Outer hair cells of the organ of Corti receive their efferent innervation from neurons whose cell bodies lie in the brainstem and whose axons reach the cochlea partly via the vestibular nerve before crossing to the cochlear division. Which pathway is being described?

• A The lateral lemniscus originating from the dorsal cochlear nucleus
• B The inferior cerebellar peduncle originating from the vestibular nuclei
• C The medial olivocochlear bundle originating from the superior olivary complex ✓
• D The trapezoid body originating from the medial geniculate body

Explanation

Medial olivocochlear neurons in the superior olivary complex send myelinated efferent axons to synapse directly on outer hair cells; many fibres cross the midline, and they run with the vestibular nerve before joining the cochlear nerve through Oort's vestibulocochlear anastomosis. This system modulates cochlear amplifier function and underlies contralateral suppression of otoacoustic emissions. The lateral lemniscus is purely ascending afferent, killing the top distractor.

Reference: Ganong's Review of Medical Physiology, 26th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.