As tissue X develops, it secrets something that induce tissue Y to develop indicating positive feedback mechanism. Related Theory Feedback mechanism is the mechanism of the body to maintain the levels of hormones in the body in the desired limits. An increase or decrease in the levels of the hormones triggers the feedback mechanism. Whenever there is a change in the normal state, the messages are sent to 'increase' secretions if there is a fall below normal or to 'decrease' secretions if there is a rise above normal to restore the normal body state. Such a mechanism is called a negative feedback mechanism.