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Question #47449
The Question
The vestibular apparatus, comprising the macula and crista ampullaris, is responsible for maintaining body balance and posture. Suppose a specific neurotoxin elevates the action potential threshold of the afferent nerve fibers innervating these structures, while leaving the mechanosensitive channels of the hair cells completely intact. Which of the following correctly describes the physiological outcome during a sudden change in head posture?
Options
- A.
The stereocilia of the hair cells will fail to bend against the tectorial membrane, preventing the generation of a receptor potential.
- B.
The hair cells will generate normal graded potentials, but the brain will fail to initiate compensatory reflexes to stabilize posture and gaze.
- C.
The macula will continuously release inhibitory neurotransmitters, causing permanent hyperpolarization of the vestibular nerve.
- D.
The endolymph in the semicircular canals will fail to move, physically preventing the stimulation of the crista ampullaris.
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
Vestibular Equilibrium Mechanics|Action Potential Threshold Logic
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Distinguishing between a 'graded receptor potential' in a sensory hair cell and an 'all-or-none action potential' in the afferent neuron.
Common Misconception: Students frequently conflate the sensory receptor cell with the sensory neuron itself, and often mix up the anatomical locations of inner ear membranes (Tectorial membrane in Cochlea vs.
Otolithic membrane/Cupula in Vestibular apparatus).
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Neural Control and Coordination - Class 11 |
| Concept | Vestibular Equilibrium Mechanics |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |