Maximum absorption of the water occurs at

(Proximal convoluted tubule) (802 - Ganong 22th) (294- K.S 4th) (652- Ganong 23rd)* In the presence / abscence of vasopressin, the greatest fraction of filtered water is absorbed in the proximal convoluted tubules* SITE OF REABSORPTIONS1. Substance Reabsorbed from PCT-Glucose, Aminoacid, Na+ ,K+ ,Ca++ ,HCO3 ,Cl- ,PO4, uric acid and water2. Substance Reabsorbed from DCT - Naf ,HCO3 and water3. Substance Reabsorbed from Loop of Henle - Na+ and Cl~**- 80-90% of bicarbonate reabsorption occurs in PCT1. Absorption of water in PCT (obligatory reabsption) i.e. independent of ADH2. Absorption of water in DCT & collecting duct (facultative - reabsorption) i.e. dependent on ADH levels