Q.13 What do you mean by feedback Mechanism? Explain.
Feedback Mechanism
Endocrine glands do not secrete their hormones at a constant rate. The rate varies with the needs of the body. Like many other functions in body, the secretion of hormones is also regulated by feedback mechanisms.
Definition:
Feedback mechanism means the regulation of a process by the output of the same process.
Types:
Feedback mechanisms are of two types i.e. positive and negative feedbacks.
In negative feedback, the output of a process decreases or inhibits the process. This mechanism works to return a condition towards its normal value. For example, when the blood glucose concentration rises, pancreas secretes insulin. It decreases the blood glucose concentration. Decline in the blood glucose concentration to a normal set-point inhibits the secretion of insulin. In other words, the blood glucose concentration (output) controls the process i.e. the secretion of insulin and glucagon.
In positive feedback the changes resulting from a process increase the rate of process. For example, suckling action of an infant stimulates the production of a hormone in mother. This hormone works for the production of milk. More suckling leads to more hormones which in turn leads to more milk production.