Solved UPSC CDS/OTA Question
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Q · Excretory Systemmedium · 45s
Which segment of the nephron establishes the medullary osmotic gradient essential for water reabsorption?
TopicExcretory System
Question Typemultiple choice
Difficultymedium
Marking+1 / −0.33
Test Duration30 min
Step-by-Step Solution
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The thick ascending limb of the Loop of Henle actively transports Na⁺, K⁺, and Cl⁻ out of the tubular fluid into the interstitium but is impermeable to water. This creates a hyperosmotic medullary interstitium, drawing water out of the descending limb and collecting duct under ADH influence.
Final Answer: Option C - Ascending limb of Loop of Henle