Regarding the afferent innervation of the organ of Corti, approximately what proportion of spiral ganglion afferent fibres synapse with inner hair cells?
- A About 25 percent
- B About 50 percent
- C About 90 to 95 percent ✓
- D About 75 percent
Correct answer: C. About 90 to 95 percent
Explanation
Although inner hair cells constitute only a single row compared with three rows of outer hair cells, they receive roughly 90 to 95 percent of all afferent fibres of the spiral ganglion, making them the primary transducers of auditory information to the brain. Outer hair cells receive mainly efferent fibres from the olivocochlear bundle and serve an active mechanical amplifier role. A student who assumes fibre number parallels cell number will wrongly pick a lower figure.
Reference: Ganong's Review of Medical Physiology, 26th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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