Overview of Endocrinology – vivo.colostate.edu

Two systems control all physiologic processes: The nervous system exerts point-to-point control through nerves, similar to sending messages by conventional telephone. Nervous control is electrical in nature and fast. The endocrine system broadcasts its hormonal messages to essentially all cells by secretion into blood and extracellular fluid. Like a radio broadcast, it requires a receiver to …

http://www.vivo.colostate.edu/hbooks/pathphys/endocrine/basics/overview.html