thermoregulation Flashcards
define thermoregulation
process by which body temperature is controlled
what are the thermoreceptors for thermoregulation
hypothalamus
skin
what are the effectors for thermoregulation
sweat glands
arterioles in the skin
hair erector muscles
skeletal muscles
liver
describe the role of the human nervous system in returning a slighly raised body temperature to its normal level
Thermoreceptors in the skin/hypothalamus detect the increase in blood temperature
They send impulses to the heat loss centre via sensory neurones
Nerve impulses are then sent down motor neurones to various effectors to lose heat
e.g. sweat glands are stimulated to release sweat + vasodilation occurs to increase blood flow to skin surface
how do sweat glands reduce the body temperature?
sweat deposits on the surface of the skin
the heat from the blood in arterioles is absorbed by sweat
the heat energy is used to break H+ bonds in the water
the water evaporates
this takes heat from the body which has cooling effects
the role of skeletal muscles
shivering causes rapid contraction of muscles
this increases rate of respiration as muscle contractions require ATP; more energy is released which warms the body
what happens at the heat loss centre
stimulate sweat glands to release sweat
vasodilation
hair erector muscles lay flat
skeletal muscles relax
what happens at the heat gain centre
inhibit sweat glands
vasoconstriction
hair erector muscles stand up
skeletal muscles constrict leading to shivering
