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Question #46339
The Question
In a premature infant lacking adequate pulmonary surfactant, alveolar compliance drops precipitously. How does the neural regulatory mechanism of respiration respond to this mechanical alteration, and what is the ultimate physiological outcome?
Options
- A.
The chemosensitive area detects rising pCO2 and increases neural drive to the diaphragm, but the stiff lungs delay the stretch receptor reflex, ultimately causing respiratory muscle fatigue.
- B.
The pneumotaxic centre in the pons detects the increased alveolar surface tension and immediately reduces the duration of inspiration to prevent lung collapse.
- C.
Receptors associated with the aortic arch sense severe hypoxia and directly stimulate Type II pneumocytes to synthesize lecithin, restoring compliance.
- D.
Stretch receptors in the bronchi and bronchioles are hyper-stimulated by the collapsing pressure, sending strong inhibitory signals to the respiratory rhythm centre.
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|Neural Regulation Feedback|Feedback Mechanism Loops
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often fail to distinguish between neural drive and mechanical lung compliance.
A common misconception is that if lungs are collapsing, stretch receptors will fire to 'warn' the brain (Option D trap).
The critical realization is that the chemical feedback loop (chemoreceptors driving inspiration due to high CO2) actually overcompensates when decoupled from normal mechanical compliance.
The lack of stretch delays the normal 'switch off' signal for inspiration, forcing the muscles to work to the point of fatigue.
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 |