90 likes | 398 Views
thermoregulation. Regulating vs. Conforming. Heat Exchange. Countercurrent heat exchange. Outgoing arteries pass heat to incoming veins Pros. Warmer blood to torso Less heat loss. Seasonal Thermoregulation. Acclimatization (Seasonal adjustment) Coat thickness Fat storage
E N D
Countercurrent heat exchange • Outgoing arteries pass heat to incoming veins • Pros • Warmer blood to torso • Lessheat loss
Seasonal Thermoregulation • Acclimatization (Seasonal adjustment) • Coat thickness • Fat storage • Expression of enzymes with different optimal temp range • Cryoprotectants • Heat-shock proteins
Torpor • Low metabolic rate and activity level • During times of scarce resources and/or extreme temps • Periodic arousals enable maintenance • Hibernation = extreme winter torpor • Estivation = summer torpor
Metabolic Rates • Standard Metabolic Rate (Ectotherms) • Depends greatly on temperature • Basal Metabolic Rate (Endotherms) • Tends to be much greater than ectotherm SMR
Thermoreview • Contrast… • regulators and conformers • adaptation and acclimatization • hibernation and estivation • standard and basal metabolic rates • What is the benefit of having arteries and veins run directly alongside each other?