Hormones assist animals to coordinate their chemical reactions. Hormone is a chemical messenger that controls a variety of physiological processes in living things. It is produced by glands in the body. Hormones work on organs that are often far removed from the gland. As a result, these hormones are released by glands in the bloodstream and delivered to the organ of action. The endocrine system is responsible for the regulation of physiological processes, as well as hormone control and coordination. The nervous system, in conjunction with the endocrine system, regulates and coordinates physiological activities in our bodies.