homeostasis - the kidney and water balance Flashcards
(24 cards)
what are the 3 ways the body can loose water
- via the lungs when we exhale
- when we sweat we loose water through the skin (the body cannot control how much water, ions and urea is lost through sweating)
- kidneys via urine which can be controlled
how many kidneys do we have
2
how does blood enter the kidney
through an artery
what does the kidney remove from the blood
the urea, as wells as the excess ions and water
what do these products leave the kidney as and where are they stored
the leave as urine and it gets stored in the bladder
what happens to the glucose in the kidneys
the kidneys filter glucose out of the blood but then reabsorb it all back into the blood
what happens to the concentration of ions in the kidneys
it decreases as the kidney filters ions out the blood but then reabsorb a certain amount back into the blood
what happens to the concentration of urea in the blood
is falls to zero as it passes through the kidneys. this is because the kidneys filter out all of the urea and do not reabsorb it
how is the chemical ammonia produced and what is the process called
when the liver breaks down the excess amino acids
the process is called deamination
why doe she liver convert mania into urea
because ammonia is very toxic
what is produced by the pituitary gland if the level of water in the blood falls
the hormone ADH is released into the bloodstream
what does ADH do to the kidney tubules
it makes them more permeable allowing more water to pass out from the kidney
what happens to the urine levels if this occurs
less urine is produced les urine is produced
what happens as the level of water in the blood returns back to normal
the pituitary gland stops releasing ADH
what happens when the concentration of water in the blood rises
- the pituitary gland stops releasing ADH
- this means that the kidneys reabsorb less water back into the blood stream
- meaning more urine is produced
what happens if the kidneys fail?
what is this called?
the water, ions and urea need to be adjusted by a machine
this is known as kidney dialysis
what happens to water concentration when a person has kidney failure
their blood will have a higher concentration of water, ions and urea then it should
why does the blood get filtered over a partially permeable membrane
it will allow the water, ions and urea through but it won’t allow larger molecules like protein
what is found on the other side of the membrane
dialysis fluid
what does dialysis fluid contain
normal concentrations of water and ions but it does not contain any urea
why is the dialysis constantly refreshed
it ensure that there’s always a large concentration gradient for the urea
why can kidney dialysis be inconvenient
- patient have to visit the hospital multiple times a week
- they must have a controlled diet to avoid over producing urea
what is a better alternative to kidney dialysis
a kidney transplant
what are the differences between a kidney dialysis and a kidney transplant
- there is no shortage on machines but thee is a shortage for healthy kidneys
- kidney transplants allow the patient to live a normal life
- kidney dialysis is expensive throughout treatment, transplants just have an initial cost
- transplant patients have to take anti-rejection drugs for the rest of their lives
