BIOA02H3 : Lec21 - Thermoregulation.doc

• School: UTSC
• Department: Biological Sciences
• Course: BIOA02H3
• Professor: Mary Olaveson

Document Summary

1 thermoregulation: types of heat exchange, categories of thermoregulation, poikilothermy / ectothermy, behavioural thermoregulation. Freeze tolerance and avoidance: endothermy / homeothermy, the vertebrate thermostat, temperature set-point, thermoneutral zone, defenses against the heat, defenses against the cold, hibernation. Four major mechanisms by which heat can be exchanged between animal and its environment: dry heat transport. No loss of water: conduction, direct transfer of heat between animal and environment (two physical bodies. Heat conduction: convective heat loss, heat loss to moving stream of air or water. Maintains large gradient: radiation, transfer of heat between two physical bodies that are not in direct contact. Liquid becomes gas (heat loss: release of energy in form of heat (exothermic reaction) Rate of dry heat transfer is proportional to t (body) t (ambient) 3 categories of thermal relations: poikilothermy, body temperature fluctuates with environment, usually associated with ectothermy, ectothermy, body heat derived from environment, homeothermy, body temperature remains constant, usually associated with endothermy.