Endocrine coordination is a mechanisme which regulates the actions of many of the body's organs, in a slow but prolonged manner.

It is carried out by the endocrine system, which is composed of a series of endocrine glands that produce and secrete hormones.

The endocrine system

The vertebrate endocrine system consists of more than a dozen glands. Some of these, such as the tyroid and the pituitary gland, are endocrine specialists; their main function is secreting hormones into the blood. Several other glands have both endocrine and nonendocrine functions. The pancres, for example, contains encocrine cells that secrete two hormones that influence the level of glucose in the blood. The pancreas also has nonendocrine cells that secrete digestive enzymes into the intestine via ducts.

The figure here shows the locations of the human endocrine glands.

There is a close association between the endocrine sytem and the nervious system. For example, the hypothalamus, which is part of the brain, secretes many hormones that regulate other endocrine glands, especially the pituitary (called also the hypophysis). We can obseve this association on the next drawing.

The hypotalamus is the master control center of the endocrine system. Its endocrine signals directly control the pituitary gland, which in turn secretes hormones that influence numerous body functions.

The hypothalamus receives information from nerves about the internal condition of the body and about external environment.