An endocrine gland , incretory gland or hormonal gland (formerly also called blood vessel gland ) is a gland that releases its substances - in contrast to an exocrine gland - directly into the blood without a duct ( endocrine "releasing inward", "inner secretory"). Since all hormones are secreted endocrine , the terms "endocrine" and "hormone gland" are used interchangeably. The endocrine glands are part of the endocrine system , which includes the hypothalamus as the “master gland” . The hypothalamus and pituitary gland control numerous functions in the vertebrate endocrine system. The endocrine system also includes isolated endocrine cells of the gastrointestinal tract. From these hormones are excreted, which regulate food intake and digestion; other endocrine cells are found in the heart and kidneys (see tissue hormones ). The scientific discipline that deals with hormones is called endocrinology .
Examples of endocrine glands are the pituitary gland , thyroid and parathyroid glands, and the adrenal glands . The pancreas is both endocrine ( islets of Langerhans ) and exocrine (digestive enzymes) active. In addition to the production of sex cells, the gonads ( testes or ovaries ) also have an endocrine function, which consists in the production of sex hormones . The placenta can also be viewed as an endocrine gland in this sense.
The endocrine system and nervous system are structurally, chemically and functionally linked. While it is common to distinguish between the hormonal and nervous systems, the boundary between these two control systems is fluid, and homeostasis is largely based on the overlap between the two.
The first experimental proof of the existence of an “internal secretion” came in 1849 from the Göttingen physiologist Arnold A. Berthold . As the first human disease to be traced back to the failure of a gland with internal secretion, the English doctor Thomas Addison described adrenal insufficiency in 1855 .
- Neil A. Campbell , Jane B. Reece : Biology. Spektrum-Verlag, 2003, ISBN 3-8274-1352-4 , p. 1148
- Neil A. Campbell , Jane B. Reece : Biology. Spektrum-Verlag, 2003, ISBN 3-8274-1352-4 , p. 1147
- Neil A. Campbell , Jane B. Reece : Biology. Spektrum-Verlag, 2003, ISBN 3-8274-1352-4 , pp. 1147-1148
- Otto Westphal , Theodor Wieland , Heinrich Huebschmann: life regulator. Of hormones, vitamins, ferments and other active ingredients. Societäts-Verlag, Frankfurt am Main 1941 (= Frankfurter Bücher. Research and Life. Volume 1), in particular pp. 9–35 ( History of hormone research ), here: pp. 12–15 and 19–21.