Physiology 2130 Lecture Notes - Lecture 1: Extracellular Fluid, Heating System, Blood Plasma

• School: Western University
• Department: Physiology
• Course: Physiology 2130
• Professor: John Bell

Document Summary

Physiology = study of function in living organisms: mechanisms by which organisms control internal environments regardless of what happens in the external environment. Internal environment= fluid in which cells of our body are bathed: interstitial fluid and blood plasma. External environment = region outside the body: space and contents of the digestive, respiratory and urogenital tracts. Homeostasis: maintenance of relatively stable conditions within the internal environment regardless of what is happening in the external environment: body maintains homeostasis by using neg. and pos. feedback control mechanisms, ex. Maintaining constant body temperature, water balance, salt concentrations, etc. Contain a set point, a control center (integrator), effector, controlled variable, sensor (receptor) Heating system in house: set point = temperature the room is set, sensor / control center = thermostat, effector = furnace, controlled variable = heat o an. Called a negative feedback system because the controlled variable eventually shuts off its own production by the effector.