VIII nerve receives afferents of
High-Yield Explanation
AUDITORY NEURAL PATHWAYS AND THEIR NUCLEI Hair cells are innervated by dendrites of bipolar cells of spiral ganglion which is situated in Rosenthal's canal (canal running along the osseous spiral lamina). The nerve receives afferents from vestibule and cochlea. Axons of these bipolar cells form the cochlear division of CN VIII and end in the cochlear nuclei, the dorsal and ventral, on each side of the medulla. Fuher course of auditory pathways is complex. From cochlear nuclei, the main nuclei inthe ascending auditory pathways, sequentially, from below upwards are: 1. Superior olivary complex 2. Nucleus of lateral lemniscus 3. Inferior colliculus 4. Medial geniculate body 5. Auditory coex The auditory fibres travel the ipsilateral and contralateral routes and have multiple decussation points. Thus each ear is represented in both cerebral hemispheres. The area of coex, concerned with hearing is situated in the superior temporal gyrus (Brodmann's area 41). For auditory pathways, remember the mnemonic E.COLI-MA: Eighth nerve, Cochlear nuclei, Olivary complex, Lateral lemniscus, Inferior colliculus, Medial geniculate body and Auditory coex. Ref : ENT textbook by Dhingra 6th edition Pgno : 13,14