Physiology 2130 Lecture Notes - Lecture 1: Ovulation, Endocrine System, Extracellular Fluid
Document Summary
Physiology 2130 distance studies module 1 introduction to human physiology. Physiology: study of function in living organisms. How organisms control internal environment regardless of external environment. Chemical and physical factors responsible for normal function and disease. Internal environment: fluid in which cells are bathed interstitial fluid + blood plasma. External environment: region outside the body, and space and contents of the digestive, respiratory + urogenital tracts. Homeostasis: maintenance of relatively stable conditions within internal environment regardless of external environment. Body does this by using negative and positive feedback control mechanisms. Components of a feedback system: set point, control center or integrator, effector, sensor, controlled variable. How the body controls temperature: control center = hypothalamus, set point = 37 degrees celsius, controlled variable = heat, sensor = nervous system. Nervous system signals blood vessels in the skin to dilate, and sweat glands to secrete body heat is lost to surroundings.