 |
Inhibitory impulse, 305.
Insomnia, 329.
Inspiratory force, 70.
Intercellular material, production of, 13, 18.
Internal ear, 360.
Intestinal juice, 152, 157.
Iris, 375.
Iron, 135.
Irritability, 6, 243, 304.
Isolation, 406.
Jejunum, 151.
Joints, 230-232, 242.
Kidneys, 201. Blood supply to, 204. Cortex of, 204. Inflammation of, 211. Pelvis of, 202. Structure, 202. Symptoms of diseased, 211. Work of, 205.
Knee jerk reflex, 322.
Lachrymal glands, 383.
Lacteals, work of, 174.
Lacunae, 220.
Laminae, 220.
Large intestine, 157. Division of, 158. Work of, 159.
Larynx, 80, 353-357. To show plan of, 368.
Lever, 251. Application to the body, 251. Classes of, in body, 251. Producing motion, diagram of, 252. To show action of, 252.
Leucocytes, 27.
Levulose, 120, 150.
Life, maintenance of, 20.
Light, 370, 371. Simple properties, illustrated, 389.
Light waves, diagram illustrating passage of, 370.
Lime water, to prepare, 101.
Liver, 52, 152-155, 178. Protection of, 210. Work of, 206.
Lockjaw, 276.
Longsightedness, 384.
Lung capacity, diagram illustrating, 89.
Lung diseases, out-door cure for, 98.
Lungs, 77-103. Capacity of, 88. Changes air undergoes in, 101. Excretory work of, 207. Interchange of gases in, 88. Observations of, 100. Supply of blood to, 82. To estimate capacity of, 103. Weakest portions of, 92.
Lymph, 65-75. Composition, 66. Movements at the cells, 71. Origin of, 65. Physical properties, 66. Where it enters the blood, 70.
Lymph movements, causes of, 69.
Lymph spaces, 66.
Lymph vessels, 66. Variable pressure on the walls of, 70.
Magnesium, 135.
Malarial fever, 401.
Malleus, 359.
Malpighian capsules, 203.
Maltose, 120.
Massage, 259.
Mastication, Muscles of, 144. Slow, 145. Thorough, 160. To show importance of, 171.
Matrix, 267.
Measles, 94. Care after, 211.
Median fissures, 289.
Medulla oblongata, 291.
Medullary sheath, 284.
Membrana tympani, 358.
Membrane, Active, 173. Basement, 197. Basilar, 363.
Membranous capsule, 377.
Membranous labyrinth, 361.
Mesentery, 152.
Metacarpals, 227.
Midbrain, 289.
Middle ear, 359. Purposes of, 360.
Milk sugar, 120.
Mineral salts, 30. Uses, 121.
Moderate drinkers, 333.
Molars, 143.
Molecules, defined, 105.
Mon-axonic neuron, diagram of, 282.
Mono-saccharides, 120.
Mosquitoes, 401-403. Remedies against, 402.
Mouth, 141.
Movable joints, Kinds of, 231. Structure of, 230.
Mucous membrane, 80, 264.
Mucus, 139.
Muscle organ, 245.
Muscles, 243-263. Alimentary, 189. Important, 254-256. Intercostal, 87. Of mastication, 144. Properties of, 243.
Muscular force, plan of using, 249.
Muscular sensations, 344.
Muscular stimulus, 248.
Muscular stimulus and contraction, to illustrate, 261.
Muscular tissue, kinds of, 243, 244.
Nails, 267. Care of, 276.
Nasal duct, 383.
Neck exercise, 328.
Nerve cells, 281, 282.
Nerve fibers, 282, 293, 294.
Nerve path, diagram of, 286.
Nerve pathways, to demonstrate, 322.
Nerves, 281.
Nerve skeleton, 280. Diagram of, 281.
Nerve stimuli, 306.
Nerve trunks, 281.
Nervous activity, wasteful forms of, 325.
Nervous control of, Body temperature, 320. Circulation of blood, 318. Respiration, 320.
Nervous energy, economizing of, 315.
Nervous impulse, 248, 305.
Nervousness, 326.
Nervous system, 279-337. Diagram of, 287. Dissection of, 302. Divisions of, 287. Hygiene of, 324-337. Nature of, 287. Physiology of, 304-323. Work of, 280.
Neural arch, 224.
Neurilemma, 284.
Neurons, 281, 282. Arrangement of, 284, 293. Diagram, illustrating, 285. Properties of, 304.
Nicotine, Effects of, 333. Relation of age to effects, 333.
Nitrogen, 134.
Non-striated cells, to show, 261.
Non-striated muscles, Purpose of, 246. Structure of, 246. Work of, 247.
Normal temperature, 269.
Nosebleed, 58.
Nucleoplasm, 14.
Nutrients (see Foods), Composition of, 135. Relative quantity needed, 123. Routes taken by, 175. Tests for, 136.
Nutriment, storage of, 177-180.
Olfactory stimulus, 347.
Opsonins, 34.
Optic thalami, 289.
Orbit, 373.
Organ, defined, 7.
Organism, defined, 19.
Organization, defined, 10.
Osmosis, 72. At the cells, 72. To illustrate, 75.
Ossein, 218.
Overstudy, 211.
Oxidation, defined, 106.
Oxygen, 104-117. Combined, 105, 113. Free, 105, 113. How it unites, 105. Main uses of, 108. Movement a necessity, 106, 108, 115. Movement in body, 106, 108, 115. Nature of, 104. Passage of, from cells, 110. Passage of, through blood, 109. Passage of, toward cells, 109. Preparation of, 113. Pressure, 109. Properties of, 113. Purpose of, in the body, 106.
Oxyhemoglobin, 27.
Pacinian corpuscles, 342, 343. To demonstrate, 348.
Pancreas, 155.
Pancreatic juice, 155.
Papillae, 266.
Patent medicines, 166.
Pelvic girdle, 226.
Pepsin, 149.
Peptones, 149, 176.
Pericardium, 41.
Perilymph, 361.
Perimysium, 245.
Periosteum, 218.
Peritoneum, 180.
Perspiration, 207.
Pharynx, 145. Openings into, 145, 146.
Phosphorus, 135.
Phrenic nerve, 302.
Physiological salt solution, 38.
Physiology, defined, 2.
Pia, 299.
Pigment granules, 266.
Pinna, 358.
Pitch, detection of, 365.
Pivot joint, 232.
Plasma, 25, 29.
Pleura, 84.
Plexus, 281.
Pneumonia, 94.
Pons, 290.
Pons Varolii, 290.
Portal vein, 154.
Primitive sheath, 284.
Proteids, 161. Circulating, 179. Kinds of, 118. Purposes of, 119. Supplied by, 125. Tests for, 135, 136. Tissue, 179.
Proteoses, 149, 176.
Protoplasm, 14.
Protozoa, 394.
Ptyalin, 145.
Public sanitation, 396.
Pulp cavity, 143.
Pupil, 375.
Pure food law, 128.
Pus, 28, 29.
Pyloric orifice, 147.
Pyramids, 202.
Quarantine, 406.
Radius, 227.
Reaction time, to determine, 323.
Reading glasses, 386.
Receptacle of the chyle, 68, 170.
Rectum, 158.
Red corpuscles, 25. Disappearance of, 27. Function of, 26. Origin of, 27. To examine, 38. To prepare models of, 39.
Red marrow, 219.
Reenforcement of sound, 352, 356, 368.
Reflection, kinds of, 371.
Reflex action, 308. Diagram illustrating, 310. In circulation of blood, 311. In digestion, 310. Purposes of, 311.
Reflex action and mind, 308.
Reflex action pathway, 309.
Refraction, 371.
Rennin, 149.
Respiration, 76-103. Artificial, 97. Internal, 89. Lung, 76.
Retina, 376.
Retinitis, 333.
Rheumatism, Effects on the heart, 56. Sequel to other diseases, 407.
Right lymphatic duct, 67.
Rods and cones, 377.
Rods of Corti, 364.
Sacrum, 224.
Saliva, 145. Composition of, 145. Uses of, 145. To show action on starch, 171.
Salivary glands, 144. Kinds of, 144. Reflex action of, 323.
Sanitation, defined, 2.
Sarcolemma, 244.
Sarcoplasm, 244.
Scala media, 363.
Scala tympani, 363.
Scala vestibula, 363.
Scarlet fever, care after, 211.
Sciatic nerve, 302.
Sclerotic coat, 374.
Secondary reflex action, 314.
Secretions, 197. Kinds of, 200.
Secretory process, nature of, 199.
Seeing, problem of, 372.
Self-control, 326, 334. Habit of, 325.
Semicircular canals, 362.
Semilunar valves, 44.
Sensations, 338-349. Classes of, 339. Production of, 338, 349. Purposes of, 340. Special, 340.
Sensations (continued). Steps in production of, 341.
Sensation stimuli, 339.
Sense organs, simple forms of, 341, 342
Serous coat, 140, 148.
Serous membrane, 264.
Serum albumin, 30.
Serum globulin, 30.
Shortsightedness, 384.
Shoulder girdle, 226.
Sight, organs of, 373.
Sigmoid flexure, 158.
Simple life, 410.
Skeleton, 216-243. How deformed, 234. Hygiene of, 233. Plan of, 221. Purpose of, 221.
Skin, 264-277. As regulator of temperature, 270. Experiments on, 349. Functions of, 267, 268. Observations on skin, 278.
Skin wounds, treatment of, 275.
Skull, 225.
Sleep, 329.
Small intestine, 151. Mucous membrane of, 151. Muscular coat of, 152. As organ of absorption, 173. Parts of, 151. Serous coat of, 152. Work of, 157.
Smell, Sensation of, 346. Value of, 347.
Sneezing, 81.
Sodium, 135.
Sodium carbonate, 155.
Sodium chloride, 122.
Soft palate, 141.
Solution, 131. Kinds of, 73.
Solution theory, 156.
Solvents, 131.
Sound, To illustrate origin of, 367. To show transmission of, 367.
Sound waves, As stimuli, 331. Nature of, 350. Reenforcement of, 352. To show effects of, 368. Value of, 353.
Speech, production of, 357.
Spinal column, 223-225. Hygiene of, 233.
Spinal cord, 280. Protection of, 299.
Spinal nerves, 295. Double nature of, 295.
Spitting, 403.
Spleen, 208.
Sprains, 239, 240.
Stapes, 359.
Starch, 162. Action of, on saliva, 171. Animal, 120. Tests for, 136.
Steapsin, 155, 156.
Stegomyia, 403.
Sternum, 225.
Stomach, 147. Mucous membrane of, 147. Muscular action of, 150. Muscular coat, 148.
Serous coat, 148.
Storage of nutriment, 177-179.
"Strenuous life," 410.
Striated fibers, to show, 261.
Striated muscles, to show, 261.
Stroma, 25.
Sugars, kinds, 120.
Sulphur, 135.
Supra-renal bodies, 208.
Suspensory ligament, 377.
Sutures, 230.
Sympathetic ganglia and nerves, 298. Work of, 316.
Synovial fluid, 231.
Synovial membrane, 231.
System, defined, 20.
Systole, 46.
Taste buds, 345.
Tea, Effects on digestion, 167. Effects on heart, 56.
Tears, 383.
Teeth, 142. Care of 163. Kinds of, 143.
Temperature, Body, 207. Corpuscles, 271, 345. Sensation, 343.
Tendon of Achilles, 256.
Tendons, 246.
Tests for foods, 136, 137.
Tetanus, 262, 275.
Thoracic cavity, 7, 85, 100, 102.
Thoracic duct, 67, 170.
Thorax, 85. Bones of, 225.
Tissue enzymes, 182.
Tissues, 4. Complex nature of, 13. Defined, 20. General purposes of, 5. Kinds of, 5, 6. Observations on, 12. Properties of, 6.
Tobacco, effect on heart, 56.
"Tobacco heart," 56, 333.
Tongue, 143.
Tonic bath, 273.
Touch, 343.
Touch corpuscles, 342.
Toxins, 394.
Trachea, 80.
Trypsin, 155, 156.
Tuberculosis, 90, 92, 94, 98. How communicated, 403. Outdoor treatment, 98. To prevent, 404.
Tympanum, 359.
Typhoid fever, 404, 407.
Ulna, 227.
Urea, 110, 205, 207, 210.
Ureters, 170.
Uriniferous tubules, 203.
Vaccination, 406.
Valves, Advantages of, in veins, 49, 63. Mitral, 43. Position of, in veins, 63. Purposes of, 49, 63. Tricuspid, 43.
Veins, 47. Functions of, 51. Renal, 202.
Ventilation, 94. Rules for, 95, 96.
Ventricles, 42. To illustrate action of, 62.
Vermiform appendix, 158.
Vertebrae, 223-225. Interlocking of, 225. Joining of, 224. Kinds, 223.
Vestibule, 361.
Villi, 152. Parts of, 173, 174.
Visual perceptions, 382.
Visual sensations, 382.
Vitreous humor, 378.
Vocal cords, 355.
Voice, 353-357. How produced, 356. Pitch and intensity, 356.
Voluntary action, 311, 312.
Voluntary action pathways, 312.
Vomiting, 151, 152.
Waste material, passage from body, 210.
Wastes, 30.
Water, Importance of, 123. Supply of, 398. Value of, 210.
Water-vapor, 208.
White corpuscles, 27, 28. Functions of, 29. To examine, 39.
Work, Hygienic value of, 328, 409.
Worry, 211.
Yellow fever, 403.
Yellow marrow, 218.
Yellow spot, 377.
FOOTNOTES
1 The body is affected by what it does (exercise, work, sleep), by things taken into it (food, air, drugs), and by things outside of it (the house in which one lives, climate, etc.). That phase of hygiene which has for its object the making of the surroundings of the body healthful is known as sanitation.
2 When classified according to their essential structure, the tissues fall into four main groups: epithelial and glandular tissue, muscular tissue, nervous tissue, and connective tissue. According to this system the osseous, cartilaginous, and adipose tissues are classed as varieties of connective tissue. See page 18.
3 The properties of substances are the qualities or characteristics (color, weight, etc.) by means of which they are recognized.
4 Certain of these cells also form deposits of fat, giving rise to the adipose, or fatty, tissue.
5 Any organized structure, such as the body, whose parts are pervaded by a common life, is known as an organism. The term "organism" is frequently applied to the body.
6 In birds, reptiles, amphibians, and fishes the red corpuscles have nuclei (Fig. 9).
7 The micron is the unit of microscopical measurements. It is equal to 1/1000 of a millimeter and is indicated by the symbol μ.
8 The peculiar shape of the red corpuscle has no doubt some relation to its work. Its circular form is of advantage in getting through the small blood vessels, while its extreme thinness brings all of its contents very near the surface—a condition which aids the hemoglobin in taking up oxygen. If the corpuscles were spherical in shape, some of the hemoglobin could not, on account of the distance from the surface, so readily unite with the oxygen.
9 The coloring matter of the bile consists of compounds formed by the breaking down of the hemoglobin; the spleen contains many large cells that seem to have the power first of "engulfing" and later of decomposing red corpuscles. A further evidence that the spleen aids in the removal of worn-out corpuscles is found in the fact that during diseases that cause a destruction of the red corpuscles, such as the different forms of malaria, the spleen becomes enlarged.
10 An infected part of the body, such as a boil or abscess, should never be bruised or squeezed until the time of opening. Pressure tends to break down the wall of white corpuscles and to spread the infection. Pus from a sore contains germs and should not, on this account, come in contact with any part of the skin. (See treatment of skin wounds, Chapter XVI.)
11 Coagulation is not confined to the blood. The white of an egg coagulates when heated and when acted upon by certain chemicals, and the clabbering of milk also is a coagulation.
12 If the blood be stirred or "whipped" while it is coagulating, the clot may be broken up and the fibrin separated as fast as it forms. The blood which then remains consists of serum and corpuscles and will not coagulate. It is known as "defibrinated" blood.
13 Certain substances, called opsonins, have recently been shown to exist in the plasma, that aid the white corpuscles in their work of destroying germs. The opsonins appear to act in such a manner as to weaken the germs and make them more susceptible to the attacks of the white corpuscles.
14 Some of the changes in the blood are very closely related to our everyday habits and inclinations. For example, a lack of nourishment in the blood causes hunger and this leads to the taking of food. If the fluids of the body become too dense, a feeling of thirst is aroused which prompts one to drink water.
15 Metchnikoff, The New Hygiene.
16 A physiological salt solution is prepared by dissolving .6 of a gram of common salt in 100 cc. of distilled water or pure cistern water. This solution, having the same density as the plasma of the blood, does not act injuriously upon the corpuscles.
17 The term "circulation" literally means moving in a circle. While the blood does not move through the body in a circle, the term is justified by the fact that the blood flows out continually from a single point, the heart, and to this point is continually returning.
18 The heart at first glance seems to bear little resemblance to the pumps in common use. When it is remembered, however, that any contrivance which moves a fluid by varying the size of a cavity is a pump, it is seen that not only the heart, but the chest in breathing and also the mouth in sucking a liquid through a tube, are pumps in principle. The ordinary syringe bulb illustrates the class of pumps to which the heart belongs. (See Practical Work.)
19 The contraction of the heart is known as the systole and its relaxation as the diastole. The systole plus the diastole forms the so-called "cardiac cycle" (Fig. 18). This consists of (1) the contraction of the auricles, (2) the contraction of the ventricles, and (3) the period of rest. The heart systole includes the contraction of both the auricles and the ventricles.
20 Martin, The Human Body.
21 The pressure maintained by the left ventricle has been estimated to be nearly three and one half pounds to the square inch—a pressure sufficient to sustain a column of water eight feet high. The pressure maintained by the right ventricle is about one third as great. In maintaining this pressure the heart does a work equal to about one two-hundredth of a horse power.
22 The location of the heart in the thoracic cavity causes movements of the chest walls to draw blood into the right auricle for the same reason that they "draw" air into the lungs.
23 Active exercise through short intervals, followed by periods of rest, such as the exercise furnished by climbing stairs, or by short runs, is considered the best means of strengthening the heart.
24 Nosebleed in connection with any kind of severe sickness should receive prompt attention, since a considerable loss of blood when the body is already weak may seriously delay recovery.
25 Newton, Practical Hygiene.
26 On account of its position in the body, the lymph is not easily collected for examination. Still, nearly every one will recall some experience that has enabled him to see lymph. The liquid in a water blister is lymph, and so also is the liquid which oozes from the skin when it is scraped or slightly scratched. Swelling in any part of the body is due to the accumulation of lymph at that place.
27 In certain small animals of the lowest types a single liquid, serving as a medium of exchange between the cells and the body surface, supplies all the needs of the organism. In larger animals, however, where materials have to be moved from one part of the cell group to another, a portion of the nutrient fluid is used for purposes of transportation. This is confined in channels where it is set in motion by suitable organs. The portion which remains outside of the channels then transfers material between the cells, on the one hand, and the moving liquid, on the other.
28 Surgeons in opening veins near the thoracic cavity have to be on their guard to prevent air from being sucked into them, thereby causing death.
29 Oxygen forms about 21 per cent of the atmosphere, nitrogen about 78 per cent, carbon dioxide about .03 per cent, and the recently discovered element argon about 1 per cent. The oxygen is in a free, or uncombined, condition—the form in which it can be used in the body.
30 The peculiar work devolving upon the organs of respiration necessitates a special plan of construction—one adapted to the properties of the atmosphere. Being concerned in the movement of air, a gaseous substance, they will naturally have a structure different from the organs of circulation which move a liquid (the blood). All the organs of the body are adapted by their structure to the work which they perform.
31 In ordinary inspirations the force that causes the air to move through the passages is scarcely an ounce to the square inch, while in forced inspirations it does not exceed half a pound. On this account the closing of any of the air passages by pressure, or by the presence of foreign substances, would keep the air from reaching some part of the lungs.
32 Coughing, which is a forceful expulsion of air, has for its purpose the ejection of foreign substances from the throat and lungs. Sneezing, on the other hand, has for its purpose the cleansing of the nostrils. In coughing, the air is expelled through the mouth, while in sneezing it is expelled through the nostrils.
33 The amount of dust suspended in what we ordinarily think of as pure air is shown when a beam of direct sunlight enters an otherwise darkened room.
34 Some children find it difficult to breathe through the nostrils on account of growths (called adenoids) in the upper pharynx. Such children should have medical attention. The removal of these growths not only improves the method of breathing, but in many instances causes a marked improvement in the general health and personal appearance.
35 The weakest portions of the lungs appear to be the tiny lobes at the top. As they occupy the part of the thorax most difficult to expand, air penetrates them much less freely than it does the lobes below. In most cases of consumption (some authorities give as high as eighty per cent), the upper lobes are the first to be affected. Flat chests and round shoulders, by increasing this natural difficulty in breathing, have long been recognized as causes which predispose to consumption.
36 The following exercise, from Dudley A. Sargent's Health, Strength, and Power, will be found most beneficial: "Stand with the feet together, face downward, arms extended downward, and backs of the hands touching. Raise the hands, arms, and elbows, keeping the backs of the hands together until they pass the chest and face. Then continue the movement upward, until the hands separate above the head with the face turned upward, when they should be brought downward and outward in a large circle to the starting point. Begin to inhale as the arms are raised and take in as much air as possible by the time the hands are above the head, then allow the breath to go out slowly as the arms descend."
37 Colds may frequently be broken up at their beginning by taking a prolonged hot bath and going to bed. After getting a start, however, they run a course of a few days, a week, or longer, depending upon the natural vigor of the individual and the care which he gives his body during the time. In throwing off a cold, the following suggestions will be found helpful:
1. Dress warmly (without overdoing it) and avoid getting chilled. 2. Diminish the usual amount of work and increase the period for sleep. If very weak, stay in bed. Save the energy for throwing off the cold. 3. If able to be about, spend considerable time in light exercise out of doors, but avoid getting chilled. 4. Keep the bowels active, taking a cathartic if necessary. 5. To relieve pain in the chest, apply a mustard plaster or a flannel cloth moistened with some irritating substance, such as turpentine or a mixture of equal parts of kerosene and lard. Keep up a mild irritation until the pain is relieved, but avoid blistering.
38 Not only do the lungs remove oxygen from the air and add carbon dioxide to it, but they separate from the body considerable moisture and, according to some authorities, a small amount of an impurity referred to as "animal matter." Odors also arise from the skin, teeth, and clothing which, if not dangerous to the health, are offensive to the nostrils. If on going into a room such odors are detected, the ventilation is not sufficient. This is said to be a reliable test.
39 E.A. Schaffer, "Artificial Respiration in its Physiologic Aspects," The Journal of the American Medical Association, September, 1908.
40 Testing the prone-posture method by suitable apparatus, Professor Schaffer has found it capable of introducing more air per minute into the lungs than any of the other methods of artificial respiration, and more even than is introduced by ordinary breathing.
41 Osier, The Principles and Practice of Medicine.
42 Huber, Consumption and Civilization.
43 To prepare limewater some small lumps of fresh lime (either slacked or unslacked) are added to a large bottle of water and thoroughly shaken. This is put aside until the lime all settles to the bottom and the water above is perfectly clear. This is now ready for use and may be poured off as needed. When the supply is exhausted add more water and shake again.
44 An element is a single kind of matter. Those substances are classed as elements which cannot be separated into different kinds of matter. Two or more elements combined in definite proportions by weight form a compound. The elements are few in number, only about eighty being known. Compounds, on the other hand, are exceedingly numerous.
45 The term energy, as used here, has the same general meaning as the word power. See Chapter XII.
46 The oxygen pressure of the atmosphere is that portion of the total atmospheric pressure which is due to the weight of the oxygen. Since oxygen comprises about one fifth of the atmosphere, the pressure which it exerts is about one fifth of the total atmospheric pressure, or, at the sea level, about three pounds to the square inch (15 x 1/5 = 3). This is the oxygen pressure of the atmosphere. The low oxygen pressure in the tissues is due to its scarcity, and this scarcity is due to its entering into combination at the cells.
47 See footnote on oxygen pressure, page 109.
48 The impression prevails to some extent that carbon dioxide, on account of its weight, settles out of the atmosphere, collecting in old wells and at the floor in crowded rooms. Any such settling of the carbon dioxide is prevented by the rapid motion of its molecules. This motion not only prevents a separation of carbon dioxide and air after they are mixed, but causes them to mix rapidly when they are separated, if they still have surface contact. The carbon dioxide found in old wells is formed there by decaying vegetable or animal matter. In rooms it is no more abundant at the floor than in other parts.
49 On account of the formation of carbon dioxide in places containing decaying material, the descent into an old well or other opening into the earth is often a hazardous undertaking. Before making such a descent the air should always be tested by lowering a lighted lantern or candle. Artificial respiration is the only means of restoring one who has been overcome by this gas (page 97).
50 While awaiting oxidation at the cells, the carbohydrates and fats are stored up by the body, the carbohydrates as glycogen and the fats as some form of fat. In this sense they are sometimes looked upon as serving to build up certain of the tissues.
51 The following table shows the main elements in the body and their relation to the different nutrients:
[Nutrient Table]
52 The recently advanced theory that the molecules of the mineral salts, by dissolving in water, separate into smaller divisions, part of which are charged with positive electricity and part with negative electricity, has suggested several possible uses for sodium chloride and other mineral salts in the body. The sodium chloride in the tissues is in such concentration as to be practically all separated into its sodium and chlorine particles, or ions. It has recently been shown that the sodium ions are necessary for the contraction of the muscles, including the muscles of the heart. There is also reason for believing that the different ions may enter into temporary combination with food particles, and in this way assist in the processes of nutrition.
53 Chittenden, The Nutrition of Man.
54 Compiled from different sources, but mainly from Atwater's Foods: Nutritive Value and Cost, published by the U.S. Department of Agriculture.
55 The calorie is the adopted heat unit. As used in this table it may be defined as the quantity of heat required to raise 1 kilogram (2.2 pounds) of water, 1 degree centigrade. The calories also show the relative amount of energy supplied by the different foods.
56 While alcohol cannot be classed as a food, it is believed by some authorities to contain food value and, in the hands of the physician, to be a substance capable of rendering an actual service in the treatment of certain diseases. It might, for example, be used where one's power of digestion is greatly impaired, since alcohol requires no digestion. But upon this point there is a decided difference of opinion. Certain it is that no one should attempt to use alcohol as food or medicine except under the advice and direction of his physician.
57 A layer of connective tissue between the mucous membrane and the muscular coat is usually referred to as the submucous coat. This contains numerous blood vessels and nerves and binds the muscular coat to the mucous membrane.
58 The saliva may continue to act for a considerable time after the food enters the stomach. "Careful examination of the contents of the fundus (large end of the stomach) by Cannon and Day has shown that no inconsiderable amount of salivary digestion occurs in the stomach."—FISCHER, The Physiology of Alimentation.
59 Perhaps the simplest method of inducing vomiting is that of thrusting a finger down the throat. To make this method effective the finger should be held in the throat until the vomiting begins. An emetic, such as a glass of lukewarm salt water containing a teaspoonful of mustard, should also be taken, and, in the case of having swallowed poison, the vomiting should be repeated several times. It may even be advantageous to drink water and then vomit it up in order to wash out the stomach.
60 Hammerstein, Text-book of Physiological Chemistry.
61 Amylopsin is absent from the pancreatic juice of infants, a condition which shows that milk and not starch is their natural food.
62 The fact that butter is more easily digested than other fatty substances is probably due to its consisting largely of a kind of fat which, on splitting, forms a fatty acid (butyric) which is soluble in water.
63 Fischer, Physiology of Alimentation.
64 Beginning the meal with a little soup, as is frequently done, may be of slight advantage in stimulating the digestive glands. To serve this purpose, however, and not interfere with the meal proper, it should contain little greasy or starchy material and should be taken in small amount.
65 Dr. William Beaumont, an American surgeon of the last century, made a series of observations upon a human stomach (that of Alexis St. Martin) having an artificial opening, the result of a gunshot wound. Much of our knowledge of the digestion of different foods was obtained through these observations. In spite of the protests of his physician, St. Martin would occasionally indulge in strong drink and always with the same result—the lining of the stomach became much inflamed and very sensitive, and the natural processes of digestion were temporarily suspended.
66 The lacteals (from the Latin lacteus, milky) are so called on account of their appearance, which is white, or milk-like, due to the fat droplets.
67 Peptones and proteoses, when injected directly into the blood, are found to act as poisons.
68 The soluble double sugars (maltose, milk sugar, and cane sugar) are reduced to the simple sugars (dextrose and levulose). Furthermore the action on the proteids does not stop with the production of peptones and proteoses, but these in turn are still further reduced.
69 Energy, which is defined as the ability to do work, or to cause motion, exists in two general types, or forms, known as kinetic energy and as potential energy. Kinetic energy is energy at work, or energy in the act of producing motion; while potential energy is reserve, or stored, energy. All moving bodies have kinetic energy, and all stationary bodies which have within them the capability of causing motion possess potential energy. A bent bow, a piece of stretched rubber, a suspended weight, the water above a mill dam, all have the capability of causing motion and all have potential energy. Examples of kinetic energy are found in the movements of machinery, in steam and electricity, in winds, and in currents of water. Kinetic is the active, and potential the inactive, form of energy.
70 As the atoms of hydrogen and oxygen that make up the molecules of water separate, they unite with atoms of their own kind—the hydrogen with hydrogen and the oxygen with oxygen atoms. Since these combinations are weaker than those of the water molecules, energy is required to bring about the change. But when hydrogen burns in the oxygen, the change is from a weaker to a stronger combination. The stored-up energy is then given up or becomes active.
71 In the evaporation of water, the energy of the sun is stored with reference to the force of gravity. In evaporating, water rises as a gas, or vapor, above the earth's surface, but on condensing into a liquid, it falls as rain. It then finds its way through streams back to the ocean. All water above the sea level is in such a position that gravity can act on it to cause motion, and it possesses, on this account, potential or stored-up energy. It is because of this energy that rapids and waterfalls are such important sources of power.
72 Energy, like matter, can neither be created nor destroyed. It can, however, be transferred from one body to another and transformed from one form to another form. Whenever work is done, energy is transferred from the body doing the work, to the body upon which the work is done. During this process there may, or may not, be a transformation of energy. In turning a grindstone, kinetic energy is passed to the stone and used without transformation, but in winding a clock, the kinetic energy from the hand is transformed into potential energy in the clock spring. Then as the clock runs down this is retransformed into kinetic energy, causing the movements of the wheels.
Not only is kinetic transformed into potential energy and vice versa, but the different forms of kinetic energy (heat, light, electricity, sound, and mechanical motion) are readily transformed the one into the other. With suitable devices, mechanical motion can be changed into heat, sound, or electricity; heat into motion and light; and electricity into all the other forms of energy. These transformations are readily explained by the fact that the different varieties of kinetic energy are but different forms of motion (Fig. 84).
73 The simplest arrangement of the parts of a gland is that where they are spread over a plain surface. This arrangement is found in serous membranes, such as the pleura and peritoneum. These membranes, however, are not called glands, but secreting surfaces.
74 In the oxidations that occur in the body it is not supposed that the nutrients are immediately converted to carbon dioxide, water, and urea. On the other hand, it is held that their reduction takes place gradually, as the reduction of sugar by fermentation, and that the wastes leaving the body are but the "end products" and show only the final results.
75 Alcohol, if used in considerable quantity, leads to cirrhosis of the liver and Bright's disease of the kidneys, both very dangerous diseases. Dr. William Osler in his treatise, The Practice of Medicine, states that alcohol is the chief cause of cirrhosis of the liver. Dr. T.N. Bogart, specialist in kidney diseases, asserts that one third of all the cases of Bright's disease coming under his observation are caused by alcohol.
76 Hall, The Purin Bodies.
77 Review "Main Physiological Problems," page 21.
78 In the production of motion in the body, as well as in the production of any kind of purposeful motion outside of the body, three conditions must be fulfilled. There is required, in the first place, a mechanical device or machine which is so constructed as to produce a certain kind of motion. In the second place, energy is needed to operate this device. And, finally, there must be some controlling force, by means of which the motion is made to accomplish definite results. The driving of a horse hitched to a wagon will illustrate these conditions. The wagon is the mechanical device, the horse furnishes the energy, and the driver supplies the controlling force. In this, as in most cases, the machinery, the source of energy, and the controlling force are disconnected except when at work; but in the body all three occur together in the same structure.
79 The dependence of the outer layers of bone cells upon the periosteum for nourishment causes a destruction of this membrane to affect seriously the bone beneath, producing in many instances a decay of the bone substance.
80 It has been claimed that the introduction of vertical writing has reduced the number of cases of spinal curvature originating in the schoolroom, and statistics appear to prove the claim. It is shown, on the other hand, that unnatural positions also are unnecessary in the slanting system of writing, and that in either system the pupil who is permitted to do so is liable to assume an improper position.
81 Lovett, Lateral Curvature of the Spine and Round Shoulders.
82 See "Hygiene of Muscles," Chapter XV.
83 On account of the striations of these cells the muscles which they form are called striated muscles.
84 The striated muscle cells, having many nuclei, are said to be multi-nucleated.
85 Every movement in the body has its opposing movement. This is necessary both on account of the work to be accomplished and for preserving the natural form of the body.
86 The distance from the fulcrum to the power is called the power-arm and the distance from the fulcrum to the weight is called the weight-arm (Fig. 115).
87 The foot in lifting the body on tiptoe appears at first thought to be a lever of the second class, the body being the weight and the toe serving as the fulcrum. However, if the distance which the body is raised is compared with the distance which the muscle shortens, it is found that the supposed weight has moved farther than the power (Fig. 118). It will also be noted that the muscle which furnishes the power is attached at its upper end to the "weight." These facts show clearly that we are not here dealing with a lever of the second class. The foot in this instance acts as a lever of the first class with the fulcrum at the ankle joint and the toe pressing against the earth, which is the actual weight. Since the earth is immovable, the body is lifted or pushed upward, somewhat as a fulcrum support is made to move when it is too weak to hold up the weight that is being lifted. In other words, we have the same lever action in the foot in lifting the body as we have when one lies face downward, and, bending the knee, lifts some object on the toes.
88 Walking is considered one of the very best forms of counter-active exercise for the brain worker (page 328).
89 The epidermis does not afford complete protection against chemicals, many of them being able to destroy it quickly. The rule of washing the skin immediately after contact with strong chemical agents should always be followed.
90 "Rough calculations have placed the number of sweat glands on the entire body at about 2,000,000." Rettger, Studies in Advanced Physiology.
91 Heat also leaves the body by the lungs, partly by the respired air and partly through the evaporation of moisture from the lung surfaces. Respiration in some animals, as the dog, is the chief means of cooling the body.
92 "The story is told of some woodsmen who were overtaken by a severe snowstorm and had to spend the night away from camp; they had a bottle of whisky, and, chilled to the bone, some imbibed freely while others refused to drink. Those who drank soon felt comfortable and went to sleep in their improvised shelter; those who did not drink felt very uncomfortable throughout the night and could get no sleep, but in the morning they were alive and able to struggle back to camp, while their companions who had used alcohol were frozen to death.... This, if true, was of course an extreme case; but it accords with the universal experience of arctic travelers and of lumbermen and hunters in the northern woods, that the use of alcohol during exposure to cold, although contributing greatly to one's comfort for the time being, is generally followed by undesirable or dangerous results."—HOUGH AND SEDGWICK: The Elements of Hygiene and Sanitation.
93 Foods that are difficult to digest, or which cause disturbances of the digestive organs (a coated tongue being one indication), have a bad effect upon the skin. It is in this way that the use of tea and coffee by some people induces a sallow or "muddy" condition of the complexion.
94 A most valuable antiseptic ointment is prepared by the druggist from the following formula:
Lanolin, 25 grams. Ichthyol, 6 grams. Yellow vaseline, 20 grams.
This is applied as a thin layer on the surface, except in the case of boils or abscesses. In treating these a heavy layer is spread over the affected part and then covered with absorbent cotton or a thin piece of clean cotton cloth.
95 In a larger sense adjustment includes all those activities by means of which the body is brought into proper relations with its environment, including the changes which the body makes in its surroundings to adapt them to its purposes.
96 Almost to the present time, physiologists have described the nervous system as being made up of two kinds of structural elements which were called nerve cells and nerve fibers. The nerve cells were supposed to form the ganglia and the fibers to form the nerves. Recent investigators, however, employing new methods of microscopic study, have established the fact that the so-called nerve cell and nerve fiber are but two divisions of the same thing and that the nervous system is made up of, not two, but one kind of structural element. The term "neuron" is used to denote this structural element, or complete nerve cell.
97 Many of the axons in the brain and spinal cord have no primitive sheath. Axons without the medullary sheath are found in the sympathetic nerves. These are known as non-medullated axons and they have a gray instead of a white color.
98 The difference in weight between the brain of man and that of woman is due mainly to the fact that man's body is, as a rule, considerably larger than that of woman's.
99 The nervous tissues present, at different places, two colors—one white, and the other a light gray. Great significance was formerly attached to these colors, because it was supposed that they represented two essentially different kinds of nervous matter. It is now known that the protoplasm in all parts of the neuron proper—cell-body, axis cylinder, and dendrites—has a grayish color, while the coverings of most of the fibers are white. Hence gray matter in any part of the nervous system indicates the presence of cell-bodies, and white matter the presence of nerve fibers.
100 In very early life the spinal cord entirely fills the spinal cavity, but as the body develops the cord grows less rapidly than the spinal column, and, as a consequence, separates at the lower end from the inclosing bony column.
101 Fibers passing between the spinal cord and the cerebrum cross to opposite sides—most of them at the bulb, but many within the cord—so that the right side of the cerebrum is connected with the left side of the body, and vice versa. This accounts for the observed fact that disease or accidental injury of one side of the cerebrum causes loss of motion or of feeling in the opposite side of the body.
102 In general, afferent neurons or fibers are those that convey impulses toward the central nervous system (brain and cord), while efferent neurons or fibers are those that convey impulses from the central system.
103 At different times the nervous impulse has been regarded as a current of electricity; as a progressive chemical change, likened to that in a burning fuse; as a mechanical vibration, such as may be passed over a stretched rope; and as a molecular disturbance accompanied by an electrical discharge. The velocity of the nervous impulse, which is only about one hundred feet per second, proves that it is not a current of electricity. It takes place with little or no exhaustion of the cell protoplasm and consequently is not due to chemical action. And the loose, relaxed condition of the nerves prevents their transmission of physical vibrations, like those on a stretched rope. The view that the impulse is a progressive molecular disturbance, accompanied by an electrical discharge, has much evidence in its favor, but it has only recently been proposed and is likely to be modified upon fuller investigation.
104 The surface of the body includes the linings of the air passages, food canal, and certain cavities, as well as the external covering or skin.
105 Derived from the Latin re, back, and flectere, to turn or bend.
106 A frog from which the brain has been removed is suspended with its feet downward and free to move. If a toe is pinched, the foot is drawn away, and if dilute acid, or a strong solution of salt, is placed on the tender skin, the feet are moved as if to take away the irritating substance. This of course shows that reflex action can take place independently of the brain.
Now if the spinal cord is also destroyed, there is no response when the irritation of the skin is repeated. The animal remains perfectly quiet, because the destruction of the cord has interrupted the reflex action pathway. This shows that some part of the central nervous system is necessary to reflex action.
107 Review description of the spinal nerves, page 295.
108 Where a deep-seated cause for worry exists, there may be occasion for grave concern. Many people have become insane through continued worry about some one thing. In cases of this kind the sufferer needs the aid of sympathetic friends, and sometimes of the physician, in getting the mind away from the exciting cause. A change of scene, a visit, or some new employment is frequently recommended, where the actual cause for the worry cannot be removed.
109 Any part of the body which is overworked or which works at a disadvantage tends to disturb, more or less, the entire nervous system and to produce nervousness. Especially is this true of such delicate and highly sensitive structures as the eyes. If the eyes do not focus properly or if the muscles that move the eyeballs are out of their natural adjustment, extra work is thrown upon these delicate parts. One of the first and sometimes the only indication of eye strain is that of some disturbance of the nervous system. For this reason it is important to carefully test the eyes in determining the cause of nervousness (page 385).
110 One form of neck exercise recommended for this purpose is easily taken on retiring at night. Lying flat on the back, without a pillow, lift the head slowly from the bed and let it as slowly settle back to the level of the body. Repeat several times, lying on the back, and then again on the face and again on each side. Practice these exercises every night during an interval of a month or until relief is secured.
111 Insurance statistics show that habitual moderate drinkers do not live so long as abstainers.
112 Organs very frequently affected by tobacco are the heart and the eyes. It induces, as already stated (page 56), a dangerous nervous derangement called "tobacco heart," and it causes a serious disorder of the retina (retinitis) which leads in some instances to loss of vision. Tobacco smoke also acts as an irritant to the delicate lining of the eyes, especially when the tobacco is smoked indoors.
113 Of 4117 boys in the Illinois State Reformatory, 4000 used tobacco, and over 3000 were cigarette smokers. Dr. Hutchison, of the Kansas State Reformatory, says: "Using cigarettes is the cause of the downfall of more of the inmates of this institution than all other vicious habits combined."
114 The term "mind" is used in this and preceding chapters in its popular, not technical, sense.
115 The problem of social adjustment is but a phase of the general problem of establishing proper relations between the body and its surroundings.
116 A vibrating body is one having a to-and-fro movement, like that of a clock pendulum or the string of a violin on sounding. Bodies to give out sound waves must vibrate rapidly, making not less than sixteen vibrations per second. The upper limit of hearing being about 40,000 vibrations per second, certain bodies may even vibrate too rapidly to be heard.
117 Somewhat as the waves on a body of water impart motion to the sticks and weeds along the shore, sound waves are able to cause bodies that are small or that are delicately poised to vibrate.
118 Some idea of how the movements of the cartilages change the tension of the cords may be obtained by holding the fingers on the larynx, between the thyroid and cricoid cartilages, and making tones first of low and then of high pitch. For the high tones the cartilages are pulled together in front, and for the low tones they separate. As they pull together in front, they of course separate behind and above, where the cords are attached.
119 It is only the central portion of the pinna that aids the entrance of sound into the auditory canal. If by accident the outer portion of the pinna is removed, there is no impairment of the hearing.
120 The middle ear is also called the ear drum, and, by the same system of naming, the membrana tympani is referred to as the drum membrane.
121 The inner projection of the temporal bone is known as the petrous process.
122 A small opening in the bone at this place is called the fenestra rotunda.
123 Consult some work on physics on the different kinds of lenses and their uses.
124 With respect to its adjustments the eye does not differ in principle from various other optical instruments, such as the microscope, telescope, photographer's camera, etc., which, in their use, form images of objects. These all require some adjustment of their parts, called focusing, which adapts them to the distance. The eye's method of focusing, however, differs from that of most optical instruments, in that the adjustment is brought about through changes in the curvature of a lens.
125 The converging power of convex lenses varies as the curvature—the greater the curvature, the greater the converging power.
126 An oculist is a physician who specializes in diseases of the eye.
127 Some of the more common symptoms of eye strain are nervousness, headache, insomnia, irritations of the eyelids, sensitiveness to bright light, and pain in the use of the eyes.
128 Pyle, Personal Hygiene.
129 "An infectious disease is one in which disease germs infect (that is, invade) the body from without. Among the infectious diseases are some that are quite directly and quickly conveyed from person to person and to these the term contagious is applied. Formerly a sharp line was drawn between infection and contagion, but to-day it is recognized that no such line exists."—HOUGH AND SEDGWICK, The Elements of Hygiene and Sanitation.
130 The arctic explorer, Nansen, states that during all the time that his party was exposed to the low temperature of the arctic region, no one was attacked by a cold, but on returning to a warmer climate they were subject to colds as usual. The difference he attributes to the absence of germs in the severe arctic climate. There seems to be no doubt but that most of our common colds are due to attacks of germs.
131 An interesting biological fact is that the female Anopheles, and not the male, sucks the blood of animals and is the cause of the spreading of malaria.
132 The habit of spitting upon the floors of public buildings and street cars, and also upon sidewalks, is now recognized as a most dangerous practice. Not only consumptives, but people with throat affections, may do no end of harm in the spreading of disease by carelessness in this respect.
133 For further information on the care of consumptives, consult Huber's Consumption and Civilization.
134 As typhoid fever is a disease of the small intestine, great care must be exercised in taking food and in the bodily movements. Solids greatly irritate the diseased lining of the intestine, and the weakened walls may actually be broken through by pressure resulting from moving about.
135 Alcoholic beverages include all the various kinds of drinks that owe their stimulating properties to a substance, ethyl alcohol (C2H5OH), which is made from sugar by the process of fermentation. They include malt liquors, such as beer and ale, which contain from three to eight per cent of alcohol; wines, such as claret, hock, sherry, and champagne, which contain from five to twenty per cent of alcohol; and distilled liquors, such as brandy, whisky, rum, and gin, which contain from thirty to sixty-five per cent of alcohol. Alcoholic beverages all contain constituents other than alcohol, these varying with the materials from which they are made and with the processes of manufacture. The distilled liquors are so called from the fact that their alcohol has been separated from the fermenting substances by distillation.
136 Duncan, The Chemistry of Commerce.
137 Alcohol is "denatured" by adding substances to it such as wood alcohol, which render its use as a beverage impossible.
138 The tobacco plant, Nicotiana tobacum, is a native of America, and the use of tobacco began with the American Indians. It was taken back to Europe by the early explorers, Sir Walter Raleigh being credited with introducing it to the nobility of England.
139 Most headaches are the result either of eye strain or of digestive disturbances, such as indigestion and constipation, and are to be relieved through the work of the oculist or through attention to the hygiene of the digestive system.
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