is to properly perform its function and life to continue, oxygen must be constantly supplied. Continued breathing of stuffy or stale air impairs the vitality and renders one susceptible to disease. Air low in oxygen or containing more than 0.04 per cent of carbonic-acid gas is unfit for breathing. The prolonged breathing of such air will produce a condition of asphyxia and finally death. To insure good health, it is estimated that a person requires at least 1,000 cubic feet of air space, and the air breathed should be frequently renewed through proper ventilation. THE DIGESTIVE SYSTEM. The digestive or alimentary apparatus consists primarily of a long tube composed of the mouth, pharynx, esophagus, stomach, and intestines, with the salivary glands, liver, and pancreas as accessory organs. This canal is about 30 feet long and varies in diameter. It extends from the mouth to the anus. Its functions are, first, to separate the nutritive material from the food and expel the residue from the body; and, second, to convert the nutritive matter into such form that it can be easily absorbed into the blood and be utilized by the tissues as food. To get a clear understanding of how this is accomplished a knowledge of the separate parts forming the digestive apparatus is necessary. The question of food, its preparation, digestion, and assimilation is such a vital one and so affects health and efficiency that a thorough knowledge by first-aid men of the anatomy and physiology of the digestive system seems essential. SUGGESTED TOPICS FOR FURTHER STUDY. The mouth, teeth, tongue, and salivary glands, the part they play in digestion; the stomach as a digestive organ; the small intestines; the large intestines; the liver. its part in digestion; the pancreas, its part in digestion; foods, their relative values. THE EXCRETORY SYSTEM. Excretion is the process of removing all waste of the tissues from the body. These waste products are carbonic-acid gas, salts, urea, and water. They are continually brought into the blood by the circulation through the capillaries. Life and health depend upon the blood ridding itself of these poisonous products through the lungs, skin, and kidneys. SUGGESTED TOPICS FOR FURTHER STUDY. The lungs as an excretory organ; the skin as an excretory organ; the kidneys as an excretory organ. THE NERVOUS SYSTEM. The different systems of the body are kept in touch with each other by the nervous system and the functions and workings of the organs are controlled and regulated by it. The elements comprising the nervous system are nerve cells or centers, and nerves. The nerves are round cords consisting of nerve fibers which form connections between the centers and ends of the nerves. The fibers can transmit nervous impressions and are of two kinds, according to the function they perform. Those that convey impressions from their tips to their centers are sensory nerves; those that transmit impressions from these centers to the parts with which they are connected are called motor nerves. The nerve centers are bunches of nerve cells and are distributed in the brain, spinal cord, and ganglia. They receive and send out nervous impressions. The nervous system is divided into the cerebrospinal and sympathetic systems; the former is composed of large nerve centers in the brain and spinal cord, the latter is a series of small centers termed ganglia running along on either side of the spine. The nervous system is too complex to be discussed in detail here. SUGGESTED TOPICS FOR FURTHER STUDY. The cerebrospinal system; the brain; the cerebrum; the cerebellum; the pons varoli; the medulla oblongata; the spinal cord; the cerebrospinal nerves; the cranial nerves and special senses; the spinal nerves; the sympathetic system. BACTERIA, SEPSIS, AND ANTISEPSIS. Bacteria, also called germs, organisms, microorganisms, and fungi, consist of minute vegetable cells. They exist in the air, in the water, in the ground, and upon the body and clothing. There are many varieties and each requires proper food, temperature, and soil for propagation. Having found a suitable soil or breeding place in the tissues of the body, they multiply very rapidly, and as they grow certain kinds may give off poisonous substances, termed toxins. The toxins may act simply as irritants or may destroy all the tissue with which they come in contact, the effect depending on how poisonous the bacteria are and on the resistance of the tissue. In some cases harmful bacteria may gain entrance or access to the general circulation and be spread broadcast through the body, exerting their poisonous influence upon every organ of the body with which they come in touch, producing septicemia or blood poisoning Bacteria most usually gain entrance to the body through wounds or abrasions, through the respiratory system, or through the digestive system. SEPSIS. Sepsis is a condition caused by the entrance of certain bacteria into a wound, whereby inflammation, with more or less severe disturbance of the general system, is produced. When harmful bacteria get into a wound, poisonous materials are produced that destroy the tissue cells, form pus or matter, and prevent healing. In order to prevent sepsis, observe the following rules: Prevent germs from entering the wound by keeping all unclean things from coming in contact with it. Destroy or prevent the growth of germs which may have gotten. into the wound at the time of the injury. (See "Dressings," pp. 49-57.) ANTISEPSIS. Antisepsis is a method of treating wounds by disinfection. The disinfectant or germicide is an agent that is fatal to bacteria and their spores or eggs. The destruction of germs of disease in clothing, in excreta, in wounds, etc., is known as disinfection. Disinfection of a wound, dressings, or instruments is called sterilization. The application of the principles of antisepsis has done more than anything else to revolutionize the treatment of wounds and to prevent sepsis or blood poisoning, which is so much dreaded by the surgeon. COMMON INJURIES AND THEIR TREATMENT. HEMORRHAGE. Hemorrhage is loss of blood. It is caused usually by an injury or by a diseased condition of the blood vessels. The danger from hemorrhage depends upon the amount of blood lost and the rapidity with. which it escapes. The loss of one-third of the blood in the body usually results fatally. There are three kinds of hemorrhage, namely, arterial, capillary, and venous. Arterial hemorrhage is most dangerous and most difficult to control. MEANS OF CONTROLLING HEMORRHAGE. Hemorrhage may be controlled by pressure, position, heat or cold, torsion, or ligation or tying of the blood vessel. The only methods which can usually be employed by the first-aid man are compression and position. Compression is more important and should be applied by the fingers, compresses, tourniquets, or constricting bands such as a handkerchief, belt strap, suspenders, etc. (See fig. 6.) In arterial hemorrhage the blood gushes forth in a bright red stream. The pressure must be made between the wound and the heart. In capillary hemorrhage, the blood oozes away slowly and is bright red. The bleeding is easily controlled by applying a clean compress of gauze directly to the injury. In venous hemorrhage, the blood is dark red or blue, and discharges in a steady stream. The compression should be made on the side of the wound away from the heart. Usually the bleeding can be controlled by applying a large compress of sterile gauze directly over the bleeding place. a Figure 6 is adapted from instruction chart of American National Red Cross. Elevation of the bleeding parts always aids in controlling the flow of the blood. As soon as the bleeding has been stopped by some one of the methods suggested the patient should be treated for shock. FIGURE 6.The relation of the principal arteries to the bones. The arrows indicate the SHOCK. Shock is a sudden depression of the vital powers arising from an injury or a profound emotion acting on the nerve centers and inducing exhaustion. The symptoms are subnormal temperature; an irregular, weak, and rapid pulse; a cold, clammy, pale, and profusely perspiring skin; irregular breathing; the person affected usually remains conscious and will answer when spoken to, but is stupid and indifferent and lies with partly closed lids. Always be sure that there is no concealed hemorrhage. The symptoms of concealed hemorrhage are practically the same as outlined above. TREATMENT. Lower the head, wrap the patient in hot blankets, and surround him with safety lamps or other heat-giving objects. Give an ordinary stimulant, as black coffee, to be sipped as hot as it can be borne; half-teaspoonful doses of aromatic spirits of ammonia may be given every 20 or 30 minutes. Small doses of whisky or brandy may be given, provided there is no hemorrhage. One or two teaspoonfuls every 15 or 20 minutes will help to tide the patient over until the doctor comes. Inhalation of oxygen is often of much service; artificial respiration may be necessary in some cases. Hot applications over the heart and spine should be used if practicable. Always hurry up the doctor. CONTUSIONS. A contusion or bruise is an injury due to the application of blunt force, the skin above being unbroken. Blood collects in the tissue under the skin over the bruised area. In many deep contusions the skin is not damaged, but over bone the skin is apt to be injured. If a large blood vessel is ruptured, much blood gathers in the tissues under the skin and causes great swelling and discoloration. The symptoms are: Tenderness, swelling, and numbness, followed by aching pain. Discoloration usually occurs quickly, especially in surface contusions; it may not occur in deep ones. TREATMENT. Elevate the injured part and bandage it tightly to arrest the bleeding and control the swelling. Apply an ice bag or towels wrung out of ice water. In the case of the aged or weak, make hot applications instead of cold. WOUNDS. A wound is a break or a division of the tissues produced usually by a sudden force. Wounds are divided into the following classes: Incised, made by some sharp cutting instrument; contused, caused by a blunt or flat or rough instrument; lacerated, caused by tearing or dragging forces, such as teeth and claws of animals or punctures made by a pointed instrument. The symptoms are: Pain, bleeding, and gaping or retracted edges. TREATMENT. First arrest the bleeding by some one of the methods described above, and put on a sterile dressing to protect it against bacteria or 97547-13- 4 |