The endocrine system is composed of a series of hormonal organs and glands that produce and secrete hormones that the body uses for a wide range of functions. They control many different bodily functions, including breathing, metabolism, reproduction, movement, sexual development and growth.
Hormones are produced by specific organs and glands and are sent through the bloodstream to the various tissues in the body. They give the tissues signals telling them what they are supposed to do. When the glands do not produce the right amount of hormones, diseases develop that can affect many aspects of life.