Homeostasis and Excretion(Kidneys) Flashcards
what is homeostasis?
the maintenance of a constant internal environment
What is excretion?
the removal of waste products
Role of the kidneys [2]
a homeostatic organ controlling water and salt(ion) concentration in the body, and an excretory organ concentrating nitrogenous waste in a form that can be eliminated
means of gaining water [3]
drinking
eating
cell respiration
means of losing water(most to least) [4]
urine
sweat
exhaled air
faeces
tissue fluid
composition[1]
role[1]
watery solution of salts glucose and other solutes surrounding all cells of the body forming pathways for the transfer of nutrients between blood and cells.
substances kept constant in the body [5]
water and salts
temperature
carbon dioxide levels
blood pH
concentration of dissolved glucose
why is homeostasis important
cells only function properly if the tissue fluid provides them with optimum conditions
tissue fluid too dilute/too much water or too concentrated/too many solutes?
cells swell/shrivel up and do not do their jobs as efficiently
tissue fluid pH wrong or body temperature much different from 37˚C
affect cell enzymes activity and efficiency
what does urea do to cells. what to do with urea?
toxic to cells. prevent from building up in blood and tissue fluids
how much waste products in 1 litre of urine
40g
main solutes in urine
urea, ammonia, nitrogenous waste, salt, ions
proteins can be stored in the body true or false
false
how are amino acids converted to carbs [3]
broken down in liver. converted to carbs stored as glycogen and the waste product urea
