Physiology - The Loop of Henle Flashcards
what is the function of the loop of henle?
generates the cortico medullary solute concentration gradient
what does the corticomedullary solute concentration gradient allow?
the formation of hypertonic urine
what are the two parts of the loop of henle?
ascending limb
descending limb
what happens to NaCl in the ascending limb?
they are reabsorbed
how is reabsorption of NaCl achieved in the ascending limb?
thick AL = active transport
thin AL = passive
what happens to water in the ascending limb?
nothing - relatively impermeable
what happens to salt in the descending limb?
nothing - not reabsorbed
what happens to water in the descending limb?
reabsorbed - highly permeable to water
what is expressed by the cells in the wall of the ascending loop of henle?
the TALH triple co-transporter
on the luminal membrane
what does the triple co-transporter transport into the cells of the loop of henle?
sodium
potassium
two chloride ions
what is found on both membranes of the cells of the thick AL?
potassium ion channels
what two transporters are found on the basolateral membrane of the thick AL?
potassium chloride co transporter
sodium potassium pump
what drugs block the triple co transporter in the thick AL?
loop diuretics
what effect does solute leaving the AL have on the fluid in the DL?
concentrates it
solute leaves AL = increased osmolality of tubular fluid = water leaves DL = increased concentration
what is the tonicity of the fluid leaving the loop of henle?
hypotonic
hypoosmotic - lower osmolality than tubular fluid
