Endocrine Histology General Information

Endocrine organs are defined by the ability to secrete chemical messengers or hormones.  Many endocrine organs are members of other organ systemsGroups of organs that work together to perform functions. as well.  Reproductive organs such as the ovary and the testes are also endocrine organs.  The hypothalamusA small but vital brain region controlling hormones, temperature, and autonomic functions. is located deepAway from the surface of the body. within the brain. It is known as a neuroendocrine organ. This indicates its dual membership in the nervous systemThe organ system that controls body functions using electrical and chemical signals. and the endocrine system.  The pancreasA gland that produces digestive enzymes and hormones like insulin and glucagon. secretes the hormones insulin and glucagonIncreases blood sugar by promoting glycogen breakdown. as a member of the endocrine system. It also secretes many digestive enzymesProteins that speed up chemical reactions in the body. as part of the digestive system.  ​

The organs that secrete these chemical messengers are the main players of the endocrine system. Equally important are the effectors, or the tissues and organs, that have receptors for hormones.  These target organsOrgans affected by specific hormones. are the effectors that produce a characteristic response when the connection is made between hormone and receptorA structure that detects stimuli..  The pancreas can make insulin all day long. However, it does not benefit someone whose cellsThe basic structural and functional units of life. no longer have receptors for insulin.  In this way, all organs of the body partake in the endocrine system as target organs.