Physiology 3 Flashcards
what is the function of the loop of henle?
To be a counter-current multiplier.
which loops of henle are involved in counter-current multiplication?
The ones in the medulla.
what does the descending limb of the loop do?
Permeable to water, impermeable to NaCl - it dilutes the interstitium.
What does the ascending limb of the loop do?
Permeable to NaCl, impermeable to water. actively secretes NaCl to increase the osmotic gradient in the interstitium.
What is the maximum osmotic conc difference at one level?
200mosmoles.
what is the concentration of filtrate as it enter the loop of henle?
300mosmoles
What is the concentration of filtrate as it leaves the loop of henle?
100mosmoles
What is the function of the vasa recta?
provide oxygen to the medulla.
Remove excess water from the interstitium to maintain the gradient.
how much water does the vasa recta reabsorb each day?
Up to 36L
what is the target of furosemide drugs?
They inhibit the movement of NaCl at the ascending limb - so theres only ever isosmotic urine.
What is the function of the collecting duct?
To concentrate the urine.
which protein leaks through the filtrate and needs to be reabsorbed?
Albumin (up to 30g)
How does the liver remove drugs and pollutants?
It changes them from lipid soluble into hydrophilic so they can be removed in the water.
How much is the minimum volume of urine we will excrete per day?
500mls
how much fluid can be removed per day by the loop of henle?
36L
