reabsorption of water Flashcards
what cm3 of fluid is filtered from the blood into nephrons each min
125 cm3
after selective reabsorption, what volume of fluid is left in bladder
1.5cm3
what are the two limbs of the loop of henle
descending and ascending
what occurs in the descending limb
diffusion of sodium and chloride into the descending limb
water leaves descending limb and enters capillaries
what occurs in the ascending limb (bottom part/ basal)
mineral ions leave fluid by diffusion causing a high water potential
what occurs at the top of the ascending limb
sodium ions and chloride ions are actively transported out of the limb into capillaries by ATP. LImb is impermeable here so water cant leave/ enter the limb. Causing a high water potential
what limb is impermeable
ascending limb only towards the top
what is glucose concentration like in the tubule
low as it is selectively reabsorped from pct
how does sodium concentration differ in the tubule fluid
concentration of sodium is high in the descending limb as it is diffusing in
but low in the ascending limb as it is actively pumped out into capillaries
what is urea concentration like
as water is withdrawn from tubule, urea is actively moved in
what is the hairpin counter current multiplier system
describes loop of henle and how the loop increases the efficiency of transferring mineral ions from ascending to descending.
what part of the kidney is the ascending limb heading towards
cortex
what part of the kidney does the loop of henle enter
medulla
where in the kidney is the glomerulus and bowmans capsule found
cortex
what products are an example of excretion
urea
carbon dioxide
what is a difference between excretion adn secretion
excretion- usually waste, removed from body
secretion- useful products, remained in body
give a example of a product secreted from the body
enzyme
antibody
hormone
what is 1 similarity of secretion and excretion
both use atp
both produced by cells and metabolism
both need to cross a membrane or leave a cell.
as medulla gets lower, what happens to water potential in the descending limb
decreases further
what is the end effect of tissue fluid water potential in the medulla
decreases near the bottom of the loop of henle
