Negative Feedback

Negative feedback systems control many hormonal secretions. In such a system, an endocrine gland or the system controlling it is sensitive to the concentration of a substance the gland secretes or to the product of a process it controls. Whenever this concentration reaches a certain level, the endocrine gland is inhibited (a negative effect), and its secretory activity decreases. Then, as the concentration of the gland's hormone decreases, the concentration of the regulated product decreases too, and the inhibition of the gland ceases. When the gland is no longer inhibited, it begins to secrete its hormone again. Such negative feedback systems stabilize the concentrations of some hormones.