Your Body

Bile is one of the digestive juices that help the body break down foods into usable elements.

It's a yellowish fluid produced by the liver and stored in a small pouch underneath the liver called the gall bladder. When food enters your small intestine, bile flows out of the gall bladder and into the intestine, where it helps break down fats.  read more »

Your spleen is a large organ inside your body, next to your stomach. But it's actually attached not to your digestive system, but to your blood stream.

Scientists have already discovered some of the spleen's functions, but they're not sure they've found them all. They do know that the spleen helps make new red blood cells, especially during childhood, and also produces certain kinds of white blood cells that help fight disease.  read more »

An anesthetic is a drug given to a person before an operation so that he won't feel pain. Even if you've never had a serious operation in a hospital, you probably received an anesthetic at some time in your life.

There are two kinds of anesthetic: general and local. A general anesthetic produces unconsciousness, so that a person can -sleep" through an operation without feeling a thing. A general anesthetic may be a gas that is inhaled or a drug that is injected directly into the bloodstream. The most commonly used are nitrous oxide (laughing gas), ether, chloroform, and sodium pentothal.  read more »

Certain kinds of baldness accompany illnesses. For instance, scarlet fever, pneumonia, and typhoid fever can sometimes result in the loss of hair. Gland problems and an imbalance of certain hormones in the body can lead to baldness. So can poor nutrition, scalp disease, and poor care of the hair and scalp.

But the kind of baldness that is the most common by far is called pattern baldness, and it has nothing to do with poor health. This is the kind of baldness that usually begins with a patch on the back of the head, or with receding hairlines around the temples.  read more »

The right half of the brain controls the left side of the body, and the left side of the brain controls the right side of the body.

In most people, the left side of the brain is better developed, so the right hand is stronger and more controllable than the left hand. But sometimes, the right side of the brain is more developed; then the person is left-handed.

Less than one person in six is left-handed. No one is sure why so many more people are right-handed. It's possible that the reasons go back to the days of the caveman.  read more »

Sometimes you might hear someone say: "You eat so much, you must have a tapeworm." A tapeworm is a kind of flatworm that lives in the digestive tract of another animal or person, and takes in food which its host has partially digested.

Many people believe that a person with a tapeworm will eat a great deal more than usual, in order to feed the tapeworm. Actually, the amount of food a tapeworm eats is small, and won't really affect a person's appetite.  read more »

When you move the muscles in your body, they produce a substance called sarcolactic acid, also called the "acid of fatigue." When too much of this acid forms around a muscle, the muscle becomes "tired."

The same sarcolactic acid is found in your blood too, as it travels to all parts of your body. So your entire body, and not just one muscle or set of muscles, becomes tired after a period of time.  read more »

The word arthritis means a swelling of the body joints, but not all arthritis involves swelling. In the type of arthritis known as rheumatism, the joints do swell up and eat into the cartilage that surrounds them.

Since this cartilage acts as a sort of "shock absorber" around the joint, the loss of cartilage and of certain minerals in the bones results in a stiff joint, which makes movement painful.  read more »

Tetanus is a disease caused by bacteria that secrete poisons. These bacteria usually enter the body through cuts or scratches. You may believe that tetanus can be caused only by cuts from old or rusty metal, but actually, a cut from any object can cause tetanus.

That's why when you get a serious cut, your doctor may give you a tetanus shot. This shot contains drugs that fight the tetanus germs. These drugs remain in the body for some time, so you don't have to get another tetanus shot every time you cut yourself.  read more »

Sometimes when your body is very tired, your lungs and the rest of your respiratory system may slow down until there's too little air in your lungs. As soon as this happens, your body sets off a quick movement, or spasm, in the muscles of your mouth, throat, and chest.

This spasm forces you to take in a deep breath of air — a reaction that we call a yawn. You yawn, then, not to stretch your jaw muscles or to relax or anything like that, but to take in more air.

Yawns can be contagious. Sometimes if you see a person yawning, you may yawn too!  read more »