B12:HomeostasisInAction Flashcards
what is your body temperature controlled by
the thermoregulatory centre in the brain
what does the thermoregulatory centre contain
receptors sensitive to the temperature of the blood
what does the skin contain
temperature receptors to send nerve impulses to the thermoregulatory centre
what happens if the body temperature is too high
blood vessels dilate and sweat is produced and both cause a transfer of energy from the skin to the environment
the name for blood vessels dilating
vasodilation
the name for blood vessels constricting
vasoconstriction
what happens if the body temperature is too low
blood vessels constrict, and sweating stops, reducing the transfer of energy to the environment, skeletal muscles contract and the exothermic reactions of respiration needed for muscle contraction raise the temperature
how does water leave the body
via the lungs and during exhalation
what is lost through the skin in sweat
water, mineral ions and urea
where is there no control of where water is lost
from the lungs
how does urea leave the body
along with water and mineral ions from the kidneys in urine
what happens if the body cells lose or gain too much water by osmosis
they won’t function efficiently
what are the kidneys important for
excretion and homeostasis
how does a healthy kidney produce urine
filtering the blood then reabsorbing all of the glucose and any mineral ions and water needed by your body
what leaves the body in urine
excess mineral ions and water along with urea
what hormone balanced the water level in the blood
ADH
what does ADH do
changes the amount of water absorbed by the kidney tubules
what is selective reabsorption
the absorption of what is needed by the body
on a hot day if you drink little and exercise a lot what effect does this have on your urine
produce very little urine
why do you produce little urine on a hot day
as you sweat a lot
what colour will your urine be after a hot day
dark concentrated yellow
on a cool day if you drink a lot and exercise a little what effect doe this have on your urine
produce a lot of urine
what colour will your urine be on that cool day
dilute, almost colourless
if your body is short of water what do your kidneys do
conserve it
