Before You Begin
Question #46397
The Question
A researcher administers a drug that selectively increases the blood flow rate through the vasa recta, effectively abolishing its function as a counter-current exchanger. Which of the following will be the most likely consequence on the renal physiology of the subject?
Options
- A.
The osmolarity of the inner medullary interstitium will peak at 1200 mOsmol/L due to excessive urea accumulation.
- B.
The subject will exhibit symptoms of diabetes insipidus despite having functional osmoreceptors and normal vasopressin levels.
- C.
The collecting duct will actively secrete water into the lumen to maintain isotonicity with the cortical interstitium.
- D.
The counter-current multiplier will immediately cease the active transport of NaCl in the thick ascending limb.
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
Urea|Loop of Henle|Counter-Current Exchanger
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often memorize that ADH is the sole determinant of urine concentration.
The trap is failing to realize that ADH only provides the permeability (via aquaporins); the actual driving force for water reabsorption is the medullary osmotic gradient maintained by the vasa recta.
Furthermore, it tests the distinction between central diabetes insipidus (lack of ADH) and nephrogenic diabetes insipidus (inability of the kidney to concentrate urine despite normal ADH due to gradient washout).
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Excretory Products and Their Elimination - Class 11 |
| Concept | Nitrogenous Waste Classification |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |