The endocrine system is a collection of glands that produces these hormones, which are necessary for normal bodily functions. The hormones regulate metabolism, growth and sexual development. These glands release the hormones directly into the bloodstream, where they are transported to organs and tissues throughout the entire body.
Nervous control is electrical in nature and fast.
The endocrine system broadcasts its hormonal messages to essentially all cells by secretion into the blood. Like a radio broadcast, it requires a receiver to get the message, that is, target cells must bear a receptor for the hormone being broadcast in order to respond.