What are the Endocrine glands and what are their purpose?
Endocrine glands are the group of glands that secrete hormones directly into the blood (rather than through a duct.) You can think of Endocrine glands as messengers in a similar way to the nervous system, but instead of communicating via nerves the glands communicate with the body by releasing hormones. These hormones have the effect of regulating a lot of your metabolic activity...mood, growth, sleep, and metabolism are examples. The major glands are:
- Pituitary (all sorts of them...GH, TSH, ACTH, FSH, PRL.)
- Pancreas (insulin, glucagon)
- Ovaries (estrogens, progesterone.)
- Testes (testosterone)
- Thyroid (TH, T4, T3)
- Adrenal (cortisol, adrenaline.)
- Hypothalamus (a neuroendocrine gland)
- Stomach (produces ghrelin.)
- Pineal (produces melatonin.)
There are others, of course, including the heart, kidney, fat cells...basically anything that secretes a hormone into the blood directly.
Endocrine glands main task is to secrete or release hormones directly into blood stream to various specific tissues or organs instructing them to carry out their functions.
Along with nervous system the endocrine system also plays role in integrating and coordinating the body functions, but it is a slow and persistent mode compared to nervous system.
- Acts through chemical messenger called hormones at the level of target cells / tissues.
- Endocrine glands release hormone directly into blood (within itself), hence called endocrine. (endon = within ; crine = secrete) Blood carries it all around (upto target cells) in the body.
- The study of endocrine glands and hormones secreted by them is known as endocrinology.