A hormone is a chemical messenger that helps regulate the activity of cells, tissues, and organs.
Hormones are produced mainly by endocrine glands and travel through the bloodstream to target organs. They influence growth, metabolism, reproduction, mood, sleep, blood sugar, and many other body functions.
Quick Fact
Only tiny amounts of many hormones are needed to produce significant effects in the body.
See Also
- Endocrine System
- Gland
- Receptor