One way this is achieved is through ‘feedback loops’. The endocrine system is a tightly regulated system that keeps the hormones and their effects at just the right level. The hormones can set off a cascade of other signaling pathways in the cell to cause an immediate effect (for instance, insulin signaling leads to a rapid uptake of glucose into muscle cells) or a more delayed effect (glucocorticoids bind to DNA elements in a cell to switch on the production of certain proteins, which takes a while to produce). If the hormone fits the cell wall, then it will work. A hormone can be thought of as a key, and its target site (such as an organ) has specially shaped locks on the cell walls. Homeostasis (constant internal balance).Ī hormone will only act on a part of the body if it ‘fits’.Some of the roles of the endocrine system include: The endocrine pancreas also releases hormones such as insulin and glucagon, which are hormones predominantly related to glucose metabolism, into the blood stream. It releases certain enzymes to aid in digestion delivered to the gut via the pancreatic duct. The pancreas is both an endocrine and exocrine organ. Exocrine glandsĪn exocrine gland, unlike an endocrine gland, is a gland that secretes substances (electrolytes, proteins or enzymes) straight to a target site via ducts or tube. The field is rapidly expanding due to understanding of the cellular pathways that hormones stimulate and the discovery of new hormones and their actions. This branch of medicine – relating to the study of the endocrine system – is called endocrinology and is practiced by endocrinologists. The endocrine system works with the nervous system and the immune system to help the body cope with different events and stresses. The hormone can also create changes in the cells of surrounding tissues (paracrine effect). Hormones can be thought of as chemical messages.įrom the blood stream, the hormones communicate with the body by heading towards their target cell to bring about a particular change or effect to that cell. Endocrine glands make chemicals called hormones and pass them straight into the bloodstream.

Adrenal cortex and medulla hormones