* Negative feedback loops are necessary for homeostasis.

•Feedback compares current conditions to the body’s comfort levels (=Set Ranges).

•Negative feedback counteracts change and brings the body back to homeostasis.
* Example
As you hold your breath, sensors in the circulatory and respiratory systems send information to the brain stem, the body’s respiratory control center. Sensors signal a gradual increase in carbon dioxide (CO2) and a decrease in oxygen (O2). The control center compares this information with the set points for these gases. When the change becomes too great, the control center takes steps to counteract it. Messages are sent to the muscles of the diaphragm and the rib cage to relax and then contract, forcing you to exhale and then inhale deeply.

	Created by Mrs. Reema Al Bitar about 9 years ago

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