Question

Statement I: Collecting duct plays a role in the maintenance of osmolarity.
Statement II: The collecting duct allows the passsage of small amout of urea into the medullary interstitium.

• A. Both the statements are true and statement II is the reason for statement I
• B. Both the statements are true and statement II is the not the reason for statement I
• C. Statement I is true while statement II is false
• D. Statement I is false while statement II is true

Answer 1

The correct option is A Both the statements are true and statement II is the reason for statement I

Along the entire length of the nephron the formation of urine takes place by ultrafiltration in the glomerulus, reabsorbtion in the tubules and the elimination by the collecting duct.
The collecting duct is a long duct extending from the cortex of the kidney to the inner parts of the medulla. Large amounts of water could be reabsorbed from this region to produce a concentrated urine. This segment allows passage of small amounts of urea into the medullary interstitium to keep up the osmolarity. Hence, both the statements are true and statement II is the reason for statement I.