Worth Publishers, Inc. Biology. Endocrinology is the science that deals with the study of the endocrine glands and their secretions, the hormones. Endocrine glands are small and are located throughout the body. They contain cells that secrete the hormones. Once the hormones are in the bloodstream they are carried to the various regions of the body where they cause certain organs to perform specific functions.
Hormones have an important effect upon body function.
Except for small amounts that may be held in the endocrine organs themselves, hormones are not stored in the body. To correct a hormone deficiency it is necessary to give repeated small doses rather than one large dose as is used for treating some other animal ailments. For good health and development, the glands must work together as a unit. If a gland should become either too active or not active enough, illness results. Reproduction in male is controlled by at least three hormones, two from the pituitary gland and one from the testes.