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Question #46389
The Question
A patient with chronic hypertension exhibits elevated levels of Atrial Natriuretic Factor (ANF) and severe tissue edema. Investigations reveal a lymphatic impairment causing an abnormally high concentration of large plasma proteins in the interstitial fluid. Which of the following best explains why the elevated ANF fails to resolve the systemic edema in this patient?
Options
- A.
ANF decreases capillary hydrostatic pressure via vasodilation, but the abnormally high interstitial oncotic pressure prevents the return of fluid to the venules.
- B.
The high protein content in the interstitial fluid increases blood colloid osmotic pressure, overriding the vasodilatory effects of ANF.
- C.
ANF stimulates the Renin-Angiotensin-Aldosterone System (RAAS) to retain water, exacerbating the edema caused by lymphatic failure.
- D.
ANF-induced vasoconstriction increases capillary hydrostatic pressure, which synergizes with the lymphatic blockage to trap fluid in the tissues.
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
Atrial_Natriuretic_Factor|Hydrostatic_Pressure|Interstitial_Fluid
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often memorize the isolated fact that 'ANF decreases BP and blood volume' but fail to integrate it with the physical forces of capillary exchange (hydrostatic vs. oncotic pressure) and the lymphatic system's role in maintaining low interstitial protein levels.
The primary trap (Option B) relies on confusing 'interstitial oncotic pressure' with 'blood colloid osmotic pressure', a classic location/terminology trap.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Body Fluids and Circulation - Class 11 |
| Concept | Lymph Composition |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |