The Endocrine Glands in Health and Disease

IN A NORMAL BODY the endocrine glands with their secretions function as a very delicately balanced mechanism. An excessive or deficient secretion of one or more of these glands may lead to an abnormal or diseased condition. Many such conditions are now recognized, several of which, such as diabetes, goiter, cretinism, and sexual impotency, may be successfully treated. This is true of man more than of animals. Some secretions are also being studied with the expectation of increasing certain'desirable bodily functions beyond what is considered normal. All animals have endocrine glands. There are nine of them : The pituitary gland, which is located at the base of the brain; the pineal body, also in.the brain; the thyroid, parathyroid, and thymus gland«, located in the neck; the adrenal glands, in the abdominal cavity near each kidney ; the pancreas, also in the abdominal cavity; and the testicles in the male and ovaries in the female. Because the secretions of these glands are emptied directly into blood vessels within themselves, instead of passing through excretory ducts as in ordinary glands, they are also known as ductless glands or glands of internal secretion.