1. An introduction to the endocrine system
The endocrine system is one of the most complicated of the body systems. It consists of glands widely separated from each other with no direct anatomical links.
This module describes the endocrine glands and the profound influences they exert on growth and development, as well as on the activities of various organs in the human body.
Endocrine glands create substances called hormones.
Unlike other glands (such as sweat glands), endocrine glands have no ducts. Instead they secrete their products (hormones) directly into the blood or lymph circulation.
By releasing hormones into the circulatory system, endocrine glands can influence and control a variety of specific organs and structures throughout the body, which may be some distance away from the gland.
The glands of the endocrine system include the pituitary, thyroid and parathyroids, adrenals, islets of Langerhans, and the gonads.