Homeostasis

Homeostatic Control Systems
Negative Feedback: The process by which a change is minimized. (COMPENSATION).
• Cold temp. causes increased heat production. Thus body temperature is elevated.
• Dehydration causes increased thirst. Decreased urine volume. This causes the body to accumulate fluid.
• Hypocalcemia causes Ca++ mobilization from bones. The increased plasma calcium corrects the hypocalcemia.
• Fall in blood pressure causes increased heart rate, force, increased blood volume. These all elevate blood pressure.
Positive Feedback: (amplification) mechanisms.
o Blood clotting. Platelets release chemicals which attract more platelets and trigger them to release their chemicals.
o Birth process: As infant moves along the birth canal, stretching tissues and stimulating stretch receptors, this cau...