40.3- Thermoregulation

40.3- Thermoregulation

·         Regulation of internal temperature

·         Endothermy- warmed by the heat of metabolism , internal heat source (humans)

o   Need more food

·         Ecothermy-  warmed by environment, external heat source (reptiles)

o   Need less food because food is scarce

o   Larger fluctuation in body temperature

o   Regulate body temperature by moving to shading and basking

·         Variation in body temperature

o   Poikilotherms

§  Variation, body temp varies with environment

o   Homeotherms

§  Same, constant body temp

o   Never use warm-blooded or cold- blooded

·         Balancing heat Loss and Gain

o   Figure 40.11

o   Integumentary (Skin)

§  Insulation- fat, hair, feathers

§  Circulatory Adaptation- vasoconstrictions, vasodilation

§  Countercurrent Exchanges

§  Cooling by Evaporation

          ·         Heat or Loss

§  Behavior Response

          ·         Migration, Hibernation

§  Adjusting Metabolic Heat Production

            ·         Vary heat production to match changing rates of heat lose

             o   Shiver

§  Acclimatization in Thermoney

·         Shedding

·         Changes in Lipids