SB7g Thermoregulation Flashcards
At what temperature should our body be around and why?
37˚C so that enzymes that control chemical reactions can work.
Explain what happens when our body temp goes above or below 37˚C.
.a temp above 37˚C results in fever
.a temp below 37˚C results in hypothermia
.both conditions affect enzyme activity
What does thermoregulation unsure?
that conditions are kept optimum for enzymes, at 37˚C .
Explain how thermoregultation takes place (the role of the dermis).
.the dermis has receptors which sense when the skin temp changes
.when a change is detected a nerve impulse sends a message to the thermoregulatory centre so that it must do something to return the body temp back to normal
What happens when we are cold? (the role of the epidermis)
.vasoconstriction
.hair erector muscle contracts (hair stands up)
.no sweat is produced
What happens when we are hot? (the role of the epidermis)
.vasodilation
.hair erector muscle relaxes (hair lies flat)
.sweat is produced
What happens when we are cold? (the role of the hypothalamus)
.sends nerve impulses to the muscles to start shivering and erect hairs
.sends impulses to the blood vessels to make them contract (less heat loss)
What happens when we are hot? (the role of the hypothalamus)
.sends nerve impulses to the sweat glands to release sweat
.sends impulses to the blood vessels to make them dialate (cool body down)
Why do we shiver when we are cold?
muscles contract and relax rapidly, energy is released to warm us up.
What does vasoconstriction do?
.narrows blood vessels
.this reduces blood flow in the capillaries near the skin surface, reducing energy transfer to the surroundings
What does vasodilation do?
.widens blood vessels
.this increases blood flow in the capillaries near the skin surface, increasing energy transfer to the surroundings
