Question

Henle’s loop along with _________ play a significant role in __________ which helps to produce concentrated urine.

• A. glomerulus; ultrafiltration
• B. glomerulus; counter current mechanism
• C. vasa recta; counter current mechanism
• D. vasa recta; secretion

Answer 1

The correct option is C vasa recta; counter current mechanism

Mammals have the ability to produce concentrated urine. The mechanism which facilitates production of concentrated urine is known as the countercurrent mechanism. The Henle’s loop and vasa recta of the nephrons play a significant role in this.
The flow of filtrate in the two limbs of Henle’s loop and the flow of blood through the two limbs of vasa recta is in counter current pattern. The proximity between the Henle’s loop and vasa recta, as well as the counter current in them help in maintaining an increasing osmolarity towards the inner medullary interstitium. Presence of such interstitial gradient helps in an easy passage of water from the collecting tubule thereby concentrating the urine.