First Book in Physiology and Hygiene by J. H. Kellogg (best books to read all time .TXT) 📕

of the body.

4. These tubes are connected with the heart.

5. The vessels which carry blood away from the heart are called arteries, and those which carry blood back to the heart are called veins.

6. The arteries and veins are connected by small tubes called capillaries.

7. The blood found in the arteries is red; that in the veins is dark blue or purple.

8. The color of the blood changes from red to blue in going through the capillaries. The change is due to the loss of oxygen.

9. In the circulation of the lungs, the blood in the arteries is blue, that in the veins, red.

10. The change from blue to red takes place while the blood is passing through the capillaries of the lungs. The change is due to the oxygen which the corpuscles of the blood take up in the lungs.

11. The pulse is caused by the beating of the heart.

12. The heart does a great deal of work every day in forcing the blood into different parts of the body.

13. Some of the white blood corpuscles escape from the blood-vessels through the thin walls of the capillaries.

14. These corpuscles return to the heart through small vessels called lymph channels or lymphatics.

15. The lymphatics in many parts of the body run into small roundish bodies called lymphatic glands.

16. The object of the lymphatics is to remove from the tissues and return to the general circulation the lymph and white blood corpuscles which escape through the walls of the capillaries.

CHAPTER XII. HOW TO KEEP THE HEART AND THE BLOOD HEALTHY.

1. The heart is one of the most important of all the organs of the body. If we take good care of it, it will do good service for us during a long life. Let us notice some ways in which the heart is likely to be injured.

2. Violent Exercise.—Did you ever run so hard that you were out of breath? Do you know why you had to breathe so fast? It was because the violent exercise made your heart beat so rapidly that the blood could not get out of the lungs as fast as the heart forced it in. The lungs became so filled with blood that they could not do their work well. Sometimes, when a person runs very fast or takes any kind of violent exercise, the lungs become so filled with blood that a blood-vessel is broken. The person may then bleed to death. It is very unwise to overtax the heart in any way, for it may be strained or otherwise injured, so that it can never again do its work properly.

3. Effects of Bad Air.—Bad air is very harmful to the heart and to the blood also. We should always remember that the blood of the body while passing through the lungs is exposed to the air which we breathe. If the air is impure, the blood will be poisoned. In churches and in other places where the air becomes foul, people often faint from the effects of the impure air upon the heart. It is important that the air of the rooms in which we live and sleep should be kept very pure by good ventilation.

4. Effects of Bad Food.—The blood is made from what we eat, and if we eat impure and unwholesome food, the blood becomes impure. We ought to avoid the use of rich or highly-seasoned foods, candies, and all foods which are not nutritious. They not only injure the blood by making it impure, but they cause poor digestion.

5. Plenty of Sleep Necessary.—If we should take a drop of blood from the finger of a person who had not had as much sleep as he needed, and examine it with a microscope, we should find that there were too few of the little red-blood corpuscles. This is one reason why a person who has not had sufficient sleep looks pale.

6. Proper Clothing.—We should be properly clothed, according to the weather. In cold weather we need very warm clothing. In warm weather we should wear lighter clothing. Our clothing should be so arranged that it will keep all parts of the body equally warm, and thus allow the blood to circulate properly. The feet are apt to be cold, being so far away from the heart, and we should take extra pains to keep them warm and dry.

7. Effects of Excessive Heat.—In very hot weather, many persons are injured by exposing themselves to the sun too long at a time. Persons who drink intoxicating liquors are very often injured in this way, and sometimes die of sunstroke.

8. Effects of Anger.—When a person gets very angry, the heart sometimes almost stops beating. Indeed, persons have died instantly in a fit of passion. So you see it is dangerous for a person to allow himself to become very angry.

9. Effects of Alcohol upon the Blood.—If you should take a drop of blood upon your finger, and put it under the microscope, and then add a little alcohol to it, you would see that the corpuscles would be quickly destroyed. In a few seconds they would be so shrivelled up that no one could tell that they had ever been the beautiful little corpuscles which are so necessary to health. When alcohol is taken as a drink, it does not destroy the corpuscles so quickly, but it injures them so that they are not able to do their work of absorbing and carrying oxygen well. This is one reason why the faces of men who use alcoholic drinks often look so blue.

10. Alcohol Overworks the Heart.—Dr. Parkes, a very learned English physician, took the pains to observe carefully the effects of alcohol upon the heart of a soldier who was addicted to the use of liquor. He counted the beats of the soldier's pulse when he was sober; and then counted them again when he was using alcohol, and found that when the soldier took a pint of gin a day his heart was obliged to do one fourth more work than it ought to do.

11. Effects of Alcohol upon the Blood-Vessels.—If you put your hands into warm water, they soon become red. This is because the blood-vessels of the skin become enlarged by the heat, so that they hold more blood. Alcohol causes the blood to come to the surface in the same way. It is this that causes the flushed cheeks and the red eyes of the drunkard. Sometimes, after a man has been using alcohol a long time, the blood-vessels of his face remain enlarged all the time. This makes his nose grow too fast, and so in time it gets too large, and then he has a rum-blossom.

12. Effects of Tobacco on the Heart and the Blood.—When a boy first tries to use tobacco, it makes him feel very sick. If you should feel his pulse just then, you would find it very weak. This means that the heart is almost paralyzed by the powerful poison of the tobacco. Tobacco also injures the blood corpuscles.

13. Tea and coffee also do their share of mischief to the heart. Those who use them very strong often complain of palpitation, or heavy and irregular beating of the heart.

14. Taking Cold.—People usually "catch cold" by allowing the circulation to become disturbed in some way, as by getting the feet wet, being chilled from not wearing sufficient clothing, sitting in a draught, and in other similar ways. It is very important for you to know that a cold is a serious thing, and should be carefully avoided.

15. Hemorrhage (hem'-or-rhage) or Loss of Blood.—A severe loss of blood is likely to occur as the result of accidents or injuries of various sorts, and it is important to know what to do at once, as there may not be time to send for a doctor before it will be too late to save the injured person's life. Here are a few things to be remembered in all such cases:

16. If the blood from a cut or other wound flows in spurts, and is of a bright red color, it is from an artery. If it is dark-colored, and flows in a steady stream, it is from a vein.

17. How to Stop the Bleeding of Wounds.—If the bleeding vessel is an artery, apply pressure on the side of the wound next to the heart. If the bleeding is from a vein, apply it on the opposite side. It is generally best to apply pressure directly over the wound or on both sides. The pressure can be made with the thumbs or with the whole hand. Grasp the part firmly and press very hard, or tie a handkerchief or towel around the wounded part and twist it very tight. If an arm or limb is the part injured, the person should be made to lie down, and the injured part should be held up. This is of itself an excellent means of stopping hemorrhage.

18. Nose-Bleed.—For nose-bleed a very good remedy is holding one or both hands above the head. The head should be held up instead of being bent forward, and the corner of a dry handkerchief should be pressed into the bleeding nostril. It is well to bathe the face with very hot water, and to snuff hot water into the nostril if the bleeding is very severe. If the bleeding is very bad or is not readily stopped, a physician should be called.

SUMMARY.

1. Violent exercise is likely to injure the heart.

2. Bad air makes the blood impure and disturbs the action of the heart.

3. Unwholesome food produces bad blood.

4. Too little sleep makes the blood poor.

5. Proper clothing is necessary to make the blood circulate equally in different parts of the body.

6. Violent anger may cause death by stopping the beating of the heart.

7. Alcohol injures the blood.

8. Alcohol overworks the heart.

9. Alcohol enlarges the blood-vessels.

10. Tobacco injures the blood.

11. Tobacco weakens the heart and makes the pulse irregular.

12. The use of strong tea and coffee causes palpitation of the heart.

13. A cold is caused by a disturbance of the circulation. A cold should never be neglected.

14. When an artery is wounded, the blood is bright red and flows in spurts.

15. When a vein is wounded, the blood is purple and flows in a steady stream.

16. To stop bleeding from an artery, press on the side of the wound towards the heart, or on both sides of the wound.

17. When a vein is wounded, press on the side away from the heart.

CHAPTER XIII. WHY AND HOW WE BREATHE.

1. An Experiment.—Let us perform a little experiment. We must have a small bit of candle, a fruit jar, or a bottle with a large mouth, and a piece of wire about a foot long. Let us notice carefully what we are about to do and what happens.

2. We will fasten the candle to the end of the wire. Now we will light it, and next we will let it down to the bottom of the jar. Now place the cover on the top of the jar and wait the results. Soon the candle burns dimly and in a little time the light goes out altogether.

3. What do you think is the reason that the candle will not burn when shut up in a bottle? A candle uses air when it burns. If shut up in a small, tight place, it soon uses up so much air that it can burn no longer. Try the experiment again, and when the candle begins to burn dimly, take it out quickly. We see that at once the light burns bright again.

4. Suppose we shut the stove draught tight, what is the result? The fire will burn low, and after a time