The Endocrine System Defined
The endocrine system is a complex network of glands that produce and secrete hormones, which are chemical messengers, directly into the bloodstream. These hormones travel throughout the body to regulate various physiological processes, acting on specific target cells or organs.
Key Glands and Their Roles
Major endocrine glands include the pituitary, thyroid, adrenal, pancreas, ovaries (in females), and testes (in males). Each gland produces specific hormones responsible for controlling different functions, from regulating metabolism and growth to managing stress responses and reproductive cycles.
How Hormones Regulate the Body
Hormones act by binding to receptors on target cells or within target cells, triggering a specific biochemical or physiological response. For example, insulin, a hormone produced by the pancreas, instructs cells to absorb glucose from the blood, thus regulating blood sugar levels.
Crucial for Homeostasis and Development
This system is essential for maintaining homeostasis—the body's stable internal environment—and plays a critical role in growth, development, sexual function, sleep, mood, and appetite. Its coordinated action ensures the body functions correctly and adapts to internal and external changes.