1. Positive and Negative Feedback Loops

2. A. Negative Feedback CO 2 O2O2 1. Control System that counteracts any change in the body that moves conditions above or below a set point. 2. Keeps internal environment stable. (Homeostasis!!) 3. Shuts off original stimulus or reduces intensity.

3. Negative Feedback Equilibrium Starting Situation

4. Example of Negative Feedback

6. Sympathetic Nervous System Parasympathetic Nervous System Fight Or Flight ResponseCalming return to Equilibrium

7. B. Positive Feedback 1.Control system that uses information from sensors to increase the rate of change away from set points. 2.Not common, only used when rapid change is needed. 3.Turns on Stimulus.

8. Positive Feedback Explosion Blocking No Equilibrium

9. Example of Positive Feedback MicrophoneAmplifier Explosion

10. Example of Positive Feedback

11. Pancreas Releases Insulin to Lower Blood Sugar Liver Releases Glucagon to Raise Blood Sugar

12. Positive Feedback Negative Feedback