What Are the Functions of the Endocrine System?
The major function of the endocrine system is to regulate numerous bodily functions, using specific hormones as messengers. Some hormones affect nearly all cells, while others regulate and affect only a single organ. Hormones act by regulating cell metabolism, by changing or maintaining enzyme activity in receptor cells, and by controlling growth and development, metabolic rate, sexual rhythms and reproduction. The amount of hormone produced at any one time is controlled by feedback mechanisms. These feedback mechanisms are interactions between the endocrine glands, the blood levels of the various hormones, and certain activities of the target organ. For example, when the pituitary gland increases the secretion of ACTH, the increased levels are detected by the adrenal gland, and the end result is more production of cortisone hormone by the adrenal glands. As the cortisol levels rise in the bloodstream, the hypothalamus eventually detects these higher levels and sends a message to the p
