Negative Feedback Loops

Negative feedback occurs when the output of a system acts to oppose changes to the input of the system, with the result that the changes are attenuated. If the overall feedback of the system is negative, then the system will tend to be stable.  That being said negative feedback loops occur all around us in the environment and in mechanisms such as thermostats. When the temperature in a heated room reaches a certain upper limit the room heating is switched off so that the temperature begins to fall. When the temperature drops to a lower limit, the heating is switched on again. Provided the limits are close to each other, a steady room temperature is maintained. 

 Another great example of a negative feedback loop is in our bodies and this would be the physiological mechanism that causes blood sugar to return a baseline concentration after eating large amounts of sugar.  

The graph above is what Dr. Rood compiled after recording his blood sugar and then eating a snickers bar and drinking a sprite and continuing to take his blood sugar.  The graph displays to how his blood sugar increased and then started to return to a baseline after it peaked 190 mg/dL.  These are both great examples as to how negative feedback loops function.