Regulation of body temp
What is balancing heat gain against heat loss?
Hs = Hm ± Hcd ± Hcv ± Hr - He
What is Hm?
heat gain via metabolism.
metabolic heat: energy released within an organism through cellular respiration.
What are Poikilotherms?
- body temperature that varies with environment
- generally ectotherms meaning they have a low metabolic rate and thus produce little heat through metabolic activity.
ex) snake
What is water regulation?
Wi = Wd + Wf + Wa - We - Ws
What is Wi?
internal water of animal
What are kangaroos in the desert?
- Shelter in the shade (Hr)
- Lick their forearms (He)
- Dig into cool ground (Hcd)
What is Hcd?
heat gain/loss via conduction
conduction: movement of heat between objects in physical contact.
What are Homeotherms?
- body temperature is relatively constant even when the temperature in the environment varies.
- generally endotherms meaning they have a high metabolic rate and thus produce high levels of heat through metabolic activity.
ex) a bobcat and a human
What are kangaroo rats?
- live in desert environments where there is little water available.
- several adaptations: don't need to drink water (no Wd), some moisture from food (Wf), a lot of moisture from oxidation of food (Wf), lose little water through secretion or excretion (Ws), most water loss in We
What is Wd?
water taken in by drinking
What are Swifts?
- consequence: difficult to land.
- drink while flying by skimming (increase to Wd)
What is Hcv?
Heat gain/loss via convection
Convection: movement of heat between a solid body and moving liquid or gas.
ex) wind and water.
What are Ectotherms?
- low metabolic rate
- use external sources of heat
- often maintain temperature using behaviour.
- generally poikilotherms
ex) lizard or snake basking in the sun.
What are desert beetles?
- little ground water but lots of fog.
- morphological adaptations that allow it to condense water from fog, giving it drinking water (increase in Wd)
What is Wf?
Water in food eaten
What is Hr?
heat gain/loss via radiation.
radiation: heat transferred through electromagnetic radiation
ex) solar radiation, radiation from out body.
What are Endotherms?
- high metabolic rate
- use internal sources of heat
- often maintain temperature using physical adaptations such as insulation.
- gernerally homeotherms
ex) birds, humans
What is Wa?
water absorbed from air
What is He?
heat loss via evaporation
evaporation: heat is lost as water evaporates form the surface of an organism.
ex) sweat.
What are examples?
Eastern fence lizards, grasshoppers.
almost all plants are poikilothermic ectotherms except family araceae. (skunk cabbage - homeothermic and endothermic)
What is We?
What is Ws?
water lost to evaporation.
water lost to secretion and excretion.