Q.30 In a nephron, _____ follows the ascending limb of the “loop of Henle”.
(A) Descending limb
(B) Distal tubule
(C) Collecting tubule
(D) Proximal tubule
The correct answer is (B) Distal tubule.
In a nephron, the ascending limb of the loop of Henle directly connects to the distal convoluted tubule, which follows it anatomically and functionally in urine processing.
Option Analysis
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(A) Descending limb: This precedes the ascending limb within the loop of Henle itself, forming the U-shaped structure that dips into the renal medulla before ascending; it cannot follow the ascending limb.
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(B) Distal tubule: Correct, as the thick ascending limb transitions into the distal convoluted tubule (DCT) in the renal cortex, enabling further selective reabsorption under hormonal control.
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(C) Collecting tubule: This receives fluid from multiple distal tubules after they merge via connecting tubules; it follows the DCT, not the ascending limb directly.
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(D) Proximal tubule: Located at the start of the nephron after the glomerulus, it precedes the loop of Henle entirely for initial bulk reabsorption.
Nephron Structure Overview
The nephron follows this sequence: glomerulus → proximal convoluted tubule → descending limb → ascending limb → distal convoluted tubule → collecting duct. This order supports the countercurrent multiplier system, concentrating urine via osmotic gradients.
In nephron anatomy, understanding what follows the ascending limb of loop of Henle proves essential for CSIR NET Life Sciences aspirants tackling kidney physiology. The ascending limb of loop of Henle creates a key osmotic gradient, directly leading to the next segment for fine-tuned urine regulation.
Loop of Henle Key Segments
The loop of Henle features:
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Descending limb: Permeable to water, concentrates filtrate.
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Ascending limb: Impermeable to water, actively pumps Na⁺/Cl⁻ out.
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Transition: Thick ascending limb connects seamlessly to distal convoluted tubule.
This sequence ensures medullary hypertonicity for water conservation.
Full Nephron Pathway After Loop of Henle
| Segment | Position After Ascending Limb | Main Function |
|---|---|---|
| Distal convoluted tubule | Immediately follows | Ion reabsorption, pH regulation |
| Connecting tubule | Merges multiple DCTs | Fine hormone response |
| Collecting tubule/duct | Final convergence | Water reabsorption via ADH |
The distal tubule after the loop of Henle handles aldosterone effects, critical for electrolyte balance.
Exam Relevance for CSIR NET
Questions like “In a nephron, _____ follows the ascending limb of the ‘loop of Henle'” test precise anatomical recall. Focus on juxtamedullary nephrons with longer loops extending deeper into medulla.
