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Question #45413
The Question
A patient suffering from chronic renal hypoxia develops metabolic acidosis, leading to a complex disruption of systemic endocrine ion regulation. Based on the integration of renal and endocrine physiology, which of the following accurately describes the resulting physiological cascade?
Options
- A.
The hypothalamo-hypophyseal portal system detects the hypoxia and stimulates the kidneys to release erythropoietin, while simultaneously inhibiting calcitonin.
- B.
Renal hypoxia increases erythropoietin production, but concurrent metabolic acidosis impairs the bone-resorbing activity of PTH and renal Vitamin D activation, disrupting calcium homeostasis.
- C.
To buffer the metabolic acidosis, the kidneys secrete calcitonin which antagonizes PTH, leading to the rapid deposition of calcium phosphate into the bone matrix.
- D.
The metabolic acidosis enhances the sensitivity of PTH receptors on osteoblasts, leading to severe hypercalcemia that suppresses erythropoiesis.
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
PTH|Erythropoietin|Hypothalamo-Hypophyseal Portal System
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often fail to compartmentalize endocrine control mechanisms.
A common misconception is assuming the hypothalamus/pituitary axis controls all hormones (Option A trap) or confusing the anatomical source of calcium-regulating hormones like Calcitonin (Option C trap).
Furthermore, understanding that renal failure simultaneously triggers a localized compensatory response (EPO) while disrupting a systemic one (Vitamin D/PTH axis) requires high-level synthesis of NCERT's Excretory and Endocrine chapters.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Chemical Coordination and Integration - Class 11 |
| Concept | Hypothalamo-Hypophyseal Portal System |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |