Thermoregulation Flashcards
What is hyperthermia
when the core body temperature rises too high
what is hypothermia
when the core body temperature falls too low
non-fever hyperthermia symptoms
panting, dehydration, reddened gums, decreased urination
mild symptoms of hypothermia
weakness, shivering, lack of alertness
moderate symptoms of hypothermia
stiffness, low blood pressure, slow breathing
severe symptoms of hypothermia
difficult breathing, fixed pupils, inaudible heart beat
how does vasoconstriction as a warming strategy work
arterioles constrict restricting blood flow to the skin
how does the piloerection as a warming strategy work
erector muscles contract to raise hairs/feathers, trapping an insulating layer of air next to the skin which reduces heat loss via evaporation and convection
how does shivering as a warming strategy work
muscles contract rapidly generating heat by friction and respiration
how does the brown adipose tissue as a warming strategy work
cells take lipids and run them through the mitochondria to generate heat
where are brown adipose tissues found commonly
in larger quantities in neonates and hibernating animals
how does behavioural changes as a warming strategy work
curling up, moving to warmer areas
how does vasodilation as a cooling strategy work
arterioles dilate, allowing more warm blood close to the skins surface
how does pilorelaxation as a cooling strategy work
erector muscles relax and hair/feathers lie flat, allowing convection/evaporation
how does sweating as a cooling strategy work
secreted by glands onto skins surface and evaporates taking heat away
how does panting as a cooling strategy work
evaporation of water from mouth, nose, lungs and air sacs in birds
how does gular fluttering as a cooling strategy work
in birds rapid, throat flapping increases heat loss via mouth
how does behavioural changes work as a cooling strategies
stretching out, moving less and seeking shade/water
how does reduced metabolic rate work as a cooling strategy
adrenal and thyroid glands secrete adrenaline in thyroxine to lower metabolic rate and therefore reduce heat generation
what is negative feedback loop
- changes in temperature stimulates thermoreceptors, which trigger action potentials to the hypothalamus
- the hypothalamus sends information to the effectors
- a response occurs such as sweating and vasodilation of the arterioles to allow heat to escape from the skin if the bodies too hot
