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Question #45748
The Question
During urine formation, tubular secretion plays a crucial role in maintaining the ionic and acid-base balance of body fluids. A patient is administered an antibiotic (Drug X) that is primarily eliminated from the body via active tubular secretion. If another compound (Drug Y) that competitively binds to the exact same organic anion transporters is co-administered, what will be the primary physiological consequence and the specific nephron segment involved?
Options
- A.
Decreased active secretion of Drug X resulting in its rapid elimination in urine; Proximal Convoluted Tubule (PCT).
- B.
Decreased renal clearance of Drug X resulting in its prolonged elevated plasma concentration; Proximal Convoluted Tubule (PCT).
- C.
Increased passive reabsorption of Drug X resulting in its elevated plasma concentration; Distal Convoluted Tubule (DCT).
- D.
Competitive inhibition of obligatory water reabsorption leading to drug toxicity; Descending limb of Henle's loop.
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Regulatory_Failure
Understand how NOT, EXCEPT, and logical constraints are used to manipulate exam results.
Concepts Behind This Question
Proximal_Convoluted_Tubule|Organic_Anion_Transporters|Penicillin
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often memorize that PCT secretes H+, K+, and NH3, but fail to apply the concept of 'active transport carriers' to exogenous substances (drugs).
Furthermore, a common misconception is confusing the directionality of secretion vs. reabsorption.
Decreased secretion means the substance stays in the blood (elevated plasma concentration), whereas decreased reabsorption means it stays in the filtrate (rapid elimination).
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Excretory Products and Their Elimination - Class 11 |
| Concept | Tubular Secretion Specificity |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |