Question

The glomerular filtrate in the loop of Henle gets concentrated in the descending and then gets diluted in the ascending limbs. Explain.

Answer 1

The descending limb of Henle's loop is more permeable to water and almost impremeable to electrolytes. As a result, filtrate gets concentrated as it moves down the descending limb of Henle's loop.
The ascending limb of Henle's loop is impermeable to water but permeable to electrolytes. As a result, the filtrate gets diluted as it moves up the ascending limb of Henle's loop.