Cranial Nerve VIII - Vestibulocochlear
Anatomy
Below is an image showing the anatomy of Cranial Nerve VIII in relation to the other nerves.
The image is taken and modified from the Wiki Commons under the Creative Commons License.
Type
Mainly sensory but some motor. Consists of a vestibular nerve and a cochlear nerve.
Origins & Insertions
| Nerve | Origin | Insertion |
| Vestibular (sensory) | Semicircular Canals | Pons & Cerebellum |
| Vestibular (motor) | Pons | Hair Cells of Semicircular Canals |
| Cochlear (sensory) | Spiral Organ | Thalamus |
| Cochlear (motor) | Pons | Hair Cells of Spiral Organ |
Foramen
The Internal Acoustic Meatus
(as shown below)
Image taken and modified from Flickr under the Creative Commons License
Function
The Vestibular Branch conveys;
- impulses related to equilibrium
- through its motor branch it can also adjust the sensitivity of the hair cells.
The Cochlear Branch conveys;
- impulses for hearing
- through its motor branch it can also adjust the hair cells response to sound waves.