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Question #46303
The Question
During voluntary facilitation of the micturition reflex, an individual often takes a deep breath, closes the glottis, and contracts their abdominal muscles. Which of the following accurately describes the respiratory capacities involved and the concurrent neuro-muscular actions?
Options
- A.
The individual retains a volume equal to their Inspiratory Capacity (IC), increasing intra-abdominal pressure to mechanically assist the parasympathetic-driven contraction of the detrusor muscle and somatic relaxation of the external sphincter.
- B.
The individual forcefully expels their Expiratory Reserve Volume (ERV) to increase intra-thoracic pressure, which reflexively triggers sympathetic outflow to contract the detrusor muscle.
- C.
The individual retains their Functional Residual Capacity (FRC), decreasing intra-abdominal pressure to stimulate the pudendal nerve, causing autonomic relaxation of the internal sphincter.
- D.
The individual utilizes their Vital Capacity (VC) to maximize intra-thoracic pressure, directly stimulating the parasympathetic nervous system to relax the detrusor muscle and contract the external sphincter.
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
Total Lung Capacity|Thoracic Pressure|Smooth Muscle Contraction
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: This question requires the synthesis of Respiratory Capacities (Class 11, Ch 17) with Neural Control of Excretion (Class 11, Ch 19 & 21).
The primary trap relies on functional confusion regarding autonomic control: students frequently forget that the parasympathetic system promotes emptying (contracts detrusor) while the sympathetic system promotes filling (relaxes detrusor).
Additionally, it tests the anatomical distinction between the autonomic internal sphincter and the somatic external sphincter.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Breathing and Exchange of Gases - Class 11 |
| Concept | Respiratory Volume vs. Capacity |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |