BIOL 3P30 Lecture Notes - Lecture 28: Billfish, Brown Adipose Tissue, Sympathetic Nervous System
22 Aug 2015
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Lecture 11 cellular adaptations to temperature changes. Exploiting futile metabolic cycles for heat production in endotherms and regional. Acute thermal stress and the heat shock proteins: mechanisms of thermal tolerance in ectotherms: There are some kind of fish that are ectotherms except in their brain and eyes. Vast majority of animal species are cold-blooded", i. e. they are ectotherms with core body temperatures = ambient temperature. Ectotherms may be homeothermy (behavioural maintain constant body temperature) or poikilothermic (tolerate a range of body temperature- energetically cheap) Lots of species, including birds and mammals, are hot-blooded", i. e. they are endotherms that produce enough extra metabolic heat to raise core temperature above ambient. Endotherms are often homeothermic because they can physiologically regulate rates of heat production and/or loss. Futile metabolic cycles increase metabolic heat production in response to cold. Mammalian brown adipose tissue (bat) the billfish heater organ. Surface area vs. volume: it"s hard being a small endotherm.
