2014 Inner Ear Physiology

Gross anatomy of the auditory and vestibular pathways

  • the 8th cranial nerve enters the cranial cavity through the internal auditory meatus, which is found in the temporal bone
    • also entering through this canal are the facial nerve and the labyrinthine artery(which provides the blood supply to the inner ear)
    • the close relationship between the VII and VIII cranial nerves can explain some of the complications of an ACOUSTIC NEUROMA

  • 8th nerve fibres enter the ventrolateral surface of the medulla at the cerebellopontine angle, anterior to the inferior cerebellar peduncle (25 on the brainstem below) and lateral to the facial nerve
    • the cochlear nuclei (the first CNS relay in the auditory pathway) are a landmark for the rostral medulla
Ventral vies brain and cranial nerves

Original Image
To test your ability to identify cranial nerves, go to this site

Lateral view of brainstem Number key

Important landmarks relative to these pathways that are identifiable on the lateral view of the brainstem:

1. medial geniculate body

2. brachium of the inferior colliculus

4. inferior colliculus

Email: Dr. Janet Fitzakerley | ©2014 University of Minnesota Medical School Duluth | Last modified: 15-feb-14 9:04 PM