Negative  feedback  to  regulate
   homeostasis.
<P>
   Animals  can  maintain  a  constant  internal environment in a process
   called homeostasis.
<P>
   Regulating  room temperature depends on a thermostat (the hypothalamus
   in humans) that detects temperature changes around a set point.
<P>
   A  stimulus  in  the  form  of  temperature  change in the environment
   triggers a response that activate mechanisms to reverse that change.