thermoregulation Flashcards
what are ectotherms
organism that obtain their heat from the enviroments
what does this mean
their body temperature fluctuates with the environmental conditons
wh yis this a negative
the temperature limits their behaviour
what are endotherms
gain their heat from internal metabolic processes and body temp remains relativiely constant
how have animals adapted to live in cold conditions
small surface area to volume
fur
small ears
what happens if the temperature of the blood rises
the thermorecptors in the hypothalamus send more nerve impulses to the heat loss centre
what does this do
send signals down the parasympathetic nerve for body to carry out acrion through effectors
what happens when the blood returns to normal
the mechanisms are switched off
what happens in vasodilation
shunt diverts blood to capillaries near the surface of the skin
allows warm blood to pass near the surgace of the skin heat loss through radiation
increased sweating
water evaporates and cools us down
what happens with animals with fur
evaporation of water from mouth and tongue through panting
lowering of body hairs
prevents trapping of air which leads to insulation so more heat lost to the environment
what makes the hair lower
the hair erector muscles relax
nehavioural mechanisms
sheltering in the shade
what happens when it is cold
the thermoreceptors in the hypothalamus send impulse to the cold centre and increase impulses down the sympathetic nervous system
