Loop of Henle Flashcards
what does the liver do to lipid soluble drugs and pollutants to facilitate their excretion
makes them polar (water soluble)
guess this makes it easier for them to be secreted and excreted from osmotic pressures etc
fluid in proximal tubule is iso/hypo/hyper osmotic to plasma
isosmotic
what is the osmolarity of plasma
300mOsmoles/L
how are do proximal tubule and plasma have the same osmolarity
because all movements have been accompanied by H20 movements
where are the proximal and distal tubules, cortex or medulla
cortex
what does the loop of henle do
concentrates urine
what is the minimum concentration of urine that can be produced
30-50mOsmoles/L (10 times weaker than plasma)
which loops of henle establish a hypertonic medullary gradient
ones in the medulla. i.e. belonging to juxtamedullary nephrons
which limb of henle loop is impermeable to H2O
ascending limb
permeabilities of descending limb
H2O permeable
NaCl impermeable
which limb of henle loop is impermeable to NaCl
descending limb
which limb of henle loop is permeable to NaCl
ascending limb
effect of ascending limb on concentration
reduces concentration (pumps out NaCl)
which limb of henle dilutes the fluid
ascending
which limb of henle concentrates the fluid
descending
when water moves out of descending limb into interstitium where does it go from there
it is reabsorbed into the vasa recta by oncotic pressure
once water moves out of descending limb into interstitium where does it go from there
it is reabsorbed into the vasa recta by oncotic pressure
describe the process of concentration in the loop of henle
ascending limb actively pumps out NaCl making the interstitial fluid more concentrated and the tubule more dilute.
the descending limb dilutes the interstitial fluid by moving out water.
but the ascending limb just keeps on pumping out more and more salt and the descending limb keeps on losing water to it.
fluid is most concentrated at end of descending.
if the active transport of NaCl doesn’t happen what is the conc of urine like
isotonic i.e. 300mOsmoles/L
what’s more dilute, distal tubule or plasma
distal tubule (100 compared to 300)
effect of loop of henle on interstitium
it makes it increasingly concentrated
what difference exist between the limbs at the same horizontal level
200mOsmole/L
what is the vasa recta
arrangement of peritubular capillaries of juxtamedullary nephrons
true/false capillaries are only freely permeable to H2O giving them a different osmolarity to the interstitium around them
false - they are freely permeable to all solutes and H2O and so equilibrate with interstitium
