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Question #46336
The Question
A mountaineer at a high altitude experiences a severe respiratory condition that compromises the secretion of pulmonary surfactant. Despite the normal high-altitude compensatory mechanisms, the individual suffers from catastrophic cellular hypoxia. Which of the following best explains why the physiological compensation fails in this scenario?
Options
- A.
The compensatory increase in 2,3-BPG shifts the oxygen-hemoglobin dissociation curve to the left, preventing oxygen unloading at the tissues regardless of alveolar surface area.
- B.
The loss of surfactant increases the thickness of the respiratory membrane, which primarily restricts the diffusion of highly soluble CO2, leading to severe respiratory alkalosis.
- C.
The low atmospheric pO2 reverses the Bohr effect at the tissue level, causing hemoglobin to retain oxygen to protect the vital organs from hypoxia.
- D.
Surfactant depletion increases alveolar surface tension, causing alveolar collapse and drastically reducing the diffusion surface area, which prevents effective oxygen loading.
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
Surfactant Function|Haldane Effect vs. Bohr Effect|Respiratory Quotient (RQ) Constants
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often memorize the high-altitude compensatory mechanism (right-shift of the Hb-O2 curve) but fail to integrate it with the physical prerequisites of gas exchange (alveolar surface area).
The trap lies in assuming that a right-shift always improves oxygenation, ignoring that effective unloading at the tissues strictly depends on successful loading at the alveoli, which is physically limited by the loss of surfactant and subsequent atelectasis.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Breathing and Exchange of Gases - Class 11 |
| Concept | Surfactant Function |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |