Zoology - Excretory Products and their Elimination Question with Solution | TestHub

Mechanism of concentration of urine: Counter current mechanism

Mammals possess the ability to produce concentrated urine. Structures responsible for the concentration of urine: 1. Henle's loop. 2. Vasa recta.
The increasing osmolarity towards the inner medullary interstitium (from 300 to about 1200 mOsmol${\mathrm{L}}^{–1}$) is maintained by the proximity between the Henle's loop and vasa recta and the counter-currents within themselves. The mentioned gradient is mainly developed due to NaCl and urea.