The cranial nerves are composed of twelve
pairs of nerves that emanate from the nervous tissue of the
brain. In order to reach their targets they must ultimately
exit/enter the cranium
through openings in the skull. Hence, their name is derived
from their association with the cranium. The following are
the list of cranial nerves, their functions, and tumor examples:
| # |
Name |
Function |
Tumor Example |
| I |
olfactory |
The olfactory nerve carries impulses for the sense of
smell. |
Esthesioneuronblastoma |
| II |
optic |
The optic nerve carries impulses for the sense of sight. |
Optic nerve glioma |
| III |
occulomotor |
The occulomotor nerve is responsible for motor enervation
of upper eyelid muscle, extraocular muscle and pupillary
muscle. |
Schwannoma |
| IV |
trochlear |
The trochlear nerve controls an extraocular muscle. |
Schwannoma |
| V |
trigeminal |
The trigeminal nerve is responsible for sensory enervation
of the face and motor enervation to muscles of mastication
(chewing). |
Malignant peripheral nerve sheath tumor (MPNST) |
| VI |
abducent |
The abducent nerve enervates a muscle which moves the
eyeball. |
Schwannoma |
| VII |
facial |
The facial nerve enervates the muscles of the face (facial
expression). |
Schwannoma (rare) |
| VIII |
vestibulocochlear |
The vestibulocochlear nerve is responsible for the sense
of hearing and balance (body position sense). |
Vestibular Schwannoma |
| IX |
glossopharyngeal |
The glossopharyngeal nerve enervates muscles involved
in swallowing and taste. Lesions of the ninth nerve result
in difficulty swallowing and disturbance of taste. |
Glomus tumor |
| X |
vagus |
The vagus nerve enervates the gut (gastrointestinal
tract), heart and larynx. |
MPNST, paraganglioma |
| XI |
accessory |
The accessory nerve enervates the sternocleidomastoid
muscles and the trapezius muscles. |
Schwannoma |
| XII |
hypoglossal |
The hypoglossal nerve enervates the muscles of the tongue. |
Schwannoma |
For more information about anatomy of brain and CNS, go to
the Nervous
System Unit of the Anatomy and Physiology module on this
Web site.
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