Endocrine System - GCSE Biology Definition

The endocrine system is a network of glands in the body that produce and release hormones. These hormones are special chemical messengers that travel through the bloodstream to organs and tissues, helping to control many important functions. For example, they regulate growth, metabolism, sleep, and mood, as well as how the body uses energy. Key glands in the endocrine system include the pituitary, thyroid, and adrenal glands, along with the pancreas and reproductive glands like the ovaries and testes. This system works alongside the nervous system to keep the body balanced and responding correctly to different situations.