Insertion. — Base of fifth metatarsal bone. The tendon passes behind the lateral malleolus. Action of these two muscles. — They extend the ankle and lift the lateral border of the foot. Nerve to both. — Superficial peroneal. Note. — As the tibialis anterior and peroneus tertius flex the foot, so the tibialis posterior and peroneus brevis extend it. Orthopedic note. — The P. longus makes a chord for the transverse arch of the foot, being the most important muscle to preserve that arch from being flattened. Fig. 91 . — Mus- cles OF THE Plan- tar Region, Mid- dle Layer. I, Accessory mus- cle; 2, long flexor of toes dividing into four tendons; 3, tendon of long flexor of great toe; 4, 5, 6, 7, 8, plantar muscles; 9, projection of fifth metatarsal bone; 10, sheath of tendon of peroneus longus; 11, calcaneus (Gould's Dictionary) . Calf Muscles (Figs. 8S, 92). Triceps surae, and plantaris. The gastrocnemius. Origin. — By two heads just above the condyles of the femur. Insertion. — On the calcaneus. Note. — The two heads form the lower boundaries of the popliteal space. The soleus is covered by the gastrocnemius. Origin. — Medial border of the tibia and lateral border of the fibula. Insertion. — The OS calcis, with the above muscle. Action of the two. — They join to form one muscle, the triceps TRICEPS SUR^ (calf MUSCLES). Ill surae (or triceps of the ealf), which has the strongest tendon in the body, the tendo calcaneus {tendon of Achilles) by which they are attached to the os calcis, and, therefore, they lift the heel. If the muscles of both legs act at the same time, the whole body is lifted on the toes. Nerve to both. — Tibial. The plantaris. Origin. — With the outer head of the gastrocnemius. Insertion. — With the tendo calcaneus. Note. — The belly is short and small; the tendon is the longest in the body. The calf muscles constitute a group of great power, as by them one lifts oneself to stand upon the toes. The sole of the foot, or plantar region, resembles the palm of the hand in having special groups of mus- cles for the great and little toes, with the long flexor tendons lying between them, and a dense fascia covering them. This is called the plantar fascia. The nerves are medial and lateral plantar. Annular Ligaments. The tendons which pass from the leg to the foot are kept in place by special ligaments, anterior and lateral, and surrounded by synovial sheaths as in the wrists. Fig. 92. — Lateral Aspect and Calf of Leg. I, 2, 3, 4, Lateral view, muscles passing in front of ankle; 5, 6, peroneus brevis and p. longus (be- hind ankle) ; 7, 8, soleus and gas- trocnemius; 9, head of fibula; 10, biceps femoris; 11, semimembra- nosus; 13, tendo Achillis; 15, an- nular ligament; 16, 17, insertions of peroneus tertius and brevis; 18, short extensor of toes; 19, plantar muscle; 20, patella (Gould's Dic- tionary) . Points. — Eversion of the foot, or lifting the medial border, is done by the tibialis anterior. Inversion. — Or lifting the lateral border, by the peroneus tertius, and pero- neus longus. Adduction.— By deep fjostcrior muscles of the leg. Abduction. — By external muscles of the leg. Observe certain similarities and differences in the extremities. Extension of the elbow is accomplished by the three-headed muscle, 112 ANATOMY AND PHYSIOLOGY FOR NURSES. the triceps. Extension of the knee requires a powerful four-headed muscle, the quadriceps. The great toe is on the medial border of the foot, the thumb is on the lateral border of the hand. This is so because the terms medial and lateral are applied to the pronated position of the lower extremity and the supinated position of the upper extremity. In the upper extremity the joints are all flexed in one direction, as though the limb might be rolled up. In the lower extremity they flex and extend alternately, as though the limb were folded back and forth. STRUCTURE AND PHYSIOLOGY OF MUSCLES. A completed muscle is a complicated structure. It consists of: First, the essential muscle substance in the muscle cells. Second, connective tissue wrappings and partitions. Third, tendons and aponeuroses. Fourth, blood and lymph vessels. Fifth, muscle nerves. The connective tissue supports all of the other structures and protects the muscle, preserving its shape and stability. The tendons and aponeuroses provide a means whereby the attach- ment to other organs is kept within a small space. Example: The biceps of the arm contains many fibers, but the slender ten- dons of this muscle occupy only small areas upon the surface of the bones. The aponeurosis of that very powerful muscle, the quadriceps femoris, re- ceives the insertion of the muscle fibers, and by this means only a narrow surface is required for insertion upon the bone. But for arrangements like these, the skeleton would of necessity be inconveniently large. The blood-vessels bring the nutritive fluid which, in the tissue- spaces, bathes each little fiber, and is gathered up by the lymph vessels. The nerves bring to each fiber its natural stimulus to action. The work of muscle tissue is done in the fiber cell. This when stimulated, contracts, bringing the two ends of the fiber nearer to each other, and naturally the fiber swells as it shortens. So with the myriad of fibers in a muscle; when they contract, the muscle swells and shortens (Fig. 93 illustrates the changes pro- duced). This results in motion, which appears as the organs attached are moved. . . PHYSIOLOGY OF MUSCLES, "3 All skeletal muscles are so attached as to be tense, that is, they are just a little stretched, so that it is easier for them to act than not. (A cut across a muscle releases it from tension and leaves a gaping wound.) The actions of muscles are regulated by their attachments, and the function* is often expressed in the name. If muscles or their tendons pass in front of a joint, for instance, causing flexion, they are frequently csdled Jlexors ; or if they pass behind such joints, they may be called extensors; and so with other muscles and joints. Examples: Flexors of the wrist, extensors of the fingers, etc. Many other examples will occur to the student, as abductors, adductors, pronators, etc. Fig. 93.— Showing Change of Shape in Contraction (Brubaker). As the location determines the function of a muscle, so it often suggests the name, as the pectoralis major and minor, the intercostals, etc. Sometimes the shape is named, as the orbicularis of the mouth or of the eyelids (orbicular muscles, or sphincters, surround and con- trol openings). Shape and location may together suggest a name sometimes, as the latissimus dorsi, the rectus abdominis (broadest of the back and straight of the abdomen)^ and others, expressing or implying the function of the muscle. One of the most useful and interesting muscles in the body is the diaphragm. Although a voluntary muscle in structure, it is asso- ciated with visceral action. (For general description see page 91.) The special interest attending this muscle arises from its location ' The full Latin name includes the word musculus {muscle) ; for the sake of brevity it is omitted. 8 114 ANATOMY AND PHYSIOLOGY FOR NURSES. as well as its structure. Situated between the great cavities of the trunk it acts upon the organs belonging to both. In contraction, it encroaches upon the cavity of the abdomen pressing upon abdominal organs, and thus aids in expelling the contents of abdominal and pelvic viscera. In this act (expulsion from abdomen, or pelvis) it is fixed in contraction (holding the breath) so that other muscles can act efficiently. Examples: defecation, parturition. Ceasing to con- tract it rises to its inactive or dome-shape; and as this is accompanied by slight abdominal pressure upward, the effect upon the thorax is to shorten it, causing gentle pressure upon the lungs. • In contraction, therefore, it compresses the abdomen and enlarges the thorax; in relaxation, it enlarges the abdomen and compresses the thorax. This alternate enlargement and compression of the thorax explains its most important function — that of a breathing muscle, or muscle of inspiration. Special points. — The lateral portions of the diaphragm are the most movable portions, being mostly muscular. Here the lungs rest upon the falling and rising floor, themselves alternately expanding and contracting. The heart lies upon the least movable portion — consequently the diaphragm supports the heart but does not press against it unless pushed up from below. Similar fimctions pertain to another muscle constituting the floor of the pelvis (the levator aniandcoccygeus taken together), which rises and falls with the displacement and functionating of abdominal organs. With the combined contraction of these two, and relaxation of the diaphragm, the whole body of abdominal and pelvic organs moves upward, and vice versa. Passing to the consideration of more complicated movements, we find that all functions of the body depend in the beginning upon muscle action. For respiration we must have the muscles of the thorax; for swallowing or deglutition, the muscles of the tongue and throat; for speaking, those of the tongue and face: The heart itself is a collection of muscles influencing the entire body, since without circulation of blood all processes of life must cease. The arms and hands become organs of prehension when by use of their numerous muscles they reach out to gather things in; the lower limbs are organs of locomotion, only because their muscles enable them to bear and transport the body from place to place. Even the FUNCTIONS OF MUSCLES. II5 ability to stand still is due to a balanced tension of muscles, which keeps the joints quiet. Finally, various emotions may be expressed by muscle-action without a spoken word, both by changes of the face (referred to, p. 82) and gestures of the body. Compare the erect posture of the person ready and alert, with the drooping figure of despondency or the lax one of indolence. Read the meaning of the firm, quick footstep, and contrast it with the uncertain and halting one. Note how the hand may welcome, or repel. Even the eye would be far less expressive were the iris immovable. Indeed, we might well see a literal meaning in the old adage — "Actions speak louder than words." Thus muscle action means much more than simple movement, and it all depends ultimately upon the specially developed attribute of the muscle cell — contractility. Muscle Tissue, a Source of Heat and Electricity. Thus far we have considered only one result of muscle action; namely, the production of fnotimi. Muscle tissue is built up of food derived from the blood — contraction means a using up of its sub- stance, and the formation of waste products. These chemical pro- cesses are going on continually, and all chemical action is accompan- ied by the production of heat. A muscle in action is therefore a machine for producing body heat, and since the muscular system comprises so large a portion of the human body (weighing nearly three times as much as the bones), it is one of the chief sources of heat; for the double reason that it includes a great deal of tissue, and that it is more constantly at work than any other tissue in the body. We all know that the body temperature rises during muscular exercise; as the vessels dilate, bringing oxygen for chemical action, heat is rapidly evolved and v/aste is swept away. (Blood- and lymph vessels carry both food and waste.) In addition to other results of muscle activity, a slight current of electricity is produced, appreciable only by certain experiments. Modifications of Muscle Action. Clinical notes. — Tetanus is a condition of the muscles in which the contractions are so rapid that the action appears to be continuous; the stimuli come so rapidly that the fibers cannot relax. ii6 ANATOMY AND PHYSIOLOGY FOR NURSES. It may be due to various causes: to drugs, as strychnine; to bacterial poisoning through invasion of wounds, or to disordered conditions of the nerve system. It may be voluntary in character. When one deliberately stiffens the body or any portion of it the rigidity thus occurring is tetanic. Cramp is sudden involuntary contraction of muscle-fiber, spasmodic in character and so violent as to be exceedingly painful. Convulsive movements or convulsions {spasms) are due to involun- tary and forcible action of several muscles or groups of muscles. The movements vary with the number of muscles involved. Fatigue of muscle tissue follows prolonged use, evidenced by sensations of pain in the muscles themselves, probably due to an accumulation of waste matters when the muscle is not quite equal to the demands made upon it. LARGE MUSCLES CLASSIFIED ACCORDING TO THEIR MOST FREQUENT ACTION. Region. Action. Muscles. ■ Trunk To enclose cavities and aid in respiration To separate cavities and aid in respiration Intercostals. Quadratus lumborum. Obliquus externus. Obliquus internus. Transversus. Diaphragm. Levator ani. Floor of trunk and aiding above muscles Head To move spine and trunk •. Coccygeus. Abdominal group. Erector spinas. Ilio-psoas. Erector spinae. Trapezius. Sterno-mastoids. To flex head Shoulder To rotate head . To lift shoulder Trapezius. Sterno-mastoid. Trapezius. Trapezius. Anterior serratus. Pectorals. Arm To pull shoulder backward To pull shoulder forward To pull arm forward. .... To pull arm backward Latissimus dorsi. To abduct (lift) arm To adduct (pull downward) To rotate arm {supination) To rotate arm {pronation) Deltoid. Pectorals. Latissimus dorsi. Infraspinatus. Teres minor. Subscapularis. Teres major. FUNCTIONAL CLASSIFICATION OF MUSCLES. 117 LARGE MUSCLES CLASSIFIED ACCORDING TO THEIR MOST FREQUENT ACTION.— (Continued.) Region. Action. Muscles. Forearm . Wrist. Hand. Thigh. Leg. Ankle . Foot. To flex forearm To extend forearm To rotate {supination) To rotate {pronation) To flex wrist To extend wrist To flex fingers To extend fingers To flex thumb To extend thumb To flex thigh To extend thigh (also to extend trunk) To rotate (outward) To rotate (inward) . To abduct To adduct To flex leg To extend leg Rotation (outward) Rotation (inward) . To flex ankle To extend ankle. . . To flex toes To extend toes Biceps brachil. Brachialis. Brachio-radialis. Triceps. Supinator. Biceps brachii. Brachio radialis. Pronator teres. Pronator quadratus. Flexor carpi radialis. Flexor carpi ulnaris. Extensor carpi radialis, (long and short). Extensor carpi ulnaris. Flexor digitorum (sublim.). Flexor digitorum (pro- fund.). Extensor digitorum (com.). Thenar group. Three extensors of thumb. Ilio-psoas. Gluteus Maximus. Biceps femoris. Semitendinosus. Semimembranosus. Glutei-med. and min. Sartorius. Four adductors. Two obturators. Gluteus min. Tensor fasciae latse. Adductor magnus (long fibers of) . Three glutei. Four adductors. Biceps femoris. Semitendinosus. Semimembranosus. Sartorius. Quadriceps femoris, (rectus and three Vasti.) Sartorius. Biceps. Tibialis ant. Peroneus tertius. Tibialis post. Peronei (long and short). Flexor digitorum (longus). Flexor pollicis (longus). Extensor digitorum (longus). Extensor hallucis (longus). Il8 ANATOMY AND PHYSIOLOGY FOR NURSES. SPINAL NERVE SUPPLY TO PRINCIPAL MUSCLE GROUPS. Region. Muscles. Nerve. Side of Neck. Thorax and Shoul- der Arm, anterior. Arm, posterior Forearm, posterior. Forearm, anterior. . Hand. Abdomen and Pelvis . Thigh Thigh, anterior. Thigh, posterior. . . Three scaleni muscles. Elevator of angle of scapula .... Intercostal Diaphragm Sacro-spinalis (erector spinae) ... Latissimus dorsi Supra- and infraspinatus Subscapularis . Teres major , Teres minor , Deltoid Pectoralis major and minor , Biceps. Coraco-brachialis , Brachialis , Triceps. Supinators and extensors of wrist Extensors of fingers Pronators and superficial flexors. Flexor carpi ulnaris and deep flexors , (The deep flexor of fingers has also a branch from median.) Thenar eminence (muscles of thumb) Hypothenar eminence (muscles of little finger) , Interossei Rectus and pyramidalis. Quadratus lumborum. External and internal oblique . Transversus . Psoas and iliacus Levator ani. Perineal muscles Piriformis Gluteus maximus Gluteus medius and minimus. Tensor f asciee latae Obturator, external and internal. Three adductors. Gracilis Quadriceps. rectus, two vasti. crureus Biceps. Semitendinosus . Semimembranosus Cervical branches of bra- chial plexus. Intercostal. Intercostal and phrenic. Spinal. Long subscapular. Suprascapular. Subscapular. _ \ Axillary, (f c \ R- — upper, middle, and lower, strengthened by a fibrous layer and lined with mucous membrane. The illustration shows that the constrictors are flat muscles attached at the sides to the structures in front of the phar3mx. Thus, from above downward, their origin is on the pterygoid process, a special ligament, the mandible, side of the tongue, hyoid bone, thyroid and cricoid cartilages. The fibers all join a fibrous line, or raphe, at the back, which is suspended from the base of the occipital bone. This is their insertion. By due contraction of these muscles the food is grasped and pressed downward into the esophagus. They are composed of striated or voluntary muscle fibers. THE PHARYNX. ■125 The upper part of the pharynx is behind the nose and is called the nasal part, or naso-pharynx. The middle part is behind the Tnonihaindis, calledihe oral pari, or oro-pharynx. (It is this part which we see when looking directly into the throat.) The lower part is behind the larynx and is called the laryngeal part, or the laryngo- pharynx. The openings of the pharynx are seven in number: the two choancB (posterior nares) communicating with the nose; the two Orbic. oris muscle "^^-^ ^u'^'^"^'^''^'"' ^^^ Special ligament Mylo-hyo.d muscle Hyoid bone Thyroid cartilage Cricoid cartilage Trachea Esophagus . Fig. 97. — The Pharynx (Holden). auditory {Eustachian) tubes communicating with the ears, and the isthmus of the fauces, communicating with the mouth. Below, it communicates with the larynx (the opening being guarded b^ the epiglottis), and opens into the esophagus. The food passes through the oro-pharynx and laryngo-pharynx, the naso-pharynx being an air-passage. In the roof of the pharynx is a small mass of lymphoid tissue called the pharyngeal tonsil. 126 anatomy and physiology for nurses. The Esophagus. The esophagus (Figs. 97, 98) begins at the lower end of the pharynx and extends downward in the neck in front of the spinal column, to pass into the thorax. It finally comes forward in front Fig. 98. — Showing Situation of Pharynx behind Nose, Mouth, and Larynx (from Deaver's "Surgical Anatomy"). b, a, c, s, d, e, Turbinal bones and meatuses of the nose; g, i, tongue; h, posterior palatine arch; y, anterior palatine arch; k, hyoid bone; j, mylo-hyoid muscle (floor of mouth); m, thyro-hyoid membrane; n, ventricle of larynx; p, q, r, sphenoid bone and sphenoidal sinus; v, hard palate; w, soft palate; x, uvula; z, tonsil; i, naso-pharynx; u, orifice of auditory tube; aa, oro-pharynx; dd, laryngo-phar}'nx; bb, epiglottis; ee, upper portion of larynx; gg, vocal bands; ^, false vocal bands; hh, lower part of larynx; ii, cricoid cartilage; jj, trachea. of the aorta, passes through the diaphragm, and terminates in the stomach. It is a tube about nine inches long, having two ^layers of muscles (circular within, longitudinal without) and lined with mucous membrane. By contraction of the different muscles from above downward the food is passed along to the stomach. ESOPHAGUS. 127 The esophagus lies at first immediately behind the trachea. The upper part is composed of striated, or voluntary muscle like that of the pharynx; in the lower part the muscle is non-striated, or involuntary , like the stomach. At the termination in the stomach, the circular fibers are most numerous, forming the cardiac sphincter which prevents the return of stomach contents. Aorta Celiac artery Gastric arter\ Artery to duo- denum ^ Head of pancreas Fig. 99. — The Stomach and Spleen (Morris). The remaining organs of digestion are contained in the abdomi- nal cavity, which is lined with a serous sac or membrane called peritoneum (see p. 299) . These organs are developed from an original straight tube behind the peritoneum. Therefore, as they grow, they press forward against it and get a covering which is called their serous layer. Their muscular coats are all involuntary or unstriped muscle. The Stomach. The stomach (gastcr, Fig. 99) is in the epigastric region of the abdomen just below the diaphragm. Shape and size: like a curved flask, ten to twelve inches long and six to eight wide at the lajger end, 128 ANATOMY AND PHYSIOLOGY FOR NURSES. which is turned toward the left side. Average capacity: five pints in distension; two pints when moderately filled. The stomach has two surfaces, two borders, two extremities and two orifices. The surfaces are the anterior — looking slightly upward; and the ■posterior — looking slightly downward. The borders are usually called curvatures; the upper border is the lesser curvature (about five inches in length); the lower border is the greater curvature (about twenty inches in length). The left extremity is the expanded portion called the fundus of the stomach (also the greater cul-de- sac), and the cardiac end (from its nearness to the heart). The right extremity is called the pyloric extremity. It is just below the liver. The orifices are at the extremities. At the left is the esophageal orifice guarded by the sphincter of the cardia; at the right is the pyloric orifice, guarded by the sphincter of the pylorus or "gate-keeper." The coats or tunics of the stom- ach are four in number — mucous, sub- mucous, muscular, and serous. The mucous layer, or mucosa, is the innermost layer. It is pink in color but becomes bright red when food is present, from the increased blood-supply necessary for digestion. It lies in folds, or rugce, running from one extremity to the other — the longitudinal folds. This layer contains the gastric glands which secrete the gastric juice and pour it through their ducts into the stomach. The gastric glands are tubular in form, microscopic in size, and very numerous (their number is estimated at 5,000,000). They differ markedly in the two portions of the stomach. The cardiac glands secrete the digestive ferments, pepsin and rennin, while the pyloric glands secrete mucus also (Fig. 100). The reaction of the gastric juice is acid (owing to hydrochloric acid). v;^- Fig. 100. — Section of Pyloric Glands from Human Stom.ach. a. Mouth of gland leading into long, wide duct (6), into which open the terminal di\'isions. c. Connective tissue of the mucosa (after Piersol). THE STOiMACH. 1 29 The suhmucosa is a network of connective tissue next to the mucous coat. It bears fine vessels, nerves and lymphatics, and connects the mucous and muscular tunics together loosely, so that when the stomach is distended the longitudinal folds simply disappear, without injury to the mucous membrane. The muscular coat (or tunic) comprises three layers of non-striated muscle: internal, middle and external. The internal layer consists of oblique fibers (it is a thin layer and is mostly confined to the cardiac portion). The middle layer is a complete layer of circular fibers. They are most numerous at the extremities of the stomach, where they form two ring-shaped bundles. One is the sphincter of the cardia, surrounding the lower end of the esophagus and the cardiac orifice of the stomach; the other is the sphincter of the pylorus, which is a strong ring-muscle diminishing the size of the pyloric orifice so that it is the narrowest portion of the alimentary tract (a half-inch, or 3 mm.). The external layer consists of longitudinal fibers (fibers running lengthwise) which are continued from the similar layer of the esophagus, and pass on to those of the intestine. The serous coat (or tunic) is a portion of the great serous mem- brane of the abdomen, called the peritoneum (page 299). The two surfaces of the stomach are covered by different layers of peritoneum which will be described elsewhere (page 137). The position of the stomach is oblique, the pyloric end being on a lower level than the cardiac. It is also the movable end. The location of the stomach is mostly in the epigastric region (Fig. 106). It is below the portion of the diaphragm which supports the heart; behind it are the largest artery and vein in the body — the aorta and the inferior vena cava. The pyloric end extends under the liver in the right hypochondrium, while the cardiac end is in the left hypochondrium, in contact with the spleen. Clinical notes. — When the stomach is empty it tends to a vertical position; when filled, it swings upward and forward to become again oblique. If much distended, as with gas, it embarrasses the action of the heart by pressure. The infant's stomach is nearly or quite vertical and easily overflows; its capacity at birth is one ounce, reaching two ounces at about the end of a fortnight. 130 anatomy and physiology for nurses. The Intestine. The intestine or bowel, begins at the pyloric orifice of the stomach and continues to the end of the alimentary tract. It is from twenty-five to thirty feet in length (Fig. loi). Appendix Small in- testine Fig. ioi. — The Intestines (Morris). Large intestine thrown upward, small intestine drawn to left. Like the stomach, it is composed of four coats or tunics — mucous ^ submucous, muscular and serous. The mucous coat is the glandular coat; that is, the glands which secrete intestinal juice are imbedded in the mucous coat, and their ducts open on its surface. THE SMALL INTESTINE. 131 In addition, small gland-like bodies of lymphoid structure are scattered throughout this coat. They have no ducts. They are probably lymph nodules — the so-called solitary glands. The submucous coat bears the fine vessels and nerves which supply the mucous coat. It connects the mucous and muscular coats together. The muscular coat comprises two layers (like the esophagus) , an inner layer of circular fibers, an outer one of longitudinal fibers. The intestine is divided into the following parts: Duodenum Small intestine { Jejunum Large intestine Ileum Cecum Colon Rectum Ascending Transverse Descending The Small Intestine. The small intestine is about twenty feet in length, and about two inches wide in its upper (widest) part. It extends from the stomach to the colon, beginning with the pyloric sphincter in the right hypochondrium and ending with the ileo-colic sphincter in the right iliac region. The mucous coat of the small intestine forms circular folds (old name, valvulae conniventes) which are permanent, that is, they never disappear however widely the bowel may be distended. They serve to increase the area of mucous membrane for purposes of digestion and absorption (Fig. 103). The secreting glands which are found in every part of the small intestine are called the intestinal glands (or intestinal follicles, or glands of Lieberkiihn) . They are tubular in shape, and secrete the greater portion of the intestinal juice. The ferment of the glands of Lieberkiihn is not known. The reaction of the secretion is alkaline. The entire mucous coat is covered with tiny projections hair- like in size (from 1/2 to i mm. long) called villi, which give it a velvety appearance (Fig. 102). In the midst of each villus is a minute lymph-capillary, surrounded by a fine network of blood-vessels and lymph-spaces, the whole covered by a layer of the special epithelium of the intestine. 132 ANATOMY AND PHYSIOLOGY FOR NURSES. The villi are absorbing structures or absorbents. (They may be demonstrated in a good light by laying a piece of intestinal wall in a shallow tray of clear water; the water will float their free extremities.) The muscular coat is in two layers — circular within, longitudinal without — pretty evenly distributed. The serous coat covers all except a portion of the first division (see duodenum). The duodentim is the first . division of the small intestine Fig. I02. — Section or Injected Small Intestine of Cat. a, b. Mucosa g. Villi, i. Their absorbent vessels, h. Simple follicles, c. Muscularis mucosse. j. Submucosa. g. e. Circular and longitudinal layers of muscle. /. Fibrous coat. All the dark lines represent blood- vessels filled with the injection mass (Piersol). Fig. 103. — Circular Fold or Val- vule Conniventes (Morris). (Fig. 104). (It is about ten inches long, begins at the pyloric end of the stomach, curves upward and backward to make a horse-shoe bend to the right and downward, and then continues across to the left side of the spinal column thus making a superior, descending and inferior part.) The circular folds of the mucous coat begin in the lower portion and are unusually large. THE SMALL INTESTINE. 133 There are special glands in the duodenum not found elsewhere, called duodenal glands or Brunner's glands; they furnish a portion of the intestinal juice. Note. — The inferior part of the duodenum is behind the peritoneum, this fart has no serous coat. 20 12 19 Fig. 104. — Liver, Paxcreas, Duodenum, Spleen and Kidneys, i, 2, 3,. Duode- num. 4, 4, 5, 6, 7, 7, S. Pancreas and pancreatic ducts. Q, 10, 11, 12, 13. Liver. 14. Gall bladder. 15. Hepatic duct. 16. Cystic duct. 17. Commonduct. 18. Portal vein. iQ. Branch from the celiac axis. 20. Hepatic artery. 2t. Coronary artery of the stomach. 22. Cardiac portion of the stomach. 23. Splenic arter\'. 24. Spleen. 25. Left kidney. 26. Right kidnev. Section of pancreas to show ducts. Liver turned upwards and stomach removed to show duodenum. The jejunum is the second division of the small intestine — so named because it is found empty. It possesses all of the char- acteristic structures: villi, circular folds, intestinal and solitary glands. It lies in the umbilical and the two lumbar regions. The Ileiun is the third division of the small intestine — so named because of its frequent twisting. There is no definite separation between the end of the jejunum and the beginning of the ileum. The villi, circular folds, intestinal glands and solitary glands are all found in the ileum. The circular folds diminish in size as the necessity for their presence grows less in the lower portion, but the solitary glands increase in size and number. They are grouped into 134 ANATOMY AND PHYSIOLOGY FOR NURSES. various oblong patches, toward the lower end of the ileum, the Peyer's patches or agminated glands. (The largest patches may measure three inches in length.) The reaction of the intestinal fluids is alkaline. Clinical note. — The solitary glands (more especially the Peyer^s patches), become inflamed and ulcerated in typhoid fever. The ileum ends in the right iliac region by opening into the large intestine. This orifice is doubly guarded; first, by two folds of mucous membrane strengthened by fibrous tissue, called the ileo-cecal valve; second, by a circular muscle called the ileo-colic sphincter; this is the more important of the two. The Large Intestine. The large intestine is about five feet long and two and one-half inches wide in the widest part. It begins where the small intestine ends (in the right iliac region), ascends through the right lumbar, crosses the abdomen in front of the small intestine, descends to the left iliac region, and thence down through the pelvis, ending in front of the coccyx. (See Regions of the Abdomen, p. 296.) The mucous coat is smooth and rather pale. No folds are present, and no villi, but the solitary and tubular glands are numerous. The circular fibers of the muscular coat are evenly distributed, but the longitudinal fibers of the cecum and colon are arranged in three bands, placed at even distances apart. These bands are shorter than the tube itself, therefore they gather it into puffs which give the bowel a sacculated appearance. By this, the large bowel may be recognized at once, even should it be really small in actual size in some portion of its extent. The serous coat covers the greater part of the large intestine; the exceptions will be noted later. The four divisions of the large intestine are the cecum, the colon, the sigmoid loop, and the rectum (Figs. loi, 105). The cecmn, or first division, is a short pouch hanging below the level of the ileocolic valve and presenting the opening of the appendix verjniformis or appendix ceci. The three longitudinal bands of the muscular coat meet at the base of the appendix, which is a small tube three or four inches long, attached to the posterior side of THE LARGE INTESTINE. 135 the cecum. It often turns upward, quite as often downward, and may lie transversely. It has all four coats, with intestinal and soli- tary glands, but is of no use. Clinical note. — Owing to its small size any substance which enters the appendix is apt to be retained, and if it is of an injurious character it will cause appendicitis. This disease is more often caused by the action of harmful bacteria than the celebrated cherry-stone. Small intestinal worms have been found within the appendix. Fig. 105. — I'he Large Intestine. The small intestine and its vessels are drawn to the right to show the sigmoid colon and the rectum. The transverse colon is thrown upward (Morris). The ilio-cecal valve consists of two folds of mucous membrane with muscle fibers between the layers. They are placed at the end of the ilium where it opens into the colon, and project toward each other, leaving only a slit-like passage. The colon begins at the ilio-cecal valve. The first part, or 136 ANATOMY AND PHYSIOLOGY FOR NURSES. ascending colon, passes upward in the right lumbar region. After making a bend under the liver — the right colic flexure (or hepatic flexure), it becomes the transverse colon, which hangs in a loop across the abdomen in front of the small intestine. Another bend occurs under the spleen, the left colic flexure (or splenic flexure); thence . the descending colon passes downward in the left lumbar region to the left iliac fossa. Here it makes an S-shaped or sigmoid bend and becomes the so-called sigmoid colon. It then enters the pelvis to become the rectum. Surgical note. — The ascending colon lies so close to the posterior abdominal wall that there is no peritoneum behind it, and the descending colon also is bare in a narrow strip at the back, consequently the surgeon may take advantage of this condition to open the colon without wounding the peritoneum, in the operation called lunibo-colotomy. The rectum is about five to seven inches long, very distensible, and so called because it has no convolutions, but simply follows the curve of the pelvic wall, lying in front of the sacrum and coccyx. In the last inch or inch and a half it bends backward {perineal flexure) to pass the tip of the coccyx. This is the anal canal, and it ends at the opening called the anus (Fig. 105). The portion above the anal canal is the widest pars — the rectal pouch. The mucous membrane of the rectum is red, and usually presents two or three special folds about two or three inches above the anus, called the rectal folds, or Houston's valves. The largest, a permanent fold, is on the right side about two and one-half inches above the anus and called the third sphincter. Two smaller ones, not permanent, are on the left side, above and below the former. The muscular coat has the two layers, circular and longitudinal. The peritoneal coat covers the front and sides of the upper part only. The reaction of the fluids in the large intestine is alkaline. Sphincters of the anus. — The circular fibers around the anal canal form the internal sphincter. The external sphincter is a flat circular muscle just under the skin around the anus. The function of the sphincters is to guard and control the anus. Clinical note.— The point of a syringe should be passed in an upward and forward direction through the anal canal, and then turned backward. THE MESENTERY. THE PANCREAS, I37 Resume. The alimentary tract begins with the mouth and ends with the large intestine, passing through the head, neck, thorax, and pelvis. It is practically a long tube of mucous membrane surrounded by layers of muscle and held to them by connective tissue. The mucous membrane contains glands which secrete the digestive fluids. The muscle layers pass the food along, that it may be acted upon in all portions of the tract; and wherever free motion accompanies the digestion of the food, a serous layer is added outside of all to prevent friction. The digestive fluid of the stomach is acid; in all other parts it is alkaline. Peristalsis Is the name given to the peculiar motion of the stomach and intestine during the passage of their contents. The circular fibers compress the food and at the same time the longitudi- nal fibers shorten the tube. This action goes on from above down- ward, causing a sort of worm-like movement which is described as peristalsis, or peristaltic movement. The mesentery is the fold of peritoneum which holds the jeju- num and ileum in place. This fold leaves the posterior abdominal wall at a line inclining downward to the right, about five or six inches long; but it includes twenty feet of intestine, and therefore it is like a very full ruffle twenty feet in length with a band of six inches. The vessels and nerves of the intestine lie between the layers of the mesenteric fold. Any fold of peritoneum which connects a portion of intestine to the wall of the trunk is a mesentery. The meso-colon connects the colon with the abdominal wall; the meso-rectum connects the rectum with the pelvic wall; the large mesen- tery holds the ilium and jejunum to the posterior abdominal wall. An omentum is a fold of peritoneum connected with the stomach. The greater omentum hangs from the greater curvature; the lesser omentum connects the lesser curvature with the liver (being called the gastrohepatic omentum) ; and the gastrosplenic omentum connects the stomach and spleen. Two layers of peritoneum pass from the under surface of the liver to the lesser curvature of the stomach, forming the lesser omentum. They then separate to enclose the sur- faces of the stomach, making its serous coat. They come together again at the greater curvature and hang down in the shape of a large serous sac with double walls, the greater omentum, which hangs in front of the small intestine. Note, — The transverse meso-colon usually becomes adherent to the greater omentum (Fig. 106). The Pancreas. The pancreas (Figs. 104, 105) is a gland situated behind and below the stomach. It is about seven inches long and somewhat 138 ANATOMY AND PHYSIOLOGY FOR NURSES. resembles a hammer in shape, the head being turned to the right and lying within the curve of the duodenum, the body crossing to the left, and the tail reaching the spleen. It secretes an abundant Fig. io6. — The Abdominal Organs (Gerrish, after Testut). The liver is turned upward to show the inferior surface with the gall-bladder. The vessels entering and leaving the porta are also seen, the lesser omentum having been removed. alkaline pancreatic fluid, conveyed by the pancreatic duct to the duo- denum. The duct opens (with the common bile duct) into the duo- denum about four inches from the pylorus. THE LIVER. 139 The three pancreatic ferments are amylopsin, trypsin and steap- sin (for starch, proteid and /a/) ('see page 147). The Liver. The liver (Fig. 106) is the largest abdominal organ, and the largest gland in the body. Its normal weight is between three and four pounds (1300 to 1700 grams). It is underneath the diaphragm, in the right upper portion of the abdomen, the thin left lobe extend- ing across the epigastric region above the stomach. Its general shape is that of a wedge, much thicker at the right side than the left, and with the thin edge turned forward. The upper surface is con- vex, and marked off by a ligament into two lobes, right and left. The lower surface is divided by five fissures into five lobes. The largest fissure is the transverse, the porta {or gate) for the passage of vessels,^ nerves and ducts. The liver secretes a yellow alkaline fluid called bile which is conveyed through the porta two by ducts, the right hepatic and left hepatic; these unite to form one, the hepatic duct proper, which is soon joined by the cystic duct from the gall-bladder. The gall-bladder occupies a fissure on the inferior surface of the liver. It is a pear-shaped sac three or four inches long, of fibrous tissue and muscle fibers lined with mucous membrane and partially covered with peritoneum. It contains a variable quantity of bile (or "gall ") in reserve. The only opening of the gall-bladder is for the cystic duct, which joins the hepatic to form the common bile-duct, or ductus communis choledochus. This opens into the doudenum with the pancreatic duct (Fig. 104, 106). Note. — The production of bile is continuous; its flow into the intestine is intermittent. It appears in the duodenum only during the process of digestion; in the interval it is stored in the gall-bladder. The substance of the interior of the liver is composed of secreting cells called hepatic cells, grouped in lobules, with a multitude of blood-vessels, lymphatics and nerves, supported by connective tissue. .\n hepatic lobule measures only about a millimeter (2V of an inch) in width. Between its cells there is a fine network of hepatic and portal blood- vessels, and lymph spaces; also bile passages. The blood-vessels empty into hepatic veins; the lymph spaces form lymph vessels, and the bile passages lead to small bile ducts which unite and reunite to form the hepatic ducts. ' Lymph vessels and hepatic artery. Hepatic veins take a different route. I40 ANATOMY AND PHYSIOLOGY FOR NURSES. Vessels passing through the porta (or transverse fissure) of the Uver: „ , . f Hepatic artery. Entering < . [ Portal vein { Two hepatic ducts. [ Lymphatics. All of the hepatic veins leave the liver at the back, opening at once into a larger vein running to the heart (the inferior vena cava). The great quantity of venous blood which the liver contains gives to it its dark color. Five ligaments of the liver hold it in place attaching it to the dia- phragm and abdominal wall — the round, the broad, the coronary, and two lateral. The round ligament is a cord (the remains of the umbilical vein) inclosed in the broad, which, with the lateral and coronary, is of peritoneum. It is the broad ligament which connects the superior surface of the liver with the diaphragm and is therefore called the suspensory ligament. It also marks off the right from the left lobe on that surface. CHAPTER IX. FOODS AND DIGESTION. FOODS. The human body is a machine constantly in motion; therefore, its cells continually use up their force, and continually need renewing. The material for this renewal is supplied by the food which we eat, and as the various parts of the body are composed of quite different tissues, so the food is of a mixed character. The composition of the tissues requires that for their growth and lepsiir four classes of food principles must be included in the dietary. 1. Proteids. 2. Carbohydrates (sugars and starches). 3. Fats. 4. Mineral salts. In the body: — 1. Proteids are found in all tissues of the body, most abundantly in the blood, as serum albumin, fibrinogen, hemoglobin; in the lymph, as serum albumin; in the muscles, as myosinogen; in the milk, as caseinogen. 2. Carbohydrates (or sugars and starches) are found principally in the blood, as dextrose; in the liver and muscles, as glycogen; in the milk, as lactose. (Glycogen is an animal starch formed within the body, the others are sugars. Dextrose and grape sugar are the same.) 3. Fats are found in subcutaneous fascice and around organs, as adipose tissue; in milk, as emulsion; in blood cells, nerves, lymph, as lecithin;^ in bones, as marrow. 4. Mineral salts are found in all tissues and fluids of the body, mfiuids especially, as water; in bones and teeth especially, as lime salts; in muscle, nerves and blood, as potassium salts; in all tissues, as sodium; in red blood cells, as iron. The blood must draw from all four classes oi food principles for its composition, since it bears to all parts of the body their food. "The blood is the life." * Probably derived from nerve tissue in the body 141 142 ANATOMY AND PHYSIOLOGY FOR NURSES. In the dietary: Proteids must be supplied to all tissues. They are the tissue builders. They may be obtained from meats, as myosin and albu- min; eggs, as albumin from white, vitelline from yolk; grains, as gluten; vegetables, as vegetable albumin (peas, beans, corn, etc.). Starches and sugars are utilized by liver and muscles and are probably the principal sources of muscle energy. They and their compounds are easily oxidized, that is, combined with oxygen. They are obtained from /rw^'/^, as sugar (dextrose); from milk, as lactose; from cereals, peas, beans and potatoes, as starch; from sugar cane, beets, etc., as cane sugar or saccharose. Fats are needed for the marrow of bones, as protective coverings, and to fill in spaces between organs. Also to preserve body heat as well as to produce it. They are obtained from animal foods, from milk, from grains, corn, oats, etc., and formed in the body from sugars. Mineral salts are needed everywhere, although in small quan- tities, as a rule. Water is the most important, being indispensable to life. It con- stitutes nearly three-fourths of the body weight and is universally present, even in the hardest tissues {e.g., enamel of teeth). Its most important uses are: 1. To hold in solution the nutritive principles and make it pos- sible that the tissues may absorb them. 2. To sweep away the waste products to organs which can excrete them. It is obtained from all foods, but must be added in bulk (Small quantities are formed within the body.) Sodium chloride stands next in importance. In an unexplained way it is necessary to the normal activities of the tissues. It must be added to other foods. Phosphate of calcium is needed by bones and teeth, forming a large proportion of their weight. It is the most abundant mineral salt (next to water). It is obtained from vegetables, grains and proteid foods. Iron is a necessary constituent of red blood cells, in hemoglobin. It is obtained from meats and other animal foods and some vegetables. Atmospheric Air as Food. — Sugars, starches and fats consist of carbon, hydrogen and oxygen (CHO). The proteids add nitrogen FOODS AND DIGESTION. I43 (CHNO) and a little sulphur (CHNOS) . (The formulae are omitted, the symbols being sufficient for our purpose.) These elements are all furnished in suitable quantities by the food as described, except oxygen. This is obtained in great measure from the air we breathe, which consists of nitrogen and oxygen. This atmospheric nitrogen does not form combinations with other elements; it is thought to serve only as a diluent for oxygen. The oxygen is the important element. It passes from the lungs into the blood and is carried by the red cells to the tissues at large. (This is further described in Chapter XIII.) With the exception of oxygen, (which is introduced into the system through the lungs), food enters the system through the ali- mentary tract, being here prepared for the uses for which it is designed, by the process of digestion. Different articles of food should be combined in such way as to secure proper adjustment of food principles to body needs. For example : with meats, vegetables should be served rather than milk or eggs. Avoid a number of starchy vegetables in the same meal. For example: to potatoes, or rice, or hominy, add green vegetables, as string-beans, spinach, celery, etc. There is good reason for adding butter to bread and oil to salad, as neither flour nor green things contain fat. Milk is well combined with starchy food, having within itself both proteids and fat. Eggs can take the place of meat to a large extent; they may be combined with milk. The shell or husk of grain contains certain mineral salts which are about our only source of silica for the hair and teeth; therefore — give whole grains to growing children. Whole-wheat flour, and ripe beans or peas, contain proteid in a vegetable form; ripe corn (cornmeal) contains more fat than other cereals, and protein as well. All vegetables contain a varying amount of fiber which is indi- gestible, but which is beneficial, since it serves to prevent the con- centration of waste matters in too small bulk for the action of the large intestine. Three reasons for cooking food are as follows: — Cooked starch is more easily digested than raw, for the following reasons : The change of starch into sugar requires that it should first be hydraled, that is, water must be added to it. It exists in granules 144 ANATOMY AND PHYSIOLOGY FOR NURSES. and each granule of starch has a covering of cellulose which is practically indigestible. In the process of cooking, the boiling water penetrates to the granule, uniting with it and causing it to free itself from the envelope. At once it can be acted upon by ptyalin if in the mouth, or amylopsin if in the small intestine. With raw starch, hydration goes on slowly or not at all. Imperfectly cooked starch is unwholesome for the same reason. Vegetables also should be thoroughly cooked both on account of the starch which they contain, and the fibrous material, which needs partial disintegration by heat. Meats are more easily digested if cooked long enough to soften their connective tissue fibers. By heat these are converted into a gelatinous substance which can be disposed of by pepsin and trypsin. Clinical note.- — The " scraped beef sandwich" so often ordered for patients, contains the substance of the muscle cell alone, which has been scraped away from the connective tissue fiber; it is easily digestible because it may at once be converted into peptone without the necessity for first digesting the tougher DIGESTION. Digestion is the process of so changing the food that its nutritive parts may be absorbed into the system. The organs described in Chapter VHI are so connected and arranged that they receive and act in consecutive order upon the food, causing a series of changes which result in separating nutriment from waste and preparing it for absorption, expelling the waste from the system. The process of digestion begins in the mouth and continues throughout the small intestine. The food is first divided into small pieces by means of the teeth. This is mastication. At the same time it is mixed with saliva; this is hydration and insalivation. By the act of swallowing, the softened mass is passed into the pharynx and down through the esophagus to the stomach. This is deglutition. (The soft palate prevents it from going upward to the nose, and the epiglottis prevents it from entering the larynx.) The stomach now takes charge. The mass is compressed and moved about by the layers of the muscular coat until it is thoroughly saturated with gastric juice, and becomes a pale yellowish fluid called chyme. As fast as this is accomplished, the pylorus, or gate- FOODS AND DIGESTION. I45 keeper, allows it to go through into the duodenum, where it meets the intestinal and pancreatic juices, and bile. Continuing through the small intestine it loses in increasing meas- ure its fluid and nutritious portions, and in the large intestine it is still-further reduced to waste alone, which is expelled from the body. The food is subjected to two sorts of processes in each division of the alimentary tract; the first is mechanical, the second chemical. The first occurrence which follows the introduction of food, is an increased flow of blood to the part and activity of the secreting cells as the food arrives, beginning with the secretion of saliva. In fact, the cells may begin to work beforehand, being stimulated by the thought of food. In the mouth the mechanical process includes mastication and insalivation. By the teeth the food is divided, then crushed and ground; at the same time it is softened by saliva. The parotid saliva does most of this, being the most abundant; it is poured into the mouth just outside the upper second molar and thus it mixes at once with the mass as it is crushed and ground. Submaxillary and sublin- gual saliva contain much more mucin, and lubricate as well as soften the food. The chemical process consists in the conversion of starch into sugar. This is accomplished by ptyalin, a ferment (or enzyme) in the saliva. Starch is not soluble, therefore, not absorbable. Sugar is both. Not all the starch taken at one time is digested in the mouth for the reason that it leaves the mouth too soon. (If it is re- tained in the mouth for some time, especially if mastication be con- tinued, the presence of the sugar thus formed will be evident to the taste.) Ptyalin cannot act in acid fluids: The saliva is alkaline. Being masticated and insalivated the food is passed through the pharynx and esophagus into the stomach. The tongue presses against the hard palate, thus giving the bolus (as the prepared mass is called) an impulse toward the isthmus of the fauces; as it passes through this space the upper pharyngeal constrictor muscle grasps it and passes it on — then the middle and the lower constrictors in turn — and it enters the esophagus. (Meanwhile the soft palate has pre- vented it from going upward and the epiglottis from entering the larynx. j Through the cardiac sphincter of the esophagus it enters the 146 ANATOMY AND PHYSIOLOGY FOR NURSES. stomach. Here the mechanical process consists in the action of the muscle coats, which move the food about that it may be still more softened and thoroughly mixed with gastric juice. The contractions of the muscles of the stomach go on in a wave-like manner toward the pylorus. They alternately constrict and relax the walls of the cavity. The chemical process in the stomach consists in the conversion of proteid substances into peptones by the action of hydrochloric acid and pepsin. Gastric juice contains two ferments or enzymes, pepsin and rennin. Pepsin attacks the proteids after they have been acidi- fied (it cannot work in alkaline fluids). In the digestion of meats, the acid softens the connective tissue fibers (which are already partially gelatinized by cooking) and thus prepares them for the action of the pepsin. Eggs are digested in the same manner but more easily, having so little connective tissue. Milk is first acted upon by rennin which sets free the albumin contained and brings out the casein from the caseinogen, in the form of a soft coagulum or curd. Pepsin then transforms both into peptone. Clinical note, — The curdled milk which a healthy baby regurgitates is a normal substance; the rennin has acted and it only needs the pepsin to complete its digestion. Vegetables are digested in the stomach only so far as the protein which they contain is concerned; sugar and starch not at all. Fats are freed from their connective tissue envelopes and float as little globules; they are not themselves digested here. Note. — The mineral salts do not require digestion. They are already dissolved in the water for the purpose of entering into combinations in the tissues. When any portion of the stomach contents is sufficiently pre- pared by gastric digestion, the pyloric sphincter relaxes and the rather thick yellowish fluid called chyme passes through it into the duodenum and thence into the jejunum and ileum. Here the mechanical process is a continuation of the peristaltic movement of the stomach. The circular fibers, by frequent constric- tions of the tube, divide the mass and force it along, at the same time preventing a too rapid passage. The longitudinal fibers assist, by a series of wave-like contractions. The chemical process consists in the further digestion of pro- FOODS AND DIGESTION. I47 teids, sugars and starch; also the digestion of fats. Therefore the intestinal fluid contains several ferments, being a mixture of pan- creatic juice, intestinal juice and bile. The intestinal juice completes the digestion of sugar (and possi- bly of starch); its ferment is invertin. The pancreatic juice acts promptly upon starch by the ferment amylopsin, changing it to sugar. It converts protein into peptones by the ferment trypsin, and it digests fats by means of the ferment steap- sin, which emulsifies them into a white fluid called chyle. The bile which is poured into the duodenum with the pancreatic fluid is an aid to digestion in ways not perfectly understood. The intestinal ferments all act in alkaline fluids, and bile is alkaline. Experiments and observation have proved that the presence of bile in the intestine is necessary to nutrition; without it a person may eat large quantities of food and still lose weight daily. It is believed that it assists the absorption of fats and it pretty certainly delays putrefactive changes in the intestines. It may also stimulate peristalsis. Clinical notes, — The reason for abstaining from ice-water during digestion is that the various ferments cannot do their work in a temperature much less than 100° F. (If people will eat ice-cream after dinner they should at least take it slowly, that the whole process of digestion be not too long delayed by the necessity of waiting for the temperature to rise again to 100°. ) The activity of the salivary glands of the infant does not begin under three or four months. The feeding of starchy foods should be delayed in accordance with this fact. The passage of food through the intestine is normally slow, and thus it is fully exposed to the surfaces of the circular folds of the mucous membrane. By the absorption of digested food the intes- tinal contents are diminished in quantity and changed in character, containing less water and approaching a firmer consistency. After passing through the ileo-colic sphincter into the large intestine there is little but waste remaining, undigested food forming the major portion. This collection of waste, liquids, coloring matter and undigested food is called feces. The coloring matter is derived partly from bile, partly from food (it may be modified by drugs; for example, iron and bismuth giving a black color to the feces). (The odor is due to sulphuretted hydrogen and to skatol — it also is 148 AXATOMY AD PHYSIOLOGY FOR NURSES. modified by food.j The consistency depends upon the amounts of water and mucus, approaching a liquid form when the intestinal contents are hurried through the tube before absorption can take place. Defecation is the act of expelling the feces. The bowel muscles contract and the sphincter ani relaxes; the abdominal muscles assist by compressing the organs from above. The dietary which con- tains the largest proportion of waste material will leave the greatest quantity of feces and lead to more frequent defecation than one which is made up of digestible substances only. The peristaltic action of the bowel is made more effective by the presence of a reasonable amount of matter to be acted upon. Diarrhea is the passing of frequent loose or watery stools. It occurs when the contents of the small intestine are hurried along too rapidly by some irritating substance which causes excessive peristalsis and a leakage of the watery portion of the blood. Ccmstipation is caused by a too concentrated diet and slow peristalsis. Since bile is a natural stimulant to the muscles of the bowel, constipation is often associated with a torpid liver; it is also caused by lack of fluids in the bowel. Therefore this is one reason why water is an important food. Absorption of Food. Accompanying the digestion of food the absorption of nutritive principles takes place. It is not proven that food is absorbed from the stomach; as fast as it is digested there, it is discharged as chyme into the small intestine. After it is acted upon by intestinal fluids it is ready to be absorbed. The villi (page 131) are the absorbents which perform this function in the intestine. The epithelial cells with which they are covered take up and transmit the new substances (formed by digestion) into lymph spaces within the \illus, from which they go either into the blood-vessels or lymph capillaries (page 149) which it contains. Wafer and mineral salts (dissolved in the water). — These must pass into the blood capillaries, thence into intestinnl veins, and through them to the portal vein (page 188). By this they are taken to the liver. Sugars, dextrose and levulose (which result from the digestion of carbo- hydrates). These pass by the same route, namely, blood capillaries and veins to the liver. Peptones also find their way in the same manner to the portal blood and the liver. ABSORPTION OF FOOD. 149 Thus it appears that all proteins, sugars, water and salts pass through the liver. There, water and salts are used for various combinations; sugars are converted into glycogen to a great extent and stored for future use; and proteids furnish tissue food and materials for bile. Fig. 107 — Section of Ixtected Small Intestine of Cat. a, b. Mucosa, g. Villi. i. Their absorbent vessels, h. Simple foUices. c. Muscularis mucosa^. 7. Submucosa. ^, e. Circular and longitudinal layers of muscle. /. Fibrous coat. All the dark lines represent blood-vessles filled with the injection mass (Piersol). Glycogen. — This product of the action of liver cells upon carbohydrates is stored in the liver. When needed it is returned to the blood (as sugar again) and distributed to the tissues, notably to the muscles. Being readily oxidized it favors the rapid changes in muscles which result in motion. Therefore, it follows that sugar and starch are sources of muscle energy. Urea. — This is another substance which appears as a result of the activity of the liver cell. It represents the final form of waste derived from the metab- olism of proteid substances. It is a very poisonous waste and is eliminated from the blood by the kidneys. Having yielded materials for these functions, the remaining food substances are carried away from the liver by hepatic veins and finally ISO ANATOMY AND PHYSIOLOGY FOR NURSES. into the general circulation, to be distributed to the tissues of the body. There remain the fats: These, being transferred by the epithelial cells to the lymph-spaces, take the other route, in the form of an emulsion known as chyle. They pass into the lymph capillaries of the intestine (so-called lacteals), which open into the lymph vessels in the submucous coat. By these vessels the chyle finally reaches the thoracic duct and is carried into the general circulation to be distributed to the tissues of the body (Fig. io8). Another view is held concerning the digestion and absorption of fats — that the results of digestion are soaps and glycerin, which are easily absorbed. However they may be absorbed by the epithelium, they are in the form of an emulsion in the lacteals. Lacteals Blood vessels Fig. 108. — Loop of Small Intestine with Lacteals (Morris). In the tissues. — The solution of nutritive substances, having been carried by the blood-vessels to the minutest channels in the body, passes into the tissue spaces as Ijmiph, which bathes the cells themselves so that they may receive the material necessary for their action and upbuilding. Different tissues appropriate their different foods, and each gives back the products of its own activities as tissue wastes, which in turn enter the blood to be carried to tissues which can make another use of them, or to organs which can dispose of them as excretions. FOODS AND DIGESTION. I51 Digestion. — Is the process of so changing the food that it may be absorbed. Absorption. — Is the process of taking up certain substances and conveying them to the blood. Circulation. — Is the process of carrying the blood and other substances to every part of the body. Assimilation. — Is the process which goes on in the tissue cells whereby they make use of the food which is conveyed to them. We have now to study the organs which distribute the products of digestion, and the composition of the food-bearing fluids — blood and lymph. Assimilation is nature's own secret, not yet revealed to the mind of man. CHAPTER X. THE BLOOD AND THE CIRCULATORY SYSTEM. THE BLOOD. The blood is the most important fluid in the body. It not only carries food to every part, but bears waste matters to those organs which can dispose of them in the form of excretions. It consists of a clear yellowish fluid called plasma and small round cells (invisible to the naked eye) called corpuscles (little bodies), which float in the plasma. The corpuscles are of two sorts, red and white. It is convenient to follow the usage common in clinical work and speak of them as red and white cells. A third, smaller, colorless cell exists in blood, named a hlood plate. Fig. 109. — Corpuscles of Blood, as seen under the Microscope. Four white ones are shown. The red ones have a tendency to form rows (Funke and Brubaker). The temperature of the blood is about 100° F. The reaction is alkaline. The red cells {erythrocytes) are non-nucleated, flexible and elastic. They are very numerous, numbering 4,000,000 to 4,500,000 in a cubic centimeter. They measure about 2^-5W of an inch in 152 THE BLOOD. 153 diameter, and their shape has been usually described as that of a flattened sphere (Fig. 109). Note. — The illustration presents the appearance under the microscope of blood which has been removed for a time from the vessels and cooled. Careful studies under other conditions, indicate that the living cells are slightly hell-shaped. .T)^^^j^j^^, cells are composed largely of hemoglobin. This itself is amb^^ j:oJ,Qred, but when a great number of cells are together as in a drop pf blood, it gives the red hue to the fluid. Hemoglobin is a proteid substance whose most important propertY^.^i^ its power to combine with oxygen and to give it up. It contai^^a minute quantity of iron in combination (hematin) which is neC|^^sa-ry to life processes. The origin of the red cells is in the red marrow of cancellous bone. The white cells or leucocytes are of different sizes (the largest be- ing about Winr of an inch in diameter). They move more slowly in the plasma and are far less numerous, numbering only about 7500 in a centimeter. Fig. 1 10 — \\'hite Corpuscles Penetrating Capillary Walls (Landois and Stirling). They are nucleated, flexible and elastic. Their shape is spher. ical (often irregular), and they consist of a transparent material containing one or several nuclei and many fine granules (of proteid substances). The white cells frequently change their shapes by means of ameboid movements, that is, like the ameba, they thrust out portions of their substance and draw them back. They can send out little 154 ANATOMY AND PHYSIOLOGY FOR NURSES. prolongations and draw floating particles to themselves, or they can wrap themselves around foreign substances. They possess also the power of slipping (squeezing) through the walls of capillary vessels. This is called diapedesis (Fig. no). Of the five distinct varieties of leucocytes the percentage of polymorpho- nuclear cells {nuclei of many shapes) is the largest. The polymorphonuclear cells (oftenest called polynuclear) and the lymphocytes are called phagocytes, because they destroy bacteria by absorbing and digesting them. This process is caXltd phagocyto- sis (to be referred to later on). o:'^--' The origin of the white cells is from two sources; the lymphocytes originate in lymph glands "and other lymphoid tissues; the poly- nuclear leucocytes and others are developed from cells in the marrow of long bones. The plasma is a thin watery saline fluid in which the corpuscles float. It contains both nutritive and waste matters in solution, and also certain elements from which fibrin is derived. The fibrin is essential to the production of a blood-clot, without which hemorrhage would never cease of its own accord. The substances dissolved in the watery portion of the plasma are: Serum-albumin Proteids. ... \ Fibrinogen Nutritive (derived from food) { Paraglobulin Sugars Fats Waste products (derived from tissue . j Urea , . Extractives Wt • -j ^ changes). [ Uric acid, etc. [ Sodium Mineral salts. Chiefly salts of \ Potassium [ Calcium The serum-albumin is the great tissue builder. The fibrinogen is the fibrin maker (paraglobulin may assist in this; its use is not fully known) . Sugars and fats are tissue foods. Mineral salts preserve the necessary alkalinity of the blood and assist in the formation of certain tissues (as bone) . Sodium chloride (common salt) is the most abundant (and to this is due the salinity of the blood).' ^ A "normal saline solution" contains salt in the proportion found in blood. PROCESS OF COAGULATION, 155 Coagulation of Blood. Blood which is exposed to the air at the usual temperature is seen to separate into distinct portions — a red, jelly-like mass and a transparent straw-colored layer which is thinner. The dark mass is the coagulum, consisting of fibrin with corpuscles entangled in it. The straw-colored layer above it is serum, which is plasma bereft of its fibrin and corpuscles (Fig. iii). This same process may occur at the mouth of a blood-vessel which has been cut or ruptured, if the stream be not too forcible, and it is nature's way of stopping the flow. I. 2. 3. Fig. III. — Diagram to Illustrate the Process of Coagulation, i. Fresh blood, plasma, and corpuscles. 2. Coagulating blood (birth of fibrin). 3. Coagulated blood (clot and serum) (Waller). A clot of fibrin may be formed within a blood-vessel if the interior surface is rough and the stream slow; this does not occur in health. The formation of fibrin from fibrinogen is a process confined to the plasma; the corpuscles remain unchanged and are simply incidental constituents of the coagulum or clot. Fibrin itself is colorless, as may be seen when it is whipped out from fresh blood by twigs or rods. The coagulation time of blood is of some importance, as it varies in health or disease; for example, it is delayed in certain inflammatory conditions. Diagram of Change from Fluid to Coagulated Blood. Corpuscles, they unite with \ Fluid blood Plasma, consists of j Fibrin to form Coagulum I Coagulated 1 blood \ Serum remains Serum Opsonins and ihe opsonic index. — It is believed that the phago- cytic action of white cells is regulated by the presence in 'the blood of chemical substances (still undescribcd) called opsonins, by which invading bacteria arc prepared for absorption and digestion by the phagocytes. The measure of the power thus residing in the blood 156 ANATOMY AND PHYSIOLOGY FOR NURSES. is expressed as the opsonic index. The opsonic index is high or low, according to the number of bacteria which the cells may be able to dispose of. There is some reason for thinking that a special opsonin exists for each kind of bacterium. THE CIRCULATORY SYSTEM. This system includes the heart and blood-vessels or arteries, capillaries and veins. They are the organs which contain the blood. The heart is a pump. The arteries are elastic tubes which receive the blood directly from the heart. The capillaries are small vessels into which the arteries lead, and the veins carry the blood from the capillaries back to the heart. Arteries. — ^Vessels which convey the blood away from the heart. They are flexible tubes whose walls consist of three layers or coats — external, middle, and internal (or tunica adventitia, tunica media, and tunica intima). The external coat is composed of fibrous tissue to which the strength and toughness of the vessel is due; the middle is composed of elastic tissue and unstriped muscle fibers, giving to arteries their yielding and contractile character; the internal is thin and smooth and is a continuation of the lining of the heart. (It is sometimes called the serous coat.) Arteries of medium size have most muscle tissue, while the larger ones have most elastic tissue. It is owing to their elasticity that arteries remain open when they are empty or cut across. Note. — The internal coat is the only one which is continuous throughout the entire circulatory system. Surgical note. — When a ligature is tied tightly around an artery the middle coat may be felt to break down under the cord, while the external one remains whole, owing to its toughness. The arteries give off branches which divide and subdivide until the smallest ones can be seen only with the microscope — they are called arterioles. The arterioles lead to the vessels which are smallest of all — the capillaries. Capillaries. — ^Vessels which receive blood from the arteries and carry it to the veins. They exist in nearly every part of the body, except cartilages, hair, nails, cuticle, and the cornea of the eye. Their walls have only the internal coat, a single layer of cells— endothelium. It is through these thin walls that the work of exchange THE HEART. 157 is performed between the blood and the various tissues of the body, nutritive material being taken from the blood and certain waste substances being returned to it. To provide vessels for this ex- change is the function of .the capillaries. Their average diameter is ^iMjg- of an inch — just enough to permit the easy- passage of the corpuscles. Veins. — The vessels which gather the blood from the capillaries and carry it to the heart; they are formed by the uniting of capillaries. They are at first very small (called venules or venous radicles) but constantly grow larger by uniting with each other, although they often branch and reunite. Veins, like arteries, have three coats, but their middle coat is neither so elastic nor so muscular, so that they are softer, and when empty or cut, they collapse. The inner coat of the veins presents, at intervals, semilunar folds, making pockets called valves, which allow the blood to flow toward the heart, but prevent it from setting backward freely. (If the veins are very well filled the location of the valves may be recognized by an appearance of puffing out at those points where they exist.) (Fig. 112.) Blood-vessels possess nerves^ which, by con- trolling the muscular coats, regulate the amount of blood flowing through them at a given time to the structures which they supply. (An organ at work needs more blood than an organ at rest.) They also possess tiny blood-vessels in their walls, the vasa vasorum. Fig. 112. — A Vein Laid Open to Show Valves. All blood-vessels have sheaths of connective tissue. In the case of the larger ones these are quite strong and sometimes inclose a vein, an artery, and a nerve together. The Heart. The heart is a hollow muscular organ through which the blood passes, placed behind the sternum and just above the central tendon of the diaphragm. Note. — The muscle tissue of the heart is called the myocardium. ' Vaso-motor nerves. 158 ANATOMY AND PHYSIOLOGY FOR NURSES. It is shaped like a cone, about five inches long and three and one-half inches wide, with the base turned upward toward the right shoulder and the apex pointing downward toward the left side. It is composed of several layers of muscle fibers which are peculiar, being involuntary and at the same time striped. The cavity of the heart is divided by a septum into right and left portions, and as it lies in the body the right heart is nearly in front of the left. Each side consists of two chambers, an auricle (atrium) and a ventricle (ventriculum) (Fig. 114). Posterior branch of // right coronary ar tery Auricular appendage Right coronary artery Preventricular branch Right marginal branch Posterior interventicu- lar branch of right coronary artery Transverse branch of right coronary artery Left coronary artery Anterior interventricu- lar branch of left coronary artery Left marginal branch Fig. 113. — Anterior Surface of Heart (Morris). The coronar}' arteries supply the substance of the heart. The auricles receive blood and pass it into the ventricles. Their walls are thin and flabby. The right auricle, or atrium, presents two large openings for the entrance of veins, and one for communication with the right ventricle. The veins are the superior vena cava from the head and upper extremities; the inferior vena cava from the trunk and lower extremities. It also has a transverse fold on the posterior wall called the Eustachian valve or valve of the inferior vena cava, and a round depression on the septum between the two auricles (atria), called the oval fossa {fossa ovalis). The left VENTRICLES OF THE HEART. 159 auricle presents two large openings and several small ones for veins, and communicates with the left ventricle. The ventricles expel blood from the heart. They include the apex of the heart and their walls are thick and strong, the left one being the thicker and larger of the two. Certain muscle libers in Fig. 114. — IxTERiOR of Left Heart. (Observe the difference in thickness of the walls in auricle and ventricle.) (Allen Thomson in Bruhaker.) I, L. atrium or auricle; 2, division between it and ventricle; 3, wall of left ventricle; 4, a band of muscle fibers severed; 5, other muscle bands; 6, a leaflet of mitral valve, with tendinous cords; 7, aorta (a large artery) laid open to show semilunar valves; 8, pulmonary artery (semilunar valves closed) ; q, arc h of aorta. the ventricles pass downward to wind around the apex of the heart and then turn upward; others are transverse, still others oblique; the arrangement causing the heart to harden in contraction, with a twisting motion from right to left and a forcible pressure against the chest wall. This is felt in the fifth interspace, at the left of the sternum and is called the cardiac impulse. i6o ANATOMY AND PHYSIOLOGY FOR NURSES. The muscle hand of His is a name given to a bundle of muscle fibers which connects the auricles and ventricles; the contraction impulse is believed to travel from auricle to ventricle by these fibers. The interior of the ventricles is marked with a number of ridges or bands of muscle fibers (the traheculcB carnece), and certain of these are attached by tendinous cords to the valves of the heart. Each ventricle opens into a large artery, which conveys the blood away — the pulmonary artery from the right ventricle, the aorta from the left. Note. — In the new nomenclature the name "atrium," or forechamber, is given to the main part of the auricle, and the word auricle applies to the auricular appendage alone; the opening from auricle to ventricle is called ostium venosum. Endocardium. — The lining of the heart. It is thin and firm, resembling serous membrane in appearance, and is continuous with the lining of the arteries and veins, thus making a perfectly smooth surface throughout, for the current of blood. The Valves of the Heart, The valves of the heart are formed by folds of endocardium strengthened by fibrous tissue and placed at certain orifices of the different chambers — two in the right heart and two in the left. The opening be- tween the right auricle and ventricle (right ostium veno- sum) is guarded by the tri- cuspid valve, which is com- posed of three leaflets. It allows the blood to flow down into the ventricle but prevents it from flowing back. The opening between the left auricle and ventricle (left ostium venosum) is guarded by the bicuspid (or mitral) valve, composed of two leaflets, allowing the blood to flow down into the ventricle but not to return. (Both the tricuspid and mitral valves are connected Fig. 115. — ^Valves of the Heart. 1. Right auriculo-ventricular orifice, dosed by the tricuspid valve. 2. Fibrinous ring. 3. Left auriculo-ventricular orifice, closed by the mitral valve. 4. Fibrous ring. 5. Aortic orifice and valves. 6. Pulmonic orifice and valves. 7, 8, 9. Muscular fibers (auricles re- moved) (Bonamy and Beau.) VALVES OF THE HEART. l6l to certain muscle bands of the ventricles by tendinous cords which control the motion of the leaflets, preventing them from flying up- ward too far when the ventricles contract.) (Fig. 114.) The opening from the right ventricle into the artery which leaves it {pulmonary artery), is guarded by three semiluna rvalves, which are half-moon shaped pockets called the pulmonary valves. Likewise the opening from the left ventricle into its artery {aorta) is guarded by three semilunar valves called the aortic valves (Fig. 115). The semilunar valves allow the blood to flow in one direction only — that is, away from the heart. Fig. 116. (Diagram.) The right auricle receiving blood and passing it through tricuspid valve into right ven- tricle, which is dilated {semilunar valves closed) (Dalton in Brubaker). Functions of the Chambers of the Heart. The auricles, having received blood from the veins opening into them (the right — blood from entire body; left — from lungs alone) gently contract together to send it down into the ventricles; quickly the ventricles contract, forcibly and together, expelling blood into the two large arteries — the pulmonary carrying it to the lungs, the aorta to all parts of the body. This process is the systole of the heart; it occupies about eight- tenths of a second, perhaps a trifle more. Then comes the resting-timc when the heart is dilating and filling again, called the diastole of the heart. l62 ANATOMY AND PHYSIOLOGY FOR NURSES. During the systole of the auricles, the tricuspid and mitral valves are open and the semilunar valves are closed. During systole of the ventricles the tricuspid and mitral valves close, and the semilunar valves are open (Figs. ii6, 117). The thickness of the ventricle wall is explained by the need for sending blood to a distance, the greater thickness of the left being made necessary by the far greater work required of it. The systole of the ventricles corresponds to the "heart-beat" It occurs at perfectly regular intervals in health, the rate being from Fig. 117. The right ventricle filled, contracts and expels blood through semilunar valves {tricuspid valve closed) (Dalton in Brubaker). sixty to seventy per minute in men, and from seventy to eighty in women. The heart's action is more rapid in the upright position than in sitting or lying, and is increased by any exercise, however gentle. Excitement or emotion will quicken it at once, and it is always fastei: in children, being about one hundred and forty in the newly born and reaching an average rate of ninety to one hundred at the age of three years; ninety in youth, seventy in adults, and eighty in old age. The Pulse. — The effect of the heart-beat upon the current of the blood may be felt in the arteries, which are distended for an instant by the blood forced into them as the ventricles contract. SOUNDS OF THE HEART. 163 This gives the effect of a beating in the arteries, which is called the pulse. The pulse-rate corresponds with the heart-beat; therefore, the rate and force of the heart's action are judged by means of the pulse. The Heart Sounds. The action of the heart causes certain sounds, named the first and secand. The first accompanies the sudden closure of the tri- cuspid and mitral valves, as the ventricles contract. It is the systolic UPPER ATTACHMENT OF PERICARDIUM ' 3RANCHES OF PUL MONARY ARTERY AORTAr. BRANCHES OF IPULMONARY ARTERY -PULMONARY ARTERY DIAPHRAGM PERICARDIUM ATTACHMENT OF DIAPHRAGM Fig. 118.- RIGHT VENTRICLE PERICARDIUM TO DIAPHRAGM -The heart in situ. The pericardium has been cut open in front, and reflected (Testut). sound — caused by the systole of the ventricles. The second ac- companies the sudden closure of the semilunar valves. It is the diastolic sound, occurring with the diastole of the ventricles. The first or systolic sound is the louder and larger, being due to the contracting of muscle fibers as well as to closure of valves. The second, diastolic sound is short and sharp, due to valve closure only. The two sounds are compared to the spoken words — luhh dupp. l64 ANATOMY AND PHYSIOLOGY FOR NURSES. When the blood is forced into the elastic arteries by a contraction or beating of the heart it stretches them. When the contraction is ended, the wall of the artery recoils and there is a setting back of the blood for an instant toward the heart, but it is stopped by the closing semilunar valves, which thus make the second sound. Clinical note. — If the valves of the heart are rough, the sounds are changed by a "murmur." If they cannot close perfectly, a portion of the blood will flow backward instead of going forward, and this is regurgitation. This, also, changes the sound of a valve and causes a murmur. The pericardium (Fig. ii8). — A loose serous sac enclosing the heart. The layer which closely covers the heart, or the visceral layer, is the epicardium. It covers the aorta and pulmonary arteries for about one inch, then leaves them to become the parietal layer or lining of the fibrous sac w^hich encloses the whole, and which is closely attached to the diaphragm below and the great vessels above. A small quantity of pericardial fluid prevents friction between the surfaces, as the smoothly covered heart beats in the smoothly lined cavity; this increases in inflammation of the pericardium, or peri- carditis, and it is sometimes necessary to remove it by tapping. Review. — ^Principal Points of Interest in the Heart. Right Auricle. Openings of two large veins bringing blood from the body. Opening of coronary sinus bringing blood from the heart itself. Oval fossa and annulus ovalis. Eustachian valve (or valve of inferior vena cava). R. Ostium venosum with tricusped valve. Right Ventricle. R. Ostium venosum and tricuspid valve. Opening for pulmonary artery, and pulmonary valves. Trabeculas carneae (fleshy bands), and the tendinous cords con- jiecting them with tricuspid valve. Left Auricle. Openings of three or four pulmonary veins. L. Ostium venosum with bicuspid (or mitral) valve. PULMONARY CIRCULATION. 165 Left Ventricle. L. Ostium venosum and bicuspid valve. Opening for aorta and aortic valves. Trabeculae carneae and the tendinous cords connecting them with the bicuspid valve. The Course of the Blood Through the Heart. Resume. — The blood enters the right auricle, passes down into the right ventricle, and out through the pulmonary artery to the lungs; it returns by the pulmonary veins to the left auricle, passes down Left carotid artery ^ Left suhclav-ia . artLTv Pulmonary artery Pulmonary veins from left lung Left auricle Coronary vessels — Anonyma Superior vena cava Pulmonary veins from right lung — Right auricle II j\ 'jT- Inferior vena cava Coronary artery Fig. iiq. — Posterior Surface of Heart. Pulmonary veins bringing pure blood to left auricle (Morris' Anatomy). into the left ventricle, and out through the aorta to every part of the body, from which it is returned by two large veins to the right auricle again. The course from the right ventricle through the lungs and back to the left auricle is called the pulmonary circulation (Fig. 119). l66 ANATOMY AND PHYSIOLOGY FOR NURSES. The course from the left ventricle through the entire body or "system" and back to the right auricle is called the systemic circulation (Fig. 120). Important notes. — ^Pure blood is carried from the heart through the systemic arteries to all tissues in the body to nourish them. This blood is called arterial blood; it is bright red in color. The terms piire blood and arterial blood are used to signify one and the same thing. Impure blood from the tissues of the body is returned to the heart by the systemic veins. It is called venous blood; it is purple-red or blue in color and contains waste matters. The terms impure blood and venous blood are used to signify one and the same thing. The venous blood from the body is poured into the right side of the heart, from which the pulmonary artery conveys it to the lungs. Consequently the pul- monary artery is unlike others, because it carries venous blood from the heart; and the pulmonary veins are peculiar because they carry arterial blood to the heart. CHAPTER XI. THE CIRCULATION AND FUNCTIONS OF BLOOD. THE PULMONARY CIRCULATIOX. This is the circulation of the blood through the lungs, that it may become aerated or purified. The puknonary artery leaves the right ventricle, carrying impure blood, and soon divides into two branches, the right and left (one for each lung), which break up into a capillary network around the air cells. From this network veins arise which, by uniting, form two from each lung, making the four pulmonary veins carrying purified blood to the left side of the heart. They enter the left atrium. THE SYSTEMIC CIRCULATION. This is the circulation of the blood through the entire body or "system," that it may nourish the tissues and organs (Fig. 120). Arteries of the Systemic Circulation.^ The aorta, having received the pure blood from the lungs, leaves the left ventricle, arches over the root of the left lung to the left side of the fourth thoracic vertebra, then (gradually coming to the front of the spinal column) passes down through the diaphragm, and ends by dividing at the fourth lumbar vertebra, (a little below the level of the umbilicus). Thus it consists of three portions: the arch, the thoracic aorta, and the abdominal aorta (Fig. 121). The arch of the aorta extends from the heart to the body (lower border) of the fourth thoracic vertebra. It reaches almost as high as the sternal (or jugular) notch. It may be felt in thin persons by pressing the finger tip down behind the bone. ' The names of all of the arteries .re given in tabular form on page 312. Only the principal ones are here described. 167 1 68 SYSTEMIC CIRCULATION. Fig. 1 20. — Scheme of Systemic Circulation. Arteries colored red; veins blue. THE AORTA. 169 RIGHT COMMON- CAROTID Jugular vein LEFT COMMON CAROTID Vagus nerve Thoracic duct L. V. anonyma LEFT SUBCLA- \IAN ARTERY ^p^ ! Nerves and ' ' veins Fig. 121. — The Aorta, showing the Three Portions (Morris). lyo ANATOMY AND PHYSIOLOGY FOR NURSES. Branches of the arch in their order: Two coronary (right and left) to heart muscle (Fig. 113). Right subclavian to right One anonyma, ij inches long. . . < upper extremity. Right common carotid to [ right head and neck. One left common carotid to left head and neck. One left subclavian to left upper extremity. Phrenic nerve Subclavian artery Subclavian vein Anterior intercostal branch Branch of mammary Common carotid Internal jugular vein Subclavian vein Scalenus anterior muscle — Sternum I Perforating branches /_j \ (supplying mam- mary gland) Superior epigastric, running down from internal mammary Inferior epigastric, running up from external iliac Fig. 122. — Showing Subclavian Artery and two of its Branches (Thyroid axis and internal mammaiy) (Morris). The Principal Arteries of the Upper Extremity. The subclavian artery (Fig. 122) passes out over the first rib and under the clavicula (therefore subclavian) to the axilla, or armpit. The brachial plexus lies above it in the neck, and the THE AXILLARY ARTERY. 171 subcla\'ian vein is in front of it. The right subcla\dan is a branch of the anonyma. Both subclavians end at the lower border of the first rib. Branches. — The vertebral branch runs upward through transverse processes of the vertebrae to the brain. The internal mammary branch runs downward inside the chest behind the ribs (giving some arteries to the mammary gland), into the abdominal muscle. Fig. 123. — Subclavian and Axillary Arteries (Testut). The thyroid axis is a short trunk; it gives a branch to the thyroid gland and others to the neck and shoulder. An axis (artery) is a short vessel dividing at once into two or three. The axillary artery is a continuation of the subclavian. It begins, therefore, where the subclavian ends — in the apex of the axilla, at the lower border of the first rib — and continues through the axillary space' (Fig. 123). ' .Axillary space, p. 300. 172 ANATOMY AND PHYSIOLOGY FOR NURSES. Branches {thoracic, subscapular, circumflex.) — To all structures around the axilla. One, the lateral thoracic, gives arteries to the mammary gland. The brachial artery begins where the axillary ends, at the lower border of the axilla, or armpit, and extends downward in Fig. 124. — Deep Palmer Arch. Made by continuation of the radial artery. This is covered by the muscles of the thenar and hypo thenar eminences. front of the arm (with the biceps muscle) to the bend of the elbow, where it divides into the radial and the ulnar arteries. Its branches supply the muscles of the humerus and the bone itself. (The median nerve lies next to this artery under the border of the biceps muscle.) (Figs. 123, 125.) RADIAL AND ULNAR ARTERIES. ^n The radial and the ulnar arteries pass downward in the radial and ulnar sides of the fore- arm to the hands. The radial supplies the muscles in front of the radius, and winds to the back of the wrist to find its way to the palm by pass- ing forward between the first two metacarpal bones. It forms the deep palmar arch, which crosses the palm under the long tendons (Fig. 124). The ulnar supplies the muscles in front of the ulna, and forms the superficial palmar arch, which crosses over the long tendons in the palm (Fig. 125). Note. — The superficial arch crosses the palm opposite the level of the web of the thumb when put "on the stretch." The deep arch crosses about a finger- width nearer the wrist. The digital arteries run in the sides of the fingers; they are branches of the superficial arch. Clinical note.^The pulsation of the radial artery is easily felt above the wrist in front, next to the tendon of the radial flexor of the wrist. Surgical note. — A direct com- munication exists between the deep and superficial arches, con- sequently severe hemorrhage easily occurs in the palm, since blood will flow from radial and ulnar arteries at one and the same time, and it is sometimes necessary to ligate both Axillary artery Median nerve Brachial artery Lateral cord Pectoral muscle Ulnar nerve and artery Radial nerve and artery Branches to hand Fig. i2<;. — Axillary, Brachial, Radial and Ulnar Arteries. Superficial Arches. 174 anatomy and physiology for nurses. Principal Arteries of the Head and Neck. The common carotid arteries. — The right is a branch of the anonyma; the left is directly from the arch of the aorta. They proceed upward on either side of the trachea, with the internal jugular vein on the lateral side and the vagus nerve behind them. They carry the blood supply of the head and neck (Fig. 121). The common carotid divides at the upper border of the thyroid cartilage into internal carotid for the interior of the head, and external carotid for the exterior of the head and the neck. Fig. 126. — Arteries of the Brain (Morris). Cerebral arteries pass from the base of the brain to all parts of the surface. The internal carotid is deep in the neck; it runs up to the head and through the carotid canal into the cranial cavity. Principal branches. — Ophthalmic, to eye and appendages, nose, and forehead. (The supraorbital artery is a branch of the ophthalmic.) Middle cerebral to the brain, anterior cerebral to the brain (Fig. 126). EXTERNAL CAROTID AND TEMPORAL ARTERIES. 175 Note. — The internal carotid makes four sharp turns after entering the carotid canal in the petrous bone, and by this means the force of the current in this large vessel is modified before it reaches the delicate tissues of the brain. The internal jugular vein and vagus nerve accompany it in the neck. The external carotid artery supplies the face, and front of the neck and scalp (Fig. 127). Principal branches. — Superior thyroid, to the thyroid gland and larynx. Lingual, to the tongue and tonsil. Facial (or external maxillary) to the face, soft palate and tonsil. Occipital, to the back of the head and neck. Clinical notes. — The external maxillary (facial) artery runs tovs^ard the bridge of the nose. It sends two labial arteries to the borders of the lips; and the one in the upper lip supplies a branch to the septum of the nose, therefore, com- pression of the upper lip will sometimes stop "nose-bleed." The lingual artery ends at the tip of the tongue, in a branch (ranine) which might be severed in cutting too freely for "tongue-tie." Fig. 127.— Facial, Temporal and Occipital .\rteries. Having given oflf its branches, the external carotid passes into the substance of the parotid gland and divides into the temporal and internal maxillary. The temporal passes through the parotid gland and across the zygoma to the side of the head, supplying temporal branches to the scalp. The internal maxillary runs between the muscles of mas- tication in the infratemporal fossa to the deep parts of the face, 176 ANATOMY AND PHYSIOLOGY FOR NURSES. including the nose and pharynx. The dental arteries are all derived from this vessel. Collateral Circulation. — An important descending branch of the occipital artery runs down under the deep muscles of the neck to unite with one derived from a branch of the subclavian, thus making a short route between the subcla- vian and the external carotid; the blood can flow in this indirect way to the head if the external carotid be ligated. Principal Arteries of the Trunk. The thoracic aorta extends from the fourth dorsal vertebra to the diaphragm (Fig. 129). Branches. — Intercostal, 11 pairs, to the intercostal spaces; bronchial to lung tissues;^ pericardial to pericardium; esophageal to esophagus, and mediastinal to glands and tissues between the lungs (the mediastinal space). Note. — These aortic intercostal arteries run rather more than half way to the front, in grooves under the borders of the ribs, accompanied by intercostal nerves, and veins. * The abdominal aorta extends from the opening in the diaphragm to the body (lower border) of the fourth Imnbar vertebra — a little above the level of the umbilicus (Fig. 128). Branches. — Phrenic to the diaphragm and lumbar (4 pairs) to the abdominal wall, sacral to sacrum and rectum. Branches to viscera: The celiac artery, dividing into gastric, for the stomach; hepatic, for the liver ;^ splenic (or lienal), for the spleen. Superior mesenteric, to the small intestine and these parts of the large intestine, namely — cecum, ascending and transverse colon. Inferior mesenteric, to the remainder of the large intestine, namely — descending and sigmoid colon, rectum. Two renal arteries, to the kidneys. Adrenal arteries, to the adrenal bodies. The ovarian arteries, to the ovaries, or the spermatic arteries to the testes. ' Bronchial arteries have very little to do with respiration; they are the nutrient arteries of the lungs. ^ The hepatic circulation is a double one: Both venous and arterial blood enter the liver. The portal vein (with products of digestion for the liver to work over) and the hepatic artery (with the oxygen with which this work is to be done) enter together through the portal fissure. (The venous blood of both leaves the liver by hepatic veins, page 189.) BRANCHES OF ABDOMINAL AORTA. 177 The ovarian artery runs downward into the pelvis and passes between the layers of the broad ligament to the ovary, freely supply- ing it and the Fallopian tubes. It ends by anastomosing with the uterine artery (Figs. 128, 132). Cystic artery Hepatic duct Cystic duct Common duct Portal vein istro-duodenal branch iperior pyloric branch Hepatic artery Right suprarenal vein ferior suprarenal artery Renal artery Renal vein Inferior vena cava Kidney Right spermatic vein Right spermatic artery Quadratus lumborum muscle ight lumbar artery and left lumbar vein Ureteric branch of spermatic artery Middle sacral vessel Left lobe of liver Esophagus Left phrenic arterv Right phrenic arter>' Superior suprarenal Gastric artery Inferior suprarenal Splenic artery Left phrenic vein Left suprarenal vein Superior mesenteric artery Kidney Ureteric branch of renal Left spermatic vein Ureter Left spermatic or ovarian artery Inferior mesenteric artery Ureteric branch of spermatic Ureteric branch of common iliac Common iliac artery External iliac artery Internal iliac artery Fig. 128. — Branches of the AnnoMiMAL Aorta (Morris). Note that the right common iliac is longer than the left. The spennatic artery runs downward and along the brim of the pelvis to pass out through the inguinal canal with the spermatic cord; it continues downward in the scrotum to supply the testes (Fig. 128). lyS ANATOMY AND PHYSIOLOGY FOR NURSES. Special notes. — The superior mesenteric lies between the layers of the mesentery. The inferior mesenteric lies partly in the left meso-colon; it termi- nates as the superior hemorrhoidal in the upper part of the rectum. The gastric artery follows the lesser curve of the stomach, and is frequently called the coronary artery. The hepatic and splenic both send large branches to the greater curve of the stomach, and also to the pancreas and duodenum, before reaching the liver and spleen. Superior vena cava Azygos major Veins Inferior vena cava The abdominal aorta divides (bifurcates) at the lower border of the fourth lumbar vertebra into the right common iliac and the left common iliac (Fig. 128). The two common iliac arteries diverge and v^^hen they reach the sides (right and left) of the lumbo-sacral joint, each divides into hypogastric (or internal iliac) and external iliac (see Fig. 128). BRANCHES OF HYPOGASTRIC ARTERY. 179 The hypogastric artery passes into the pelvis and gives off branches which supply the parts within and without the pelvic wall, including the perineum, and all of the pelvic viscera except the ovaries. Cecum Appendix Fig. 1.30. — Superior Mesenteric Artery anx» Vein (Morris). Supplying the whole of the small intestine, and about one-half of the large intestine. Visceral branches. — Middle hemorrhoidal, to the rectum/ Vesical (two) to the bladder. Uterine to the uterus. Vaginal (several) to the vagina. ' The blood-vessels of the rectum are called hemorrhoidal; those of the bladder, vesical. ,i8o ANATOMY AND PHYSIOLOGY FOR NURSES. The uterine artery (Fig. 132) passes between the layers of the broad ligament to the cervix of the uterus, then runs upward along the side of the body, supplying it freely with blood, and anastomos- ing with the ovarian artery. The arteries of the organs in the lower part of the pelvis are numerous. There are: three (or four) vaginal arteries, three (or more) vesical arteries, three hemorrhoidal arteries, all derived from Mesenteric branches Middle sacral Colic artery Inferior mesenteric artery Iliac vein % Sigmoid vessels 4^ Surerior hemorrhoidal Rectum Fig. 131. — Inferior Mesenteric Artery (Morris). Supplying a portion of large intestine only, ending as hemorrhoidal. the hypogastric or its branches, except the superior hemorrhoidal which is the terminal portion of the inferior mesenteric. There are also two perineal arteries. These all anastomose freely with each other and with other arteries, so that a wound in this region is followed by an abundant flow of blood from more than one vessel. ARTERIES OF LOWER EXTREMITY. l8l Note. — The hypogastric arteries in the fetus are large. After gi\'ing off their branches they turn upward to the umbihcus where they leave the body of the child, and become the two umbilical arteries twining around the umbilical vein in the umbilical cord. After birth, these portions of the vessels no longer transmit blood but dwindle to fibrous cords lying close to the anterior abdominal wall. Uterine Branch to round Fimbriated extremity of branch hgament Fallopian tube Cervical branch of uterine artery Uterine artery Hypogastric artery Vaginal arteries Azygos artery of vagina Fig. 132. — Uterine and Ovarian Arteries. (Uterine, a branch of hypogastric; ovarian, a branch of aorta, location of the ureter (Morris). Note the Principal Arteries of the Lower Extremity. The external iliac distributes its branches almost entirely to the lower extremity. It is about four inches long and follows the brim of the pelvis to the inguinal ligament where it becomes /ewom/. Collateral circulation. — The inferior epigastric branch of the external iliac anastomoses with the superior epigastric branch of the internal mammary, in the substance of the rectus muscle, thus making an indirect route from the arch of the aorta to the iliac vessels if the abdominal aorta or iliac artery be ligated. l82 ANATOMY AND PHYSIOLOGY FOR NURSES. Femoral artery Femoral vein Deep branch The femoral artery (Fig. 133) is a continuation of the external iliac, passing through the femoral trigone and the adductor canal to the popliteal space/ where it becomes the popliteal artery. Its branches supply the skin and fascia of the abdomen and ex- ternal genital organs, and all structures of the front and sides of the thigh. The largest branch is called the deep femoral, which lies close to the medial side of the femur and gives three perfor- ating branches to pass through the adductor magnus muscle and supply the back of the thigh. Note. — The femoral vein is on the medial side of the femoral artery until it reaches the popli- teal space. The popliteal artery is a con- tinuation of the femoral, begin- ning at the end of the adductor canal (the opening in the ad- ductor magnus) and running through the popliteal space. Its branches supply the boundaries and floor of the space and the knee-joint; it divides into an- terior and posterior tibial arteries (Fig- 134)- The anterior tibial (Fig. 143) comes forward between the tibia and fibula, supplying the front of the leg; it then becomes Fig. I33--THE Femoeal Artery. ^^^ dorsalis pedis (upon the .dorsum of the foot), ending between the first and second toes. - - See p. 303, Popliteal Space. Anterior tibial nerve .Ant enor tibial artery VEINS. DEEP AND ARTIFICIAL. 183 gf^ACeuS\/»e m¥ > Gluteal n. ^r Z~i^^'fo._^, Sciatic n. ^j\y ^ Popliteal artery Tibial n. . Peroneal n. The anterior tibial passes in front of the ankle-joint, with the Ion tendons of the toe muscles. The posterior tibial (Fig. 134) supplies the back of the leg and sole of the foot. It lies between the calf muscles and the deep mus- cles, and runs behind the medial malleolus, dividing then into medial and lateral plantar arteries for the medial and lateral portions of the sole, or plantar region. The Veins. All veins^ run toward the heart. Beginning as very small vessels formed by the union of capillaries, they unite and reunite until they make two sets of larger vessels called the deep and superficial veins. The deep veins accompany arteries, being enclosed in the same sheath with them, and receiving veins corresponding to the branches of these arteries. Arteries of me- dium size usually have two com- panion veins (or venae comites); large ones have but one, and it sometimes bears a name differing from that of the artery. (Example — internal carotid artery, internal jugular vein.) The superficial veins do not usually accompany arteries. They lie in the superficial fascia, gather- ing blood from skin and fascia, and many of them are called cutane- \T c i.1 it- J ] Fig. 1^4. — The Popliteal Artery. ous. Very frequently the deep and ■^^ superficial veins communicate, through short connecting branches. ' The names of all of the veins are given in tabular form on page 378. Only the principal ones are here describeri. . Ant. tib. artery Tibial n. Post. tib. artery 184 anatomy and physiology for nurses. Principal Veins of the Head and Neck (Figs. 127, 139). Deep. — From the deep face and cranial cavity; they empty into the internal jugular vein (Figs. 121, 127). The internal jugular is a continuation of the transverse sinus, (a venous channel inside the skull, which ends at the jugular fora- men). This vein lies on the lateral side of the internal carotid artery in the upper part of the neck, and further down at the side of the common carotid artery, with the vagus nerve between and behind them. It ends by uniting with the subclavian vein. Fig. 135. — Deep Arteries in Sole of Foot. I, Internal plantar; 2, external plantar (Holden). Superficial. — From the scalp, ear, and face, bearing the names of the arteries (usually) ; they empty into the external jugular vein .which opens into the subclavian. There are many veins in the spongy bone between the compact layers of cranial bones, and these communicate by emissary veins with the sinuses and also with the scalp veins. Principal Veins of the Upper Extremity. Deep. — ^From the hand and wrist; they form ulnar and radial veins (running with arteries of the same name) which unite to form brachial veins. The brachial veins in turn unite to form the axillary, and the axillary becomes subclavian. The external jugular vein empties into the subclavian at about the middle of the clavicula. It is easily seen through the platysma muscle. Superficial. — From fore arm; groups of veins,both anterior and posterior, form two, called the basilic and cephalic, which empty into the axillary vein. A median vein in front of the elbow connects the basilic and the cephalic. Fig. 136. SUPERFICIAL VEINS OF EXTREMITIES. 185 Ulnar vein ^^^ Fig. 1.36. — Superficial Veins, Upper Extremity. Fig. 137. — Superficial Veins, Lower Extremity. i86 ANATOMY AND PHYSIOLOGY FOR NURSES. The subclavian, having gathered blood from the entire upper extremity, unites with the internal jugular to form the innominate vein; the anonyma veins {right and left) unit to form the superior vena cava. The left anonyma vein is the longer of the two, since it must cross to the right side to join the right vein. The Superior Vena Cava. The superior vena cava is formed by the union of the two anonyma veins. It lies on the right side of the arch of the aorta, and opens into the right atrium of the heart (Fig. 121), Veins of the Thorax. Blood from all of the intercostal veins (except in the first space) finally reaches the great azygos vein, which opens into the superior vena cava (Fig. 129). The blood of the heart itself is returned directly to the right atrium by a coronary vein called the coronary sinus. All other thoracic organs re- turn their blood to azygos veins and these to superior vena cava. Summary. The venous blood from all struc- tures above the diaphragm (except the heart) is returned through the superior vena cava to the right heart (right atrium) (p. 165). Principal Veins of the Lower Extremity. Deep. — ^From the dorsum of the foot the veins form the anterior tibial veins; from the sole of the foot, the posterior tibial. Fig. 138. —Superficial VEnsrs, ANTERIOR. THE INFERIOR VENA CAVA. 187 The tibial veins unite to form the popliteal, which continues as the femoral, and these two veins receive others corresponding in name to the branches of the arteries which they accompany. Superficial. — From the lateral part of the foot and leg, by the small saphena vein, to the popliteal (Fig. 137). From the dorsum and medial part of the foot and leg by the great saphena vein to the femoral, passing through the oval fossa in the fascia lata, below the inguinal ligament (Fig. 138). The femoral vein becomes external iliac. \^Eixs OF THE Pelvis and Abdomen. The veins of the pelvic organs are large and numerous. In the vaginal walls and around the lower end of the vagina, also in the rectum especially, they form close net- works or plexuses which when wounded bleed profusely. The veins of the anal canal are prone to become congested and assume a varicose condition constituting hemorrhoids. The pelvic veins empty into the hypogastric, and the hypogastric and external iliac veins unite to form the common iliac. The right and left common iliac veins unite to form the inferior vena cava (Fig. 139). The Inferior Vena Cava. Fig. 139. — Showing Forma- tion OF THE Large Veins. I, Superior vena cava, 2,3, innominate veins; 4, right sub- clavian; 5,6, int. and ext. jugu- lar veins; 8, inferior vena cava; 14, common iliac veins. (Re- maining references not given.) (Holden.) This is formed by the union of the two common iliac veins at the right side of the bifurcation of the adbominal aorta (at the level of the lower border of the fourth lumbar vertebra). It runs upward through the abdomen, on the right side of the aorta, close to the spinal column, to pass through the diaphragm and enter the pericardium and right atrium of the heart. 1 88 ANATOMY AND PHYSIOLOGY FOR NURSES. From the abdominal walls the phrenic and lumbar veins open into the inferior vena cava. From abdominal viscera the renal and adrenal veins open into the inferior vena cava. Fig. 140. — Scheme of Formation of Portal Vein, by Veins from Spleen, Stomach and Intestines. The right ovarian and right spermatic veins open into the in- ferior vena cava; the left ovarian and left spermatic veins open into the left renal vein which carries their blood to the inferior vena cava. The splenic (or lienal), gastric, and mesenteric veins form the THE PORTAL CIRCULATION. 189 portal vein, which is four inches long and enters the liver at the transverse fissure or porta (Figs. io6, 140). THE PORTAL CIRCULATION. This is the circulation of venous blood through the liver. The portal vein bears the products of digestion from stomach and intestines; entering the liver it divides into branches which form an extensive net-work in its substance. Having been distributed through these fine capillaries, the blood leaves the liver by the hepatic veins, which open directly into the inferior vena cava. SUMMARY. The venous blood from all structures (practically) below the diaphragm, is returned through the Inferior Vena Cava to the heart (right atrium). Opening closed by tricuspid valve " Foramen ovale Coronary sinus Location of Eus- tachian valve Fig. 141. — Infant's Heart. Showing interior of right atrium (Holden). THE FETAL CIRCULATION. The fetus is nourished by blood brought from the uterine (placental) arteries of the mother, through a special vessel called the umbilical vein. After circulating in the body of the child it is returned to the placenta by two special vessels called the umbilical arteries. (Fig, 142.) During intrauterine life the lungs do not contain air, therefore, I go ANATOMY AND PHYSIOLOGY FOR NURSES. the interchange of oxygen and carbon dioxid in the blood must be accomplished elsewhere. This also is brought about by means of the placental vessels. The plan of fetal circulation requires still other special provision, namely : The foramen ovale. — An opening in the septum between the two atria (Fig. 141). The Eustachian valve. — A fold of endocardium in the R. atrium, (so placed as to direct the blood from the inferior vena cava through the foramen ovale). The ductus arteriosus. — A short trunk (1/2 inch long) which connects the pulmonary artery with the arch of the aorta. The course of the blood is as follows: Arterial blood is brought through the umbilical vein which enters the body at the umbilicus, runs upward under the liver giving branches to that organ; and terminates (as the ductus venosus) by opening into the inferior vena cava, just below the diaphragm. It flows at once into the right atrium- of the heart, where it is guided by the Eustachian valve through the foramen ovale into the left atrium; from there it passes into the left ventriculum an^ through the aorta, to be distributed. The greater portion of this current goes to the head and upper extremities, from which it returns to the right atrium again and passes down into the right ventriculum; thence into the pulmonary artery, but not to the lungs (except a very small portion); it is delivered instead by the ductus arteriosus to the aorta, at a point where the arch begins to descend, and joins the small current already there, to supply the trunk and lower extremities. The greater portion of this blood leaves the fetus before it reaches the lower extremities, by way of the two umbilical arteries, and returns to the placenta for re-oxygenation; while that which goes to the lower extremities is later emptied into the inferior vena cava to be again mixed with blood from the umbilical vein on its way to the fetal heart. Notes. — The liver is the only organ to receive blood just as it comes from the mother; the baby's liver is very large. The head and upper extremities are next supplied, although v^'ith a slight admixture of venous blood (which came through the inferior vena cava); they are vi^ell developed. The pelvis and lov^rer extremities receive but a small supply of venous vi^ith a slight admixture of arterial blood; they are not so well developed. THE FETAL CIRCULATION. 191 < --X Fig. 142. — The Fetal Circulation (Morris). 192 ANATOMY AND PHYSIOLOGY FOR NURSES. The placenta. — The placenta is formed in a portion of the linmg membrane of the uterus, by an intricate arrangement of the uterine vessels of the mother with the umbilical vessels of the fetus. It is here that the umbilical arteries coming from the fetus, end; and the umbilical vein going to the fetus, arises. Here also the inter- change of gases and of waste and nutritive matter between fetal and maternal blood, is carried on. The umbilical cord connects the placenta and the fetus. It comprises the two arteries and the one vein, protected by a gelatinous substance or "Wharton's jelly," in which they are embedded. PHYSIOLOGY OF THE BLOOD. We have learned that the nutritious portions of the food are, after digestion, poured into the blood and circulated throughout the body; also that cell action results in waste which is returned to the blood. Again, that tissue changes are chemical in their nature and chemical action is accompanied by heat; this is imparted to the blood, which can in turn convey heat to other parts. Here then, are three important functions of the blood: 1. To convey food (including oxygen from the lungs) to the tissues.^ 2. To convey waste (including carbon dioxide) from the tissues. 3. To equalize the hody temperature. Add to these: 4. To provide water for dissolving waste substances to be removed from the body by skin, kidneys and intestine. 5. To be a medium for transporting internal secretions (page 220). 6. To furnish its own remedy for hemorrhage by bearing the factors of coagulation. (The blood is the source of water supply as well as food supply for the body.) The special functions of the hlood cells have been outlined, ' namely: The oxygen-hearing property of red cells and the phago- cytic power of the white. Any irritation of the tissues is promptly followed by an increase in the blood and lymph supply of the part, and (if long continued) crowding of cells in the capillaries. The leucocytes put forth little prolongations of their substance which penetrate the vessel wall, ^ It must not be forgotten that oxygen makes tissue changes possible — hence the im- portance of the blood as an oxygen carrier. PHYSIOLOGY OF BLOOD. I93 and gradually the cells themselves work their way through. This causes a hardened or indurated condition which will soon disappear if not excessive^ but with severe irritation the process goes on to inflammation (the cells crowding each other to death) and pus results. In case of bacterial invasion, the leucocytes surround and absorb the offending organisms, thus protecting the body from the effects of their toxins. This they are doing continually because we are constantly taking bacteria of various sorts into our systems. So long as the number is not too great the phagocytes can take care of them, it is only when there are too many, that they cannot be over- come. It is due to the character of the capillary walls, that the blood cells can migrate into the tissues (diapedesis). Consisting as it does of a single layer of endothelial cells, the capillary wall also renders possible the interchange of fluids between the blood-vessels and the tissues. This interchange is accomplished by the physical process of osmosis, which may be defined as the diffusion of two liquids or solutions through an intervening membrane. Simple diffusion is the mixing of two liquids when poured together, to form a uniform solution. Filtration is the passing of a liquid through a membrane or other substance for the purpose of removing some portion altogether. It is probable that all three processes go on in the tissues. 13 CHAPTER XII. THE LYMPHATIC SYSTEM. The l)rmphatic system comprises an extensive arrangement of lymph vessels or lymphatics, and lymph nodes or glands — both deep and superficial (Fig 143). This system pervades the entire body for the circulation of lymph — a nutritive fluid derived from the blood. It is by this means that foods which have been absorbed from the digestive organs and poured into the blood, are separated out for the use of the tissues and conveyed to them. Ljrmph spaces. — Between the cells and collections of cells of every tissue, except cuticle, hair and nails, are found minute tissue spaces or lymph spaces, communicating freely with each other. There are also spaces around the smallest blood-vessels and nerves (called respectively perivascular and perineural spaces). These all communicate with the beginnings of lymph-capillaries (just how, is disputed). L3rmph. capillaries. — ^These resemble blood capillaries in that they have but a single coat (of endothelium). They permeate the tissues in every direction, forming a close network, from which lymph vessels or lymphatics originate by the uniting of small channels to form larger ones (as veins originate). Lymph vessels. — Are delicate and transparent, but have three flexible coats. (One elastic, two fibro-muscular.) They are pro- vided with valves, formed by folds of the lining at very short intervals, which give the appearance of beading to the vessels. This arrange- ment allows the lymph to flow toward the heart but prevents it from moving in the other direction. The lymph vessels of the intestines have been called lacteals because of their milky appearance during the process of digestion the whitish color being due to the presence of fat globules trans- mitted by the lymph capillaries of the villi. This fat-bearing lymph is called chyle. 194 LYMPH VESSELS. 195 Within the tissues of the body the lymph vessels are too small to be seen by the naked eye, but they unite again and again, to form larger ones (although still very small) which in some places may be seen entering or leaving glands, until finally two remain — • the right lymphatic duct and the thoracic duct, which have a diameter of 3 or 4 mm. Lymph is a transparent watery saline fluid with lymph corpuscles floating therein. It contains nutritive substances for the tissues and waste matters derived from them. ■'f.l-...^5'U'.- t'lG. 143. — Lymphatic Vessels and Nodes. I and 2 are portions of the Thoracic Duct (Holden). The description of plasma applies very well to lymph, always keeping in mind that lymph is more watery and carries lymph cells while plasma bears blood cells; also it will coagulate, but slowly and not so firmly, with a pale clot because of the absence of red cells. The origin of lymph is primarily from the blood. The walls of the blood-capillaries allow a transudation of thin plasma or serum 196 ANATOMY AND PHYSIOLOGY FOR NURSES. into the tissue spaces, and this is the source of nutritive principles. Waste matters are added as the result of the activities of the tissues themselves; they represent the '^tissue wasted This fluid, conveyed by lymph-capillaries to lymph-vessels is carried to lymph glands, where it gathers the lymph corpuscles which float in it. Lymph glands or lymph nodes are small round or oval bodies of a reddish color, varying in size from that of a pin head to a small bean, and intersecting the lymph vessels in certain regions of the body. They are numerous in the neck, axilla and groin, also in the thorax and abdomen. A lymph gland is invested with a thin but firm capsule (fibro- muscular) which sends septa or partitions into the interior, to support the gland substance in small compartments. The gland substance lies loosely in this capsule and in the compartments, leaving spaces for the passage of lymph around the different por- tions and around the whole. It contains great numbers of young corpuscles, which are added to the lymph stream as it washes through the gland, and appear later as the lymphocytes of the blood. L5miph is brought to the glands by afferent lymph vessels, usually several for each gland. After flowing through the various spaces in and around the gland substance, it leaves by efferent vessels, which unite to carry the stream on its way toward the large veins. A specimen taken from an efferent vessel and examined under the microscope will show a greater number of lymphocytes than one taken from an afferent vessel. Clinical notes. — ^Edema is an accumulation of lymph in the tissue spaces. We have seen that an interchange between the blood and lymph capillaries is continually going on, the blood providing lymph, the tissues receiving it, abstract- ing nutriment and adding waste; returning it to the blood, but in less quan- tity than was received; the excess which remains in their spaces being carried by lymph vessels to the venous blood. Should this balance of interchange be disturbed, the effect is evident at once. A too abundant supply, or an obstruction to the outflow, would overwhelm the tissues with fluid, causing edema. Clinical Notes. — Inflammation of serous membranes, if severe, results in the accumulation of lymph or serum in their cavities — this is an effusion. Inflammation in the tissues themselves causes an excess of lymph accompanying the increased flow of blood. The accumu- LYMPH DUCTS. 1 97 lation of lymph with leucocytes and red cells from the blood, causes induration. The largest lymph vessel is called the thoracic duct (Fig. 121). It is about 18 inches long, having an average diameter of a small goose-quill. It begins at the second lumbar vertebra, in a litde pouch called the receptacle of the chyle (or receptaculum chyli) and runs up behind the aorta, through the diaphragm. It then continues upward through the thorax to the level of the seventh cer\'ical vertebra, where it arches to the left to open into the sub- clavian vein, at the junction with the left internal jugular. Thus the lymph and chyle join the current of venous blood on its way to the heart for circulation and distribution. The right lymphatic duct is a short vessel, a half inch in length, which opens into the right subclavian vein at the junction with the right internal jugular. Through this channel lymph alone joins the venous blood on its way to the heart. Note. — The cavities of serous membranes, as peritoneum, pleura, pericardium and others, belong to the system of lymph-spaces, but of a special kind. They are surrounded by capillaries which com- municate with them by tiny openings in the membrane, called stomata. SITUATION OF THE PRINCIPAL GROUPS OF GLANDS OR NODES. Below the Dmphragm. Lower extremity. — Popliteal, in the popliteal space, inguinal (important) at the oval fossa and along the inguinal ligament (Fig. 145). Pelvis : External and internal iliac, with the external and internal iliac vessels. Abdomen : Mesenteric, between the layers of the mesentery (about 150); lumbar, in front of the aorta and vena cava. These are numerous. Above the Dlvphragm. Upper extremity. — Epitrochlear , above the internal epicondyle; axillary, under the axillary walls, and clavicular, along the subclavian vessels (Fig. 146). The axillary glanrls are superficial, under the borders of the muscle boundaries; and deep around the axillary vessels. These are very important. 198 ANATOMY AND PHYSIOLOGY FOR NURSES. Head : Occipital, below the occiput; auricular, behind the ear; parotid, upon the parotid gland; submaxillary, under the angle of the jaw. Neck : Superficial cervical, near the external jugular vein; deep cervical, with the large vessels (carotid arteries and internal jugular vein.) (Important.) Thorax : Mediastinal, with the vessels in the mediastinum;^ bronchial, with bronchial tubes and vessels — these are numerous. one and sphenoidal sinus; t, naso-pharjmx; v, hard palate (floor of nose). The remaining references are explained in another chapter (p. 126). The Pharynx. The pharynx is the space behind the nose, mouth, and larynx. Its use is to transmit a'r from the nose, and food from the mouth. As an air-passage it is included with the respiratory organs. (The air passes from the nose through the pharynx to the larynx.) 204 ANATOMY AND PHYSIOLOGY FOR NURSES. The Larynx. The larynx is situated below the hyoid bone, in front of the pharynx, and projects slightly forward in the neck. It is con- structed of fibro-cartilages connected with each other by ligaments and lined by mucous membrane. The largest fibro-cartilage is the thyroid, which forms the prominence of the larynx known as "Adam's apple." Below the thyroid is the cricoid cartilage, shaped like a seal ring, and placed with the broad part at the back, where two small pyramid-shaped cartilages rest upon it; they are the arytenoids. These are all connected by gliding joints. (Other cartilages, very minute, are not men- tioned.) The epiglottis is a leaf-shaped flexible cartilage extending upward from the thyroid in front, and resting against the base of the tongue. During swallowing this is bent backward over the entrance of the larynx by the action of small muscles, to allow the food to pass over it into the esophagus. (For the Larynx, the Organ of the Voice, see page 281.) Fig. 148. — Interior of Larynx (Left Side Re- moved). 2, Epiglottis; 5, so-called "false vocal cord"; 9, vocal band; 13, thyroid cartilage; 14, arytenoid cartilage. The other figures refer to parts not mentioned in the text. The Trachea. The trachea is a flexible tube about one inch in diameter and four and one-half-inches long, extending downward from the larynx to the level of the fourth thoracic vertebra. It is fibrous and elastic, and stiffened with rings of cartilage which are incom- plete at the back; unstriped muscle fibers take their place, consti- tuting the tracheal muscle. The tracheal muscle by the action of its fibers, varies the size of the trachea and makes the tube soft where the esophagus lies next to it. The trachea divides into two branches called bronchi. The right bronchus is one inch long; the left is two inches long. (It passes under the arch of the aorta.) The bronchi divide into branches called bronchial tubes which subdivide again and again until the smallest tubes, called bronchioles^ THE BRONCmAL TUBES. 205 are formed. These lead to the spaces called alveoli, and the air cells clustered about them. ■• The bronchi and larger bronchial tubes are like the trachea in structure, con- sisting of fibrous and elastic tissue with incomplete rings of cartilage. In the smaller tubes the rings become irregular plates or discs, and in the bronchioles the cartilage is absent altogether. The walls are here very thin and contain circular muscle fibers (non-striated), the bronchial muscle. ;, v|pjfi%\ Thyroid cartilage Cricoid cartilage Left bronchus Fig. 149. — Larynx, Trachea, axd Bronxhi (Morris, modified from Bourger>-). The entire tract from the trachea down to the air cells is lined with mucous membrane, bearing ciliated epithelium as far as the smallest tubes. The cilia of the air passages are fine hair-like projections from the surface; they have a waving motion. The Lungs. The lungs are two in number, right and left, situated in the right and left sides of the thorax, occupying the space enclosed by the ribs (not that portion between the sternum and the spinal 2o6 ANATOMY AND PHYSIOLOGY FOR NURSES. column). They resemble a flattened cone in shape, the apex extenduig one inch above the clavicle, the base resting upon the diaphragm. The right lung is broader and shorter than the other, but it has three lobes, upper, middle, and lower. The left lung has two lobes. Note. — The left lung is narrower than the right and does not cover the apex of the heart, otherwise it would be exposed to the motion of the "heart beat." The lung substance consists of branches of the bronchi and their divi- sions down to the bronchioles, and the Fig. 150.— Clusters of Am- spaces terminating in air-cells. These CELLS (Holden, from KoUiker) . '■ structures are surrounded by blood-ves- sels, nerves, and lymphatics, grouped together in lobules, supported by fine fibro -elastic connective tissue and wrapped in pleura. Each bronchiole terminates in a lobule (Fig. 150). The root of the lung is composed of the large bronchial tubes, blood- vessels, and nerves (see illustration (Fig. 151). The bronchial tubes are the primary divisions of the bronchi; the blood-vessels are — first, the bronchial arteries for the nutrition of the lung substance; second, the pul- monary arteries which form a fine network of capillaries around the air-cells, third, the bronchial and pulmonary veins. Fig. :;i. — The Lungs utth Hear:i Between Them. The Pleura. Each lung is covered (except at the root) by a thin transparent sac of serous membrane called the pleura. One side of this sac is THE PLEURA. 207 closely applied to the lung, forming the pulmonary pleura; the other side fits as closely to the ribs, forming the costal pleura. Within the sac is a small quantity of serous fluid (secreted by the endothelium of the pleura) , which prevents friction when the ribs move and the lungs expand or contract. Although the hony thorax is bounded above by the first rib, the thoracic cavity extends an inch above the rib on each side, bounded by an expansion of the costal pleura and lodging the apsx of the lung. R. mammary artery R. phrenic nerve Fig. 152. — The Pleural Sacs. The dotted lines indicate the pleural sacs, with space between the layers (Holden). Clinical note. — If the pleura becomes inflamed the quantity of fluid diminishes and the surfaces rub together, causing acute pain and a fine crackling sound as of friction. This condition is pleurisy (or pleuritis). Resume. — In respiration, or the act of breathing, the inspired air enters the nasal chambers, passes through the naso-pharynx, oro- pharynx, larynx, trachea, bronchi, bronchial tubes, and bronchioles, to the aveoli and air-cells or air vesicles. THE PHYSIOLOGY OF THE RESPIRATORY PROCESS. The function of the respiratory apparatus is first, to accomplish an interchange in the lungs, between the oxygen of the air and carbon dioxide of the blood, in other words — to bring nutriment to the blood and to remove waste from it. 2o8 ANATOMY AND PHYSIOLOGY FOR NURSES. We have seen how the blood returns from the digestive organs laden with food which is to be distributed throughout the body, and that these products of digestion are made over in the tissues by a process of oxidation. The source of the oxygen for this process, is the air we breathe. It passes through the air vesicles and the capillary walls into the blood, thence into the lymph spaces and tissue cells, the tissue products returning (through the spaces and the vessel walls) to the blood. Thus, the gas called carbon dioxide (resulting from tissue action) is brought by the blood to the lungs; passing through the capillary walls and the air vesicles, it is exhaled in the breath and thus removed from the body. Consequently, respiration is a process not only of nutrition but of elimination as well. This interchange is accomplished in part by the physical process of diffusion of gases. (The epithelium of the air vesicles may have a special function to this end, and is called respiratory epithelium.) By inspiration we take air, with its oxygen, into the lungs; by expiration we expel it with carbon dioxide, small quantities of ammonia and organic waste matter, and moisture. This important process is made possible by the movements of the thorax as follows: In inspiration. — The external intercostal muscles elevate the ribs and spread them apart, increasing the width of the chest ;^ the diaphragm contracts, pulling down its central tendon and thus increasing the depth of the chest; the lungs expand and receive the in-drawn air. In expiration. — The ribs fall easily back into place, assisted by internal intercostals and abdominal muscles; the diaphragm relaxes, returning to its dome shape, and the air is pressed out. These acts are performed, in health, with regularity, that is, rhyth- mically. The number of respirations in a moment varies from about 40 in the newly born to 18 in the adult. Normal respiration is slowest when one is lying down or when sleeping. The rate is increased during physical exercise or by emotion, and in visceral inflammations, as pneumonia, pleurisy, peritonitis, etc., also in fevers generally. ' The Pectoralis Major and some others assist in deep breathing or forced inspiration. PHYSIOLOGY OF RESPIRATION. 209 Average respiratory rate at dijBferent ages: At one year 30 " six years 25 " twelve years 20 Soon after this age, the normal proportion between the number of respirations and the pulse rate, is as one to four. The normal respiratory sound has been well compared to the rustling of leaves when the gentlest of breezes is blowing through them. The tissues which are most active require most oxygen. Con- sequently we can create a demand and obtain a supply by volun- tary muscle exercise in good air, thus feeding the blood and through it the whole body, with this most important element of food. Respiration contributory to body heat by providing oxygen for tissue change. Of all organs the muscles are most constantly at work; they can dispose of more oxygen than any other part of the body. By rapid oxidation they generate more heat, but only so long as the respiratory organs keep pace with the demand for rapid breathing. It is natural to breathe more rapidly as well as more deeply on a cold day, because a low temperature of the surrounding air stimu- lates (reflexly) the various activities of the body to meet the call for warmth, and the respiratory process must be among the first to respond. Summary. — Respirationis a. nutritive process, a.neliminative proc- ess and a contributing source of body heat. Special Modifications of Respiratory Movements. Rapid breathing is called hyperpnea. Temporary cessation of breathing is called apnea. Labored breathing, is dyspnea. Dyspnea follows any interference with the interchange of gases in the lungs. It may be caused by diminishing the entrance of oxygen, or by increasing the CO 2- It is usually due to imperfect circulation in the pulmonary vessels. Asphyxia is the condition resulting from a complete cutting off of oxygen or an excessive increase of carbon dioxide. It may be sudden or gradual, but if unrelieved, ends only in death. 14 2IO ANATOMY AND PHYSIOLOGY FOR NURSES. The change of color noted in the face of one suffering from, dyspnea and still more from asphyxia, is due to the accumulation of cabon dioxide in the blood. The importance of fresh air in sufficient quantity cannot be over-estimated. One thousand cubic feet of space for each adult, (equal to a room lo feet in height, length and breadth) renewed about three times hourly, is not too much. CHAPTER XIV. THE KIDNEYS. THE SKIN. ELIMINATION. The kidneys (renes) are organs of excretion; that is, they separate certain waste matters from the blood, in a definite form for removal from the body. They are situated for the most part in the posterior lumbar region, just in front of the quadratus lumborum muscles, extending from Left kidney Right urettr Left ureter Fig. 153. — The Kidxeys (Morris). about the tenth rib to within two or three inches from the crest of the ilium. They are shaped like a bean, about four or five inches long and one and one-half inches wide, with the concave border, or hilus, turned toward the spinal column; and they arc imbedded in fat behind the peritoneum. The kidney is hollow, the cavity within being called the sinus. It is covered by a fibrous capsule which also lines the sinus. 212 ANATOMY AND PHYSIOLOGY FOR NURSES. Structure. — A kidney is a mass of minute tubes, the uriniferoiis tubules. At the beginning of each is a bulb-Hke enlargement, indented to form a deep hollow (Bowman's capsule, Fig. 154) which encloses a tuft of renal blood-vessels. The capsule and vessels together constitute a Mal- pighian or renal corpuscle. As the tubule leaves the bulb it twists and turns many times and is called the convoluted tubule. It has a network of blood- vessels around it. The convoluted tube finally be- comes straight, and at last several straight ones unite Fig. 154. — -Scheme of the Renal or Malpighian Corpuscle. I. Interlobular artery. 2. Afferent vessel. 3 . Efferent vessel. 4. O uter wall. 5. Inner wall. 6. Glomerulus. 7. Neck of tubule (Stohr). to form a collecting tube which opens into the sinus. Malpighian corpuscles and convoluted tubes occupy most of the portion of the kidney near the surface, forming the cortex (or cortical portion) . The straight or collecting tubes are grouped together into pyramids, pointing toward the interior and forming the medullary portion. The apex of each pyramid projects into the sinus, presenting the openings of several collecting tubes (Fig. 155). The cells which line this system of tubes do the work of excreting the urine from sub- stances in the blood, thus relieving it of poisonous elements which would surely cause death if allowed to remain. The urine is conducted from the kidney to the bladder through the ureter, a slender musculo-fibrous duct about twelve inches long, the upper end of which is enlarged and called the pelvis of the kidney. (It occupies the sinus.) It has a thin layer of muscle fibers and is lined with mucous membrane. The two ureters Fig. 155. — Section os Kidney (Potter). PHYSIOLOGY OF THE KIDNEYS. 213 extend into the true pelvis to the base of the bladder, where they terminate about one inch apart. (The course of the ureter is further described on page 283 with the description of the bladder.) Clinical notes. — The amount of urine excreted by a person varies greatly, but in health averages 48 ounces or 3 pints daily; it is directly affected by the quantity of fluid which the person drinks and the amount of perspiration formed. Renal colic is caused by the attempt to pass a small stone, or calculus, through the ureter. PHYSIOLOGY OF THE KIDNEYS. This is to remove waste matters from the blood in the form of an excretion called urine. Urine is a watery fluid of amber color, somewhat heavier than water (1010-1020), with a characteristic odor, and having the temperature of the body at the time of voiding. Its reaction is normally acid. The coloring matter is derived from bile pigments; it is deep or pale, as the urine contains less or more water. The weight is due to the salts contained, both organic and inorganic (or mineral) and this also is modified by the amount of water. Both water and salts vary markedly with the dietary of the indi\ddual. Clinical notes. — The color and odor may both be modified by drugs or by articles of food. (For example, turpentine causes the odor of violets, vi'hile that imparted by asparagus is well known.) Urine containing blood cells is smoky in appearance; and every nurse knows what methylene blue will do. The most important substance to be excreted in the urine is urea. This represents the absolutely useless material remaining from proteid foods. It is prepared for excretion in the liver. It is the substance which if allowed to accumulate in the system becomes a deadly poison, causing death by uremia. Uric acid is proteid waste in another form and smaller quantity. Phosphates of sodium, potassium and calcium are present normally, also other mineral salts, sodium chloride (common salt) being the most abundant. Water is necessary for the solution of all these solids (they would be solid without water). This varies in quantity in many systemic conditions. Increased activity of the lungs and skin, for example, removes water from the blood and leaves the urine more dense. Fevers arc always accompanied by a decrease in the quantity. It 214 ANATOMY AND PHYSIOLOGY FOR NURSES. may be increased by nervous excitement; nervous urine is pale and thin, since it is the water which is increased. Suppression of urine means inability of the kidney to act. The process of excretion in the kidney is one of filtration and secretion. The kidney has a large blood supply through the renal artery, which enters at the hilum and divides at once into several branches. The capillaries from these arteries are very numerous. They enter first the capsule of the Malpighian body {afferent vessels) and form a cluster or tuft there, from which the water and salts are filtered out and pass into the tubule. They then leave the capsule {efferent vessels) and twist themselves about the convoluted tubules, whose epithelial cells select the organic substances — urea, iiric acid and others. These are washed down by the watery solution coming from the capsule, to the apices of the pyramids and there discharged into the pelvis of the kidney, as urine. The ureter conducts the urine from the kidney to the urinary bladder, where in due time it is expelled through the urethra. The act of expelling the urine is micturition (clinically we often speak of it as urination). The bladder walls contract, the sphincter of the urethra relaxes, and the urine escapes. If the bladder is not able to expel its contents we say the patient has retention of urine. This inability may be so complete that the bladder becomes entirely filled and the sphincter can no longer act; the urine dribbles away and the condition is one of "retention with overflow" from inability of the bladder to contract. THE SKIN. The skin, or integument, is the elastic and protective covering of the body. It consists of two layers, a deep one called the corium, and a superficial one called the epidermis. The corium or "true skin" {cutis vera) is a vascular, elastic and sensitive layer, red and soft; resting upon a loose subcutaneous tissue. Its deep portion is well supplied with vessels and nerves {tactile cells) supported by a fibrous and elastic network (reticular layer) which contains non-striated muscle fibers and fat. In this layer are the blood-vessels, nerves and lymphatics. Tiny projections called papillce rise from this network portion, each papilla containing a special nerve-ending called a touch cor- puscle. They are arranged in rows forming ridges which are cir- cular on the front of the finger tips. It is a remarkable fact that THE SKIN. 215 no two fingers or toes are alike in this respect, hence the thumb- or finger-mark is a means of identification. The papillae constitute a "papillary layer." There are still other nerve endings in the corium for different sensations. The epidermis (or cuticle) completely covers the corium. It con- sists of layers of cells of varying character and thickness. The deeper cells are soft and nucleated, but near the surface they become flat and dry, until finally they are mere tiny scales. The epidermis has no vessels and scarcely any nerves, consequently it is not sensitive and does not bleed. The deep layers of the epidermis contain the coloring matter or pig- ment of the skin, which comes away with a blis- ter. The pigment varies in different people and races. Exposure to heat and sun deepens it. Fig. 156. Showing the layer.s of the skin (greatly magnified) , with the sweat glands and oil glands, and a hair in its follicle (Brubaker). Clinical notes. — The insensitive and bloodless character of the epidermis or cuticle are plainly demon- strated in the dressing of a blister, when it is incised to allow the escape of serum which has accumulated between it and the corium or true skin. The surface of the epidermis is continually wearing away and new layers of epithelial cells are exposed, to become dry and scaly, and to be shed in their turn. It varies in thickne.ss according to the degree of friction, or pressure, or exposure which it encounters. Witness the palms of the hands, and the soles of the feet. The elasticity of the skin is demonstrated when a cut is made through the corium. The edges retract and some effort is required to bring them together again. The elasticity is due not only to the 2l6 ANATOMY AND PHYSIOLOGY FOR NURSES. elastic fibers in the deep layer of the cerium, but to the muscle fibers, small though they be. The glands of the skin are in the corium; their ducts pass through the epidermis to open upon the surface. They are of two kinds — the sebaceous glands and the sweat glands {sudoriferous glands) . The sebaceous glands are found in the skin of all parts of the body except the palms and soles. They are most numerous upon the face. They produce an oily substance called sebum which renders the skin soft and pliable. Their ducts open into the depres- sions (follicles) for the roots of hairs, consequently they preserve the softness and glossiness of the hair. Ear wax, or cerumen, is secreted by specialized glands in the auditory canal. Note.^ — ^The vernix caseosa which is found upon the skin of the new-born child is an accumulation of sebaceous matter which has served to protect the skin from the effect of long submersion in the amniotic fluid. The sweat glands (sudoriferous glands) are found in the skin of the entire body. Each gland consists of a coiled tube embedded in the corium, with a duct opening upon the surface; these ducts open upon the ridges made by the rows of papillae. With an ordinary magnifying glass the droplets of sweat may be seen. The sweat or perspiration is a thin watery fluid (highly acid, but saline to the taste), containing a number of substances in solution, derived from the vessels in the network of the corium. The most important are salt, phosphates, urea and carbon dioxide. It is estimated that the 2,000,000 or more glands secrete nearly a liter of perspiration daily, in health. The process goes on continually; when the rate of excretion is moderate and uniform we are not aware of it, because the moisture is removed in various ways as soon as formed — this is insensible per- spiration. When the removal does not keep pace with the production, the accumulation on the skin becomes sensible perspiration. The appendages of the skin are the glands already described, the nails and the hairs. The nails belong to the cuticle (being modifications of its epi- thelium). They give protection to, and add power and ease in using the digits. They lie upon a bed of corium called the matrix, from which they grow; if the matrix be destroyed the nail is lost and no new one will grow in its place. The root of the nail is embedded PHYSIOLOGY OF THE SKIN. 21'J in a fold of skin; the white semicircle at the root is called the lunula (little moon). The hairs also belong to the cuticle. They are distributed over the greater part of the surface of the body, being conspicuous on the scalp. A hair consists of a root and a shaft. The root rests upon a minute papilla in the bottom of a depression or hair follicle. The nerves and blood-vessels do not run beyond the papilla. The shaft extends outward from the root, and contains the pig- ment which decides the color of the hair. The hairs lie obliquely on the skin but may be made to stand erect by the contraction of a tiny muscle bundle placed at the root of each one. These are the erectors of the hairs. It is their action which gives the appearance called "goose-flesh." The softness and the gloss of hair are due to the oil which is poured into the follicles by the oil glands. Note. — The fine hair on the skin of the new-born child is called lanugo. It begins to grow at about the fifth month of intra-uterine life, and wears away soon after birth. The hairs which border the eyelids are called cilia. PHYSIOLOGY OF THE SKIN. The skin has a triple function. It is the protective covering of the body; an organ of excretion and an organ of the special sense of touch. As a protective it is mechanical only; the insensitive layers receiving first the impressions of external forces — heat, cold, blows, etc., diminish their effects on deeper and sensitive ones. As an organ of touch it is referred to on page 271. Its most important function is that of secreting perspiration. Perspiration is a clear watery fluid consisting of a solution of certain waste products of metabolism (tissue waste), in other words, water and solids. It is acid in reaction; saline to taste. The quantity excreted by a healthy active person in twenty-four hours, has been estimated as one quart. Although the amount of solids in the perspiration is small, it is enough to embarrass the system if retained, and to relieve it if the kidneys are disabled. Urea is one of the substances contained in perspiration, and in diseased conditions of the kidneys the skin is able to excrete an increased quantity of urea. 2l8 ANATOMY AND PHYSIOLOGY FOR NURSES. The removal of tissue waste is, however, not the only important use of perspiration. By bringing water to the surface of the skin, it is a most efficient agent for regulating the temperature of the body. Muscle exercise, for example, which increases heat production, is accompanied by increased activity of the sweat glands, and the consequent evaporation of water carries off the excess of heat gener- ated in the muscles. Again, high temperature of the surrounding atmosphere causes dilatation of the cutaneous vessels, and more perspiration and consequent evaporation. Conversely, a cold atmos- phere stimulates the cutaneous vessels to contract, and stops the production of sensible perspiration. Clinical note. — From these facts one may understand why it is so important to conserve the surface temperature of a patient with nephritis, or with diminu- tion of urine from any cause, by the use of blankets and warm clothing; and to increase it oftentimes by the use of hot baths, packs, etc. In health the quantity of perspiration is modified by the dietary, particularly by the amount of liquid taken, and the kind of liquid; also by the character of clothing, the season of the year, etc. It may be noted that the activities of the skin and kidneys alter- nate with change of season; in summer when the skin is active the urine is scanty. In winter, when the skin is inactive the urine is free. In fevers, cutaneous vessels are dilated, but the nerve stimulus to cell action is dulled; the effect of baths upon the skin is to abstract heat, improve the tone of cutaneous structures, and favor the action of the glands. In renal diseases, activity of the skin is to be promoted; in fevers, activity of the kidneys is encouraged as well as of the skin. Summary. — The skin is protective, excretory, an organ of special sense and of heat regulation. CHAPTER XV. MAMMARY GLANDS. DUCTLESS GLANDS. GENERAL METABOLISM. THE MAMMARY GLANDS. The mammary glands are placed between two layers of super- ficial fascia in front of the thorax, occupying a space between the third and sixth ribs, inclusive. They are covered by a layer of adi- pose tissue and lie between two layers of superficial fascia. They Acrola Fig. 157. Showing enlarged milk ducts during lactation (Morris). consist of little tubes, lined with milk-secreting cells and grouped in small lobules, held together by connective tissue imbedded in adipose. The lobules unite to form lobes, 18 or 20, each with its own duct, consequently 18 or 20 milk ducts approach the nipple and open at its summit. The nipple is surrounded by a ring of darker modified skin called the areola. The function of the mammary gland is the secretion of milk. This is a true secretion; the cells of the tubules forming a new sub- 219 220 ANATOMY AND PHYSIOLOGY FOR NURSES. stance from materials brought by the blood, which, although not utilized in the body where it is formed, is not only useful but capable of sustaining life. Milk is a bluish-white fluid consisting of clear plasma {milk plasma) holding nutritive substances in solution and floating myriads of oil globules, to which it owes its white color. It is a natural emulsion. The variety of nutritive substances contained is suffi- cient for the development of the body of the infant. The special proteid of milk is caseinogen, from which casein is derived in the process of digestion (see p. 146). (Artificial coagulation of milk separates the casein and fat from the plasma, the curd from the whey.) The sugar of rnilk is lactose. The salts are the various salts found in foods and body tissues. During pregnancy the areola acquires a deeper color, which is permanent. (A secondary areola may form.) At this time the blood supply of the gland increases, the glands become large, and changes occur in the lining of the tubules, which result in the secretion of milk. This is perfected soon after the end of pregnancy. The first fluid which is drawn from the breast is called colostrum; it contains an excess of sugar and inorganic salts, and a substance which acts as a laxative for the infant. The secretion of milk is influenced by the diet of the mother and may be modified in both quantity and quality by food selection. A still greater effect is produced by the condition of the nervous system; it is well known that fright or anger, or intense emotion, affect the milk so as to make it injurious to the infant. Fatigue, worry, loss of sleep etc., are all to be avoided by the nursing mother. Surgical note. — Mammary abscess is caused by infection through a break or fissure in the skin of the nipple, the pus forming between the lobules of the gland. Post-mammary abscess is in the fascia behind the gland. THE DUCTLESS GLANDS. These are the organs which resemble glands but have no ducts. They are supplied with sympathetic nerves, and possess many lymphatics and blood-vessels; the secretions which they produce are carried in these vessels. The most important ductless glands are the spleen, adrenal bodies and pancreas in the abdomen; thyroid, parathyroid, and thymus bodies in the neck. SPLEEN. PANCREAS. 221 The Spleen. The spleen (or lien) is situated at the left of the stomach, directly beneath the diaphragm by which it is entirely covered. It is oval in shape, convex on the lateral surface and concave on the medial, where a depression called the hilus is seen for the passage of vessels and nerves (Fig. 104. p. 133). The fibromuscular capsule which forms the surface of the spleen sends numerous septa into the interior, and within the spaces of the network thus formed the splenic pulp is contained. This consists of blood which has escaped from the open terminals of numberless capillaries, of lymphoid cells and broken down red cells, coloring matter and particles of waste. Small collections of lymphoid cells around the capillaries may be seen upon section of the organ; they are the Malpighian bodies of the spleen; their function is obscure. The splenic artery is the largest branch of the celiac axis and the consequent large blood supply gives a dark red color to the spleen. The peritoneal covering completely surrounds it, except to allow vessels and nerves to pass through the hilus. The function of the spleen is not well understood, as both animals and human beings have been known to live in health after its removal, but from its structure and the results of examinations of blood from both the splenic artery and splenic vein, it is thought that white cells are there added to the blood, and worn-out red cells are destroyed. Clinical notes.— The elasticity of the capsule allows frequent variations in size, which in health are normal; it is always larger during digestion and smaller in fasting. In certain diseased conditions it is much increased in size, as in malaria; and notably in leukemia, which is characterized by an enormous increase in the number of white cells in the blood, as w^ll as in the size of the organ itself. The Pancreas. In addition to the digestive ferments of the pancreas it would seem that it produces another substance, which either disposes of sugar in the blood, or is associated with the glycogenic function of the liver, or both. This is supposed to be the special function^ of I Now disputed 222 ANATOMY ANY PHYSIOLOGY FOR NURSES. groups of cells called "islands of Langerhans" which are embedded in the substance of the pancreas. They resemble glands but have no ducts; they are surrounded by a network of capillaries and their internal secretion is probably transmitted by these vessels. The blood supply to the pancreas is very free, being derived from the hepatic, splenic and superior mesenteric arteries. This indicates the importance of the gland (Figs. 104, 105). The Adrenal Bodies. The adrenals {suprarenal capsules), are two small gland-like bodies resting on the upper extremities of the kidneys, hence their name. They are triangular in shape, yellowish in color, and have many blood-vessels and nerves. They are important organs, as it is found that when they are removed death follows soon, but their use is not yet fully understood. It has, however, been determined that their internal secretions, adrenalin, epinephrin, stimulate the muscles of the heart and arteries, thus in- creasing blood pressure. In the disease called "bronzing of the skin," or Addison's disease, these bodies are found to be changed. The Thyroid Body. The thyroid body is situated in the an- terior part of the neck. It has two lateral lobes lying close to the trachea and connected by a middle portion called the isthmus. These lobes are about one and one-fourth inches wide, and extend about two inches upward along the sides of the larynx. The substance of the thyroid body is made up of closed sacs con- taining a thick semifluid substance {colloid substance). They are surrounded by many capillaries ; the thyroid arteries being four in number, the blood supply is very free. The function of the thyroid body is important but not well ex- plained. It is observed that the development of both mind and body is arrested if the thyroid be absent, or if it does not itself develop in childhood; this condition is known as cretinism. Degeneration or complete removal, in adult life, is followed by Fig. 158. — The Adenal Body is seen resting UPON THE Kidney. PARATHYROID AND THYMUS BODIES. 223 excessive growth (but imperfect development) of connective tissue and skin elements, or myxedema. From these and other clinical observations it is evident that the internal secretion of this body exercises an important influence upon nutrition. It also stimulates cardiac action, and restrains a tendency to obesity. Simple enlargement of the thyroid body constitutes goiter, which is said to be frequent in certain countries where the drinking water contains much lime. Median portion of crico- thyroid membrane Crico-tyroid muscle UTERAL LOBE OF THYROID BOD» THYROID ISTHMUS Fig. 159. — Thyroid Body (Morris). The Parathyroid Bodies. The parathyroid bodies are small bodies situated above and laterally to the thyroid, two on each side. They have an abundant blood supply. Their function is not explained but it is now known that their removal is followed by convulsive affections, tremor, etc., suggesting the presence of an irritant which did not exist before. Consequently it may be that their internal secretion is capable of destroying or perhaps preventing the formation of certain toxic substances. Both parathyroid and thyroid bodies contain iodin in combina- tion within some other substance. The Thymus Body (Fig. 160). The thymus body is an organ of fetal and infantile life, situated below the thyroid, being mostly in the thorax and reaching down to 224 ANATOMY AND PHYSIOLOGY FOR NURSES. the pericardium. It is two and one-half inches long at the age of two years, but dwindles slowly from that time on, leaving only some shreds of tissue at the age of fourteen. The Pituitary Body (Fig. 179). The pituitary body {hypophysis cerebri) is now included among ductless glands. It rests in the sella turcica of the sphenoid bone. By investigation it has been learned only that degeneration of this THYROID LUNQ. LIVER Suspensory ligament SMALL INTESTINE BLADDER TRACHEA LUNG RIGHT AURICLE RIGHT VENTRICLE PART OF TRANSVERSE COLON Hypogastric artery Fig. 160. — -Viscera at Birth. Note the Thymus Body, the Size of the Liver AND the Location of the Bladder and the Hypogastric Arteries (Morris after Rudinger). body accompanies the disease called acromegaly, which is charac- terized by an overgrowth or hypertrophy of the bones of the face and extremities. Certain conclusions have been founded upon this association, presupposing that it produces an internal secretion which regulates the growth of bones. It probably has some effect upon the force of cardiac action. SECRETIONS. 225 SECRETION, ELIMINATION, HEAT PRODUCTION. We have now studied the various organs which form secretions, or substances which may either be devoted to a special use in the body, or expelled as of no further use. These latter are known as excretions. Following, is an enumeration by way of review, of the principal organs whose secretions are used in the body: First. — The epithelial cells of all surface membranes and cavities should be included: Those of mucous membranes, secreting mucus. Those of serous membranes, secreting serum (as in the pleural, peri- cardial and peritoneal cavities, and the subdural and subarachnoid spaces of brain and spinal cord). Those of synovial membranes, secreting synovia. The secreting cells of glands come next. The salivary, gastric and intestinal glands secrete saliva, gastric and intestinal juices. The liver secretes bile (and forms glycogen). The mammary glands secrete milk. The lacrimal glands secrete tears. The sebaceous glands secrete sebum. Of the secretions of so-called ductless glands. That of the pancreas favors glycogen-processes in the liver. That of the adrenal bodies increases blood pressure. That of the thyroid body influences tissue metabolism, increases cardiac action, and diminishes obesity. That of the parathyroids prevents or destroys toxins in the blood. That of the pituitary body (or hypophysis) restrains growth of osseous tissue. Th& spleen arid lymph glands svi^t^ly -whitQ. cq[\s . . 1 ,, , The marrow of bones supplies red cells / The ovaries produce ova. The testes produce spermatozoa. Thus, the secretions of the organs named, serve various purposes, aiding or influencing nutrition or assisting in the formation of other substances. IS 226 ANATOMY AND PHYSIOLOGY FOR NURSES. Excretions. — These are the substances which must be elimi- nated from the body. All tissue action uses up some material, leaving a varying remnant of waste matter which cannot be utilized — like the ashes from a fire. These wastes appear either dissolved in water as urine and perspira- tion, or in the form of gas or vapor. Tissue waste may be reduced ultimately to comparatively few substances, the most important being urea, carbon dioxide, various salts and water. Urea is most abundant in urine, CO 2 in exhaled air, and all of these in small quantity in perspiration. Therefore, the organs of elimination are: The kidneys, which excrete urine. The skin, which excretes perspiration. The lungs, which exhale carbon dioxid, organic matters, am- monia and water. ANIMAL HEAT. The cell activities described in the preceding pages, in other words — the processes of metabolism, all generate heat. This is an important matter, as an internal temperature of about 100° F. is necessary to the normal activity of the body tissues. This, the tissues themselves can accomplish with proper materials in the form of food, and oxygen for the chemical work, the latter being supplied in the air we breathe. A slight rise of temperature normally accompanies digestion, especially if hot fo.ods be taken. The kind of food which is eaten has a direct effect upon the production of heat; proteid substances yield more than starchy foods, while fats yield more than proteids and starches together. As the body is continually generating heat so it is continually losing it in various ways — to the surrounding atmosphere by radi- ation, to clothing by conduction, by evaporation from the lungs and the skin, etc., etc. In cold weather heat production is desired. This can be accom- plished by selecting heat-generating foods, by taking hot foods and by muscle exercise; the heat thus generated can be conserved by clothing the body in materials which prevent radiation and con- duction, as wool or silk. In hot weather heat production is to be THE BODY HEAT. 227 avoided and heat dissipation is sought; this is facilitated by the selection of starchy and proteid foods, taking cool drinks and wear- ing lighter garments, as cotton or linen. For health and comfort it is necessary that a proper relation be maintained between heat production and heat dissipation. For this, the body possesses its own self-regulating mechanisms; for example, muscle exercise produces heat, but the associated activity of the sweat glands so favors heat escape, that the injurious effect of excessive body heat is prevented. Again, the viscera concerned in digestion (notably the liver) generate much heat; by the blood it is carried to the cooler extremities. A high temperature of the surrounding atmosphere so affects the nerve centers, that the respiratory function is stimulated and evaporation from the lungs increased, at the same time activity of the skin is very marked and evaporation of perspiration follows. These natural processes of mutual accommodation result in preserving a necessary uniform temperature of the body, which makes it independent, within reasonable limits, of external surround- ings. The normal temperature, 98.4° F., is maintained so long as heat production and heat escape are properly adjusted to each other. Elevation of temperature is caused when production is too rapid or dissipation is too slow. Very high temperature indicates excessive metabolism and impaired dissipation. (Another result of excessive metabolism is seen in the "wasting of the body in fevers, as typhoid fever.) Subnormal temperature indicates diminished Lissue change or metabolism, suggesting impairment of vitality. (A temperature of 77° F. is followed by death, as cell activity cannot go on in a temperature so low.) Range of normal temperature. — The normal adult tempera- ture is 98.4° F. in the axilla, in the mouth slightly higher. It is a degree higher in the rectum. During early life when metabolism is active it is slightly higher than in later years. In old age it is often a degree higher than in middle life. A difference of a degree is noted, in health, between the temperature of early morning and evening, for example, at 5 A. m. and 5 p. M. 228 ANATOMY AND PHYSIOLOGY FOR NURSES. Average range of body temperature for different ages: In infancy 99 — 99.5 At puberty 99 In adult life: Axillary 98.4 Oral 98.8 Rectal 99.2 Practical Conclusions and Clinical Notes. The temperature of a patient should be taken before a meal, or after digestion, not during it. In cold weather hot foods containing fats are appropriate for the generation of heat; in hot weather starchy foods and cool drinks are in order. Alcohol causes a temporary sense of warmth by quickening the circulation, but this is followed by dilation of the surface capillaries and a consequent radiation of heat. The use of alcohol before exposure to a low temperature should be avoided, unless some very reliable measure is taken for preventing surface radiation. Muscle exercise is accompanied by dilation of surface vessels and escape of heat; this continues for some tirne after the exercise has ceased, therefore, care should be taken to guard against too great loss of heat and a consequent "cold" due to chilling of the surface, especially when exposed to a draft of air. The fact that the body loses heat rapidly by conduction, should warn the nurse against putting cold garments on a delicate patient, and especially against placing a patient in a cold bed. Remember that the body of the patient must furnish the heat to warm the bed and this makes an unnecessary demand upon vitality already impaired by illness. CHAPTER XVI. THE NERVE SYSTEM. NERVE TISSUES AND THE SPINAL CORD. The foundation cells of which nerve tissues are composed are microscopic in size and called neurons. A neuron consists of a nucle- ated cell body, an axan, and terminal divisions. The cell body has short branches called dendrites, one of which (sometimes two) grows longer to form the axon or axis cylinder which becomes a nerve fiber. Note. — The term nerve cell is often used to signify the cell body of a neuron. Dendrites Xcrve cell Medullated liber Xerve cell Fig. i6i. I.ig_ ^,,2. Figs. i6r, 162.— Nerve Cells (Brubaker). When the axon is invested with a sheath, the medulla, it is a medidlated nerve fiber, and such are found in voluntary muscles and all sensitive parts of the body. Axons without sheaths are known 229 230 ANATOMY AND PHYSIOLOGY FOR NURSES. as non-medulated nerve fibers, and such are found in involuntary muscles and in the walls of internal organs. Structures composing a medullated nerve fiber: 1. The axon or axis-cylinder. 2. Medulla or myelin (white substance of Schwann). 3. Neurilemma, a transparent membrane inclosing the myelin (sometimes absent) . Structures composing a non-medullated nerve fiber: 1. The axon or axis -cylinder. 2. Neurilemma (sometimes absent). Medullated nerves are found in voluntary muscles, skin, mucous and serous membranes, joints and special sense organs. Non-medullated nerves are found in glands, vessels, hollow viscera, and muscle fibers at roots of hairs. The axons or nerve fibers terminate in fine branches, which connect them either with various organs or with the dendrites of other cell bodies, as the case may be. For want of more accurate language, we say that impulses are transmitted through fibers either to or from cell bodies. If to the body, the fiber and cell constitute an afferent neuron (afferent, bearing toward); \ifrom the cell body the neuron is efferent (efferent, bearing away). Important to remember. — The cell body is necessary to the life of the fiber. THE TWO DIVISIONS OF THE NERVE SYSTEM— CEREBRO-SPINAL, SYMPATHETIC.^ The Cerebro-spinal Division of the Nerv:e System. The brain and spinal cord with their nerves constitute the cerebro-spinal system, and since the brain and cord contain the largest and most important centers, this is often called the central nerve system (Fig. 163). Nerve tissues in the cerebro-spinal system appear to the eye as of two kinds, gray and white. The gray tissue, commonly called "gray matter," is composed of cell bodies and their branches. The so-called "white matter" is composed of medullated fibers belonging to the cells. ^ For description of the Symphathetic Division see page 262. ^ For description of the Brain and Cranial Nerves see page 249. NERVES AND NERVE CENTERS. 231 A nerve (of the cerebro-spinal system) consists of many fibers bound together; it resembles in appearance a white cord and may be so small as to be distinguished with difficulty, or as large as a child's finger — like the great sciatic nerve. A nerve is constructed after the same plan as that of a muscle. A connective tissue sheath {epi-ncnriiini) sends partitions {peri-neurium) between bundles of fibers, and a delicate membrane {endo-neurium) sur- rounds each fiber. Nerves divide into branches which may interlace with others or join them in a common sheath, but no fiber ever unites with another. Each one con- tinues throughout the length of the nerve of which it forms a part. Nerve centers are the gray cell bodies to which nerves belong, and which are necessary to the life of the fibers. This term is commonly used to signify a collection of cells whose fibers form nerves having a special function, or which preside over a group of movements. (A definite collection of gray cells is also called a ganglion.) Motor nerves transmit motor im- pulses from centers to muscles, while sensory nerves transmit impressions from the various parts of the body to the centers which receive them. (We commonly speak of motor nerves as running down, and sensory nerves as run- ning up, referring them to the spinal cord or brain.) The Spinal Cord, Fig. 163. — The Brain AND Spinal Cord (Quain, after Bourgery). The spinal cord lies within the spinal canal in the spinal column, being continuous with the brain. It is a round white structure about seventeen inches long, extending from the atlas to the second lumbar vertebra, where it ends in a slender terminal filament which continues to the end of the canal. The thickness is about half an inch, being greater in the lower cervical and lower dorsal regions, making the cervical and lumbar enlargements where nerves are 232 ANATOMY AND PHYSIOLOGY FOR NURSES. given off for the extremities. It presents a median fissure in front and another at the back, marking off. its right and left halves. Other fissures divide each half into anterior, lateral, and posterior columns or tracts. A transverse section will show that the interior of the cord is grayish in color instead of white, and this portion is largely made up of the gray cell-bodies and their branches, arranged in masses which are continuous throughout the length of the cord. The section will also show that the area occupied by the gray portion, roughly resembles two crescents (one in either side), connected together across the mid- dle. The extremities of the crescents are called the anterior and posterior horns. A canal runs through the center of the gray portion called the central canal, which may be traced throughout the length of the cord, but is easily seen only in the upper part. The white portion consists of the bun- dles or tracts of the cord. There is a general division into three in each half — the anterior, lateral, and posterior tracts. The fibers in the anterior and a portion of the lateral tracts are connected with the cells of the anterior horn. They conduct motor impulses. The fibers in the poste- rior and a portion of the lateral tracts are connected with the posterior horn, and conduct sensory impressions. Fig. 164. — Three Sections OF Spinal Cord. A, Cervical region; B, thoracic region; C, lumbar region; p, posterior horn; a anterior horn (Holden) . Membranes of the Spinal Cord. The pia mater. — A delicate membrane which bears the blood- vessels and is very closely applied to the surface of the cord (the vascular membrane of the cord). The arachnoid (web-like). — Outside of the pia mater.- A serous membrane containino; fluid to make a water-cushion for the cord. MENINGES OF THE CORD. 233 The dura mater.— A strong white fibrous membrane, tubular in shape, in which the cord is loosely suspended. It is attached above to the margin of the foramen magnum. The space between the dura and the arachnoid is the subdural space; that between the arachnoid and pia is the subarachnoid space; they contain cerebrospinal fluid. The subarachnoid space is largest, in the lower portion. (The fluid in this space mixes with that of the central canal through a small opening in the pia, at the base of the brain.) The membranes are also called the meninges, and their blood-vessels are the meningeal vessels. Spinal menin- gitis is inflammation of the meninges of the cord. Surgical note. — The operation of lumbar puncture is for the purpose of opening the dura and arachnoid and drawing off a cer- tain quantity of cerebro-spinal fluid. Spinal Nerves. A spinal nerve is a collection of motor and sensory fibers connected with the spinal cord by two roots — an anterior root running from the motor cells and tracts and a posterior root running to the sensory tracts and cells. The two roots become imbedded in one sheath at the interverte- bral foramen which transmits the nerve from the spinal canal. Fig. 165. — Membranes of Spinal Cord. I, Dura mater; 2, arachnoid; 3, post, root of nerve; 4, ant. root of nerve, divided; 5, pia mater; 6, linea splendens (Morris, after Ellis). Note. — The "ganglion of the root" is a small ganglion on the posterior root where the true root fibers arise. The ganglion contains the cell-bodies of fibers in the' posterior roots: they are necessary to the life of these roots. Two axons arise from each ganglion cell ; one becomes part of a spinal nerve and ends in a sensitive part of the body (skin, mucous membrane, muscle tissue and lining of joints) ; the other forms a fiber of the posterior root of the same spinal nerve, and enters the cord to become associated with cells of both posterior and anterior horns. (The fibers of the anterior roots arise in the cells of the anterior horns.) 234 ANATOMY AND PHYSIOLOGY FOR NURSES. Clinical note. — Since the spinal nerves contain both motor and sensory fibers, they are called mixed nerves; and since the antero-lateral divisions of the cord are motor tracts, and the postero-lateral divisions are sensory tracts, we can understand how injury in one region will cause paralysis of motion, and injury in the other will cause paralysis of sensation; while injury of a mixed nerve will cause loss of both motion and sensation in the parts to which the nerrc belongs. CHAPTER XVII. THE SPINAL NERVES. There are thirty-one pairs of spinal nerves. They leave the spinal canal at the intervertebral foramina in the differ- ent regions and are named accordingly. Cervical 8 Thoracic 12 Lumbar 5 Sacral 5 Coccygeal i The first cervical, emerging above the atlas, is called the suboccipital. The Cauda equina. — The spinal cord, being 17 inches long, reaches only to the second lumbar vertebra, therefore the nerves emerging through the foramina below this level must have lain in the canal for some distance before leaving it, especially those vi^hich appear in the lowest or pelvic region. If the canal be opened at the back and the cord lifted out, these long nerves are seen hanging from it in a crowd, suggesting the appearance of a horse's tail, the "cauda equina," which therefore is composed of the lumbar, sacral, and coccygeal nerves while they are still in the neural canal. The terminal filament extends dowTiward in their midst. All spinal nerves divide at once into posterior and anterior divisions, both divisions containing motor and sensory fibers (Fig. 168). The posterior divisions send nerves to posterior regions of neck and trunk; the anterior divisions (communicate with the sympathetic system, and then) send nerves to anterior and lateral regions of the neck and trunk, and to the upper 235 8 Cervical 12 Thoracic \ 5 Lumbar 5 Sacral Fig. 166. — Diagram of Spinal Nerves. 236 ANATOMY AND PHYSIOLOGY FOR NURSES. and lower extremities/ In all regions except the thoracic, the an- terior divisions interlace with each other to form plexuses before giving off nerves. The most important plexuses are: The cervical plexus (formed by the upper four cervical nerves). The brachial plexus (formed by the lower four cervical and jirst thoracic nerves). The lumbar plexus (formed by the upper three and part of the fourth lumbar nerves). The sacral plexus (formed by the lower lumbar, and upper three and most of fourth sacral nerves) . The larger nerves only are described in the text. Resumes are added for reference. For nerves supplying the joints see page 69. CERVICAL NERVES. Posterior divisions. — These send branches to the back of the head as well as muscles and skin of the neck. Largest posterior branch. — The great occipital (from second cer\dcal), to supply the scalp. Anterior divisions. — The upper four form the cervical plexus. The lower four enter the brachial plexus. Fig. 167. — Cauda Equina (Morris) . Fig. 168. — Showing Division of Nerve. I, Dura mater; 2, arachnoid; 3, ganglion of post, root; 4, ant. root; 5, space contain- ing spinal fluid; 6, post, division of nerve (Holden). The cervical plexus. — Most of the branches of this plexus supply muscles of the neck (front and side). One exception is the * The communicating branches to sympathetic ganglia are of great importance, serving to connect the cerebro-spinal and sympathetic division into one great nerve svstem. THE PHRENIC NERVE. 237 great auricular {auricularis magnus) which supplies the external ear. Another is the — - Most important nerve of this plexus, the phrenic. — It passes downward through the thorax (between the lung and heart) to supply the diaphragm (Fig. 169). Its importance is due to the fact that the diaphragm is one of the principal breathing muscles, Fig. 169. — The Phrenic Nerves, Right and Left, run downward on either Side of the Great Vessels and the Heart (After Morris). and the nerve has for that reason been called the "internal respiratory nerve of Bell." (Sir Charles Bell was a famous anatomist in former times.) The brachial plexus. — This plexus is so named because most of its branches supply muscles of the upper extremity (including the shoulder)* and those connected with it. First important branch, given off in the neck— the long thoracic. It passes downward along the side of the thorax to supply the anterior 238 ANATOMY AND PHYSIOLOGY FOR NURSES. serratus muscle (p. 95). This muscle is used in forced respiration and the nerve has been called therefore the ^^ external respiratory nerved The greater part of the branchial plexus is situated in the axilla; most of its branches are given off there T) 1. c A ^ 7 ^ [ supraspinatus Branches: Suprascapular, to { . ' . [ infraspinatus Three large cords: Lateral, medial, posterior. Branches of the cords: From lateral cord: Thoracic, to pectoral muscles. Musculo-cutaneous, to biceps and brachialis (and their integument). Upper root of median nerve. From medial cord : Lower root of median nerve. Thoracic, to pectoral muscles. Cutaneous, to integument of forearm. Ulnar, to ulnar muscles. [ subscapularis, teres major, From posterior cord: Subscapular to ] latissimus dorsi (the long [ subscapular). Axillary, to deltoid and teres minor. Radial, to posterior of forearm and hand. The three large nerves derived from the brachial plexus are: The ulnar from the medial cord. The median from the medial and lateral cords. The radial from the posterior cord. The ulnar nerve runs downward in the medial side of the arm, passes behind the medial epicondyle into the forearm, and ends in the palm (Fig 170). In the forearm it supplies: Flexor carpi ulnaris. Flexor digitorum (profundus). In the hand it supplies: Interossei. Little finger muscles. Thumb muscles (one and a half). The median nerve runs downward in the arm, close under the border of the biceps muscle. It then passes in front of the elbow joint into the forearm, and continues between the layers of flexor muscles to the palm. BRACHLA.L PLEXUS AND BRANCHES. 239 Axillary artery Median nerve Brachial artery Suprascapular nerve and artery Lateral ^^ cord Pectoral muscle Ulnar nerve and artery Radial nerve and artery Branches to hand ^ ^ Fig. 170. — Brachial Plexus and Anterior Nerves. Post, interosse ous nerve Fig. 171. — The Radial Nerve. 24© ANATOMY AND PHYSIOLOGY FOR NURSES. In the forearm it supplies: Flexor carpi radialis. Flexor digitorum (sublimis). Flexor digitorum profundus (partially). Supinator. In the hand it supplies: Thumb muscles (except one and a half). The radial nerve passes to the back of the arm, winding across the humerus in the radial groove, under the triceps muscle (Fig. 171). Just above the elbow it divides into two branches, the deep and superficial branches of the radial nerve. The superficial branch is a cutaneous nerve. It runs downward in the radial side of the forearm to supply integument of the hand and fingers posteriorly. The deep branch passes to the back of the forearm, lying under cover of extensor muscles, all of which it supplies. Branches of the radial nerve: In the arm: To the triceps. To brachio-radialis. To brachialis (partially). Branches of the deep branch of the radial nerve: In the forearm: To the extensor carpi radialis (long and short) . To the extensor digitorum (comunis). To the extensor of index finger. To the extensor of little finger. To the extensors of the thumb. Resume. — The general distribution of the muscle nerves arising from the brachial plexus, is to deep muscles of the neck and the external respiratory muscle (anterior serratus); to shoulder and axillary muscles; arm, forearm and hand. The three long muscular nerves derived from the brachial plexus are the ulnar nerve from the medial cord, running down behind the medial epicondyle into the forearm and hand (supplying ulnar muscles, little finger muscles and the interossei, and a part of the thumb group) ; the median nerve from the medial and lateral cords, running down along the medial border of the biceps muscle into the forearm, to end in the palm (supplying the biceps and brachial muscle, all of the flexors of the forearm except on the ulnar side, ULNAR, MEDIAN, AND RADL\L NERVES. 241 and most of the thumb muscles); the radial nerve from the pos- terior cord, running in its groove to the front of the lateral epicondyle, and dividing into the deep and superficial branches of the radial nerve. By the radial and its deep branch all of the posterior muscles of the arm and forearm are supplied, Nerves of the skin of the hand. — Front of the thumb, index, middle, and one-half of the ring finger, the median nerve Back of thumb, index, middle, and one-half of ring finger, the superficial branch of the radial nerve. Both front and hack of little finger and one-half of ring finger, the idnar nerve. Fig. 172. — Dorsal SunrACE of Left Hand (Morris). Fig. 173- -An Intercostal Nerve (Holden). Points of interest. — The ulnar nerve in the arm is with the inferior pro- funda artery and passes behind the medial epicondyle; it may be easily felt in the groove behind the epicondyle, where pressure causes a sensation of pain and tingling as far as the little finger. In the forearm it is on the ulnar side of the ulnar artery and they pass in front of the wrist. The median nerve, in the arm, is with the biceps muscle and brachial artery, and they pass in front of the elbow; in the forearm, it lies between the deep and superficial muscles and passes with their tendons in front of the wrist. The radial nerve lies in the groove for the radial nerve between two heads of the triceps muscle, with the superior profunda artery, and comes to the front of the elbow. The superficial branch of the radial nerve in the front of the forearm is on the radial side of the radial artery; it winds around behind the wrist-joint. The deep branch of the raial nerve is in the back of the forearm with the dorsal interosseous artery; they do not extend below the wrist. Note. — For the distribution of nerves to the principal joints, see page 69. 16 242 ANATOMY AND PHYSIOLOGY FOR NURSES. THORACIC NERVES (FIG. 173). There are twelve pairs of thoracic nerves: Posterior divisions. — These send branches to muscles and skin of the back. Anterior divisions. — These form the intercostal nerves; the first assists in the formation of the brachial plexus. All run in the grooves under the borders of the ribs, supplying inter- costal muscles and the upper portion of the abdominal muscles, also the skin over the muscles. They accom- pany intercostal arteries. LUMBAR NERVES There are five pairs of Lumbar Nerves. Posterior divisions. — These send branches to muscles of the back; and skin of the back, hip, and sacral region. Anterior divisions. — The upper three and a portion of the fourth form the lumbar plexus. The remainder of the fourth and the whole of the fifth form the lumbosacral cord (Fig. 174). The lumbar plexus. — This plexus lies within the abdomen, in the sub- stance of the psoas muscle. Its branches supply abdominal walls, and front and sides of the thigh (also integument of both regions). They are all given off in the abdomen.. Fig. 174. — The Femoral Nerve. I, Femoral nerve; 2, 3, small nerves from lumbar plexus; 4, 5, 6, 7, 8, 9, 10, II, II, branches of femoral nerve; 12, 12, 13, 14, long" saphenous nerve and its branches; 15, obturator nerve; 16, 17, 18, 19, branches of obturator nerve; 20, 21, lumbo-sacral cord; 23, ex- ternal cutaneous nerve (Gould's Dictionary). Branches: the principal are: Ilio -hyp agastric, cutaneous to hypogastrium, and over the ilium (dorsum). Inguinal, to internal oblique and transversus muscles. Genito-femoral, to round ligament of uterus, cremaster muscles of sper- matic cord. THE GREAT SCIATIC NERVE. 243 Obturator, to the external obturator and the four adductors. Femoral, to the quadriceps muscle (rectus and three vasti). The femoral nerve {anterior crural) is the largest branch of the lumbar plexus. It passes from the abdomen, under the inguinal ligament,* into the thigh (on the lateral side of the femoral artery), and breaks up at once into branches — cutaneous and muscular, for the four large divisions of the quadriceps extensor muscle and the integument which covers them. The long saphenous branch of the femoral nerve is the longest nerve in the body, running nearly the whole length of the extremity; it supplies integument only, on the medial side of the leg and foot. • The lumbo-sacral cord passes into the pelvis to unite with sacral nerves and to form the sacral plexus. SACRAL NERVES. Posterior divisions. — These send branches to muscles and skin of the back of the pelvis. Anterior divisions. — The upper three, and greater part of the fourth, join the sacral plexus. The sacral plexus. — The branches of this plexus supply the muscles within and around the pelvis, the posterior part of the thigh, and the entire leg and sole of the foot. Branches: (All leave the pelvis through the great sciatic foramen.) Gluteal, two {superior and inferior) to glutei muscles. Pudic, to the levator ani, rectum (sphincter ani), perineum, and external genital organs. Small sciatic, to posterior thigh and external genital organs. This is a cuta- neous nerve. Great sciatic, to posterior thigh, and entire leg and foot (except medial bor- der) muscles and skin. The great sciatic nerve is the largest nerve in the body. It leaves the pelvis by way of the great sciatic notch and runs downward between posterior thigh muscles to the popliteal space, where it divides into tibial and common peroneal nerves (Fig. 175). The only portion of the great sciatic nerve which is not covered by muscles, lies in the deep groove between the great trochanter of the femur and the tuberosity of the ischium. 244 ANATOMY AND PHYSIOLOGY FOR NURSES, Branches: To the Biceps, Semitendinosus. Semimembranosus. \Gt,iiSeu,s\^e, ■ Gluteal n. 7, — Sciatic n. f-jf -' Popliteal artery - Tibial n. Peroneal n. Ant. tib. artery Tibial n. Post. tib. artery Fig. 175. — The Sciatic Nerve. The division of the great sciatic nerve occurs in the upptr part of the popHteal space. The tibial nerve {internal popliteal) runs down through the popliteal space (with the popliteal artery and vein) to the leg. It then descends under cover of the calf muscles to the ankle; be- low the medial malleolus it divide^ into medial and lateral plantar nerves. Branches: In the leg. — To the Tibialis posticus. Flexor digitorum (longus). Flexor hallucis. In the foot. — By medial plantar, to great toe muscles and interossei. By lateral plantar, to muscles of little toe. The tendons of the first three (tibialis and two long flexors of toes) pass behind the lateral malleolus. They extend the foot. The common peroneal nerve {external popliteal) winds round the neck of the fibula to the front of the leg, and divides into the deep pero- neal and superficial peroneal nerves. The deep peroneal (formerly an- terior tibial) descends to the ankle, and ends on the dorsum of the foot between the jBrst and second toes. Branches: In the leg. — To the Tibialis anticus. Extensor hallucis. Extensor digitorum (longus). Peroneus tertius. In the foot. — Extensor digitorum (brevis). PHYSIOLOGY OF SPINAL CORD. 245 The tendons of the muscles in the leg — (tibialis, two long extensors of toes, and one peroneus) pass in front of the ankle-joint. Thty flex the foot. The superficial peroneal (musculo-cutaneous) runs downward in the substance of the peroneal muscles to the foot. Branches: Muscular. — To the Peroneus longus, peroneus brevis. Cutaneous. — To dorsum of foot. Their tendons pass behind the lateral malleolus. They extend the foot. Points of interest. — The superior gluteal nerve, with the superior gluteal artery; the sciatic nerve, with the sciatic artery; and the pudic nerve, with the pudic artery, all pass out from the pelvis through the great sciatic foramen; the pudic nerve and artery return through the small sciatic foramen. The obturator nerve and the obturator artery pass through the obturator foramen. The femoral nerve is on the lateral side of the femoral artery, under the inguinal ligament. THE COCCYGEAL PLEXUS. The remaining sacral nerves and the coccygeal nerve communi- cate in a small plexus, which is important in that it sends branches to the viscera of the pelvis. Summary. The spinal nerves are distributed to all skeletal muscles and integument except those of the front of the head, face, and chin. Through sympathetic connections they also supply secreting cells of glands and walls of viscera. FUNCTIONS OR PHYSIOLOGY OF THE SPINAL CORD AND SPINAL NERVES. The spinal cord is so intimately connected with the brain by conducting fibers in the tracts, that it is impossible to explain all of its functions without referring to the brain, but certain ones may be exercised independently, and a few of these will be considered briefly in this connection. The spinal cord a center for reflex action. This is one of the most important of its functions and the simplest form of nerve and muscle action. (Acts which may be performed without thinking of them are reflex.) 246 ANATOMY AND PHYSIOLOGY FOR NURSES. We have already seen that the cord comprises an interior portion of gray nerve tissue surrounded by white; cell bodies and their branches forming the central gray portions and white fibers forming the columns or tracts. In each lateral half of the cord the cell tissue is grouped in crescents. Fibers in the posterior tracts transmit sensory impulses from various parts of the body to cells in the posterior horns of the crescents. Fibers in the anterior tracts transmit motor impulses ■from cells in the anterior horns to various parts of the body (their axons arise in cells of the anterior horns) (Fig. 176). .spc. Fig. 176. Diagram Showing the Structures Involved in the Production OF Reflex Actions (G. Bachman). r.s. Receptive surface; af.n. afferent nerve; e.c. emissive or motor cells in the anterior horn of the gray matter of the spinal cord, sp.c; ef.n. efferent nerves distributed to responsive organs, e.g., directly to skeletal mus- cles, sk.vt., and indirectly through the intermediation of sympathetic ganglia, sym. g., to blood vessels, b.v., and to glands, g. The nerves distributed to viscera are not represented. Here we have the apparatus for reflex muscle action. — A sensory or afferent nerve receives an impression, and transmits a series of impulses to the spinal cord. These are received by a cell which in its turn is stimulated, and liberates energy to be con- ducted by a motor or efferent nerve to a muscle, and the muscle contracts. This act is comparatively simple. Most muscle activities, however, are complex, requiring the com- bined action of several organs; in these cases many motor cells and nerves must be stimulated, and this is accomplished by means of REFLEX ACTION. 247 additional neurons within the cord, whose libers associate the activi- ties of different regions. For instance, an unsuspected blow upon the hand is followed instantly by a drawing back of the hand and arm; most of the muscles of the upper extremity will have been called into action; in other words, many motor cells (in the lower cervical region of the cord) have been stimulated to a sudden lib- eration of energy, showing the effect of one stimulus when conducted by connecting fibers to many cells. Walking was in the beginning a voluntary act, but education of the centers has made them independent and it has become reflex. So with piano-playing, and many others. Tendon reflex. — A familiar example is the "knee jerk" or patellar reflex. This may be elicited by striking the patellar tendon when partly stretched. The impression thus produced, quickly reaches the motor cells which innervate the quadriceps muscle, and the leg is slightly extended. (There are several tendon reflexes.) Skin reflex. — Irritation of the sole of the foot causes the plantar muscles to contract (a plantar reflex). Scratching the skin of the side of the abdomen causes contraction of abdominal muscles {abdominal reflex). There are other skin reflexes. The spinal cord also contains centers for controlling the tone of vessel walls or vascular tone. Also for stimulating the action of secreting glands, and for muscle action of viscera. These functions are exercised through the sympathetic ganglia with which it is widely connected. Finally, it contains centers which influence (or control) certain processes of nutrition — trophic centers. It appears at once that the spinal cord is able, from the wide distribution of its nerves, to provide for most of the activities of the body. Taken as a whole it may be regarded as a great common center of sensation and motion; and because of many connecting fibers running upward, downward, and transversely, it can combine and to some extent regulate, the functions of many different parts so that systematic groups of movement, or series of movements, may be executed by organs more or less distant in the body. In other words, the spinal cord can to some extent coordinate the functions of the spinal nerves and skeletal muscles. 248 ANATOMY AND PHYSIOLOGY FOR NURSES. To repeat the functions of the spinal cord, they are to preside over: 1. Reflex action. 2. Muscle tone. 3. Vessel tone. 4. The action of secreting glands. 5. Nutrition (trophic action). These may all be exercised independently by cells in the anterior horns and their nerve connections. (Other functions will be mentioned in connection with those of the brain.) The function of the spinal nerves is to connect all parts of the body (except face, chin and anterior part of head) with the spinal cord, for the purpose of conducting sensory and motor impulses to and from the cord. In referring to motor nerves we have thus far mentioned their natural stimulus only, that is, — the impulse generated by a motor ^ cell. The electric current applied to a motor nerve in any part of its course will excite its activity, showing in muscle contraction, etc. This is an artificial stimulus, and the most powerful one known. (The special functions of individual nerves have already been, considered in foregoing pages.) CHAPTER XVIII. THE BRAIN AND CRANIAL NERVES. The cerebro-spinal or central nerve system comprises the Brain and Spinal Cord with their nerves. The spinal cord and its nerves are already described in Chapters XVI and XVII. The brain^ is ovoid in shape, composed of gray cells and white fibers, situated within the cranial cavity and continuous through the foramen magnum with the spinal cord. ¥io. z-]-]. — The External Surface of the Brain (Deaver). The surface consists of gray cells and their branches and is called the cortex of the brain, while the interior is white, with several ganglia (collections of "gray matter") imbedded within it. The surface or cortex of a well-developed brain is marked by many fissures, separating curved ridges called convolutions (or gyres), the number and depth of which correspond with the degree ' A review of pages 229 and 230 is recommended before studying the description the brain. 249 250 ANATOMY AND PHYSIOLOGY FOR NURSES. of development, the brain of a new-born child being comparatively smooth. The white portion is composed of white fibers (the medullated axons of the cell bodies). They run in many directions. Some connect the different main divisions of the brain; others run from one part of the cortex to another; others still, in great number, connect the brain and spinal cord (Fig. 178). Taken together, they make up the mass of the brain itself. ' ' Fig. 178. The letters mark the white fibers. They connect the cortex with other parts, also different parts of cortex together. Many fibers are seen to pass through the basal ganglia. The Roman numerals indicate nerves (Brubaker, after Starr). The white fibers (Fig. 178) connect the cortex with the spinal cord; some connect diilerent parts of the brain together. Taken together they compose the bulk of the brain, as already stated. The brain has four principal parts, the cerebrum, cerebellum, medulla oblongata, and pons Varolii. The cerebrum is the largest division and occupies nearly the whole cranial vault. It is divided into two hemispheres, right and left, by a longitudinal fissure. At the bottom of this fissure white fibers are seen to pass from one side to the other, thus forming a THE BRAIN. 251 transverse commissure, connecting the hemispheres, and called the corpus callosum (Fig. 179). Each hemisphere is marked off by specially deep fissures, into lobes, the principal ones being the frontal, parietal, occipital, and temporal. The principal fissures between the lobes are: the fissure of Rolando between the frontal and parietal; the parieto-occipital, between the parietal and occipital; and iYvQ fissure of Sylvius, between the temporal lobe below and the frontal and parietal above it. Important note. — The fissure of Rolando is often called the central fissure, and the convolutions in front of and behind it, are called the central convolutions (anterior and posterior). Fig. 179. — Median Surface of a Hemisphere, sii Xeft Fulmonari/ plexus CARDIAC PLEKUS •all IH^ — V- 7 \Smcdlest\ "'■'inUlrcroci ,,wgmfflca y-Diaphra^m ; i J ^-Phrenic ^fhrj^^^Z^.^ il______^ ^palic p/exus *' Autrbacm '-fleiusesoj^ & \ Meissner\ Aidominal Aortic pUiu* flYPOCASmiC PLEXUS Coccygeal nerve Gan^liori CcKcycftum impar Fig. 189.— Principal Ganglia and Plexuses of the Sympathetic System (Morris). 266 ANATOMY AND PHYSIOLOGY FOR NURSES. of saliva {salivary cells are stimulated — think of a lemon). Fright or anxiety may inhibit or prevent the secretion of saliva; or inter- fere with digestion through a similar effect upon other digestive fluids; and it is well known that the secretion of milk is greatly modified by mental or emotional influences. So with general vaso-motor action. We all know the blanched face of fright or mental shock; the flush of joyous excitement; or the blush of embarrassment. Again the effect of vaso-motor action may be seen when intense cold is applied to the skin. The cutaneous vessels contract, the blood is driven out, the skin becomes white. The opposite condition is caused by heat — the vessels dilate, the blood flows in and the skin is red. By alternate action of the two kinds of vaso-motor nerves (vaso-dilators and vaso-constrictors) , the blood-supply is adapted to special and varying needs of different parts of the body, and the balance of pressure preserved in all of their vessels. When an organ has work to perform its vessels dilate and the necessary blood is supplied. When the work is finished the vessels return to their usual size (their vessel-tone being restored by vaso- constrictors). The process of digestion, for example, requires that there should be much blood in many organs; the same is true of general muscular exercise. Consequently, to exercise violently after a full meaL is a mistake, because the muscles would deprive the digestive organs of the extra blood which they need, and an attack of indigestion might follow; at best, digestion would be delayed. It would be better to delay the exercise. Many examples might be given and will probably occur to the mind of the student, of the interactions of different parts of the sympathetic system. These are the processes which must go on more or less continu- ously. Some may be suspended temporarily, as gland secretions, or digestion, or the formation of excretions, but they never entirely cease without causing the death of the individual. Summary. The sympathetic nerves supply all involuntary muscles, the coats of blood-vessels and the cells of secreting glands. They are PHYSIOLOGY OF THE NERVE SYSTEM. 267 the nerves of unconscious life, as the cerebrospinal nerves are the nerves of voluntary and conscious life. SUMMARY OF THE FUNCTIONS OF THE NERVE SYSTEM AS A WHOLE. We have now concluded the study (briefly) of the entire nerve system, and we have seen how intimately its various parts are con- nected. Only through a knowledge of these connections can the functions of the system be understood. Different parts of the spinal cord are associated one with another "by conduction fibers, and the cord is connected with the hrain above "by many more, running upward or downward through the medulla and pons. (On the inferior surface of the brain we see these fibers as crura or penduncles, disappearing in the substance of the cerebrum and cerebellum; they are finally connected with the gray cells of the cortex.) In the spinal cord and its nerves we find the apparatus for reflex action which appears in so many phases — as muscle contraction, muscle-tone, vessel tone, etc. The spinal cord, then, is a great reflex center, a conducting pathway, and an organ of coordination of ■skeletal muscles. Included in the medulla are centers for still more important reflexes: the respiratory center; the cardio-vascular center or center for heart-action and vessel-tone combined; the heat regulati.ig center; deglutition center, and others. Certain of these may be modified by the will; for example, the respiratory act — we may take a long full breath or a short and shallow one; breathe rapidly or slowly, at will. Deglutition is still nearer to the realm of voluntary movements — only when food reaches the esophagus, is the act of deglutition purely reflex. (Here is the first appearance of unstriped muscle in the digestive tract.) Going higher we find the cerebellum presiding over the coordi- nation of conscious and voluntary movements, through its connec- tion with the cortex of the cerebrum on one hand, and the pons, medulla and cord on the other. Also upon the cerebellum depends the maintenance of body equilibrium. For this it is necessary that the semicircular canals of the internal ear should be normal and in perfect connection with the cerebellum. Other sensory connections 268 ANATOMY AND PHYSIOLOGY FOR NURSES. Fig 190.— Diagram Showing the Relation oe Skeletal, Muscle and Nerve Tissues (G. Bachman). f.a. Bones of the forearm representing the skeletal tissue; e.y. the elbow joint, the fulcrum of the lever formed by the bones of the forearm; W_. a weight acting in a downward direction and representing the passive force of gravi_ty|^ sk m. a skeletal muscle acting in an upward direction and the source of the active power to be applied to the lever; sp.c. transection of the spinal cord showing the relation of the white and the gray matter: m.c. a motor cell in the anterior horn of the gray matter; ef.n. an efferent nerve-fiber connecting the motor cell from which it arises with the skeletal muscle and contained in the ventral roots of the spinal nerves; aj.n. an afferent nerve-fiber arising from the ganglion cell along its course and connecting the skin, 5., on the one hand with the spinal cord on the other hand and contained in the dorsal roots of the nerves; c.s.c. coronal section of the cerebrum showing the relation of the gray to the white matter; v.c. a volitional or motor cell; i.a. a descending axon PHYSIOLOGY OF THE NERVE SYSTEM. 269 also contribute to the exercise of this function; for example, to walk unaided without vision is possible, but not in a straight line; or, to walk with feet benumbed is difficult, more so to stand motionless; showing that the cerebellum is stimulated to the coordination by which equilibrium is maintained, by more than one sort of stimulus, probably by many. Going still higher, we find in the cerebrum the perfecting of the plan for bringing the whole sentient and moving organism into the domain of consciousness and the will. This is by means of the connections of the cerebrum through the pons, medulla, and cord and their nerves, with every part of the body from which afferent impulses and to which efferent impulses may be transmitted (Fig. 190)- Concerning the reception and originating of ideas, the exercise of thinking — in other words, intellectual processes — we know nothing, except that these activities certainly depend for their normal manifestation upon a normal cerebrum. A well-developed cerebrum has good convolutions and deep furrows. These indicate mental power, being of more importance than the mere size of the brain. The brain of the infant possesses all of the interior parts, as ganglia, etc., but the cortex is almost smooth. With the growth of the child and quickening of the mind, the convolutions and furrows appear and develop. The sympathetic division of the nerve system is the medium of communication (through communicating branches) of nerve impulses between the cerebro-spinal system and the organs con- cerned in involuntary processes (notably those connected with nutrition and growth) through control of secreting cells and vessel- tone. or nerve-fiber connecting the volitional cell from which it arises with the motor cell in the spinal cord; s.c. a sensor cell; a.a. an ascending axon or nerve-fiber connecting a receptive cell from which it arises (not shown in the diagram) with the sensor cell in the gray matter of the cerebrum. The nerve-fibers which pass outward from the spinal cord to the glands, blood-vessels, and the muscle walls of the viscera, have for the sake of simplicity been omitted from the diagram. CHAPTER XX. THE SPECIAL SENSES AND THE VOICE. In studying the structure and functions of the nerve system, we learn that sensory stimuh are received in every part of the body by afferent nerves, and conducted to sensory cells in the spinal cord; there, they either evoke a muscle response of reflex character, or are transmitted by connecting tracts to the brain, where the result is sensation of some sort: as for example, of temperature — whether of the surrounding air, or of bodies which we touch; or of other con- ditions— whether hard or soft, wet or dry, rough or smooth, etc., etc. These are common and definite sensations and by them we gain knowledge of the world about us.^ Others there are, which are definable in general terms only, and are not definitely located, although plainly felt. For instance, we are hungry, or thirsty or tired; after pain we have a sense of relief, etc., the route for stimulus and response in these matters is through visceral and vaso-motor nerves and their spinal and cerebral con- nections, and by them we gain acquaintance with our individual selves. Still other mechanisms are adapted to a more definite class of sensations, by which we learn still more extensively to know the world in which we live; these are called the organs of the special senses. The special senses are: smell, touch, taste, hearing and sight. The organs concerned are the nose, the skin, the tongue, the ear and the eye. It is understood that all consciousness of sensation is based upon the final reception of sensory impressions by the brain. So far as a "sense" may be said to reside anywhere, it resides in the hrain, for without it there are no senses as we know them. ^ We do not now refer to cranial nerves in which the arrangement is similar but more intricate. 270 THE SENSE OF SMELL. 271 The nose is the organ of the sense of smell. In the nasal chambers is a layer of special cells — olfactory cells — supported by a basement membrane, forming the Schneiderian membrane (or pituitary membrane). The upper part only of the nose is the olfactory region. Here the sensory nerves arise which proceed through the foramina in the roof of the nose (the cribriform plate) to the brain. In quiet respiration most of the air passes in and out through the lower parts of the nasal chambers, diffusing gradually into the upper parts. Although most odors are readily perceived as soon as one comes into the atmosphere containing them, a slight odor is better appreciated by means of an effort to draw the air through the olfactory region, in other words, a sniff. The odorous particles are thus brought into contact with the olfactory cells, and the impressions made upon them are transmitted by the delicate olfactory nerves through the cribriform plate to the olfactory bulbs and thence by the olfactory tracts to the olfactory center in the temporal lobe of the brain. The sense of smell is valued for the pleasurable sensations which it affords, as an adjunct to the sense of taste, and as a sentinel to warn us of danger when in the vicinity of irritating or poisonous gases, etc. The degree of development of this sense in lower animals is remarkable; they readily "scent danger." THE SENSE OF TOUCH. The skin and the mucous membrane of the mouth constitute the organ of the special sense of touch (all mucous membranes are sensitive to temperature and pain, but only that of the mouth is sensitive to touch). The special nerve endings are situated in the deeper layers and the papillae (general description page 214). And upon their number and nearness to the surface, depends the acuteness of this sense. (An area covered by thick layers of epidermis is not so sensitive as one where it is thin; and vice versa.) There are several forms of nerve endings : tactile cells, for common sensations, found throughout the skin in the deeper layers and the papillae; touch corpuscles, also in the papillae and especially numerous in the palm and fmger tips, where sensation is particularly acute; 272 ANATOMY AND PHYSIOLOGY FOR NURSES. other forms in muscles and tendons; others still, for the perception of heat and cold, etc., etc. The sense of touch includes many varieties of impressions by- means of which we may judge of surroundings, and gain the neces- sary knowledge concerning the external world whereby we can adjust ourselves to its conditions. Simple contact evokes no sensation without a certain degree of pressure; touch and pressure are therefore closely related; with increased pressure comes the impression of weight. If pressure is sufficiently increased, fain will be felt, which is due to the disturb- ance of nerves more deeply situated. Again, a touch imparts also a sensation of place, the place where it occurs; therefore the sense of touch includes the place sense. THE SENSE OF TASTE. The tongue is spoken of as the organ of taste, since it bears the taste buds. (For general description of the tongue see page 121.) The sense of taste may be regarded as a specialization of the sense of touch and the two mechanisms somewhat resemble each other. The nerve endings which are developed for this purpose are scattered over the surface of the tongue, and in (certain of) the papillae, in the palate and palatine arches (possibly sometimes in the pharynx). They are found in small oval bodies called taste buds, which are in direct connection with the gustatory nerves. In order to excite the nerves of taste, substances must be either already in solution or soluble by the saliva; a perfectly dry substance may be felt by the tongue and its temperature, etc., will be appreci- ated, but it cannot be tasted. Although all flavors may be recog- nized in all parts of the tongue, some are more keenly appreciated in one portion than another; for example: the bitter flavors are more plainly tasted in the posterior region, while perception of sweets is more marked in the anterior parts. The borders seem to apprehend acids more quickly than the dorsum. Touch, temperature, and smell are all associated with taste. If a substance is too hot the sense of taste is overcome by the sense of pain. Many people who have been deprived of the sense of smell (by disease or injury) assert that they no longer possess the sense of taste, or that, if present, it is greatly impaired. THE EAR. 273 Fossa Tragus Lobule — Fossa Helix Antihelix THE SENSE OF HEARING. The organ of the sense of hearing is the ear. It has three di\Tsions: external, middle, and internal (Fig. 191). The external ear is that part which is on the outside of the skull. The expanded portion, mostly of cartilage covered with skin, is the auricle; the deepest depression is the concha, and the opening at the bottom of the concha leads to the external audi- tory canal (or meatus). This auditory canal is one and one-quarter inches in length, formed partly by the cartilage of the auricle and partly by the temporal bone. It curves slightly upward, and then Antitragus downward and forward. It is lined with skin which bears stiff hairs in the outer portion, and contains the glands which secrete "ear wax" {ceruminous glands). It is important to remember the length and direction of this canal. The membrane at the end of the canal is called the membrana tympani, or membrane of the drum. It is a fibrous membrane covered with very sensitive skin on the outer surface, and mucous membrane within (Fig. 192). The middle ear is the tympanum, or drum. It consists of a small cavity in the petrous bone, on the inner side of the membrane of the drum. Its height is barely half an inch, and the other measurements are smaller still. It contains the little bones and forms the beginning of the auditory tube. The auditory (or Eustachian) tube begins in the wall of the middle ear and ends as a roll of cartilage opening into the pharynx. The tympanum is really an air chamber, since it communicates with the throat by the auditory (or Eustachian) tube, and both tube and tympanum are lined with a continuation of the same mucous membrane. An ojjcning at the back of the tympanum leads into 18 Fig. 191. -The External Ear (Morris). 274 ANATOMY AND PHYSIOLOGY FOR NURSES. the mastoid antrum, and through this, inflammation of the middle ear frequently extends to the mastoid cavities. Note. — The mucous membrane of the pharynx is continued through the auditory tube into the tympanum, and through that into the mastoid cells. Two openings lead from the tympanum to the internal ear — the oval (or vestibular) window and the round (or cochlear) window. The round window is closed by a membrane called the secondary membrane of the tympanum. The oval window is closed by a fibrous layer and the base of the stirrup bone (p. 275). Semicircular Wax canals glands Drum membrane Cochlea Cavity of tym panum or drum Parotid gland Styloid process Internal carotid artery Auditory tube Fig. 192. — The Ear (Morris). The internal ear is still more deeply situated in the petrous bone. It is extremely complicated, consisting of semicircular canals, vestibule, and cochlea, and well named the labyrinth. There are three semicircular canals placed at right angles to each other; the cochlea resembles a snail-shell in form, and both communicate with the vestibule which is between them. AUDITORY NERVE. 275 The cochlea communicates with the tympanum by the round or cochlear window, and the vestibule communicates with the tympanum by the oval or vestibular window. The internal ear or labyrinth, contains a clear fluid called perilymph. Lying in the perilymph is a membranous labyrinth containing endolymph. The mem- branous labyrinth is of the same shape, having all the different parts as the bony labyrinth. Ossicles. — A chain of three ossicles (or httle bones) is suspended across the tympanum — the malleus, incus, and stapes. The malleus (or hammer) is attached by the handle to the membrane of the drum, the incus (or anvil) comes next, and then the stapes (or stirrup) with its base fitting the oval window of the middle ear. Any vibration of the membrane of the tympanum is at Fig. 193. — Bones of the Ear once transmitted by this chain of bones across the tympanum, and through the oval window to the nerves of the internal ear (Fig. 193). Nerves of the Internal Ear. The cochlear division of the auditory nerve is the true nerve of hearing. Its terminal filaments are within the cochlea; they receive impressions transmitted by the vibrating chain of bones in the tympanum, through the oval window, and conduct them to the brain. The vestibular division of the auditory nerve is distributed in the vestibule and semicircular canals; it is not concerned in hearing, but is necessary to the power of preserving equilibrium in standing, walking, etc. A person in whom this nerve has been destroyed cannot walk steadily, and is not subject to sea-sickness. Summary. — The function of the external ear is to gather and direct the sound waves to the membrane of the tympanum. In the middle ear (or tympanum) the vibrations of the membrane are trans- mitted by the chain of ossicles to the oval window, and through the perilymph of the internal ear to auditory nerves within the cochlea. The impressions thus made arc conducted to the brain and we hear. The vestibular branch of the auditory nerve is not stimulated in this manner, but by certain changes in the i)osition of the body, .sometimes of the head alone. 276 ANATOMY AND PHYSIOLOGY FOR NURSES. THE SENSE OF SIGHT. The eye is the organ of sight. It is situated in the orbital fossa. It is a sphere or globe having for its surface three layers called the coats or tunics of the eye — namely the sclera and cornea (fibrous) , the choroid and iris (vascular) , and the retina (nervous) . They contain three transparent structures — the aqueous humor, crystalline lens and vitreous body. The sclera is the "white of the eye." It is dense and tough, protecting the more delicate structures within. One-sixth of the surface of the ball in front is occupied by the cornea instead of the Retina Choroid Sclera m~ Cornea Iris Ciliary processes Lymph canal Ciliary muscle Fig. 194. — A Section of the Eye (Holden). I, Anterior chamber; 2, posterior chamber. The aqueous humor occupies the two chambers. sclera, and this also is dense and tough, but transparent for the admission of light. It contains no blood-vessels, but many tiny lymph-spaces. It is the most prominent part of the eyeball, and its convexity may be seen by looking across an eye from the side. The junction of the cornea with the sclera resembles the fitting of a watch-crystal in its case. The portion of the sclera which is visible when the eyelids are separated, and also the cornea, are both covered by a thin membrane called the conjunctiva; it is a modified mucous membrane, bearing blood-vessels which can be easily seen, especially if a little dilated. The choroid. — The middle coat, next to the sclerotic, is neither dense nor tough, but is made up of fine tissue fibers bearing a very THE EYE. 277 delicate and close network of blood-vessels. It is the vascular coal of the eye, and lines the sclera only, not the cornea. Many pigment cells are contained in the choroid coat, gi\'ing to it a deep brown color so that it makes a dark chamber of the eye (Fig. 195). The iris. — There is no choroid behind the cornea. Its place is supplied by the iris, which resembles a circular curtain attached by its edge to the choroid, and ha\-ing a round aperture in the center called the piipil or the " star of the eye." The iris contains a network Fig. 195.— The Choroid axd Iris (Holden;. of fine vessels and pigment cells, varying in color according to the amount of pigment. (Blue eyes have least, black eyes most.) It has muscular fibers arranged in two sets — circular, or ring fibers, and so-called radiating, or straight fibers. The circular fibers surround the pupil. Thus, when they contract, as in a bright light, they diminish its size. The straight fibers run from the outer border of the iris toward the pupil, and therefore when they contract they act upon the margin to enlarge the opening. Briefly, the pupil is contracted by the circular fibers, and dilated by the straight or radiat- ing fibers, thus regulating the amount of light admitted within the eye. The retina is the innermost coat, of many layers, wdthin the cho- roid. This is a very delicate structure in which are the beginnings of the optic nerve fibers. It is the coat which is essential to vision — no retina, no vision. The outermost layer of the retina is the one which contains the rods and cones, or the visual cells. Like the sclera and choroid, the retina is incomplete in front. From the cells in the retina delicate fibers are prolonged and gathered together to make the optic nerve, which pierces the choroid 278 ANATOMY AND PHYSIOLOGY FOR NURSES. and the sclerotic, passes through the optic foramen of the orbit, and thence back to the brain. The optic disc is the spot where the optic nerve leaves the retina; it is situated a little to the nasal side of the center of the retina (Fig. 196), The macula lutea is a spot in the center of the retina opposite the mid-point of the normal pupil. In the center of this spot is a depression called the fovea centralis which is the center of vision; only the c©ne-shaped visual cells are here present. Macula ' L I W ^-, -ZIXl^^ Retinal vessels Fig. 196. — The Retina as seen w^ith the aid of the Ophthalmoscope (Morris). The vitreous body is glass-like, as its name signifies, both in appearance and transparency. It consists of a jelly-like substance contained in a hyaloid membrane within the three coats. It trans- mits and directs the rays of light to the retina; also it aids in pre- serving the shape of the eyeball (Fig. 194). The crystalline lens is situated immediately in front of the vitreous body, in a shallow depression like a cup on the anterior surface, and held there by delicate fibers which act as a suspensory ligament. It is a double convex lens with a capsule, both perfectly transparent so that light may pass through, and it is able to converge the rays of light so that they will fall correctly upon the retina. The lens is behind the iris, the margin of the pupil resting lightly upon it. The ciliary muscle is in the interior of the eyeball, around the junction of the choroid and iris, thus lying a little farther forvi^ard than the border of the lens. Its action modifies the shape of the lens, by which arrangement the eye is able to accommodate itself to the different distances of surrounding objects. This is the process of accommodation. To "paralyze the accommodation" is to make the ciliary muscle powerless, so that the eye cannot try to see near objects, as it always does unconsciously, in its normal condition. Atropin will do this. Clinical notes. — Inflammation of the iris, or iritis, may cause adhesions to the lens unless the margin of the pupil be drawn away. This is the reason for APPENDAGES OF THE EYE. 279 the use of atropin, which weakens the circular fibers while it stimulates the straight ones, or, in other words, dilates the pupil. Cataract is a thickening of the lens which makes it opaque and gives it a milky appearance. The remedy is excision or removal of the lens, after which a convex lens of glass in front of the eye gives a good degree of vision. A cataract is in an eye, not over it, and must be taken out, not off. Aqueous humor and chambers of the eye. — The space be- tween the cornea and the lens is partially divided by the iris into two portions — the anterior and posterior chambers of the eye. They con- tain a thin clear fluid, called the aqueous humor, which floats the iris and aids in preserving the shape of the cornea (Fig. 194). Note. — The rays of light which fall upon the retina must first pass through the media (or structures which direct their course) in the following order: the cornea, aqueous humor, crystalline lens, and vitreous body. Should any one of these lose its transparency, vision would be impaired or perhaps lost. The capside of Tenon is a fibrous'capsule outside the eyeball, loosely investing it and its muscles. It is disposed like a serous membrane — having two layers, one of which lines the orbit and the other is loosely applied to the eyeball. Appendages of the Eye. The eyebrows, resting upon the superciliary ridges, or ele- vations caused by the frontal sinuses (p. 17). Superior lacrimal gland Inferior lacrimal gland - — Ducts from superior gland Upper eyelid partly divested of skin Upper punctum Lacrimal sac, near its fundus Common duct, formed ,^^ by junction of upper t" and lower ducts Lower punctum Naso-lacrimal duct Fig. 197. — Lacrimal Apparatus (Morris). The eyelids (or palpebral) , attached to the margin of the orbits and necessary for the protection of the eye. They have five layers, ■ — skin, smooth and thin; fascia — thin and delicate; muscle — the palpebral portion of the orbicular muscle; fibrous — containing a stiff 28o ANATOMY AND PHYSIOLOGY FOR NURSES. plate of connective tissue, the tarsal plate; and mucous — the layer which lines the lid (Conjunctiva). The tarsal glands are in the tarsal plates; their oily secretion prevents the lids from adhering to each other. (They are called Meibomian glands.) The angles formed by the extremities of the eyelids are the medial and the lateral angles (inner and outer canthi). At the medial angle, each lid presents a small elevation, the lacrimal papilla, with a minute opening {punctum) where the tears enter a small canal which leads to the lacrimal sac; from the lacrimal sac they flow through the nasal duct to the nasal cavity. The eyelashes, or cilia, are kept soft and flexible by an oily substance secreted by their own oil glands in the margin of the lid. Fig. 198. — The Muscles of the Eyeball (Holden). A small section of the upper eyelid is shown. Lacrimal gland. — The gland which secretes the tears. It is situated in the lacrimal fossa of the frontal bone, beneath the lateral end of the orbital arch, and has several ducts for the discharge of the tears under the upper eyelid. Conjunctiva. — This is the sensitive mucous membrane which is attached to the margins of the eyelids to line the lids and cover the eye. The tears flow across it and keep it bathed, preventing the injurious effect of dust and other foreign substances. They are then conducted by the little lacrimal canals and nasal duct to the nose. THE VOICE. 281 Clinical Note. — The conjunctiva is supplied with blood-vessels most of which are invisible except when they become congested. In active inflammation or conjunctivitis they are so enlarged as to give the membrane a bright red color. The lids are closed by the action of the orbicularis (the palpebral fibers) (p. 84). They are opened by the levator palpehroe, which lifts the upper lid, uncovering the eye, while the orbicularis relaxes. Motions of the eyeball. — The eyeball is moved by six slender muscles which have their origin at the apex of the orbit, and their insertion upon the sclera at a little distance from the cornea. The superior rectus rolls the ball upward. The inferior rectus rolls the ball downward. The internal rectus rolls the ball inward. The external rectus rolls the ball outward. The superior oblique rolls the ball downward and outward. The inferior oblique rolls the ball upward and outward. Clinical note. — If these muscles are well balanced the pupil is directed straight forward while they are at rest, but if they are of quite unequal strength the eye will be turned habitually in some special direction. This condition is called squint or strabismus, or "cross-eye." It oftenest happens with either the internal or external rectus. THE VOICE. The voice, by which we establish most frequent communication with the outside world, is a special endowment for the expression of ideas awakened by consciousness of the senses. It is therefore not inappropriately considered in this connection. The larynx is the organ of the voice. (The larynx, lips, tongue and teeth are the organs of speech.) A brief description of the larynx is given on page 204. The structures which are specially concerned in the production of the voice, in addition to the cartilages there described, are the vocal bands (also known as vocal cords, and true vocal cords). These are stretched across the larynx from front to back, being attached to the thyroid cartilage anteriorly and the cricoid poster- iorly, and dividing the cavity into upper and lower portions (Fig. 148). 252 ANATOMY AND PHYSIOLOGY FOR NURSES. They are composed of fibrous and muscle tissue covered with mucous membrane. The space between them is the glottis. Small muscles, belonging altogether to the larynx, control the position and tension of the vocal hands by their action on the carti- lages to which the bands are attached, thus producing the differ- ent tones of the voice as the breath passes between them. Tense bands and a narrow glottis are necessary for a high note. Lax bands and a wide glottis are the conditions for a low note. Above them are two membranous folds, one on either side, formerly called /a^^e vocal cords. Note. — It has been generally taught that the voice is caused by vibrations of the vocal bands, but accurate observations by Miss Alice Groff, of Philadelphia, and other investigators, have proved that this is not the case, the voice-sounds being like those of a horn rather than a stringed instrument. With the aid of lips, tongue, and teeth, the voice sounds are so modified that speech becomes possible, and with it the expression of ideas, and communication between individuals. CHAPTER XXI. THE PELVIC ORGANS. In the Male Pelvis. In The Female Pelvts. The rectum. The rectum. The urinary bladder. The urinary bladder. The prostate gland. The uterus. The ovaries, and uterine tubes. The vagina. The Rectum is already described (page 136). The Bladder is the receptacle and reservoir for the urine and is situated, in the pelvis just behind the pubic bones. It is a 7ion- striated muscular sac, lined v^ith mucous membrane which lies in irregular folds when the sac is empty, but becomes smooth when it is filled. It has an incomplete serous covering above and posteriorly. The upper portion of the bladder is the vertex; the lower part is the base. There are three openings in the bladder wall, two for the entrance of urine and one for expelling it. The urine enters through the two ureters (p. 213) or ducts of the kidney, which, having reached the pelvis, proceed below the broad ligaments, to run forward and enter the base of the bladder, there discharging the urine. The opening for the escape of the urine is called the internal orifice. It leads into a canal called the urethra which ends at the external orifice (or meatus) , and through it the urine is expelled from the body. The internal orifice is guarded by circular muscle fibers forming a sphincter — the sphincter ve sic ce (sphincter of the bladder). The openings of the ureters are about one inch from the internal orifice, and the same distance apart, thus these three openings mark the corners of a triangle at the base of the bladder, called the trigone. The urethra is a fibro-muscular canal lined with mucous mem- brane. It begins at the internal orifice of the bladder, ends at the 283 284 ANATOMY AND PHYSIOLOGY FOR NURSES. external orifice or meatus urinarius, and conducts the urine from the body. The female urethra is about one and one-half inches long and I /4 inch wide, but is very distensible. It curves slightly downward toward the external meatus. Clinical note. — The catheter should pass a little upward after entering the urethra (Fig. 199). A urethral caruncle is an exceedingly painful little tumor pro- jecting from the urethral mucous membrane. It is a collection of sensitive blood-vessels and nerves. Bladder Uterus Urethra Anus (rectum distended) Fig. ic -Pelvic Organs, Female Pelvis (Holden), Dotted lines indicate peritoneum. The prostate gland is situated at the base of the male Uadder, immediately in front of the rectum and surrounding the first portion of the urethra. Clinical Note. — When empty, the bladder lies entirely in the pelvis, but if it contains more than eight ounces it begins to rise into the abdomen. It has been known to extend as high as the umbilicus. Surgical note. — The peritoneum covers the vertex and a portion of the posterior surface only; therefore, the bladder may be entered in front through an incision just above the symphysis pubis without wounding the peritoneum. THE PELVIC ORGANS. 285 THE UTERUS AND APPENDAGES. These constitute the internal generative organs. The appendages are the uterine (or Fallopian) tubes and the ovaries (Fig. 200). The Uterus. The uterus, or womb, is situated between the bladder and the upper part of the rectum. It is a hollow organ shaped somewhat POSTERIOR SURFACE OF BODY OF UTERUS TTtero-ovarian ligament OVARY FALLOPIAN TUBE Broad ligamenfc Infundibulum Fimbria Broad 1 gament \aginal walls Fig. 200. — LihKub amj .vi'i'i-ADAGtb, POSTERIOR (Morris). like a pear, about two and one-half or three inches long, and one and one-half inches wide at the larger end, which is called the fundus and is placed uppermost. The uterus is composed of non-striated muscles arranged in three layers, and lined with mucous membrane bearing ciliated epi- thelium. Its walls are about three-eighths of an inch thick. It consists of two portions, the body and the neck or cervix, the body being a little longer of the two. 286 ANATOMY AND PHYSIOLOGY FOR NURSES. The body is flattened, but is more convex at the back than in front, while the cervix is round. The cavity of the uterus corresponds to the general shape of the organ, being triangular in the body and round in the cervix. At the upper angles of the body are the openings which lead into the Fal- lopian tubes. Between the body and the cervix is the internal os, the opening at the lower extremity of the cervix being called the external OS, which is bordered by the anterior and posterior lips. The uterus is cov- ered with peritoneum, ex- cept in front of the cervix. When the uterus re- cieves an impregnated ovum its function is ex- ercised in protecting and nourishing the growing embryo until it becomes a fully developed fetus. The mucous membrane thickens to form a bed for the embryo, and becomes a part of the placenta or "afterbirth." The muscle fibers grow in size and number and the weight increases from the original ounce and a half to one or more pounds. The function of the uterus is concluded with the expulsion of the fetus and placenta. It then contracts rapidly, and the process of involution softens and discharges the remains of tissue which it no longer needed. Clinical note. — Subinvolution is incomplete involution. Position. — The fundus of the uterus is normally inclined somewhat forward,, while the oo externum looks downward and backward. If the fundus turns toa ar forward this is anteversion; if it inclines backward, retroversion. A bend may exist where the neck joins the body. This is Jlexion. When the body is bent forward, this is anteflexion; when backward, retroflexion. The Uterine Tubes (Fallopian Tubes). The uterine tubes (Fallopian tubes) two in number (Fig. 200), extend outward from the upper angles of the uterus; they have a Fig. 201. — The Uterus. Showing cavity and attachment of vagina (Morris) THE OVARIES. 287 fibro-muscular structure and are lined with mucous membrane. Each tube is about four inches long. At the beginning it is only large enough to allow the passage of a small bristle, but it becomes larger toward the end, expanding into a trumpet-shaped extremity called the infundibulum, which is fringed or fimbriated, and which is con- nected with the ovary below by a slender band {or fimbria). The function of the uterine (or Fallopian) tube is to convey the ovum from the ovary to the cavity of the uterus. The Ovaries. The ovaries, two in number, lie on either side of the body of the uterus, each one being connected to it by a short cord called the ovarian ligament. An ovary is about three-quarters of an inch long, a half-inch wide, and shaped like an almond (Figs. 200, 202). The ovaries ore covered with peritoneum (except at the border where vessels enter and leave). Structure of the ovary. — A collection of connective-tissue fibers enclosing many vessels and nerves, and a multitude of little ovisacs (egg sacs) called Graafian follicles. These fol- licles are at first microscopic in size, but when developed they may be seen by the naked eye. Each one contains an ovuniy or egg. Ovulation. — As the follicle with its ovum grows in size it ap- proaches the surface of the ovary, and when it is mature the sac ruptures and the ovum escapes, to be taken by the uterine (or Fal- lopian) tube to the uterus, from which it is discharged through the vagina, usually with a quantity of blood. The function of the ovary {ovulation) begins with puberty, which is the maturing of the pelvic organs and mammary glands. It is usually established at about fourteen years of age (earlier in warm climates, later in cold). From that time the development of at least one ovum occurs in about every twenty-eight days. Menstruation is the periodical discharge of blood from the uterus. The mucous membrane thickens and sheds its superficial Fig. 202. — Ovary with Mature Graafian Follicle about ready to Burst (Ribomont-Dessaignes-Lewis) . 255 ANATOMY AND PHYSIOLOGY FOR NURSES. cells, which are renewed after the flow ceases. This probably accom- panies ovulation. When an impregnated ovum reaches the uterus menstruation is suspended. The cessation of menstruation is the menopause or climacteric. It occurs at about forty-five years of age (and may be as late as fifty or over). It is followed by gradual atrophy of the generative organs. Corpus luteum is the name given to a yellow substance which forms in the ruptured Graafian follicle. It ordinarily shrinks and disappears within a month. The corpus luteum left by an impregnated ovum, however, grows larger and remains present until the end of pregnancy. The Vagina. The Vagina is the muscular canal extending from the uterus to the surface of the body, where it terminates at the vaginal orifice (Figs. 199, 200). It is situated between the base of the bladder in front and the lower portion of the rectum behind, from which organs it is separated by connective tissue septa {vesico-vaginal, and recto-vaginal septa). It curves slightly forward, and is four inches long in its posterior wall and about two and three-quarter inches in the anterior. It has two layers of muscles, strengthened by fibrous tissue and lined by mucous membrane which lies in transverse folds. The columns of the vagina are two median ridges, one on the anterior and one on the posterior wall, extending throughout their length. The vagina is attached to the cervix of the uterus at a little distance above the external os (about half an inch in front and three- quarters of an inch at the back) ; therefore the examining finger may feel the cervix projecting into the canal. This is the infra-vaginal portion of the cervix (Fig. 199, 200). Note. — The urethra lies close to the anterior vaginal wall, feeling like a thick cord in the septum between the two canals (the urethro- vaginal septum). Ligaments of the Uterus. The uterus is sustained in the pelvis by folds of peritoneum which connect it to the pelvic walls and to the bladder and rectum. The principal ones are the broad ligaments. THE EXTERNAL GENERATIVE ORGANS. 289 The hroad ligaments are folds of peritoneum extending laterally from the sides of the uterus, like wings, to the sides of the pelvic cavity. Each fold encloses the uterine tube, ovary, and round liga- ment of its own side. The round ligaments are two muscular and fibrous cords, which extend from the angle of the uterus lateral- ward and forward through the inguinal canal, to be attached to the tissues upon the pubic bone. They aid in preserving the normal position of the uterus with the fundus forward. The External Generative Organs. The pudendum muliebre {vulva). — The name given to the parts situated in front of the pubic arch of the female pelvis. They are: The mens veneris, a cushion of adipose and fibrous tissue in front of the body of the pubic bone. The labia maj era. — Two folds of skin containing adipose and loose connective tissue, continuous in front with the mons, and joined together posteriorly by a fold of skin called the posterior commissure, about an inch in front of the anus. (The depression in front of this commissure is \h.Q fossa navicularis.) The space between the labia majora is the pudendal cleft. The labia minora. — Two folds situated between the labia majora, about one-half as long, and joined anteriorly in the hood of the clitoris. Between them is the space called the vestibule. (They sometimes unite posteriorly in a thin fold called the frenulum.) The clitoris. — A small body, somewhat less than an inch in length, nearly covered by the hood. It contains many vessels and nerves. The extremity is called the glatts of the clitoris; the hood is normally free from the glans and if adhesions form they should be separated, since they are a source of nervous irritation. The vestibule. — A triangular space below the clitoris, and between the labia minora. In the middle of the vestibute is the orifice of the urethra, or external meatus. Below the vestibule is the orifice of the vagina, or vaginal orifice, partially closed by a circular fold of mucous membrane called the hymen. 19 290 ANATOMY AND PHYSIOLOGY FOR NURSES. The ragged edges left by rupture of the hymen are called carunculcs myrti- formes. An imperforate hymen is one which extends entirely across the vaginal orifice, closing it altogether. A little way, laterally, from the middle of the hymen are the openings of the ducts of the glands of Bartholin, one on either side. The peritonetim of the pelvis (Fig. 199) is a portion of the general perito- neum. It lines the pelvic walls, covers the rectum (except the lowest part) and other pelvic organs, and the floor. In the male pelvis it dips between the rectum and bladder forming the recto-vesical pouch. In the female pelvis it forms a utero-vesical pouch in front of the uterus, and a utero-rectal pouch behind it. It also extends over the tubes, ovaries, and round ligaments at the sides, thus making the folds called the broad ligaments, which connect the uterus with the sides of the pelvic cavity. The utero-rectal pouch is the pouch of Douglas (or Douglas's cul- de-sac). It is the lowest part of the peritoneal cavity, extending down an inch or more behind the vagina. Note. — The pelvis of the infant^ is undeveloped and the pelvic organs lie partly in the abdomen. As growth advances they are finally contained in the pelvis, at about the fourteenth year. Perineum . — The name Fig. 203. — Showing Testis and Ductus . , . . _ Deferens Suspended by Spermatic Cord perineum properly Signifies (^°^^^")- the parts bounded by the out- let of the pelvis, but we generally apply it to the portion in front of the rectum. In the female perineum, the part between the lower ends of the vagina and rectum is the perineal body. This is a triangular body composed of connective tissue and adipose, the base of the triangle being covered by skin and measuring about one inch, between the vulva and the anus. It contains several muscles, some of which are connected with the sphincter ani. The perineum is distensible, and stretches to a remarkable extent during labor. From the male perineum a pouch of skin and fascia is suspended, called the scrotum. The fascia contains scattered muscle fibers and is called the dartos. THE TESTES AND SPERMATIC CORD. 29I The scrotum contains the testes which are two in number, the right and the left. They consist essentially of minute tubes in which the seminal fluid is secreted, and which open into larger ones leading to the duct of the testis, or the ductus deferens. The ductus deferens passes upward from the testis through the subcutaneous ring and the inguinal canal, then down into the pelvis and beneath the bladder, where it runs forward to enter the urethra. The spermatic cord. — The testis is suspended in the scrotum by the spermatic cord, which reaches from the abdominal inguinal ring to the bottom of the scrotum, and contains the cremaster muscle. Contraction of the cremaster muscle lifts the testis and draws it upward in the scrotum (Fig. 203). Descent of the Testis. — During fetal life the testis is situated in the abdominal cavity, just below the kidney, but it slowly descends to pass through the inguinal canal, reaching the subcutaneous ring at about the eighth month, and at birth it should be in the scrotum. It may descend more slowly, or may be arrested at any point, but usually finds its place in time. In the scrotum it is surrounded by a double sheath of the peritoneum {tunica vaginalis) which accompanied it, and which became shut oflf from the great peritoneal sac as the subcutaneous ring closed around it. In caring for the male infant it is important to note the condition of the foreskin (or prepuce). This is a fold of skin which covers the glans penis. It should be sufficiently loose to be easily drawn back, or retracted, in order that careful cleansing of fhe parts may prevent accumulations of sebaceous material, or smegma. If this is not done, irritation is caused by retained substances, and also by adhesions which are apt to form. Circumcision is cutting off the foreskin (literally — cutting around). CHAPTER XXII. A BRIEF STUDY OF IMPORTANT REGIONS. THE HEAD AND NECK. The scalp. — Observe the larger arteries — the supraorbital in front, the temporal and posterior auricular at the sides, and occipital at the back — that their general course is upward toward the vertex, and therefore a bandage may be so adjusted around the head as to cut off the blood supply to a great extent. The nerves have similar names and take a similar course. The tense temporal fascia covers the temporal muscle above the zygoma. The Face. The main artery, external maxillary (or facial) , runs obliquely upward toward the side of the nose; its course is tortuous, so that the play of the facial muscles will not interfere with the passage of the blood current. The facial vein is lateral to the artery and not very close to it. Pulsation of the artery may be felt where it crosses the lower border of the mandible, about one inch in front of the angle. The external carotid artery bifurcates in the "f^g. 204.-SUPERPICIAL Vessels^of Head. substance of the parotid gland in front of the ear, forming the temporal and internal maxillary arteries. The pulsation of the temporal is felt as it crosses the zygoma, and both here and 292 THE REGION OF THE NECK. 293 over the external maxillary on the border of the mandible, the character of the heart's action may be appreciated while the patient is under the influence of ether. The motor nerves (facial nerve) come through the parotid gland and radiate on the side of the face, transversely toward the nose, upward toward the eye and forehead, and downward the toward the neck. Sensory nerves, branches of the trifacial {trigeminus) , appear at the three foramina mentioned elsewhere — supraorbital, infraorbital and mental — the three particularly sensitive spots in the front of the face. Practical note. — The tongue muscles and the floor of the mouth {mylo-hyoid muscle) are both connected with the mandible. There- fore, if the jaw be held forward and upward, it will control the posi- tion of the tongue when the muscles are relaxed, as under ether. Hence, the necessity for this precaution to prevent the tongue from falling back into the throat. The Neck. The skin of the back of the neck is very tough and X\yQ fascia very dense. These facts account for the pain of inflammation here, due to the consequent pressure upon the rather numerous nerves, as in carbuncle. The spine of the seventh cervical vertebra is always easily felt. This is the vertebra prominens. The two sterno-cleido-mastoid muscles are conspicuous at the side of the neck, situated near each other at their origin, and diverg- ing above. The thyroid cartilage of the larynx projects in front — - the so-called Adam's apple. The external jugidar vein runs from behind the ear downward, toward the middle of the clavicle, and is covered by the platysma muscle. It is sometimes selected for the operation of "bleeding," or phlebotomy, and the incision to expose the vein is made across the muscle fibers, because by their retraction the vessel is well uncovered (Fig. 71, p. ^T)). The sternomastoid and trapezius are the muscles affected in the commonest form of wry-neck or torticollis, which is usually due to spasm of the muscles. 294 ANATOMY AND PHYSIOLOGY FOR NURSES. The Triangles of the Neck (Fig. 205). These are spaces between certain muscles, as follows: In front of the sterno-mastoid is an anterior triangle divided by the superior belly of the omo-hyoid into two, called the carotid and muscular triangles ; behind the sterno-mastoid is a posterior triangle divided by the inferior belly of the omo-hyoid into two, called the occipital and subclavian triangles. Fig. 205. — Triangles of the Neck. C, Carotid triangle; M, muscular triangle; O, occipital triangle; S, subclavian triangle; D, digastric triangle. In the muscular triangle is the common carotid artery, with the internal jugular vein on the lateral side of it, and the vagus nerve behind them both. In the carotid triangle the same structures are found, but here the artery divides, forming the external and internal carotid arteries at about the level of the upper border of the thyroid cartilage, or Adam's apple. Surgical note. — The carotid is called the triangle of election because, since the vessels are near the surface, the surgeon would naturally choose, or elect, this place for the operation of ligation. In the muscular triangle the vessels THE THORAX. 295 are more deeply placed and covered by the lower portion of the sterno-mastoid. Ligation of the artery would be done here only under necessity, so it is called the triangle of necessity. Occipital triangle. — The occipital artery and nerve run through this triangle. Subclavian triangle. — Most important structures are sub- clavian artery and vein, brachial plexus, and phrenic nerve. Clinical note. — Pressure in this triangle, close to the clavicle, will be felt by the nerves of the brachial plexus. Pressure downward and backward close to the sterno-mastoid will compress the subclavian artery against the first rib. Its pulsation is plainly felt. Submaxillary triangle. — This is a small space marked off from the carotid by the digastric muscle. It contains the submaxillary gland and external maxil- lary artery. The Thorax and Thoracic Viscera. The bony thorax is narrow above and broad below, but the proportions are reversed in the completed human body by the presence of the large muscles which connect the upper extremity to the thorax. Observe the transverse ridge on the sternum, marking the junction of the first and second pieces (the manubrium and the body) , The second rib joins the sternum at this ridge (Fig. 206). The boundaries of the completed thorax are the spinal column at the back, the sternum in front, and the ribs at the sides, with the intercostal muscles in the intercostal spaces and the diaphragm in the floor. It is covered behind by the muscles of the back, while the anterior serratus is on the side and the pectoral muscles are in front. The shoulder-blades are placed behind the thorax. The intercostal arteries and nerves are protected from injury by their position under the borders of the ribs. A stab-wound would have to be directed upward to reach them. All muscles which are attached to the ribs are muscles of res- piration, the intercostals having considerable power, but the dia- phragm being most important. When it contracts it is depressed, increasing the depth of the thoracic cavity, while the other muscles broaden the cavity by lifting the ribs, and thus room is made for expansion of the lungs in inspiration. As the ribs fall and the diaphragm ceases to contract, it rises, returning to its dome shape, 296 ANATOMY AND PHYSIOLOGY FOR NURSES. and thus the air is pressed from the lungs in expiration. These two acts complete a respiration, or an act of breathing, which occurs normally about eighteen times in a minute. If respiration is very difficult other muscles are called into play, as in asthma, when the struggle for breath is so great that "forced inspiration" is necessary. The erector spinge muscles are always on duty, to steady the spine in order that the ribs may have a point of departure. Fig. 206. — Thoracic and Abdominal Viscera, Anterior. The cardiac impulse is felt (sometimes it may be seen) between the fifth and sixth ribs, half way between the sternum and the nipple line. The mammary gland covers the front part of the spaces from the third to the fifth ribs. It lies between layers of the superficial fascia in front of the pectoralis major muscle. The superior opening transmits the trachea, esophagus, and THE ABDOMEN. 297 important vessels and nerves. The floor (or diaphragm) has three openings — one for the passage of the aorta and thoracic duct, one for the inferior vena cava, and one for the esophagus and vagus nerves. The thoracic viscera are the esophagus, trachea and bronchi, lungs, and heart. The esophagus lies close to the spinal column, and the trachea is in front of the esophagus, dividing into the large bronchi, whose branches are the bronchial tubes. The heart and large vessels are in the anterior and middle part of the thoracic cavity (Fig. 206). The heart is wrapped in the pericardium, and each lung is wrapped in a pleural sac which is placed between the lung and the chest wall. An incision through that part of the wall which is bounded by the ribs would pierce the costal pleura and open the pleural cavity. A wound of the lung would injure the pulmonary pleura (Fig. 152). The large nerves in the thoracic cavity are the vagi, lying close to the esophagus, the sympathetic, whose branches form cardiac and pulmonary plexus, and the two phrenic nerves, right and left, running down on either side of the pericardium to the diaphragm. The mediastinum is the space between the lungs. In it all of the thoracic viscera except the lungs are situated. The Abdomen, Abdominal Visceil\, and Peritoneum. The boundaries of the completed abdomen are the spinal column and quadratus lumborum muscles at the back, the hip-hones below, the rectus muscles in front, and the hroadjlat muscles at the side. The diaphragm is its roof. The transversalis fascia lines the cavity, and the peritoneum is within the fascia, held to it by areolar tissue called subperitoneal or subserous tissue. On the anterior surface of the abdomen observe the outline made by the lower ribs, between the thorax and abdomen, the two sides meeting in the subcostal angle just below the sternum. The scrobiculus cordis, or pit of the stomach, is a slight depression at the very point of the subcostal angle, caused by a weak spot in the attachment of the abdominal muscles. If the abdomen is distended, the depression disappears. The linea alba is between the two rectus muscles, and the semilunar lines (or linece semilunares) arc at the sides of the recti. The transverse lines {linea transversce) may be seen when the recti contract. 298 ANATOMY AND PHYSIOLOGY FOR NURSES. The subcutaneous inguinal ring is just above the tubercle of the pubic bone; the abdominal inguinal ring is a half inch above the middle of the inguinal ligament. The conjoined tendon is behind the subcutaneous ring. The abdominal muscles and skin are supplied by the lower inter- costal and first lumbar nerves. The regions of the abdomen are outlined in the following manner: Imagine a horizontal plane passing through the abdomen at the level of the tenth costal cartilage, and another at the level of the anterior superior spine of the ilium. These would divide Tip of ensiform cartilage Costal border Upper horizontal plane Lower horizontal plane A, at level of tubercles of iliac crest Lower horizontal plane B, at evel of anterior Uiac spines Vertical plane A, from middle of Poupart's ligament \'ertical plane B, at outer _ border of rectus (semi- lunar line) Summit of symphysis pubis Fig. 207. — Diagram of the Abdominal Regions (Morris). it into three portions — upper, middle, and lower. Then imagine two vertical planes passing through the middle point of the inguinal ligament on either side, and dividing each of these three portions into three regions, making nine in all. The middle region is called the umbilical, having the umbilicus on the anterior surface. Above that is the epigastric, and below it is the hypogastric. At the sides of the epigastric region are the right and left hypochondriac. At the sides of the umbilical region are the right and left lumbar; and at the sides of the hypogastric region are the right and left iliac, or inguinal. THE PERITONEUM. 299 The abdominal viscera are the stomach, intestines, liver, spleen, pancreas, kidneys, and adrenal bodies. The great vessels are at the back. The sympathetic ganglia are at the sides of the vertebrae, with the celiac and other plexuses situated on the large vessels. The kidneys are behind all of the other viscera, and the ureters run down close to the posterior wall of the abdomen on their way to the bladder. The receptaculum chyli, or beginning of the thoracic duct, is in front of the second lumbar vertebra. The inferior vena cava lies on the right side of the aorta. The principal organ in the epigastric region is the stomach; in the right hypochondriac, the liver; in the left hypochondriac, the spleen. The umbilical region is occupied mostly by small intestines. The right and left kidneys are in the two lumbar regions, with the ascending colon in front of the right, and the descending colon in front of the left kidney. The cecum and appendix are in the right inguinal region; the bladder, in the hypogastric. Each region contains portions of several viscera in addition to those named. Scarcely any organ save the spleen and cecum can be said to belong to but one region. The peritoneum is a closed sac of serous membrane like a water-bag, which is placed between the abdominal wall and abdom- inal viscera. It is practically in front of the viscera, and tucked in around them at the sides. One side of the sac is closely applied to the abdominal wall, and is called the parietal peritoneum, while the other side is fitted to the viscera, and called the visceral peritoneum. Normal peritoneum is perfectly transparent, and the viscera are plainly seen through the visceral layer. The peritoneal cavity con- tains a little serous fluid and nothing else. An incision in the abdominal wall, including the parietal perito- neum, opens the peritoneal cavity. An incision into one of the organs involves the visceral peritoneum, with these exceptions : The posterior surface of the liver. The posterior surface of the ascending colon. The kidneys. The transverse portion of the duodenum. The front of the bladder behind the symphysis. These parts have no serous layer. The lowest portion of the peritoneal cavity is in the pelvis, extending down about three and a half inches in front of the rectum. 300 ANATOMY AND PHYSIOLOGY FOR NURSES. In the female this is called the recto-uterine fossa, or pouch of Douglas In the male it is the recto-vesical fossa. The folds of the peritoneum which are connected with the stomach are called omenta (p. 137). The folds which connect the intestines to the abdominal wall are called mesenteries (p. 137). The folds which connect other organs to the abdominal or pelvic walls are called ligaments. Those for the bladder are called vesical ligaments. The ligaments of the liver are the broad, the round, the coronary, and the two lateral ligaments, which connect it to the diaphragm and the anterior abdominal wall. Sometimes certain little pockets, or fossae, exist in the peritoneum, behind the different portions of intestine. If a loop or knuckle of bowel slips into one of these fossae it may press its way through it and pass behind the peritoneal sac. This is a retro-peritoneal hernia. The Ischio-rectal. Fossa. This is a space between the ischium and the rectum. It is filled with loose connective tissue and adipose, and a few vessels and nerves are therein contained. The skin of the buttock forms the floor of the fossa; the lower part of the rectum is the medial wall; the fascia of the obturator muscle forms the lateral wall. Surgical note. — If infection occur in this region, a very large abscess might result, the pus burrowing freely in the loose tissues. Ischio-rectal abscess is often caused by internal fistula. The Axillary Space. The axilla is the armpit. Its shape is that of a pyramid, with the apex under the shoulder-girdle at the level of the first rib, the base of the pyramid being the floor of the space and composed of the skin and fascia crossing from the thorax to the arm. The walls of the space are formed by muscles — the serratus (principally) on the medial wall, covering the ribs; the long tendon of the biceps in its groove on the lateral wall; the pectoral muscles in the anterior wall, and the subscapularis, latissimus dorsi and teres major in the poste- rior wall. The importance of this space is due to the large vessels and THE FEMORAL TRIGONE. 301 nerves, and the lymph nodes, which are found in it. The vessels are the axillary artery and vein; the ners^es are the brachial plexus and branches. A chain of superjicial lymph nodes lies under the border of the pectoralis major, and a collection of deep ones is grouped around the large vessels; there are also a few near the posterior wall. The Ante-cubital Space. A triangular space in front of the elbow-joint. Boundaries. — The hrachio-radialis, pronator teres, and an imaginary line connecting the two epicondyles. Important structures. — Biceps tendon, brachial artery and veins, median nerve. The artery is between the tendon and the nerve, Axillary artery Ijing on the brachialis mus- cle. Tendon on lateral side of artery — T-endon, A-rtery, N-erve. The artery divides here. Median nerve Brachial artery Lateral cord Fig. 208. — Axillary Space. Axilla laid open by division of anterior wall. Fig. 209. — Ante-cubital Space. Pronator muscle divided to show ulnar artery. Scarpa's Triangle (Trigonum Femorale). This triangle is on the front of the thigh. The base is formed by the inguinal ligament, the lateral border by the upper half of the sartorius, the medial border by the adductor longus, and the apex by the crossing of these two muscles on the medial side of the thigh at about the middle. The most important structures in the triangle are the femoral artery and vein lying side by side, in a line from the middle of the 302 ANATOMY AND PHYSIOLOGY FOR NURSES. base to the apex. The femoral nerve and branches are to the lateral side of the artery. Order of structures as they pass under the inguinal ligament: V-ein, A-rtery, N-erve, the vein being medialward. Hunter's Canal (Adductor Canal). This is a passage from the front of the thigh around the medial side to the posterior, beginning at the apex of Scarpa's triangle and ending in the popliteal space by an opening in the adductor magnus muscle. The femoral artery passes through this canal, with the femoral vein on the medial side of the artery. The long saphenous nerve is sometimes within the canal and sometimes outside it. Femoral artery Femoral nerve Feraoral vein Deep branch Fig. 2IO. — Structures in Scarpa's Triangle; portion of Sartorius removed. Fig. 211. — Popliteal Space (Holden). a, Biceps; h, peroneal nerve; c, plantaris; d, lateral head of gastrocnemius; e, semi- tendinosus; /, semimembranosus; g, gracilis; h, sartorius; i, medial head of gastrocnemius. The Popliteal Space. This is a deep diamond-shaped space behind the knee-joint. Itsjloor is formed, from above downward, by the popliteal surface of INGUINAL AND FEMORAL CANALS. 3O3 the femur, the posterior ligament of the joint, and the popliteus muscle. The boundaries of the upper half of the space are made by the biceps tendon on the lateral side, and the semitendinosus and semimembranosus on the medial side. The boundaries of the lower half are the lateral and ynedial heads of the gastrocnemius. These muscles are all very prominent, making the space deep. The popliteal space owes its importance to the large vessels and nerves which it contains — the popliteal artery, the popliteal vein, and tibial and common peroneal nerves. They are all deeply situated, the artery being the deepest, and are imbedded in adipose tissue and covered with strong fascia, being thus well protected. The Inguinal Rings and Inguinal Canal. There is an opening in the aponeurosis of the external oblique muscle just above the pubic bone, which is called the subcutaneous inguinal ring, being under the skin in the inguinal region. There is an opening in the transversalis fascia, half an inch above the mid-point of the inguinal ligament. This is called the abdominal inguinal ring, opening into the abdominal cavity in the inguinal region. The passage from one ring to the other is the inguinal canal. The internal oblique and transversus muscles form the conjoined tendon immediately behind the subcutaneous ring, and their lower muscle fibers arch over the canal, forming its upper boundary. The Femoral Ring and Femoral Canal. The femoral ring {annulus femorale) is a weak place in the pelvic wall, under the inguinal ligament, where the femoral vessels do not occupy the whole of the space in their sheath. It is on the medial side of the vein, bounded medially by Gimbernat's ligament (which is at the medial extremity of the inguinal ligament) and closed by transversalis fascia only, which at this spot is called the crural septum {septum crurale). The femoral canal extends downward from this ring about three-quarters of an inch in the sheath of the femoral vessels. Hernia. Hernia is defined as a tumor formed by the protrusion of con- tents of a cavity through its wall. This may occur at any weak place 304 ANATOMY AND PHYSIOLOGY FOR NURSES. in the wall, but is most frequent in the region of the inguinal or femoral canals. If any structure slips accidentally through the inguinal canal it forms an inguinal hernia, which most commonly contains a loop of bowel. To replace the bowel or other structure is to reduce the hernia. If the loop cannot be replaced, the hernia is irreducible; and should it become so distended as to interfere with the circulation, it will be strangulated. In direct inguinal hernia the contents of the tumor have passed directly through the conjoined tendon and subcutaneous ring. In indirect inguinal hernia the contents of the tumor have passed through the whole length of the inguinal canal — that is, first the abdominal ring, then the canal, then the subcutaneous ring. Umbilical hernia occurs at the umbilicus; ventral hernia at any other part of the abdominal wall, except one or both rings. Diaphragmatic hernia occurs at a weak or defective point in the diaphragm where an abdominal structure may press its way into the thorax. In femoral hernia the bowel or other organ passes through the femoral ring into the femoral canal and pushes its way through the femoral sheath at the oval fossa, or saphenous opening. The Extremities Compared. Both extremities are servants of the head and trunk. The lower ^ being fashioned for bearing weight and also for walking or running, are organs of locomotion, transporting the body from place to place as necessity or convenience may dictate; while the upper are organs of prehension, since they can reach forth and secure various things which are required for the use of the body. " Flexion of the arm is accomplished by a two-headed muscle — the biceps; flexion of the thigh by a double muscle, the ilio-psoas. Extension of the elbow is accomplished by a three-headed muscle, the triceps; extension of the knee requires a powerful four-headed muscle, the quadriceps. We have learned to apply the terms medial and lateral to the body while in the anatomical position, in which the forearm is supinated; therefore the thumb is said to be on the lateral border of the hand, but the leg cannot be supinated, and the great toe lies on the medial border of the foot. THE EXTREMITIES COMPARED. 305 Observe that the toes of civilized man are freely flexed and ex- tended, but have no other independent motions. They are slightly affected by the action of plantar muscles, but the foot has lost the suppleness it might have had without wearing shoes. The fingers, however, can all be moved sideways; the median line of the hand is a line drawn to the tip of the middle finger, and the digits are said to be abducted or adducted, according as their motion is from or toward this line. The freedom and mobility of the thumb add very greatly to the usefulness of the hand in grasping, carrying, etc. If the finger tips approach each other, the hand falls into a gently curved posi- tion forming a cup, the "cup of Diogenes." If the hand be closed forcibly with the thumb holding the fingers against the palm, it becomes a solid irregular mass, the "fist," and so an ever-available weapon of offense or defense. The shoulder (and whole upper extremity) is pidled forward by the action of the anterior serratus on the shoulder blade, and if this motion is accompanied by a sudden forcible exten- sion of the arm and forearm, that is " striking out from the shoulder.' Ulnar nerve and artery Radial nerve and artery- Branches to hand Fig. 212. — The Forearm, Anterior. Review Notes Concerning the Extremities. The upper extremity — ^From the shoulder down, the anterior surface is xYieflexor surface, and the posterior is the extensor surface of the extremity. Arm. Anterior. — The biceps muscle, with the median nerve and brachial vessels on its medial border. Posterior. — Triceps muscle, with radial nerve in the groove between the two humeral heads. 3o6 ANATOMY AND PHYSIOLOGY FOR NURSES. Suprascapular nerve and artery Forearm. Anterior (Fig. 212). — Superficial jiexor muscles and the round pronator from the internal epicondyle. Deep flexor muscles from shafts of the radius and ulna, and median nerve be- tween the superficial and deep groups. Posterior. — Extensor muscles and the short supinator from the external epicondyle. Lateral or radial side, hrachio- radialis from the external epi- condylar ridge. The hand. Palm. — Observe the thenar eminence of thumb muscles; the hypothenar emi- nence of little-finger muscles, and between them the hollow of the hand, where the long flexor tendons lie. The deep palmar arch is underneath the tendons; the superficial arch lies upon them; the strong palmar fascia holds the tendons in a compart- ment lined with synovial mem- brane. Dorsum. — The extensor tendons are plainly seen. The radial artery may be felt in the "anatomic snuff-box" (between two of the extensors of the thumb as it winds around the first metacarpal bone to reach the deep palm) (Fig. 212). The long flexor and extensor tendons of the fingers may be plainly felt and seen at the wrist. Deep branch Posterior interosseous Fig. 213. — The Arm and Forearm, Posterior. The lower extremity. — The inguinal ligament stretches from the spine of the ilium to the tubercle of the pubes. THE THIGH. THE LEG. 307 The femoral artery, femoral vein, 2ind femoral nerve pass under the ligament, the artery lying on the psoas muscle. Their order from the medial side outward is V-ein, A-rtery, N-erve. From the hip down, the anterior surface is al- ternately j?exor and extensor The posterior surface is exactly the reverse . Flexor for hip. Extensor for knee. Flexor for ankle. Extensor for toes. Extensor for hip. Flexor for knee. Extensor for ankle. Flexor for toes. Thigh. — Anterior and sides of the femur are covered by the quadriceps muscle, which extends the knee. The sartorius muscle crosses from the anterior spine of the ilium to the middle of the medial side of the thigh and down to the tibia, and when it contracts it makes a depression rather than an elevation, because it binds the soft tissue under it. Posterior. — The biceps, semimembranosus and semitendinosus muscles flex the knee; they are hamstring muscles, making the upper boundaries of the popliteal space. The medial side of the thigh is occupied by the adductor muscles, with the obtu- rator nerve and vessels. Leg. Anterior. — The medial surface of the tibia is called sub- cutaneous because it is not covered by muscles; the long saphenous nerve and vein extend the whole length of this surface. The anterior tibial muscles occupy the neighboring surfaces of the tibia and fibula, and their tendons all pass in front of the ankle-joint Xoflex it (dorsal flexion). The lateral side of the leg is occupied by the peroneus longus and brevis whose tendons pass behind the lateral malleolus to extend the foot. They are accompanied by the super- ficial peroneal nerve which supplies them (ant. tibial nerve). The long tendons for the toes are plainly visible on the dorsum or top of the foot, and also those of the short flexor, which has four tendons belonging to the four medial toes. Posterior. — The calf muscles, which lift the heel, completely cover the deep muscles whose tendons pass into the sole of the foot behind the medial malleolus to extend the foot. The deep, or posterior tibial muscles, lie between tibia and fibula bound down by the deep transverse fascia of the leg. 3o8 ANATOMY AND PHYSIOLOGY FOR NURSES. Femoral nerve Femoral "f, / / artery i^K / Femoral Ml/. J vein Anterior tibial nerve Anterior tibial artery Sciatic nerve Peroneal nerve Ant. tib. artery Tibial nerve Post. tib. artery Fig. 214. — The Femoral Artery. Fig. 215. — The Sciatic Nerve VESSELS AND NERVES OF EXTREMITIES. 309 The large nen^es for the lower extremity are the femoral and the sciatic. The femoral comes under the inguinal ligament into Scarpa's triangle and immediately breaks up into branches which supply the structures of the thigh, the long saphenmis nerve being the only branch to go below the knee. It runs all the way to the medial border of the foot. The sciatic comes through the great sciatic notch, descending between the great trochanter and the tuber of the ischium into the back of the thigh, to divide into the tibial and the common peroneal nerves. The tibial nerve continues under the calf muscles and into the plantar region. The peroneal nerve winds around the head of the tibia to the front of the leg, sending the deep peroneal branch to the anterior muscles, and dorsum of the foot. Location of Large Vessels and Nerves in the Extremities. The vessels and nerves are so placed as to be in the least possible danger from pressure or blows. For example, the axillary vessels and brachial plexus are deep in the axilla; the brachial vessels and median and ulnar nerves are on the less exposed side of the arm, and they pass in front of the elbow- joint where the motion of the joint will not interfere with them. So in the forearm, the radial and ulnar arteries and nerves are protected by muscles. At the wrist they also pass into the hand on ih.t flexor surface. The large nerve which passes behind the humerus, the radial nerve, is covered by the thick triceps muscle and winds to the front of the bone to pass the elbow-joint on its way to the forearm. The femoral vessels and nerves are in the fold or flexure of the groin, and they wind around the femur to reach the flexor surface of the knee. Both anterior and posterior tibial arteries are well protected by muscles — the posterior tibial especially — which is under the calf muscles and the transverse fascia of the leg. As it passes the ankle-joint it lies under strong ligaments on the medial side of the joint, where is would not be put on the stretch during any natural motion of the foot nor exposed to blows. Again, the large arteries of the hand are in the palm, while those of the foot are in the sole. * 3io anatomy and physiology for nurses. Points for Compression of Larger Arteries. The temporal, on the zygoma. The external maxillary, on the lower border of the mandible. The subclavian on the first rib, behind the clavicle (downward and backward). The axillary, on the humerus, in the lower part of the axilla. The brachial, on the humerus, under medial border of the biceps muscle. The radial and ulnar, on the bones of same name, in the lower part. The femoral, against the ramus of the pubic bone, just below the inguinal ligament. Note. — The subclavian artery is crossed by the scalenus anticus muscle which divides it into first, second, and third portions. The axillary artery is crossed by the pectoralis minor muscle, which divides it into first, second, and third portions. The common carotid artery is crossed by the omo-hyoid muscle; the portion below the muscle is in the muscular triangle of the neck; the portion above is in the carotid triangle. CHAPTER XXIII. REFERENCE TABLES. u H C/D CO in H .J .s^ss o rt rt c a < Ji u o o u c a w 1- •< •K~;a;0 >J J >, ■tj ,^ w ty] o o E J^ _£J ^ -fcj Q a> 0 !l! 0 0 Z 1) ^ 0 -M *J < ■32:25 z u p'-sip c/5 0 H D n a s xt. cai It. can It. car xt. car u 5 M H.^.S V, S SoioijHa m Q a H Q Z h Oi 0 . <: z < E 0 0 1; Di 0 < J ^ < < z H oi Q^ h 0 X -< H 312 3^3 Circle around hip. ' Crucial anastomosis.' ^ §.2 s a tag a^ O o o o e: o o o o e >■- a c — j; ■* a (LI (U cS ^ G 5 ;:: i-- -M s-^ o o u ;j3 c O O o ^ o s c S ^ ^p- l.^tJU'-' uUp^^-iw^ 0-C ^1^S Oo3C- •5 ?. W = H o o -] J n S b w H w u «■ U1 o < a. W OS w 0. H w < hJP . J ^ fe " Q O • X 3 PS U o U W '^ »- ■< a! 5 -' cu fc ^ w u < < ^ ^ kJ J J Q BiJ:: ^-^ y « "^ 5 uS~^E E E '^ o -1 cnt/3(fiQ O Q , S 5 w ^ Vh 01 C ^ ft C J o I o « 3 J ^ i- u o « 2 < y « J O z z "^ E5 3 O ^ S H>" -d V 3 o a; c.> 3-0 UJJJ tifl 5 O O >xl ■' ^ ■" -£ H • ■ ■ I) rt . . ^ - . b.^ 5 a . is-r c ^ oi c "O -S § o ^ .H ,\ °T ^ .2, I- o e 0_rt *;; '^ 3 ca 3 > .S3 o o v.- 1- "> ^ o <: o IJ UI «= OS 3 rt O ^ == i! fl i ^W 314 Connection between A. CAROTIS EXTERNA AND A. SLBCLAVIA. 3^S w H O H O iz; I— I Q Pi O U O < H I— I Pi H H Pi < O s: o o o u u V 0) « < s J a! o U5 p O ft w > Q 5 0! tn w r; < D ^ k D a, 0< N U U ai '£<< D u u 2 U3 [/) - D D %%% < < < < W 2 < 2 h J Q W " 8£

- w S S £ g w K S U D S ^ £ J ^ w « in < < H h X "5 C/3 m in ■< •< u u «! 316 Circle around hip-joint. "Crucial anastomosis." <««<«««< « S a. w J- t S- ■ Sj3 >■ 0!J3 Z P o Z H o 0 "1 c > -^ VENA CAVA INFERIOR. V. IHACA COMMUNIS V. ILIACA DEXTRA (2 inches). sinistra COMMUNIS (2 inches). .a^ .a-s ? ° tuOl-. 3 J3 u ► t' c ci ^ t^jq > p- h • T3 C3 h fc^ y^ h w V" Ph K a K t; C> Bc; e<5^ k) :S 5 -c E i ^ c "J S Si ^ oj c ,„ r iJ ^ E cr r< ^ s y w i4 K a H 'I pd 4J K W ^ hJ u iTD 1) ■" *; c « r « 2 E a: K-a 33 j: 3 > aMO ^"^^ 5 5 o ^ > > hJ eJ ?i8 g fH W « M O O ^ •5 *a > - ►J 5 •ooi « rt rt S « 'ii n i. 'in 5 2 fer c.= e ri u 5 > ;► ^ e- ti. = > 55 o UU < < .n 7. Z S 0 w a 3 -> E ■ .2 " ••5 > 1 > > 0 0 >2 o o 2 nl w S5 n u b-t< I- w Q ^ (u c ^v K X _ •«■« S.3 'S•■^ .« 'J •S-y V V •S E •«■« ~ o a " II u ow. The longer bone in the medial side of the forearm. Umbilicus. From a Latin word, umbo, the name of the elevated or depressed point in the middle of an oval shield. 330 GLOSSARY Ungual. Belonging to the nail or unguis. Urea. A substance representing the chief nitrogenous product of tissue waste. Ureter, The duct of the kidney, which conveys urine to the bladder. Urethra. The passage through which urine is expelled from the bladder. Uvula. From uva, a grape, or cluster of grapes (which hangs down from the branch where it grows. Vaginal. Like a sheath. Vallate. Situated in a cavity which is surrounded by a ridge. Valvulae conniventes. Little valve-like folds. Seen on the mucous coat of the small intestine. Vascular. Having many blood-vessels. Vaso-motor. Literally, vessel-mover. Applied to the nerves which dilate blood- vessels or contract them. Velum. Veil. Velum palati, the veil, or soft hanging portion of the palate or roof of the mouth. Vena cava. A large hollow vein. Venesection. Cutting a vein. "Bleeding" or phlebotomy. Ventral. Toward the front of the body, as the ventral cavity. Ventricle. Literally, a little belly. Fom the Latin venter. A cavity in the brain, or in the heart. Vermiform. Worm-shaped. Vertebra. From a Latin word meaning to turn. Certain movements of the vertebrae turn the body from side to side. Vertex. The crown of the head. Vestibule. A cavity of the internal ear through which stimulating impulses are transmitted to auditory and vestibular nerves. Villus. A hair (pi. villi) . The villi of the intestine are hair-like in shape and belong to the mucous coat. Viscus. An internal organ of the head or trunk. (Plural, viscera.) Vitreous. Glassy. The vitreous humor resembles glass in appearance. The vitreous layers of the skull are brittle like glass. Volar. Belonging to the palm or vola. Xyphoid. Sword-shaped. The third piece of the sternum is the xyphoid or ensiform appendix. Zygoma. A yoke. The arch of bone at the side of the face formed by zygomatic processes of frontal and maxillary bones. INDEX. Abdomen, abdominal organs, 297 regions of, 2y8 Abdominal brain (Solar Plexus) 264 Abdominal wall, 88 Absorption, 14S, 151 Accommodation, 278 Acromegaly, 224 Adipose tissue, 3 Adrenal bodies, 222 Air, or atmosphere, 143, 202 Alimentary canal, 120 Ameboid movements, 153 Anatomic position and use of terms, i .\nimal heat, 226 Antibrachium or forearm, 52 Antrum of Highmore, 2 1 Aorta, 167 169 Apnea, 209 Aponeurosis, description of, 79 Apophysis, 12 Apparatus, 6 Appendbc ceci (vermiformis) , 134 Aqueduct of Sylvius (of cerebrum), 253 Aqueous humor, 279 Arachnoid of brain, 255 of cord, 232 Arbor vitae, 252, (illus. 251) Arches of foot, 68 of hand, 172, 173 of vertebrae, 35 Areolar tissue, 3 Arm, bone of, 52 muscles of, 96 Arterioles and arttvies, 156 Articular surface, 10 Articulations or joints, 14 of cranium, 20 of face, 24 of lower extremity, 63 of pelvis, 46 of spinal column, 38 of thorax, 43 of upper extremity, 56 Ascites, 6 Asphyxia, 209 Assimilation, 151 Atlas, 36 Auditory tube (Eustachian), 125, 273 Auricle of heart, 158 Axillary space, 300 Axis (artery), 171 (bone), 36 Axon, 229 Bifurcation of aorta, 178 Bile. 139, 147 Bladder, 283 Bioplasm, 2 Blood, 152 Bone, articular, 14 markings, 10 repair of, 72 tissue, 8 Bones, completion of, 70 in infancy, 71 of abdomen, 44 of cranium, 16 of ear, 275 of face, 20 of lower extremity, 59 of neck, 31 of pelvis, 44 of spinal column, 35 of thorax, 40 of upper extremity, 50 shapes of, 11 Brain, 249 fissures of, 251, 252 hemispheres of, 2 50 lobes of, 251 Breast (mammarj' gland), 219 muscles of, 96 Bronchi, 204 Bronchial muscle, 205 Bursa (pleiiral, bursa), 67, 77 Callus, 72 Canal, adductor, 302 anal, 136 auditory, 273 carotid, 19 central (of cord), 232 femoral, 303 Haversian, 9 Hunter's (or adductor), 302 inguinal, 303 internal auditory, 19, 273 medullary, 9 nasal (or lacrimal), 30 neural, 39 nutrient, 70 semicircular, 274 spinal (neural or dorsal), 49 Cancellous or spongy tissue, 9 Capillaries, 156 Capitulum (capitellum) , 52 Capsule, Bowman's, 212 internal, 251 of joints, 14 of lens, 278 of Tenon, 279 Cardiac impulse, 196 331 2>2,- INDEX Cartilage, 4 articular, 14 costal, 41 fibro-, semilunar, 65 sterno-clavic, 56 triangular, 57 Cauda equina, 235 Cavities of body, 48 dorsal or neural, 49 ventral or visceral, 49 Cecum, 134 Cell, description, 2 Cell body (nerve), 229 Centers, brain (illus.), 260, 261 nerve, 231 of ossification, 11 Central fissure, 251 Cerebellum, 252 Cerebral localization, 260 Cerebro-spinal fluid, 233 system, 230 Cerebrum, 250 Cervical nerves, 236 Cervix uteri, 285, 286 Chambers of eye, 279 Choroid coat of eye, 276 Chyle, 147 Chyme, 144 Cilia, of air passages, 205 of eyelids, 217 Ciliary muscle, 278 Circulation, (def.), 151 collateral, 176, 181 fetal, 189 portal, 189 pulmonary, 167 systemic, 167, 168 Circumcision, 291 Clitoris, 289 Coagulation of blood, 155 Coccyx, 38 Cochlea, 274 Colon, 135 Colostrum, 220 Compact bone tissue, 9 Compression of arteries, 310 Condyle (def.), 10 Condyles, occipital, 17 of femur, 60 of mandible, 23 of tibia, 61 Conjoined tendon, 90, 298 ■ Conjunctiva, 276 Connective tissue, 75 Corium of skin (cutis vera), 214 Cornea, 276 Corpus callosum, 251 Corpuscle of blood, 152, 153 of kidney (Malpighian), 212 of skin (touch), 214 of spleen, 221 Corpus leutum, 288 Cortex of brain, 249 Cranium, 16, 25 Crest (def.), 10 Crura of cerebrum, 253, 267 of diaphragm, 91 Crystalline lens, 278 Cutis vera (skin), 214 Dartos, 290 Defecation, 148 Deglutition, 144 Dendrite, 229 Dentition (eruption of teeth), 32 Diameters of pelvis, 48 Diapedesis, 154 Diaphragm, 91, 113 of pelvis, 103 Diaphysis, 12 Diastole of heart, 161 Digestion, 144, 151 Digestive fluids, 121 Dorsal cavity, 48 Duct, common bile, 139 cystic, 139 hepatic, 139 lacrimal, 279, 280 pancreatic, 13S right lymphatic, 197 Stenson's, 124 thoracic, 197 Wharton's, 124 Ductus arteriosus, igo communis choledochus (or common bile duct), 139 deferens (vas def.), 291 Duodenum, 132 Dura mater, brain, 255 cord, 233 Dyspnea, 209 Ear, 273 Edema, 196 Elastic tissue, 3 Elimination, organs of, 226 Endocardium, 160 Endosteum, 10 Endothelium, 6, 156 Enzyme (def.), 121 Epicardium, 164 Epicondyle of femur, 60 of humerus, 52 Epidermis, 214 Epigottis, 204 Epiphysis, 12 Epithelium, 4 ciliated, 5, 205 respiratory, 208 Erythrocyte (red cell), 152 Esophagus, 126 Ethmoid notch, 17 Eustachian tube (auditory), 125, 273 Excreting organs, 6, 226 Excretion, 226 Expiration, act of, 208 INDEX 333 External genital organs, 289 Extremities compared, 304 Eye, 276 Eyebrows, 279 Eyelids, 279 Face, bones of, 20, 27 muscles of, 84 vessels and nerves, 292 Fallopian or uterine tubes, 286 Fabc cerebri, 255 Fascia of body, deep, 75 iliac, 103 lata, 76 lumbar, 77 palmar, 102 pelvic, 103 plantar, in superficial, 77 temporal, 84-292 transversalis, 93 transverse of leg, 307 Feces, 147 Fibrin, 155 Fibrous tissue, 3 Fissure of Rolando (central), 251 of Sylvius, 251 transverse of liver (porta), 139 Floor of mouth, 121 of pelvis, 103 of thorax, 91 Fontanelles, 28 Foods, 141 Foramen (def.), 10 infraorbital, 21 intervertebral, 40 jugular, 26 magnum, 17 mental, 23 Munro, 253 obturator or thyroid, 46 optic, 30 ovale, 190 sciatic, 47 supraorbital, 17 transverse, 36 vertebral, 36 Forearm, bones of, 52 muscles of, 98 Foreskin (prepuce), 291 Fossa (def.), 10 glenoid, 51 interconriyloid, 60 ischio-rectal, 300 lacrimal, 17 ' navicularis, 289 ovale (heart), 158 (thigh), 77 subscapular, 51 Fossae of skull, 28 Frenum lingua: (bridle of tongue), 122 Gall bladder, 139 Ganglia, basal, 251 semilunar, 264 sympathetic (autonomic), 263-5 Ganglion, 231 Gasserian, 257 root of spinal nerve, 233 Gastric juice, 128 Glabella, 17 Gland (definition), 5 of Bartholin, 290 ceruminous, 273 ductless, 220 intestinal, 131, 133, 134 Peyer's, 134 lacrimal, 280 lymph, 196 mammary, 219 Meibomian (tarsal), 280 prostate, 284 salivary, 124 sebaceous, 216 sudoriferous, 216 tissue, 5 Glossary, 321 Glottis, 282 Graafian follicle, 287 Greenstick fracture, 72 Glycogen, 149 Hair, 217 Hamstring tendons, 108 Heart, 157 diastole of, 161 function of chambers, 161 muscle, 158 sounds, 163 systole of, 161 tendinous cords of, 160 Hearing, 273-5 Heat (body), 226 Hemoglobin, 153 Hemorrhoidal arteries, 180 Hernia, 304 retro-peritoneal, 300 Hip-bone (os coxrc), 44 Housemaid's knee, 67, 77 Hvmen, 289 Hypophysis cerebri, 224 Hyperpnea, 209 Ileum, 133 Ilium (os), 44 Inguinal rings, 298, 303 Inorganic substances of bone, 8 Insertion of muscles, 79 Inspiration, act of, 20S Instep (arches of foot), 68 Intercellular substance, 3 Intermuscular septa, 76 Interosseous sjjaces, 53, 55, 61, 63 Internal secretions, 220 Intestine, 130 large, 134 334 INDEX Intestine, small, 131 Iris, 277 Joint or articulation, 14 immovable, 14 motions of, 15 movable, 14 yielding, 15 Jugular notch, 40 veins, 184 Kidneys, 211 Labia majora, 289 minora, 289 Labyrinth (ear), 274 Lacteals, 150 Lanugo, 217 Large vessels and nerves, 309 Larynx, 204 Leucocytes, 153 Leukemia, 221 Ligament, annular, loi, in of Bigelow (Y), ileo-femoral, 65 broad, 289-90 crucial, 66 deltoid, 67 dorsal of wrist, 102 elastic, 38, 68 Gimbernat's, 303 inguinal (Poupart), 47, 76, 90, 298 of liver, 140 orbicular, 58 of patella, 105 sacro-sciatic, 46 structure of, 14 suspensory of lens, 278 transverse of ankle, 67 Ligaments of uterus, 288 Ligamentum nuchae, 39 teres, 63, 64 Linea alba, 90 aspera, 60 semilunaris, 89 Lineffi transversae, 91 Liver, 139 Lumbo-sacral cord, 242 Lungs, 205 Lymph, 150, 195 capillaries, 194 corpuscles, 196 nodes (lymphatic glands), 196 origin of, 195 spaces, 194 vessels, 194 Lymphatic ducts, 197 system, 194 Lymphocytes, 196 Malleolus, lateral, 61 medial, 61 Manubrium, 40 Marrow, 9 Mastication, 145 Meatus, external auditory, 273 of nose, 202 of urethra, 283 Median line, 2 Mediastinum, 297 MeduUa (of brain), 252 of bone (marrow), 11 fatty sheath of nerve fiber, 229 Medullary canal, 11 Medullated fibers, 229, 230 Membranes of body, 5 of brain, 254 of spinal cord, 232 Menopause (climacteric), 288 Menstruation, 287 Mesentery, 137, 300 Metabolism, 6 Metacarpus, 54 Metatarsus, 63 Metastasis, 201 Micturition, 214 Milk, 220 Mons veneris, 289 Motions of eyeball, 281 Mouth (oral cavity), 121 Movable joint, description of, 14 Mucous membrane, 5 Muscles, action of, 113, 116 of abdomen, 89 of back, 80 of breast, 96 of face, 84 of head and neck, 82 of lower extremity, 102 of mastication, 84 of pelvis, 102, 104 of upper extremity, 94 ribbon, 86 structure of, 79, 112 tension of, 113 Muscle band of His, 160 tissue, 78 Myocardium, 157, Nails, 216 Nares, 204 Nasopharynx, 125 Necrosis (of bone), 10 Nerve centers, 231 cylinder, 229 supply to joints, 69 to muscle groups, 118, 259 tissue, 230 Nerves, cervical, 236 coccygeal, 245 cranial, 255 lumbar, 242 motor, 231 sacral, 243 sensory, 231 spinal, 233, 235 thoracic, 242 INDEX 335 Neural cavity. 49 Neurilemma, 230 Neuron, 229 Nose, 202 Notes, blood, 153 blood-vessels, 1 56, 157, 160, 173, 175, 176, 181, 182, 190 bones, 20, 50, 52, 55, 61, 63, 66, 67, 72 digestive organs, 123, 133, 137, 139, 146 lymph system, 197, 200 muscles, 77, 78, 82, 91, 96, 97, 98, 100, 102, 106, 108, 109,110,111 nerve system, 229, 233, 264, 274 pelvic organs, 288, 290 respiratory organs, 206 skin, 216, 217 special senses, 279, 282 Notes clinical, blood-vessels, 164, 173, 175 bones, 22, 24, 30, :i2, 34, 39, 51 digestive organs, 123, 129, 134, i35> 136, 144, 146, 147 kidney, 213 (two) lymph system, 196 (two), 201 muscles, 82, 88, 115, 116 nerve system, 253, 255, 258 pelvic organs, 284, 286, regional, 295 respiratory, 207 skin, 215, 218 special senses, 278, 281 (two) spleen, 221 Notes obstetric, 28, 46 Notes practical and special, blood-vessels, 166, 178 bones, 53, 61, 68, 73 muscles, 76, 84, 90, 92, 100, 103, 104, no, 114 nerve system, 230, 241, 245, 251 regional, 293, 310 Notes surgical, bones, 24, 59, 67, 70, 72, 73 muscles, 77 abscess, 93, 220 Nucleus and nucleolus, 2 caudate, 251 lentiform, 251 Nutrient artery, 10 Obturator membrane, 46 Olfactory region, 271 Omentum, 137, 300 Opsonic index, 155 Optic commissure (chiasm), 256 disc, 278 nerve, 256, 277 thalamus, 251 Orbit, 29 Organ and organic substance, 6, 8 Origin of blood cells, 73 of muscles, 79 Os coxa; or hip bone, 44 Osmosis, 193 Osseous tissue, 3, 8 Ossicles, 275 Ossification, 11 Ostium venosum, 160 Ovary and ovum, 287 Ovulation, 287 Palate, hard, 22 soft, 121 Palatine arches, 123 Palm, or metacarpus, 54 Pancreas, 137, 221 Papilla, hair, 217 of skin, 214 tongue, 122 Parathyroids, 223 Patella, 63 Peduncles of brain, 253 Pelvic floor, 103 girdle, 47 organs, 283 Pelvis, 47 Pepsin, 128, 146 Peptones, 146 Pericardium, 164 Perichondrium, 4 Perineal arteries, 180 Perineum, 290 Perineurium, 231 Periosteum, 10 Peristalsis, 137 Peritoneum, 299 Perivascular spaces, 194 Perspiration, 216 Peyer's patches, 134 Phagocytes, 154 Phalanges, 55 Pharynx, 124, 203 Physiology of blood, 192 of bone, 73 of brain, 260 of cord, 245 of digestive organs, 144 of kidneys, 213 of lymph system, 201 of muscle, 112 of nerves, 231, 248 of nerve system, 267 of ovary, 287 of respiratory organs, 207 of skin, 217 of sympathetic nerves, 264 of uterus, 286 Pia mater of brain, 254 of cord, 232 Pillars of fauces, 123 Pituitary body (hypophysis), 224 Placenta, 192 Plasma, 154 Pleura, 206 Plexus, cardiac, 264 celiac, 264 cervical 236 Z2,^ INDEX Plexus, brachial, 237 hypogastric, 264 lumbar, 242 pulmonary, 264 sacral, 243 Pons varolii, 253 Popliteal plane, 60 space, 106, 107 Porta of liver, 139 Portal vein, 189 Pouch of Douglas, 290 Process (def.), 10 acromion, 51 alveolar, 22 articular, 35 coracoid, 51 coronoid, 53 frontal, 21 mastoid, 18 odontoid, 36 olecranon, 53 palate, 21 pterygoid, 20 spinous, 35 styloid, 18, 26 of fibula, 61 of radius, 53 of ulna, 53 transverse, 35 unciform, 54 zygomatic, 18, 22 Promontory, 38 Pronation, 58, 59 Protoplasm, 2 Ptyalin, 145 Pubic arch, 45 symphysis, 46 Pudendum, 289 Pulse, 162 Pylorus, 128 Pyramids and tracts (medulla), 252 decussation of, 252 Rachitis, 72 Receptaculum chyli, 197 Rectum, 136 Reference tables, 311 Reflex action, 246 Reflex, abdominal, 247 patellar, 247 plantar, 247 skin, 247 Rennin, 128, 146 Respiration, 202 air in, 207 rate of, 209 Resume, alimentary tract, 137 course of blood in heart, 165 lower extremity, 68 upper extremity, 55 Retina, 256, 277 Ribs, 40 Sacrum, 37 Saddle joint, 58 Saliva, I24 Sartorius or "tailor muscle," 105 Scalp, 292 Scarpa's triangle, 301 Schneiderian membrane, 30 Sciatic nerves, 243 Sciatic notches, 45 Sclera, 276 Scrobiculus cordis, 297 Scrotum, 290 Secreting organs, 6, 225 Secretions, 6, 225 Semilunar notch, 53 Sensory impressions, 232 Septum, 30 Serous membrane, 5 Sheath of rectus, 91 Shoulder girdle, 50 Sigmoid groove, 18, 255 Sight, 276 Sinus, ethmoid, 19 frontal, 17 of kidney, 211 maxillary, 21 sphenoid, 20 transverse (lateral), 184 Sinusitis, 30 Skeleton, 12, 13 Skin, 214 Skull, as a whole, 25 at birth, 28 at different ages, 70, 71 bones of, 16 completion of, 71 points of interest, 25 Smell, 271 Special senses, 270 Speech, 282 Spermatic cord, 291 Sphincter, anal, 136 cardiac, 127 ileo-colic, 134 pupillary, 277 pyloric, 128 vesical, 283 Spina bifida, 72 Spinal canal, 39 column, 39 cord, 231 Spine (def.), 10 intercondyloid, 60 of ilium, 45 of ischium, 45 of pubes, 45 of scapula, 51 Splanchnic nerves, 264 Spleen, lien, 221 Spongy or cancellous tissue, 9 Sternum, 43 Stomach (gaster), 127 Straits of pelvis, 48 INDEX 337 Supination, 58, 59 Summary, cerebro-spinal nerves, 259 functions of cranial nerves, 261 of skin, 218 of spinal cord, 248 nerve system, 267 respiration, 209 return of lymph, 201 return of venous blood, 189 spinal nerves, 245, 248 Superciliary arch, 17 Supraorbital margin, 16 notch (or foramen), 17 Surgical neck of humerus, 52 Sutures, 20 Sympathetic (autonomic) nerves, 262 Symphysis pubis, 45 sacro-iliac, 46 Synovial membrane, 5 System (def.), 6 Tactile cells, 271 Tables of skull, 25 /» Tarsus, 61 Taste, 272 Teeth, 31 eruption of, dentition, 32 Temperature of body, 227 Tendinous cords, 160 Tendon of Achilles or tendo calcaneus, 107, III Tendons 79 Tentorium cerebelli, 255 Terminal filament, 231, 235 Testes, 291 Thenar eminences, 102 Thorax, bones of, 40, 43 Thymus body, 223 Thyroid (thyreoid) body, 222 Tissues, 3 Tissue spaces, 194 Tongue, 121 Tonsil, 123 lingual, 123 palatine, 123 phar}'ngeal, 125 Touch, 271 Trachea, 204 Triangles of neck, 294 Trigone, biadrier, 283 femoral, 301 Trochanters, 59 Trochlea, 52 Trophic centers, 247 Trunk, 13, 40 Tuber ischii (tuberosity), 45 Tubercles of humerus, 52 Tuberosity of calcaneus, 62 Tympanum, 273 Umbilical artery, 181 cord, 192 vein, 189, 192 Urea, 149, 213 Ureter, 212, 283 Urethra, 284 Urethral caruncle, 283 Urination (micturition), 214 Urine, 213 Uterine tubes (Fallopian), 286 Uterus, 285 Uvula, 121 Vagina, 288 Vaginal synovial membranes, 100 Valve, Eustachian, of heart, 158, 190 Valve, Houston's, 136 ileo-cecal, 134 Valves of heart, 160 of veins, 157 Vasa vasorum, 157 Vaso motor nerves, 266 Veins, structure, 157 Velum palati, 121 Vena cava inferior, 187 superior, 186 Ventral cavity, 48 Ventricles of brain, 253 of heart, 159 Vermis (of cerebellum), 252 Vertebrae, 35, 36, 37 Vertebral aponeurosis, So Vertex of skull, 2 5 Vestibule (ear), 274 (pudendum), 289 Villi, 131, 148 Vitreous body, 278 layer (cranial bones), 25 Viscera, abdominal, 299 thoracic, 297 Visceral cavity, 49 "Vital knot" (noeud vital), 261 Vocal bands and voice, 281 Vola, palm, 68 Wharton's jelly, 192 Xyphoid appendix, 40 Y-ligament, 65 Zygoma, 18 rate oi, . Resume, aliiriv course of blc^ lower extremity, upper extremity, ^^ Retina, 256, 277 Ribs, 40 DUE DATE apT I 1 1993 40V 1 1 ^^ OJ 201-6503 Printed in USA COLUMBIA UNIVERSITY LIBRARIES Ihsl.stx) QM 28 B88 1912 C.I Text- hnnl nf Jir-^f|-||-|^Y and Bund}/ Text-book of anatomy and physiology for nurses. QM28 B88 1912