Final answer:
An endocrine hormone is a chemical messenger secreted by endocrine glands into the bloodstream that travels to and affects only cells with matching receptors, leading to a specific biological response.
Step-by-step explanation:
The term you are looking for is an endocrine hormone. An endocrine hormone is a chemical messenger molecule that is secreted by a gland of the endocrine system and released into the bloodstream.
Once in the bloodstream, the hormone travels until it finds a specific target tissue that possesses the receptor it can bind to. For instance, a hormone like estrogen is released from endocrine glands, travels through the body, and interacts only with cells that have estrogen receptors.
These target cells, upon binding with the hormone, will exhibit a specific response.
How hormones work in detail: Hormones are considered the messenger molecules of the endocrine system and are vital for maintaining homeostasis. For example, hormones from the pituitary gland may stimulate other glands to release additional hormones, which in turn affect body functions.
Each hormone affects only certain cells because these cells have receptor proteins that are specific to that hormone, whether they are located on the cell surface or within the cell itself.
The binding of a hormone to its receptor is a crucial event. It triggers a series of biological processes within the target cell that leads to a specific response, involving regulation, or adjustment of physiological processes.