<P> By means of a countercurrent multiplier system , which uses electrolyte pumps , the loop of Henle creates an area of high urea concentration deep in the medulla , near the papillary duct in the collecting duct system . Water present in the filtrate in the papillary duct flows through aquaporin channels out of the duct , moving passively down its concentration gradient . This process reabsorbs water and creates a concentrated urine for excretion . </P>
<P> By means of a countercurrent multiplier system , which uses electrolyte pumps , the loop of Henle creates an area of high urea concentration deep in the medulla , near the papillary duct in the collecting duct system . Water present in the filtrate in the papillary duct flows through aquaporin channels out of the duct , moving passively down its concentration gradient . This process reabsorbs water and creates a concentrated urine for excretion . </P>
where does the filtrate flow from in the kidney
where does the filtrate flow from in the kidney
in the papillary duct flows through aquaporin channels out of the duct ,
in the papillary duct flows through aquaporin channels out of the duct ,