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Question #46325
The Question
A neurotoxin that specifically inhibits voltage-gated calcium channels is applied to the afferent nerve terminals of the carotid and aortic bodies, as well as the neurons of the central chemosensitive area projecting to the medullary respiratory rhythm center. If the subject experiences a sudden, severe increase in arterial pCO2, which of the following is the most likely physiological outcome?
Options
- A.
The respiratory rhythm center will directly detect the elevated pCO2 and increase the respiratory rate.
- B.
The subject will develop hypercapnic respiratory failure due to the failure of synaptic vesicle exocytosis.
- C.
The peripheral chemoreceptors will fail to generate action potentials in response to the increased H+ concentration.
- D.
The pneumotaxic center will detect the hypercapnia and stimulate the diaphragm via the phrenic nerve.
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
Synaptic_Vesicle_Exocytosis_Trigger|Neural_Regulation_Feedback|Neural_Control_and_Coordination
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Distinguishing between the generation of an action potential (sensory transduction) and the chemical transmission of that signal across a synapse.
Students often confuse the inability of the brain to 'respond' to a stimulus with the inability of the receptor to 'detect' it.
Furthermore, it tests the strict NCERT anatomical distinction between the 'Respiratory rhythm center' (which generates the rhythm) and the 'Chemosensitive area' (which detects the chemical changes).
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Breathing and Exchange of Gases - Class 11 |
| Concept | Neural Regulation Feedback |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |