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Question #46327
The Question
A premature infant born at 28 weeks of gestation develops severe respiratory distress. Analysis reveals a deficiency of a specific phospholipid secreted by Type II alveolar cells. Which of the following best describes the primary consequence of this deficiency on the infant's pulmonary mechanics?
Options
- A.
Decreased anatomical dead space with enhanced oxygen diffusion across the respiratory membrane.
- B.
Increased alveolar surface tension causing atelectasis, which functionally increases physiological dead space and leads to hypercapnia.
- C.
Decreased physiological dead space due to compensatory hyperventilation, resulting in respiratory alkalosis.
- D.
Reduced alveolar surface tension leading to emphysema-like hyperinflation and impaired carbon dioxide washout.
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
Dead Space Ventilation|Surfactant Function|Alveolar Surface Tension
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often confuse the inverse relationship between surfactant and surface tension.
The trap lies in distinguishing between anatomical dead space (which is fixed by the conducting zone structures) and physiological dead space (which increases when alveoli collapse and fail to participate in gas exchange).
Failing to recognize that surfactant deficiency increases surface tension and decreases lung compliance leads to selecting distractors involving hyperinflation or reduced surface tension.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Breathing and Exchange of Gases - Class 11 |
| Concept | Dead Space Ventilation |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |