Biology Forums - Study Force

In negative feedback, a change in the variable that is being monitored triggers the control mechanism to stop or reverse that change. This is recognized with the release of the ADH Hormone. When the body is dehydrated, osmoreceptors in the hypothalamus shrink. Water moves into the blood stream trying to compensate. AHD is then released to reabsorb more of the water and nutrients in the kidney. When the kidneys retrieve more water and less urine production, homeostasis is achieved. This causes the hypothalamus to swell, inhibiting the release of AHD (Anti-diuretic hormone).

In positive feedback, the change is amplified. For example, a decrease in progesterone, a hormone associated with pregnancy, is believed to initiate small contractions of the uterus or womb. In turn, the contractions bring about the release of another hormone, oxytocin, which causes much stronger contractions of the uterus. Once the baby is expelled, the uterine contraction stop, which in turn stops the release of oxytocin.

Is this supposed to be your question?