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Question #45713
The Question
Atrial Natriuretic Factor (ANF) acts as a physiological check on the Renin-Angiotensin-Aldosterone System (RAAS). When increased blood volume stretches the atrial wall, ANF is released, inducing vasodilation. Which of the following best explains how this ANF-induced hemodynamic change directly impairs the kidney's counter-current mechanism to promote diuresis?
Options
- A.
By increasing blood flow velocity through the vasa recta, which washes out the hyperosmolar medullary interstitium.
- B.
By actively inhibiting the Na+/K+/2Cl- symporters in the thick ascending limb of the Loop of Henle.
- C.
By decreasing the permeability of the collecting duct to urea, preventing its recycling into the interstitium.
- D.
By causing profound vasoconstriction of the efferent arteriole, which reduces the Glomerular Filtration Rate (GFR).
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Comparative_Analysis
Sharpen your ability to evaluate multiple scenarios and distinguish between competing potential answers.
Concepts Behind This Question
Loop of Henle|Atrial Natriuretic Factor (ANF)|Vasa Recta
Why This Question Is Tricky
Common Mistakes
The Conceptual Pivot lies in bridging hemodynamics with tubular physiology.
Students often memorize ANF as a simple 'vasodilator' or 'renin inhibitor' (NCERT fact) but fail to realize that increased medullary blood flow directly disrupts the static osmotic gradient maintained by the counter-current multiplier, a phenomenon known as 'medullary washout' (NCERT-Plus application).
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Excretory Products and Their Elimination - Class 11 |
| Concept | Counter-Current Mechanism Multiplier |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |