STRESS

Problem. What causes you to feel sick when an illness strikes?

Background. There is a great difference between feeling sick and being sick. Being sick means that some part of the body is being damaged by an infection, a wound, or a deficiency of some kind.

Feeling sick is different. When you feel sick you have a headache, a fever, or some other discomfort. You feel this way when you are getting any of a number of diseases.

Explanation. Dr. Hans Selye noticed that sick people generally complain of the same symptoms when they first contract a disease. Selye wondered what causes these symptoms and why they were similar for so many diseases.

After years of research, he discovered that these feelings of sickness have many causes. They are not limited to physical causes. Emotional factors seem to cause many of the same symptoms. Fear, excitement, anger, or great enthusiasm can cause the symptoms as easily as a cold virus. Selye called all these causes stress.

He performed many experiments on rats. In each, he subjected a group of rats to intense cold, or a virus, or a frustrating situation, and certain reactions developed. The most noticeable were stomach disorders, an enlarged adrenal cortex, and shrunken lymph structures.

Selye realized that these three reactions  could be caused by any stress. Continued stress, however, brought about a second reaction; the internal symptoms disappeared! In cases where there was no disease, but there was stress, the body apparently was able to adjust to the stress and continue to function efficiently. Selye concluded that the body can accustom itself to stress and, if the stress is not too severe, can continue to function.

Selye also found that rats cannot tolerate stress forever. If stress is too severe, they eventually die. Fortunately, people are seldom required to tolerate such extreme degrees of stress.

Most people often experience the first two reactions to stress. Your feeling of sickness when you are first catching cold is your reaction to stress.

You have often experienced the second phase of the stress reaction, too. Remember when you got your "second wind" during a tiring game or long period of activity? That was an adaptation to stress.

Today, doctors are finding out more and more about Dr. Selye’s concept of stress. The more they learn, the better they can treat patients who are experiencing one of the three degrees of stress.

Health & Growth - Activity for Health and Fitness

Exercise for Fitness
Bouncing Ball. When performing this exercise, remember to keep your body rigid and to support your weight on your hands and toes. For variety you can clap your hands each time you have pushed your body into the air.

Team Activity
Foot Volleyball. This game is a variation of regular volleyball. You can play the game with a soccer ball or a regular football. Older boys play the game on a field that is 100 feet by 200 feet. Younger boys and girls can play the game on a field that is 95 feet long and 40 feet wide.

Look at the illustration to see how the field is divided into two playing courts and a neutral area. Notice that there is no net and that the neutral area is 15 feet long.

The object of the game is to kick (punt) the ball into the opponent’s playing court so that no one can catch it and kick it back. A team scores a point when its opponent allows the ball to touch the ground or when its opponent punts the ball out of bounds, into the neutral zone, or into its own court.

The serve is made by punting the ball into the opponent’s playing court from the middle of the server’s playing court. The serving team continues to serve as long as it continues to make points. A team can only score when it has the serve.

When a ball is served into the proper court, a player must catch it and kick it back to the server’s playing court. The serving team tries to catch it and return it in a like manner.

Seven to fourteen players make up a team. They rotate in a clockwise direction each time a serve is made so that each player assumes a new position. Only the serving team rotates before each serve. In this way, each team member is given a chance to serve.

Part of the skill involved in playing foot volleyball is the ability of the team members to play their own positions and not interfere with each other’s actions.

You will find that this game is fast-moving. It requires skill, but it can be played by anyone.

Adolescent Skin - Part 1

Changes in the skin. During your adolescent years your appearance becomes more important to you. Your skin, for example, begins to concern you more and more. Some people com plain  of oily skin and pimples. Others complain of dry skin. Still others are concerned about acne, dandruff, or the odor of perspiration. All these problems are common during adolescence. Fortunately, few of them develop into serious medical problems.

Your skin is not just an attractive covering to hide bones, muscles, and other internal parts. It is a complicated layer of glands, blood vessels, nerves, hair, and tissue. It helps the body maintain its temperature, protects the internal organs, eliminates some wastes from the body, and helps to prevent infections in the body.

Glands in the skin. The parts of the skin that cause most problems for teen-agers are the glands in the skin. There are two types of glands in the skin: the sweat glands, which secrete almost pure water, and the sebaceous glands, which secrete an oily substance called sebum.

The sweat glands always give off a tiny amount of salt dissolved in water. Usually the water evaporates quickly, leaving a thin coating of salt on the surface of the skin. In hot weather, when you perspire more freely, this coating can build up rapidly. This coating is not offensive because it has no odor. Daily washing and bathing removes it.

During adolescence a different type of sweat gland appears in the body. These glands secrete the normal salty-water solution, but they also secrete Products that can be broken down by bacteria that are normally on the skin. It is this bacterial action that produces the unpleasant odor that has become associated with perspiration. These special sweat glands are concentrated under the arms; consequently, it is from this area that the offensive odor comes.

You can avoid perspiration odors by bathing regularly and by using a deodorant that does not irritate your skin. But everyone needs to keep in mind that nothing is as effective as frequent bathing in eliminating skin bacteria and dissolved salts.

Skin problems. One of the problems many teen-agers face is oily skin. Some people’s skin becomes oily because the sebaceous glands in the hair follicles produce too much sebum during adolescence. This oily substance keeps the hair flexible, but in excess, can cause oily skin. The best way to remove the excess oil is to wash twice a day with soap and water. Pay particular attention to the nooks and crannies at the edges of the nose, eyes and ears. These places often collect more than their share of oil because the sebaceous glands are numerous on the nose and forehead.

Sometimes the glandular activity in a teen-ager’s skin causes another problem: blackheads and pimples. Contrary to popular opinion, these are not formed by dirty pores. They are formed when the tiny amount of dirt normally present on the skin combines with sebum, which clogs pores and sebaceous glands. Due to the concentration of bacteria in the sebum, there is a likelihood that the pores will become infected, swell up, and form pimples. When many pores become inflamed, the condition is known as acne.

Posture

A good impression. In a sense, your posture is a reflection of you. People who see you standing or sitting naturally and gracefully are apt to think well of you. Their first impression of you can be of great value to you.

Good posture not only gives others a good impression of you, but it helps you feel well. Because a slouching stance or a slumped sitting position can place a strain on your muscles, these positions are tiring. When correct posture becomes a habit, your muscles are more likely to be relaxed. Therefore you are less likely to tire easily.

Assuming good posture. Good posture is not hard to define, nor is it hard to maintain. It is a natural, easy stance in which the parts of the body are generally in a straight line. Or, when reclining or seated, it is important to have each part of your body supported. It is especially important to have your back supported while you are reclining. Look at the pictures on this page to see some examples of good posture.

Sometimes girls and boys who have
suddenly become taller slump or slouch in an attempt to conceal their height. Perhaps they do not realize that they are slouching. The poor posture, however, only serves to call attention to them and show that they are self-conscious. How much better it is to maintain a balanced posture that gives an impression of grace and self-confidence. You can see that balanced posture is a valuable goal.

Try This

Assume a slouching position and try to take a deep breath. Stand straight and take a deep breath. Which is easier?

Adolescence and Internal Change

The endocrine change. Do you remember the names and functions of the endocrine glands? You will remember that the endocrines hold the keys to many body functions and that the pituitary is the keystone to several of these functions.

One of the most important hormones of the pituitary is secreted during adolescence. This hormone starts the process by which adolescents become mature men and women. It causes the secretion of male hormones in men and female hormones in women. It is these hormones that produce  the marked physical changes that occur during adolescence.

The female hormones produce the changes in body structure, appearance, and voice that make a mature woman. The male hormones produce the changes in body structure, appearance, and voice that make a mature man. These changes are stimulated by the pituitary, and are controlled by heredity. Some boys and girls will begin to mature early in their adolescence and others will begin to mature later. The timing of the change, however, has nothing to do with the eventual maturity of the individual or with his or her attractiveness. You may have guessed that these factors are controlled by heredity, too. Adolescent voice changes. One of the most easily observed adolescent changes is a change in voice quality. In boys, the rapid change in the larynx, or voice box, creates a new voice, which is lower in pitch. In girls, where the change in size of the vocal folds, or cords, is not as great, the changes in pitch and quality are not so pronounced.

Sometime during his adolescence every boy goes through a period when his voice is unreliable. It may be high pitched one moment and deep the next. This uncomfortable situation is temporary and is caused by the changes in the voice box. During adolescence the voice box falls to a lower position in the throat and the vocal folds lengthen. The longer the folds become, the lower the boy’s voice becomes.

While the boy’s vocal folds are changing, he may not have complete control over them. When he is excited or tired, the muscles controlling the vocal cords may tighten, and the boy’s voice will rise in pitch. Happily, this condition does not last long.

Think for Yourself

How can a boy whose voice is changing help to avoid the in pitch that sometimes occur?

Solving Growth Problems

Eating habits. Do you often skip breakfast because there is not time or because you are not hungry? Unfortunately, many teen-agers do. Also, many teen-agers eat one or two snacks a day during their years of rapid growth. These eating habits are common and may contribute to growth or weight problems in adolescents.

Underweight. When boys and girls suddenly grow tall, they sometimes think they have become underweight. Actually, their bodies have not had time to fill out because of their sudden spurt upward. Many teen-agers’ fear of being underweight is due to this unevenness in growth.

In rare cases, teen-agers are underweight. Nutrition is one cause; glandular disturbances, worry, lack of rest, or infection are other causes. When being underweight is caused by one of these problems, a doctor should be consulted. It is not a good idea to try to adjust your diet to gain weight without a doctor’s advice. This kind of self-treatment can cause nutritional problems and should be avoided.

Overweight. Problems of being overweight are much more common than problems of being underweight. One cause may be the many snacks teen-agers eat. Another cause of being overweight may be that a person may eat too much of a certain type of food. In any event there are several things you can do if excess weight is one of your growth problems.

The first step you should take in coping with a weight problem is to consult your doctor. He may find that your weight gain is a normal part of your own growth pattern. Many people become chubby during certain periods of adolescence, only to lose the unwanted weight at a later time. If the doctor finds that you do have a weight problem, he can recommend a sensible diet to overcome it.

Dieting is a common practice. Unfortunately, many teenagers, particularly girls, follow diets that are poor   in   essential  body  nutrients. When the body does not have these vital foods, or has too much of the wrong kinds of food, it is hindered in its development. Such an unwise diet can cause poor bone formation, tooth decay, and increased susceptibility to illness.

Dieting is not the only solution to problems of being overweight. You can use exercise to hold your weight within reasonable limits. Exercise alone is not a good way to take off weight. You would, for instance, have to walk thirty-five miles to take off one pound. However, a good program of exercise will take off some weight, and will use up energy that would otherwise be converted to fat.

Weight charts. You may see weight charts that state that a person your age and height should weigh a certain number of pounds. These charts may appear to be accurate, but they are actually misleading. Because everyone grows at his own rate and has many purely individual characteristics, there is a good chance that he will not be similar to the "average" in height or weight. From this information, you can see that you cannot conclude you are overweight or underweight simply because you differ from a figure given on a chart. If such a
chart makes you seem seriously overweight or underweight, see your doctor. He will be able to judge your weight in relation to your growth rate, bone structure, general health, and height.

Sleep needs. You have learned that your body is growing "in all directions at once" during your teen years. You are also aware of the great demands of your increasing schedule of activities: sports, homework, hobbies, and projects. Sometimes you may be tempted to make time for all these activities by cutting down on sleeping time.

This method only works for a short time, however. After a few days your lack of sleep will cut down on the energy you have for your activities. Your lack of sleep would also hurt your body’s efforts to grow during this period of great body change. From this information you should see that the recommended eight to ten hours sleep is, in fact, a necessity for growing adolescents.

Think for Yourself

Why is being overweight more common than being underweight in America today

Heredity and the Growth Spurt

The internal clock. As you have learned, every cell in your body contains chromosomes, which determine your physical and mental capacities. From your knowledge of heredity, you know that these characteristics were passed on to you by your parents and that neither you nor they can change them. These chromosomes act as a sort of internal clock that sets the time when you will have an adult physique, or body build.

This internal clock controls the beginning of your growth spurt, the rate of your growth, and the time when it will end. It even times the growth of the parts of your body.

You can blame it if your feet get too large or your nose too long. In fact, this clock also helps to determine your body build, athletic capabilities, and a great deal of your personality.

The chromosomes in your internal clock determine all these characteristics only if other factors do not interfere. Your chromosomes might influence your body to grow tall. If you had very poor nutrition, however, you would not grow as tall as you could have. Nutrition, exercise, diseases, and other factors can change the plans of your internal clock.

Predicting size and build. If you look carefully at your parents, you can probably detect many similarities between them and you. However, it is not very often that a person has all or most of his parents’ traits. It is most likely that you will inherit some traits from one parent and some traits from the other.

Because your size is largely determined by your inheritance, you may be able to get a rough idea of your size at maturity by looking at your parents. However, this method is not always accurate. A short mother not a tall father can have tall, medium, and short children. Because of the peculiar way chromosomes work parents of medium height may have tall children, short children, and any size between. Look at the chart to see how parents’ heights affect their children.

Your bone structure, weight, and physical appearance are determined in the same way as your height. However, each of these characteristics is more complex than height. Consequently, it is not likely that you will look exactly like your parents in any of these ways. However, you may have many similar characteristics. Prediction of these characteristics is extremely difficult even in the best of circumstances.

Severe growth problems. If you think that you have serious growth problems, it would be wise to see your doctor. You will remember that the parathyroids, pituitary, and other endocrines control your skeletal growth and physical development. Occasionally, these glands may secrete too much or too little of the hormones that control growth. Doctors can treat this glandular problem by reducing the activity of the gland or by giving regular doses of the necessary hormones. You must realize, however, that there are only a very few cases of glandular difficulty. Most teenagers’ growth problems are not based on glandular problems and can be solved by several relatively simple methods.

Try This

Take two or three of your outstanding physical characteristics and trace them back to your grandparents. Are all your outstanding traits inherited from one side of your family?

Health During the Years of Growth

What is the right height for a thirteen-year-old girl? What is the proper height for a fourteen-year-old boy? How much should an eighth-grade boy weigh? These questions are impossible to answer. The truth of the matter is that there are a thousand correct heights and weights for adolescents who are thirteen or fourteen years old.

What accounts for the fact that people your age may vary so much in height and weight? Why is it that one eighth grader can weigh twice as much as another? The answers, of course, lie in the teen-ager’s heredity and physiology. During adolescence the teenager’s body undergoes great changes in height, weight, appearance, and internal structure. Every teenager grows at his own rate and matures at his own rate.

Every part of your body will undergo some change during the teen years. Whole glands will disappear. Others will change. The size and proportions of your body will change. All this will happen quickly.

Sometimes it is the speed of growth that causes you to worry about your height or weight. In this chapter some of the reasons for these growth problems will be given, as well as some solutions to the problems of growth.

Can You Find Out?

If you can find out your height when you were two years old, you can predict your adult height. You can probably obtain this information from your parents or your family doctor. You can use this figure to predict your adult height if you multiply your height in inches by a number. Girls should multiply by 100/53, and boys should multiply by 100/48.5. The resulting figure will be a good prediction of your height at maturity. Like all predictions, however, it should be viewed with caution. No prediction can account for everything that might influence your adult height.

The Endocrine System - Part 2

The pancreas. Another of the essential organs is the pancreas. Within it are the islets of Langerhans, groups of cells that secrete insulin, a hormone essential to the conversion of sugar to energy. The pancreas also controls the way fats are stored in the body.

The disease that results from a deficiency of insulin is called diabetes. This disease was fatal until Dr. Frederick Banting and four other Canadian  doctors  discovered  that secretion of the islets in the pancreas would stop the symptoms of diabetes They found that insulin controlled the way the body uses sugar. By injectiing insulin into patients, the disease could be arrested.

The thyroid gland. The thyroid is another part of the endocrine system The thyroid is a gland which straddles the trachea. The hormone thyroxin produced in this small gland, influences the body’s ability to use foods; consequently, it controls body weight, growth, development of intelligence, and certain other processes.

One of the important factors in the functioning of the thyroid is iodine. If sufficient iodine is not present in the diet, the thyroid enlarges and forms an ugly swelling in the neck, called a goiter. A goiter condition can be prevented by eating sufficient iodine in the form of seafood, iodized salt, or certain plants. People living in regions where iodine is especially common in foods do not need iodized salt.

The parathyroids. Buried in the thyroid gland are four parathyroid glands. These glands are tiny spots on the thyroid gland and are vital life. They secrete a hormone that controls the level of calcium in the blood This calcium controls muscle bility. A muscle deprived of calcium will twitch uncontrollably. Too much parathyroid hormone, on the other hand, will cause the bones to give up calcium to the blood, a condition equally undesirable.

The other endocrines. There are other endocrine glands of varying degrees of importance. These glands also work through the blood stream and control various body functions.

Balance in the body. The chemical controls in the body are just part of the interlocking systems that normally function so well together. Doctors long ago devised the concept of homeostasis, or automatic balance, to explain this balance. The body is such a complex series of dependent parts that damage
to one part will affect dozens of others. The body’s homeostasis automatically corrects for many of these imbalances, and brings the body parts into harmony again. In sickness, homeostasis may cure you without help from a doctor. It adjusts your functions to compensate for diet, temperature change and all manner of other upsetting factors in your environment. Without such a capacity for maintaining balance, you would not have a chance to lead a healthy, comfortable life.

The Endocrine System - Part 1

The control centers. The endocrine glands secrete chemicals which control the growth and development of the body. These chemicals are secreted into the blood stream and are carried to all parts of the body. Because they are in general circulation, these chemicals, called hormones, can act in areas far from the gland that secreted them. They may even act on several organs at once.

The endocrine glands have a certain similarity to the nervous system because they help to integrate the activities of widely separated organs. Emotional strain, for example, causes one of the endocrines to enlarge and secrete a chemical which speeds up the action of the heart.

The master gland. In the base of the skull is a tiny gland called the pituitary, or hypophysis. This gland is called the master gland because it controls growth and the action of the adrenal, thyroid, and male and female glands. Through these glands, it has an enormous effect on the other systems of the body.

The pituitary gland secretes at least eight hormones in order to exercise its control over body functions. Each hormone controls a particular body function. Examine the chart below to see what functions these eight hormones control.

The adrenals. The adrenal glands are two of the glands that are regulated by the pituitary. The adrenals are two glands located above the kidneys. Each adrenal is composed of two parts: an inner part, called the medulla, and an outer layer, called the cortex.

The hormone secreted by the medulla, called epinephrine, is probably the best known hormone in the body. Commonly called adrenalin, this hormone stimulates most of the emergency reactions within the body. It increases the heart beat, releases sugar from the liver into the blood stream, delays fatigue in the skeletal muscles, raises the blood pressure, and performs many other functions.

In view of these effects you would think that epinephrine is essential to the function of the body. Such is not the case, however. Parts of the autonomic nervous system can control these functions even when the adrenal medulla is removed from the body! It is likely that the medulla serves only to help the autonomic nervous system in times of danger, but that it is not necessary for the body’s functioning.

The adrenal cortex. The adrenal cortex, on the other hand, secretes substances which’ are vital to the body. A person deprived of his adrenal cortex would die within a few days. It is the secretion of the hormone from the adrenal cortex that is controlled by ACTH, a hormone secreted by the pituitary. Scientists are not sure why the cortex is essential, although they have found that cortisone is very useful in alleviating some symptoms of disease.