Question

Fluid within loop of Henle is concentrated in–

• A. Thick ascending limb
• B. Descending limb
• C. Hair pin bend between descending and ascending limbs
• D. Bend between the ascending limb and the distal tubule

Answer 1

The correct option is C Hair pin bend between descending and ascending limbs

Loop of henles plays a major role in the maintenance of high osmolarity of interstitial fluid of medulla. Descending limb of Henle’s loop is permeable to water but almost impermeable to electrolytes. This concentrates the filtrate as it moves down. The ascending limb is impermeable to water but allows transport of electrolytes actively or passively. Therefore, as the concentrated filtrate pass upward, it gets diluted due to the passage of electrolytes to the medullary fluid.
So, filtrate is maximum concentrated in the hairpin bend between descending and ascending limbs of the loop of Henle.