1. Homeostasis Homeostasis: The ability of the body to stay with in certain temperature and chemical(ph) range Homeostasis: The ability of the body to stay with in certain temperature and chemical(ph) range Set Point: the average value with in a given range Set Point: the average value with in a given range Dynamic Equilibrium: The fluctuation of the system with in a given range Dynamic Equilibrium: The fluctuation of the system with in a given range

2. Negative Feedback, Stability Most common in body, checks & balance Most common in body, checks & balance

3. Positive Feedback, Rapid change Very rare in the body, due to rapid change can cause death or disability quickly Very rare in the body, due to rapid change can cause death or disability quickly Positive feedback is frequently a normal way of producing rapid change. However, positive feedback can be harmful to the body. For example, if the body temperature rises above 104o F a dangerous positive feedback loop may be created. This high temperature will increase the metabolic rate, thus producing heat faster than the body can get rid of it. Thus, temperature rises still further, increasing metabolic rate and heat production even more. This becomes fatal at approximately 113o F.