BIOLOGY 20 Lecture Notes - Lecture 17: East Los Angeles College, Feedback, Negative Feedback
Document Summary
The body"s ability to detect change, activate mechanisms that oppose it and thereby maintain relatively stable internal conditions. State of the body fluctuates (dynamic equilibrium) within limited range around a set point. Negative feedback keeps variable close to the set point. 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. Loss of homeostatic control causes illness or death. Integrating (control) center: control center that processes the sensory information makes a decision" and directs the response. Effector: carries out the final corrective action to restore homeostasis. Brain sense change in blood temperature: if too warm, vessels dilate (vasodilation) in the skin and sweating begins (heat losing mechanism). If too cold, vessels in the skin contract (vasoconstriction) and shivering begins (heat gaining mechanism) Increased target organ hormone levels inhibit release of hormones.
