University:
Kentucky State University
Course:
BIO 301 | Human Anatomy
Academic year:

2021
Views:

227

Pages:

1
Author:

Leilani Contreras

Hormones and Endocrine Glands Endocrine glands are distinguished from another type of gland in the body called exocrine glands. Exocrine glands secrete their products into a duct, from where the secretions either exit the body (as in sweat) or enter the lumen of another organ, such as the intestines. By contrast, endocrine glands are ductless and release hormones into the blood (Figure 11.1). Hormones are actually released first into interstitial fluid, from where they diffuse into the blood, but for simplicity we will often omit the interstitial fluid step in our discussion. Figure Exocrine gland secretions enter ducts from where their secretions either exit the body or, as shown here, connect to the lumen of a structure such as the intestines or to the surface of the skin. By contrast, endocrine glands secrete hormones that enter the interstitial fluid and diffuse into the blood, from where they can reach distant target cells. Figure summarizes most of the endocrine glands and other hormone-secreting organs, the hormones they secrete, and some of the major functions the hormones control. The endocrine system differs from most of the other organ systems of the body in that the various components are not anatomically connected; however, they do form a system in the functional sense. You may be puzzled to see some organs—the heart, for instance—that clearly have other functions yet are listed as part of the endocrine system. The explanation is that, in addition to the cells that carry out other functions, the organ also contains cells that secrete hormones.