Endocrine Glands

The endocrine system is made up of ductless glands that secrete chemical substances called hormones into the bloodstream. These hormones regulate the internal environment of each cell and organ, and aid in maintaining homeostasis throughout the body.

The endocrine glands are the pineal, pituitary, thyroid, parathyroids, thymus, adrenals, pancreas, and the gonads (ovaries or testes). Together they are referred to as the endocrine system. The hypothalamus is a gland in the brain that serves as the command center; it operates the endocrine system through the pituitary, a pea-sized gland located under it, which directs the work of all the other glands. The thyroid, a gland in the neck, regulates the body's metabolism. The parathyroids, which are attached to the thyroid, control the amount of calcium and phosphate in the bloodstream. The adrenal glands, located near the kidneys, produce adrenaline, which arouses the body to respond to stress and emergencies and regulates other hormones active in carbohydrate metabolism. The pancreas secretes insulin, which regulates the level of sugar in the bloodstream. The gonads regulate sexual development, ovulation, and growth of sex organs.

See also Fight-flight reaction; Hormones ; Hypothalamus .



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(MLA 8th Edition)