Laura Cheney, age 8, of Murray, Utah, for her question:

WHAT ARE GLANDS?

If our body's gland system becomes upset, doctors can often treat the problem successfully and put us back into good health. If a gland is not producing enough of its hormone, for example, medical men can often give needed hormones. Or if a gland secretes too much hormone, at times a surgeon can be called upon to remove the gland.

A gland is an organ that manufactures and secretes needed substances into or out of our bodies. There are two kinds of glands: exocrine and endocrine.

An exocrine gland discharges its product through tubes or ducts into the intestines or outside the body.

Among the exocrine glands are the salivary glands, the mucus glands, the tear glands, the sweat glands and the liver. Also included are the mammary glands that produce milk, the sebaceous glands that produce oil, and the glands of the stomach and intestines that produce substances needed for food digestion. The pancreas is both an exocrine and an endocrine gland.

Releasing their products directly into the bloodstream are the endocrine glands, often called ductless glands or glands of internal secretion.

Endocrine glands produce substances called hormones. Small amounts of these hormones affect the growth of the body and its shape. They also affect the way in which the body uses food. Most important of all, hormones allow the body to make the proper adjustments to changes in the outside world.

A balance of the endocrine glands is important. For a person to be in good health, his body's glands must work together as a unit.

Here are the important endocrine glands: the pituitary, the hypothalamus, the pineal gland, the thyroid, the parathyroid, the thymus, the pancreas, the adrenal glands, the sex glands and the glands that produce hormones in the stomach and intestines.

One of the most complex glands is the pituitary, which is located at the base of the brain. It has three parts and produces many different hormones, some of which are designed to control the activities of other endocrine glands.

Another of the important glands is the pancreas. Two hormones are produced here: insulin and glucagon. Insulin helps blood sugar gain entrance to the body cells so that it can be used for energy. Glucagon acts on the liver, causing it to release stored sugar into the bloodstream.