Ques. 1AIPMT 2003
If Henle's loop were absent from mammalian nephron, which one of the following is to be expected?
- There will be no urine formation.
- There will be hardly any change in the quality and quantity of urine formed.
- The urine will be more concentrated.
- The urine will be more dilute.
Answer
(4) The urine will be more dilute.
Solution
As per NCERT, the Henle's loop and vasa recta form the counter current mechanism, which maintains an increasing osmolarity towards the inner medulla (from 300 to about 1200 mOsmol L-1).
⇒ This medullary gradient allows water to be reabsorbed from the collecting duct, so concentrated (hypertonic) urine is formed.
⇒ Without Henle's loop, no gradient ⇒ much less water reabsorption.
∴ Urine will still be formed, but it will be more dilute.
Answer: (4)