NEET PG DENTAL EXAM

Detailed explanation-1: -Urea recycling is a process in kidneys that involves the reabsorption and secretion of urea several times, which contributes to the high concentration of solutes in the renal medulla and helps to establish and maintain the corticopapillary gradient.

Detailed explanation-2: -Urea recycling in the inner medulla also contributes to the osmotic gradient generated by the loops of Henle. Antidiuretic hormone increases water permeability, but not urea permeability in the cortical and outer medullary collecting ducts, causing urea to concentrate in the tubular fluid in this segment.

Detailed explanation-3: -The primary locus at which urea transport is regulated is the medullary section of the collecting ducts. The ultimate amount of urea resorbed in the collecting ducts is dependent on the permeability and the tubular concentration of urea in this segment. Both of these factors are affected by the presence of ADH.