Final answer:
Feedback is a system's response to a change that affects the change itself, with negative feedback reducing excessive responses and positive feedback intensifying responses until an endpoint is achieved. Examples include blood glucose regulation for negative feedback and childbirth for positive feedback.
Step-by-step explanation:
Feedback is the response of a system when a change is made that itself influences the change. There are two main types of feedback mechanisms: negative feedback and positive feedback.
Negative feedback serves to reduce an excessive response and maintain a state of equilibrium within the body's systems. An example of a negative feedback mechanism is the regulation of blood glucose levels. When blood glucose levels rise, the pancreas secretes insulin to lower it, and when blood glucose levels fall, the pancreas secretes glucagon to raise it.
Positive feedback serves to intensify a response until an endpoint is reached. Examples of positive feedback include blood clotting, where the presence of a clot stimulates the formation of more clot, and childbirth, where contractions increase in strength and frequency until delivery.