<prompt> Concentrating ability of kidney is lost by damage to?GlomerulusLoop of Henle collecting ductMacula densaRenal Pelvis  <response>: Ans. b Loop of Henle collecting duct. Ref. Ganong, Physiology, 21stpg.721NEPHRONS Proximal convoluted tubule-- reabsorbs all of the glucose, inorganic phosphate, Cl, lactate and amino acids and most of the bicarbonate, sodium, and water. Secretes ammonia, which acts as a buffer for secreted W.QThin descending loop of Henle--passively reabsorbs water via medullary hypertonicity impermeable to sodium. Thick ascending loop of Henle--actively reabsorbs Na, Mg2 and Ca2, impermeable to H2O, H: and K extrusion occurs. Glomerulus does the fuction of filtering. Macula densa secretes renin Renal pelvis one of the part of PC system that collects urine. 