osmo and thermoregulation

endotherm definition

able to produce heat through metabolic processes such as respiration

ectotherm definition

relies on external environment to produce heat

sweating to lose heat

evaporation of water requires heat E
latent heat for vaporisation of water is high for water, sweating releases a lot of E
lose heat by radiation

when cold/trapped etc. why do we lose heat

heat generated by metabolic rate - respiration, insufficient food to maintain high metabolic rate, no heat lost by radiation
(if small) large SA:Vol ratio, lose heat quickly)

heat and animal

muscle contraction/respiration releases heat energy
core temperature does not rise as much as skin temperature
blood temperature rise detected by hypothalamus from receptors of skin
vasodilation causes skin temperature to rise
water from sweat evaporates
evaporation removes heat so skin temperature rises and then levels off

positive feedback for cold

body cools, positive feedback makes it colder. bcs respiration is slower, enzymes have less kinetic E, metabolism releases less heat E