Unlike negative feedback, positive feedback loops amplify a stimulus, moving the system further away from its initial state. These mechanisms are less common and are typically used for processes that need to reach a specific completion point quickly. Childbirth and Oxytocin The process of labor is a classic positive feedback loop. Stimulus: The baby's head pushes against the cervix.
Mastering Biological Balance: A Guide to Feedback Mechanisms
Homeostasis is the state of steady internal conditions maintained by living things.
Blood Clotting: When a blood vessel is damaged, platelets release chemicals that attract even more platelets to the site until a plug is formed.
Stimulus: A change in the internal or external environment that triggers a response.
Feedback Mechanisms: How Biological Systems Maintain Balance
Students are typically asked to identify the Stimulus (what started it), the Effector (the muscle or gland that acts), and the Response (the physical outcome).