Emotions Affect the Body

Emotional life. Have you ever broken out in a cold sweat, blushed deeply, or felt "butterflies" in your stomach? If you have, you have noticed a typical reaction to strong emotion–the physical effects of emotions. In your teen-age years you are likely to react more emotionally to events than your younger brothers and sisters or your parents. Part of this increased feeling is due to the adjustments you are making to the changes in your body and to the changes in your responsibilities.

Whenever you feel a strong emotion, such as fear, embarrassment, anger, or joy, the organs in your body react. A cold sweat, a blush, and a "nervous stomach" are evidence that the sweat glands, blood vessels, and stomach are reacting to the emotions. These three reactions to emotion are evidence that there is a link between the brain and each of the organs involved. The link between the emotions and the organs of the body is the autonomic nervous system. The nervous system connects the brain with the skin, stomach, intestines, heart, and blood vessels, as well as with the glands of the body.

Whenever you feel a strong emotion, the message is transmitted to certain parts of the body and physical reactions occur.

Physical reactions to stress. Everyone has physical reactions when he feels a strong emotion. The physical reactions are the body’s way of preparing to meet an emergency. However, if the strong emotion lasts longer than a few hours, the physical reactions become harmful to the body. In cases in which people are under great emotional tension for long periods of time, their stomachs may develop ulcers, or sores, due to the prolonged increase in stomach acidity. Ulcers are common body reactions to chronic, or greatly prolonged emotional tension. Other common reactions to chronic emotional stress are high blood pressure, skin allergies, asthma, and excess weight.

It is fortunate that the periods of emotional stress and strain during the teen years are relatively short. Teenagers who develop healthy ways to cope with their emotions do not develop these physical reactions to chronic emotional strain. Probably they handle their emotions so successfully that they are seldom subjected to emotional stresses for long periods of time.

THE BLUEPRINT OF LIFE

Problem. What controls heredity ? What makes you grow up to look like you and not someone else? The answer to this question is the key to life.

Background. For centuries men have wondered why men look like men. Some people thought that the blood of a mother and father mixed and the characteristics carried in the blood of the parents were passed on to the children.This theory was proven false in 1902, when Walter Sutton discovered the chromosomes. The chromosomes are tiny threadlike structures in the nucleus of a cell that contain the heredity of the cell.

Each human cell has forty-six chromosomes, which are split into forty-six identical pairs whenever the cells divide. Each of the daughter cells receives one-half of the chromosomes. But scientists did not know why or how the chromosomes split into two identical groups.

Explanation. The key discovery in the study of heredity was made by molecular biologists who discovered the chemical make-up of the chromosomes. They found that the chromosomes are made of a certain nucleic acid, called deoxyribonucleic acid. Biologists usually refer to this by its abbreviation, DNA.

In 1953 Doctors Francis Crick and James Watson perfected a three-dimensional model that explained all the characteristics of DNA. The model showed that the molecule was shaped like a spiral staircase. The sides of the stair treads were made of two chemicals and the "treads" were made of four other chemicals.

Many experiments proved that it is the arrangement of these four kinds of "treads" that determines a person’s characteristics.

The cells of the body contain about three feet of DNA, if the molecules are laid end-to-end. There are three or four encyclopedias of information in these DNA molecules. They use another nucleic acid, RNA (ribonucleic acid), to translate this information into the proteins that make up new tissue.

Further research. For an excellent discussion of DNA, read The Cell, one of the books in the Life Science Library.

The Respiratory System

Respiration. You have learned that cell respiration takes place when the cells take in oxygen and give off carbon dioxide. This process maintains the life of the cell by providing oxygen for the burning of food in the cell.

Body respiration, or breathing, takes place in the lungs. When you breathe, you draw air into your lungs by moving a large sheet of tissue called the diaphragm, and by the action of the rib muscles. Look at the illustration to see how the diaphragm causes the lungs to expand and contract.

When air is drawn into your lungs, it passes through several parts of the respiratory system. It is first drawn through the nose and mouth. There it is cooled or warmed by the moist tissues that line the passages. Foreign bodies are filtered out by tiny hairs in the nose.

The air passes through the nasal passages and the throat and is drawn into the trachea, or wind-pipe, and the bronchial tubes. These tubes lead to air sacs called alveoli. In the alveoli, the transfer of gases into the blood takes place.

Oxygen in blood. The alveoli are surrounded by a dense concentration of capillaries that carry the blood from the veins. This blood has a high concentration of carbon dioxide and a low concentration of oxygen. Because the walls between the capillaries and the air sacs are so thin, both carbon dioxide and oxygen can pass through them.

Carbon dioxide passes out of the blood, and oxygen passes into it. The oxygen is picked up by a compound called hemoglobin. Hemoglobin gives the blood its red color.

After the blood obtains oxygen in the alveoli, it is pumped to the left side of the heart, then through the arteries to the capillaries, and then to the cells of the body, where cell respiration takes place, and the process begins again.

The Circulatory System

The function of blood. Blood carries not only food from the intestines to the cells of the body, but also carries oxygen from the lungs to the cells. These are its two most important functions. In addition to these functions, blood helps fight disease, supplies water to the cells, and carries waste products from the cells to the liver and the kidneys, where the waste products are removed.

The heart. The central part of the circulatory system is the heart. The heart is a special muscle that pumps blood through the circulatory system. It pumps blood through the pulmonary artery to the lungs, from the lungs via the pulmonary veins back to the heart itself, from the heart through the arteries, and from the arteries through the capillaries and veins back to the heart.

The action of the heart was discovered nearly three hundred and fifty years ago by William Harvey. He noticed that the blood circulates from the heart, through the blood vessels and back to the heart. His discovery was a milestone in the study of the human body, because it showed that the flow of vital fluids was explainable by logical, natural laws, and that it could be studied by scientists.

Once Harvey had discovered that blood circulates in a closed system, other men began to discover the details of the circulation. Harvey had known that a chamber called a right ventricle pumps blood into the arteries. He did not know how the blood passes from the arteries to the veins, which bring it back to the heart. He thought it passed through invisible spaces in the tissue.

What Harvey did not know was that the blood passes from arteries to veins through the capillaries. The missing link was discovered by Mar-cello Malpighi, who actually saw the tiny blood vessels that link the arteries and the veins.

The capillaries. The capillaries are more than junctions between the arteries and the veins. Because the walls of the capillaries are so thin, liquids and gases can pass through them into the spaces between the cells in body tissues.

Oxygen passes through these walls and is picked up by the cells in all tissues of the body. Carbon dioxide is given off by the cells and passes back through the capillary walls. This passage of gases is called cell respiration, which is described in the section on the respiratory system.

The lymph system. While the blood passes through the capillaries, part of the  liquid,   or  plasma, passes through the capillary walls and into the spaces between the cells. Here it bathes the cells, giving them food and picking up bacteria and solid wastes. Some of this fluid passes back into the blood. The remainder, called lymph, passes among the cells and is picked up by an intricate system of tiny lymph capillaries, which lace the tissue of the body.

The lymph capillaries carry the lymph into larger lymph vessels. The ever-larger lymph vessels carry the lymph toward the heart and finally empty it into the veins near the base of the neck.

Before the lymph passes into the veins, it is filtered by a series of bean-shaped nodes that are plentiful throughout the lymph system. These lymph nodes remove bacteria and solid wastes from the lymph and thus help keep bacteria from entering the blood stream. They form one of the body’s defenses against disease.

Veins. Once the blood has passed through the capillaries, it enters the veins. Here it takes on a bluish appearance because it has lost the oxygen that gave it its bright red color. The veins carry the blood back to the right auricle of the heart. From this chamber it flows into the right ventricle, or pumping section, of the heart.

The right ventricle pumps the blood through the capillaries of the lungs and back to the left auricle, from which it flows to the left ventricle. From here it is pumped into the arteries to begin its life-giving circuit once again.

Think for Yourself
What are the systems that are directly linked with the circulatory system?

The Skeletal System

The growth of bones. The system that is growing fastest at your age is probably your skeletal system. During the time between your tenth and eighteenth birthdays, some of your bones may actually double in length. Not only do they grow, but they complete the hardening process that occurs from the time you are born until you are twenty or twenty-five.

When you are born, your bones are mostly cartilage, or gristle. As you grow, calcium, phosphates and other minerals are deposited in the cartilage, and the bones become hard. However, there is always a cartilage covering of the ends of the bones, particularly where the bones end in movable joints.

Function of bones. Bones are not dead sticks that hold you upright and help to keep your internal organs in their place. They are living organs. All bones are laced with blood vessels, and the centers are filled with fatty tissue and red marrow. Besides serving as the support for the body, the bones are the body’s red-blood-cell factories. The red marrow produces millions of red blood cells per second. These cells are carried into the blood stream by the system of blood vessels, which penetrate the bones.

Holding the skeleton together. Another part of your skeletal system is the tissue that holds one bone to another. This tissue forms connections between bones that are called ligaments. If this tissue were to disappear, you would literally fall apart. The ligaments that hold bones together may hold them firmly, as in the spine, or flexibly as in the elbow joint. The ligaments also serve as cushions between bones, and as well-oiled ball bearings between bones in movable joints.

Muscles. Although the ligaments hold the joints together, movement ofthe arms and legs is entirely dependent upon muscles. Each movement generally involves two muscles. One muscle relaxes while another tightens. In the illustration you can see two of the muscles that relax and tighten whenever you raise and lower your forearm. The biceps contracts, and the triceps relaxes when you lift your forearm. When you lower it, the opposite occurs.

Many muscles increase in size as they are used. They become smaller if they are not often used. For this reason, a program of vigorous exercise will promote the tone and size of your skeletal muscles. Regular vigorous exercise also improves your circulation and respiration.

FRACTURED BONES

Problem. How does the body heal fracitured bones ? How well do broken bones heal themselves?

Background. Did you know that your bones are as alive as your skin or any other tissue in your body? Most people think that the bones in the skeleton are made of dead material. A close look would reveal some different information, however. Your bones grow rapidly during your first sixteen to eighteen years. Then they harden to form your adult skeleton. The marrow within some bones forms essential parts of your blood. Broken bones heal so completely that it is difficult to find the healed fracture. This evidence certainly points to the conclusion that bones are alive, in spite of their hardness.

Late in the seventeenth century an English physician, Dr. Clopton Havers, discovered that there are thousands of tiny canals lacing the bones. These canals, called Haversian canals after their discoverer, carry the blood vessels and nerves to the interior of the bones.

Around each canal is a group of cells called osteocytes. These cells form much of the living matter in the bones. One kind of osteocyte, an osteoblast, deposits the minerals that make up bones. This hard mineral content forms about 45 per cent of the weight of the skeleton. The other kind of osteocyte, the osteoclast, dissolves the hard calcium and other minerals in the bones. This dissolving

Explanation. When a bone breaks, whether it has split, broken into many pieces, or only cracked, there is apt to be damage to the blood vessels and nerves in the bone as well as to the bony substance itself. The repair of the break necessitates a repair of these vessels and nerves as well as a new deposit of calcium mixture at the site of the break.

As soon as the bone fragments are set so that they are close to each other, the osteocytes in the area begin to repair the break. The blood vessels grow back and help to carry away the debris dissolved by the osteoclasts. The osteoblasts deposit new calcium between the bones to cement them together. The osteoclasts dissolve away the rough edges and "polish up" the job. Finally, the break is so completely healed that it is not easily distinguished from the original bone.

First Aid for Sprains and Strains

Sprains. Do you know what a sprain is? Do you know the difference between a sprain and a strain? Both are common injuries resulting from running and walking accidents. A sprain occurs when a ligament, or tissue surrounding a joint, is damaged.

Many times a sprain is so severe that the blood vessels are also damaged. Blood and other fluids seep into the area to cause swelling and pain. For this reason the injured part should be elevated to help the fluids drain away. Applications of cold cloths will also help to reduce swelling and pain.

In all severe sprains there is the possibility that a bone may be broken or a ligament severely damaged. For this reason, it is wise to take the injured person to a doctor for professional treatment.

Strains. A strain is an injury to a muscle or to the tendons. These are cords that are attached to muscles and help move parts of the body. A strain is not as severe as a sprain. Often rest is the only first aid needed. If there is any doubt about the seriousness of a strain, put a cold compress on the affected area and consult a doctor.

Walking safely. It is often possible for you to prevent strains and sprains by observing a few simple rules and habits. You should clear all walkways of toys and other hazards. Make sure that snow and ice are cleared from walks and that all handrails are safe. Care should be taken to lift heavy loads properly so that the danger of strains is reduced. Observance of these rules in your home can mean the difference between safety and a painful sprain or strain.

Think for Yourself

What parts of the body do you think are most liable to sprains? What parts to strains?

First Aid for Fainting

Causes of fainting. Cartoons often show women shrieking and fainting at the approach of a mouse, or a snake, or a singing star. It is not very often that you will have to give first aid for this sort of a condition. How­ever, fainting can be caused by great fear or any other condition which causes blood to drain away from the brain.

Perhaps you have heard of someone who has fainted after sitting for a long time in a stuffy room. The stuffy air was probably only one of the causes. Lack of sleep, tension, fatigue, and poor diet might have been other causes.

Helping a victim. You can treat a fainting victim by laying him down and elevating his feet slightly. This will help the flow of blood to the brain. If the person is sitting and feels faint, he should place his head between his knees to help revive circulation to the brain.

Women are not the only ones who faint. Soldiers who are forced to stand at attention in the heat of the sun for long periods often faint. The heat causes the blood vessels to expand. Because of the soldier’s inactivity and the tension he is under, the blood collects in the lower parts of the body.

If a person faints from any of the
previously mentioned causes, the first-aid measures already described should revive him within a few minutes. If the person does not respond quickly, there is probably something else wrong. The alert first-aider should then check for an injury suffered during a fall or some other complication. If simple first aid does not produce a quick recovery, a doctor should be consulted at once.

First Aid for Bleeding

Preventing wounds. Flesh wounds are the most common injuries requir­ing first aid. They would be less com­mon if people would take some measures to eliminate dangerous situ­ations. Some things you can do to eliminate dangerous wounds are:

1. Wear a safety belt while riding in a car.

2.Keep firearms under lock and key.

3. Store knives, razor blades, scissors, and other sharp objects out of the reach of children.

4. Caution youngsters who run with pointed objects in their hands that this is a dangerous practice. Make them walk. Show them how to carry the object with its point down.

5. Be very careful while using knives or dangerous tools such as saws, rotary mowers, or power tools.

Tetanus. Any wound, whether it is a tiny nick from a thorn or a gaping wound from a fall, may cause tetanus, or lockjaw. The danger of contracting this disease is especially great if the wound is deep and ragged, or is contaminated by soil or other foreign matter.

You should clean the wound with boiled water (at body temperature). Then you should help the patient to a doctor. The doctor may or may not
give the victim an anti-tetanus shot, depending on the circumstances.

Severe injury. Sometimes a wound involves serious bleeding that must be stopped at once, as you will remember from Rule Two. Since the body can lose a quart of blood or more in a minute, it is necessary to stop the flow of blood as soon as possible. In a case of this sort you must act quickly and without hesitation. The best first aid is the compress.

Compress pressure. When used to stop heavy bleeding, the compress is a large pad of folded cloth or cotton. The more sterile, or germ free, the cloth, the better.

When stopping bleeding, quickly fold a cloth into a compress. Press it firmly over the wound and hold it firmly in place with a bandage or strip of cloth you have cut from material at hand. If blood seeps around the edge of the compress, place additional pads of cloth on top of the original piece. Re­moving the first compress would be likely to start bleeding once again. If this method of stopping bleeding does not work, use the pressure points to help stem the flow of blood.

Pressure points. There are several points on the body where finger pressure can be applied to arteries to help stem the flow of blood. By press­ing the artery against a bone, the first-aider can reduce the flow of blood from the heart to the affected part. You should use the pressure point located between the wound and the heart.

The pressure points are located on the inner parts of the upper arms, the inner parts of the upper thighs, and on the neck, temples, and shoulders. Study the illustration to find the exact locations of these pressure points.

Using a tourniquet. If severe bleeding cannot be stopped by the use of any other method, a tourniquet, should be used. It is a piece of cloth or other material that is wrapped around an arm or leg and twisted to stop the flow of blood.

To apply it, place a two-inch band­age near the wound on the side toward the heart. Wrap it around the limb twice. Tie the ends in a square knot. Leave a loop in the knot so you can insert a strong stick. Insert and twist the stick until the blood stops flowing from the wound.

A strip of folded cloth, a belt, or a necktie may be used in place of a two-inch bandage. Do not use rope, string, a thin strip of cloth, or wire. These materials will cut into the flesh and cause the victim severe pain. Once the tourniquet is in place, get the victim to a doctor as quickly as possible. Any loosening of the tourniquet before a doctor sees the patient may cause a renewal of bleeding and danger to the patient.

Think for Yourself
If you were giving first aid to a person who had a deep cut on the back of his head, where would you apply pressure? Would you use a tourniquet?