kidney hormones Flashcards
what hormones does the kidney release
erythropoietin
calcitriol
renin
what two organs release erythropoietin
kidneys and liver(neonates predominantly)
what might stimulate increase in erythropoietin
being at altitude, loss of red blood
cells due to haemorrhage or excessive red blood cell destruction and increased tissue oxygen
demands.
reduced O2 carrying capacity of the RBC
what determines release of erythropoietin
ability of the blood cell to carry oxygen
how does erythropoietin work
stimulates bone marrow cells that are committed to becoming RBCs
what can the effect be on erythropoietin in renal failure
scarring leads to decrease in functioning cells, drop in the release of erythropoietin leading to anaemia
synthetic erythropoietin can be used
what is cholecalciferol
vitamin D
what organ converts vitamin D to 25-hydroxycholecalciferol
liver
what do the kidneys convert 25-hydroxycholecalciferol to
calcicitrol
aka 1, 25- dihydroxycholecalciferol
what hormone promotes conversion of 25-hydroxycholecalciferol to calcitriol
parathyroid hormone
it is inhibited by high plasma phosphate levels
what does PTH do
increases levels of calcium in the blood
decreases levels of phosphate
what is the function of calcitriol
increase the absorption of ingested calcium by increasing expression of calcium channels used to transport calcium across the cell membrane
also increases phosphate absorption
an simulates calcification of the bone matrix
stimulates osteoblasts and clasts to remodel the bone
describe the conversion of cholecalciferol
liver hydroxylates it first
then kidneys to produce calcitriol
reaction is promoted by PTH
What causes hyper parathyroidism
kidney failure > reduced levels of calcitriol> increased production of PTH in order to try to raise calcitriol > growth of gland
what are some consequences of renal failure
osteomalacia
osteoporosis
hyperparathyroidism
