Platelet aggregation and accumulation in response to injury is an example of positive feedback. Negative feedback brings a system back to its level of normal functioning. Adjustments of blood pressure, metabolism, and body temperature are all negative feedback.
The control of blood sugar (glucose) by insulin is a good example of a negative feedback mechanism. When blood sugar rises, receptors in the body sense a change. In turn, the control center (pancreas) secretes insulin into the blood effectively lowering blood sugar levels.
Examples of processes that utilize negative feedback loops include homeostatic systems, such as: Thermoregulation (if body temperature changes, mechanisms are induced to restore normal levels) Blood sugar regulation (insulin lowers blood glucose when levels are high ; glucagon raises blood glucose when levels are low)
