<prompt> Frusemide acts onAscending limb of LOHPCTDCTCollecting duct  <response>: Ans: a Ascending limb of Ref: Katzung 11th edLoop diuretics selectively inhibit NaCl reabsorption in the Thick Ascending Limb.Frusemide is a loop diuretic. Because of the large NaCl absorptive capacity of this segment and the fact that the diuretic action of these drugs is not limited by development of acidosis, which is usually seen with the carbonic anhydrase inhibitors.Loop diuretics are the most efficacious diuretic agents currently availableSegmentFunctionsDiuretic with Major ActionGlomerulusFormation of glomerular filtrateNoneProximal convoluted tubule PCTReabsorption of 65 of filtered Na K CA2, and Mg2; 85 of NaHC03 , and nearly 100 of glucose and amino acids. I sos mo tic reabsorption of water.Carbonic anhydrase inhibitorsProximal tubule, Straight segmentsSecretion and reabsorption of organic acids and bases, including uric acid and most di ureticsNoneThin descending limb of Henl es loopPassive reabsorption of waterNoneThick ascending limb of Henles loop TALActive reabsorption of 15-25 of filtered Na7 K7 CP; secondaryreabsorption of Ca2 and Mg2Loop diureticsDistal convoluted tubule DCTActive reabsorption of 4-8 of filtered Na and Cl; Ca2 reabsorption under parathyroid hormone controlThiazidesCortical collecting tubule CCTNa reabsorption 2- 5 coupled to K and H secretionK-s paring diureticsMedullary collecting ductWater reabsorption under vasopressin controlVasopressin antagonist 