PS263 Study Guide - Midterm Guide: Ghrelin, Cholecystokinin, Histamine
Document Summary
Biologically, the necessary condition for life is a coordinated set of chemical reactions. Every chemical reaction in a living body takes place in a water solution at a rate that depends on the identity and concentration of molecules in the water, and the temperature of the solution. Behaviour is organized to keep the right chemicals in the right proportions at the right temperature. Homeostasis: biological processes keep body variables within a fixed range, sometimes is a set point. Allosasis: adaptive way in which body anticipates needs and avoids errors rather than correcting them. Most of the calories we expend a day go to basal metabolism (energy used to maintain constant body temperature while at rest) Poikilothermic/ectothermic animals: cold blooded, depend on external sources for body heat, regulate temperatures behaviourally. A warmer animal has warmer muscles and runs faster with less fatigue. Physiological changes that regulate body temperature depend on areas in and near hypothalamus.
