excretion/kidneys Flashcards
what 3 main roles of the kidney
removal of urea in the blood
adjusting salt levels
adjusting water levels
what happens during ultrafiltration
1) blood from renal artery flows through to the glomerulus
2) builds a high pressure which squeezes water, urea, ions and glucose out of blood and into the Bowman’s capsule
3) these membranes act as filters so big molecules like proteins can’t escape
what is the glomerulus
a bundle of capillaries at the start of the nephron
where does ultrafiltration occur
in the nephron
where does reabsorption occur
in the nephron
what is selective reabsorption
1) all glucose is reabsorbed from the proximal convoluted tubule to be used in respiration. this uses active transport
2) sufficient ions are reabsorbed
3) water is reabsorbed from the collecting duct into the blood stream by osmosis
what is the final role of the nephron
removal of waste
how is waste removed
the remaining substances form urine. this continues out of the nephron, through to ureter down to the bladder to be stored before being released by the urethra
what is osmoregulation
the body constantly balancing the water coming in against the water going out
3 main ways which water is lost in the body
sweating, breathing, urine
how do the kidneys affect osmoregulation
adjusting the amount of water the excreted e.g. if someone is sweating a lot the kidneys reabsorb more water so less is lost in urine
what are 2 excretory products in the body
carbon dioxide, urea
how is urea made
breakdown of amino acids in liver
what is making urea called
deamination
