The Endocrine System
The endocrine system is the body's network of glands that produce more than fifty different known hormones or chemical messengers to maintain and regulate basic bodily functions. It is second only to the nervous system as the great controlling system of the body. Whereas nerve impulses from the nervous system immediately prod the body into action, hormones from the endocrine system act more slowly to achieve their widespread and varied effects. The bodily processes regulated by the endocrine system go on for relatively long periods of time. Some go on continuously. These life processes include growth and development, reproduction, immunity (the body's ability to resist disease), and homeostasis (the body's ability to maintain the balance of its internal functions).