Puberty and Growth - Stimulants and alcohol



Initial exposure to caffeine, tobacco, drugs, and alcohol usually occurs during adolescence. Teenagers should be fully educated regarding their physical effects and potential danger. They should learn how to use them, if at all, sensibly and in moderation, and to resist peer-group pressures.

Caffeine

Caffeine, which is naturally present in coffee and tea and is used in many carbonated beverages and medications, stimulates the central nervous system to overcome fatigue and drowsiness. It also affects a part of the nervous system that controls respiration so that more oxygen is pumped through the lungs. In large amounts, caffeine can increase the pulse rate, but there are few long-range effects because the substance is broken down by the body tissues within a few hours and excreted. Because of the action of caffeine in stimulating an increased intake of oxygen, it sometimes is used to combat the effects of such nervous system depressants as alcohol.

Nicotine

Nicotine, one of nearly 200 substances in tobacco, has recently been declared “addictive” by the FDA. It affects the human physiology by stimulating the adrenal glands to increase the flow of adrenaline. The blood vessels become constricted and the skin temperature drops, producing effects not unlike exposure to cold temperatures. When comparatively large amounts of nicotine are absorbed by the body, the pulse becomes rapid and the smoker has symptoms of dizziness, faintness, and sometimes nausea and diarrhea. The release of adrenaline, triggered by nicotine, will produce temporary relief from fatigue by increasing the flow of sugar in the blood. However, the effect is transient, and the feeling of fatigue will return again after the increased blood sugar has been expended.

Other Properties of Tobacco

The nicotine in tobacco can be absorbed simply by contact with the mucous membranes of the mouth; the tobacco does not have to be smoked to get the nicotine effects. Burning tobacco produces a myriad of substances found in the smoke of many plant materials when they are dried and burned. More than 50 different compounds are known to occur in concentrations of one microgram or more in each puff of tobacco smoke. Again, laboratory tests have demonstrated that the substances in burning tobacco do not have to be inhaled; most of the chemical compounds can be absorbed through the mucous membranes while a puff of smoke is held in the mouth for a few seconds. At least ten of the substances in tobacco smoke have been shown to produce cancer in animals. Other chemicals in tobacco tars are known as carcinogens; although they do not produce cancer themselves, they react with other substances to produce cancers.

Smoking and Disease

The relationship among tobacco smoking and cancer, heart disease, and emphysema-bronchitis is well established, even if some of the cause and effect links are missing. Despite a major governmental prevention program, there has been a sharp rise in teenage use. Large-scale studies of the death rates of smokers and non-smokers have been carried on for more than 20 years. One group, consisting of nearly a quarter-million war veterans, yielded results indicating that smokers are from 10 to 16 times as likely to die of lung cancer as non-smokers. (The higher ratio is for heavy smokers.) Similar results have been obtained from studies of smokers and nonsmokers with heart disease and lung ailments.

Buerger's Disease

One of the possible, although rare, effects of smoking is the aggravation of symptoms of a particularly insidious circulatory disorder known as Buerger's disease . As noted above, one of the effects of nicotine is a drop in skin temperatures. Smoking a single cigarette can cause the temperature of the fingers and toes to drop as much as 15 degrees Fahrenheit; the average is a little more than a 5-degree drop. The temperature change results from constriction of the blood vessels at the extremities. Blood clots may develop in the vessels that have been constricted, cutting off the flow of blood to the tissues of the area. When there is numbness or pain in the extremities, the condition should receive swift medical attention to prevent serious consequences.

Carbon Monoxide Accumulation

Another little publicized effect of smoking is the accumulation of carbon monoxide in the blood. Carbon monoxide is one of the lethal gases emitted in automobile exhaust. It is also produced by burning plant materials such as tobacco. It is a dangerous gas because of its strong affinity for the hemoglobin of red blood cells. Unlike oxygen and carbon dioxide, which become temporarily attached, then released, from the hemoglobin molecule, carbon monoxide becomes permanently locked into the red blood cell chemistry so that the cells are no longer effective for their normal function of transporting oxygen to the body tissues. With the oxygen-carrying capacity of part of the red blood cells wiped out, brain cells and other tissues suffer a mild oxygen starvation and the results are a form of intoxication.

A strong whiff of carbon monoxide can be fatal. Smokers, of course, do not get that much of the substance into their blood, but they do pick up enough carbon monoxide to render up to eight percent of their red blood cells ineffective. Experiments at Indiana University show that pack-a-day smokers have the same level of carbon monoxide in their blood as subjects who inhale an atmosphere of one-fourth of one percent carbon monoxide. That level of carbon monoxide increases the shortness of breath during exercise by approximately 15 percent, and, the study shows, about three weeks of abstinence from smoking are required to permit the oxygen-carrying capacity of the blood to return to normal. It is the carbon monoxide of burning plant materials that produces most of the “high” associated with the smoking of many substances.

Alcohol

Alcohol usually is not considered a potentially dangerous drug because it is easily available at bars, restaurants, and liquor stores and is served generously at parties. Alcohol has been used by man for thousands of years, at times as a sedative and anesthetic, and when used in moderation has the effect of a mild tranquilizer and appetite stimulant. But when consumed in excess amounts, alcoholic beverages can produce both psychological and physical dependence. It can produce a letdown of inhibitions due to the weakening of some functions of the central nervous system, particularly in the cerebral cortex.

Parents and teachers share an important responsibility to educate young people about the use and misuse of alcohol. Like marihuana, the effects of alcohol on human beings are not thoroughly understood. Some users develop a tissue tolerance for alcohol so that their body tissues require increasing amounts. When alcohol is withdrawn from such users, they develop tremors, convulsions, and even hallucinations. However, there are many varied reactions to the use of alcohol, and an individual may react differently to alcoholic drinks at different times. See Ch. 29, Substance Abuse .



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