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Question #45744
The Question
A healthy individual shifts to a strict high-protein diet, leading to elevated blood urea levels. To excrete this increased metabolic waste while preventing excessive water loss (osmotic diuresis), the renal system must maintain a high medullary interstitial osmolarity. Which of the following accurately describes the mechanism involved in this process?
Options
- A.
Active transport of urea from the thick ascending limb of Henle's loop into the medullary interstitium.
- B.
Facilitated diffusion of urea from the inner medullary collecting duct into the interstitium, returning via the thin ascending limb.
- C.
Active secretion of urea into the Proximal Convoluted Tubule (PCT) to increase the filtered load.
- D.
Obligatory reabsorption of urea in the Distal Convoluted Tubule (DCT) under the influence of Aldosterone.
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
Ornithine_Cycle|Glomerular_Filtration|Proximal_Convoluted_Tubule
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Differentiating the specific permeabilities and transport mechanisms of different nephron segments.
Students often confuse the active transport of NaCl in the thick ascending limb with the passive recycling of urea between the collecting duct and thin ascending limb.
Furthermore, they must connect a high-protein diet (increased urea) to the physiological need for enhanced urea recycling to maintain the medullary osmotic gradient.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Excretory Products and Their Elimination - Class 11 |
| Concept | Urea Recycling |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |