MICROANATOMY

Detailed explanation-1: -Although a given hormone may travel throughout the body in the bloodstream, it will affect the activity only of its target cells; that is, cells with receptors for that particular hormone. Once the hormone binds to the receptor, a chain of events is initiated that leads to the target cell’s response.

Detailed explanation-2: -Once hormones find a target cell, they bind with specific protein receptors inside or on the surface of the cell and specifically change the cell’s activities. The protein receptor reads the hormone’s message and carries out the instructions by either influencing gene expression or altering cellular protein activity.

Detailed explanation-3: -Mechanism of Hormone Action Hormones are carried by the blood throughout the entire body, yet they affect only certain cells. The specific cells that respond to a given hormone have receptor sites for that hormone. This is sort of a lock-and-key mechanism.

Detailed explanation-4: -A steroid hormone directly initiates the production of proteins within a target cell. Steroid hormones easily diffuse through the cell membrane. The hormone binds to its receptor in the cytosol, forming a receptor–hormone complex.