In the absence of vasopressin, the greatest fraction of filtered water is absorbed in the
Proximal tubule.
Loop of Henle.
Distal tubule.
Cortical collecting duct.
Because the ratio of the concentration in tubular fluid to the concentration in plasma (TF/P) of the nonreabsorbable substance inulin is 2.5 to 3.3 at the end of the proximal tubule, it follows that 60–70% of the filtered solute and 60–70% of the filtered water have been removed by the time the filtrate reaches this point.