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Question #45454
The Question
A patient with chronic hypervolemia exhibits sustained stretching of the cardiac atrial walls, leading to the continuous release of Atrial Natriuretic Factor (ANF). While ANF primarily acts as a check on the Renin-Angiotensin-Aldosterone System (RAAS), its prolonged action on the distal convoluted tubule (DCT) indirectly disrupts the homeostasis of another vital ion. Which of the following best explains this secondary interference?
Options
- A.
ANF directly inhibits the release of Thyrocalcitonin (TCT), leading to excessive calcium reabsorption in the DCT.
- B.
Prolonged natriuresis alters the electrochemical gradient required for the basolateral Na+/Ca2+ exchangers, interfering with the calcium-conserving action of Parathyroid Hormone (PTH).
- C.
ANF stimulates the juxtaglomerular cells to secrete renin, which competitively binds to calcium channels in the DCT.
- D.
The peptide hormone acts synergistically with aldosterone to promote simultaneous excretion of sodium and calcium ions.
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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
ANF|PTH|Calcitonin|Calcium Homeostasis
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students typically compartmentalize ANF strictly to fluid/blood pressure regulation (RAAS antagonism) and PTH strictly to calcium homeostasis.
The pivot is recognizing that renal ion transport mechanisms are coupled (Na+ and Ca2+ in the DCT).
Therefore, a primary shift in sodium handling (via ANF) will inevitably disrupt the electrochemical gradients required for calcium reabsorption (the domain of PTH).
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Chemical Coordination and Integration - Class 11 |
| Concept | Atrial Natriuretic Factor (ANF) |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |