Physiology 2130 Lecture Notes - Lecture 1: Endocrine System, Extracellular Fluid, Thermostat
17 Jan 2017
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Document Summary
Our internal environment consists of the interstitial fluid and blood plasma. Our external environment is not only the region outside of our body but also the space and contents of respiratory/digestive/urogenital tracts. Homeostasis is the maintenance of relatively stable conditions of the internal environment regardless of the external one. The body maintains homeostasis using negative and positive feedback. Ex: house heating system set point is the temperature at which the room is set. Control center and sensor is the thermostat. And this is negative feedback because the controlled variable is stopped not the effector is the thermostat the controlled variable is heat turned on. Mechanism where the controlled variable actually stimulates its own production. Both negative and positive feedback control systems rely on 2 control systems to function properly: 1) the nervous system the nervous system (brain, spinal cord and all nerves) is good for rapid communication.
