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Question #45729
The Question
A patient with chronic end-stage renal disease presents with severe fatigue, a significantly low hematocrit, and the continuous production of large volumes of dilute urine, despite severe dehydration and elevated blood levels of vasopressin. Which of the following statements correctly explains the physiological basis of this dual systemic collapse?
Options
- A.
Destruction of juxtaglomerular (JG) cells halts erythropoietin production, while damaged distal tubules and collecting ducts become unresponsive to circulating ADH.
- B.
Chronic hypoxia in the renal tissue suppresses erythropoietin release, while high plasma osmolarity inhibits the hypothalamic osmoreceptors.
- C.
The kidney prioritizes oxygen-carrying capacity over volume regulation, causing a compensatory downregulation of ADH receptors to flush out toxins.
- D.
Failure of the macula densa to release renin directly inhibits bone marrow erythropoiesis and prevents the activation of the counter-current mechanism.
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
Juxtaglomerular apparatus|Peritubular capillaries|Osmoreceptors
Why This Question Is Tricky
Common Mistakes
The 'Conceptual Pivot' is distinguishing between the physiological trigger of a hormone and the structural integrity of its source/target tissue.
Students often memorize 'hypoxia triggers EPO' and 'dehydration triggers ADH' but fail to apply the pathophysiology of organ failure.
The trap lies in assuming that elevated ADH will always result in concentrated urine, ignoring the receptor-level failure (tubular unresponsiveness) and the anatomical destruction of the EPO source (JG cells) in chronic renal disease.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Excretory Products and Their Elimination - Class 11 |
| Concept | ADH (Vasopressin) Logic |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |