Compare and contrast the two feedback mechanisms our bodies use to maintain homeostasis what would happen if our thermoregulation used positive feedback to maintain homeostasis

To compare and contrast the two feedback mechanisms our bodies use to maintain homeostasis, we need to understand what these mechanisms are.

1. Negative feedback: This is the most common type of feedback mechanism used by the body. It works to keep a variable within a narrow range or set point. When the variable deviates from the set point, negative feedback mechanisms act to bring it back to normal. For example, in thermoregulation, when body temperature rises above the set point, negative feedback mechanisms cause responses like sweating and vasodilation (expansion of blood vessels near the skin) to cool down the body. If body temperature drops below the set point, negative feedback mechanisms cause shivering and vasoconstriction (narrowing of blood vessels near the skin) to warm up the body.

2. Positive feedback: Unlike negative feedback, positive feedback mechanisms amplify the deviation of a variable from the set point. They are not typically used to maintain homeostasis but rather to create a rapid change or response. A common example of positive feedback is blood clotting. When there is an injury and blood vessel damage occurs, platelets release chemicals that attract more platelets to the injury site, leading to the formation of a blood clot. As more platelets accumulate, the signal for clotting becomes stronger, resulting in the clot growing until bleeding stops.

Now, if our thermoregulation used positive feedback to maintain homeostasis, it would create an unstable situation. Positive feedback would amplify the deviation of body temperature from the set point rather than correcting it. For example, if body temperature increased slightly above the set point, positive feedback mechanisms would intensify the rise in temperature, potentially leading to a dangerous condition like heat stroke. Similarly, if the body temperature dropped below the set point, positive feedback mechanisms would further decrease the temperature, potentially leading to severe hypothermia.

In summary, positive feedback mechanisms are not suited for maintaining homeostasis, as they tend to create a self-amplifying cycle. Negative feedback mechanisms are the primary means our bodies use to bring variables back to the set point and maintain stability.