The main function of Henle's loop is

Which adaptation is shown by desert organisms?

Describe the counter-current mechanism.

$A$: The final reabsorption of water from urine into blood occurs through the collecting duct of a mammalian nephron,resulting in the production of hyperosmotic urine.
$R$: The loop of Henle is responsible for the formation of a sodium gradient across the depth of the medullary interstitium of a mammalian kidney.

The concentration of urine depends upon $........$.

Name the following:
$A$ loop of capillary running parallel to the Henle's loop.