BIOLOGY 225 Lecture Notes - Lecture 10: Thermoregulation, Absorbance, Ice Crystals
Document Summary
Temp. has profound effects on biological functions: heat balance look at ppt, heat transfer. Conduction direct transfer of kinetic energy of molecular motion; takes place between physical bodies that are in contact w/ each other. Influenced by the medium water is v good conductor of heat: higher resistance (insulation) = lower conductance. Convection mass movement of gas or fluid contributes to renewal of fluid at the boundary; accelerates heat transfer constant loss of heat. Radiation heat transfer takes place in absence of direct contact gain heat through this due to emission of electromagnetic radiation. Evaporation always removes heat from body. Need 2 factors: high temp. and low humidity. Rate depends on convection and radiation: reflectance & absorption of light. Absorbance + reflectance = 1: common insulators. External (on body surface): hair, feathers, air. Ectotherms animals that depend on environmental temp to maintain body temp. Endotherms physiological thermoregulation by producing heat through metabolic means.
