cranial nerves · MS Living Library

This historical table retains the original anatomical descriptions, symptom associations and spelling. These have not received current medical review and should not be used to identify the cause of new neurological symptoms.

The twelve pairs of Cranial Nerves are nerves that exit from the bottom surface of the brain. The Cranial Nerves serve the sense organs, muscles and internal organs. The Cranial Nerves are represented with both Roman and Arabic numerals or a name, for example Cranial Nerve VI, CN VI, the 6th Cranial Nerve and Abducens Nerve all refer to the same nerve. Cranial nerves III through XII arise in the Brainstem.

Here is a table of the twelve Cranial Nerves.

Nerve	Name	Arises	Serves	Signs and Symptoms
I	Olfactory	Olefactory Bulb	Sense of smell
II	Optic	Lateral geniculate nucleus and superior colliculus	Vision (Retina)	Optic Neuritis
III	Oculomotor	Midbrain	Eye movement and pupil dilation	Ptosis (drooping eye), loss of pupil constriction and lateral (side to side) diplopia (double vision)
IV	Trochlear	Midbrain	Downward and outward eye movement	Vertical diplopia (double vision)
V	Trigeminal	Pons	Facial sensation, tongue, teeth, chewing muscles	Trigeminal neuralgia (Facial pain)
VI	Abducens	Pons	Outward movement of eye	Sixth nerve palsy - lateral (side to side) diplopia (double vision)
VII	Facial	Pons	Facial expression and sensation	Bell's Palsy (facial paralysis), myokymia (facial twitching)
VIII	Vestibulocochlear	Pons	Hearing and sense of balance	Dizziness, vertigo, vomiting, deafness and tinnitus
IX	Glossopharyneal	Medulla Oblongata	Movement and sensation of throat, nasal passages and tongue	Numbness and paralysis of the palate, and throat, difficulty swallowing and disturbance of taste
X	Vagus	Medulla Oblongata	Throat, nasal passages, larynx, heart, lungs, stomach	Acid reflux, gagging, difficulty in swallowing or talking
XI	Spinal/Accessory	Medulla Oblongata	Head and shoulder movement	Drooping of the shoulder and inability to rotate the head away from the affected side
XII	Hypoglossal	Medulla Oblongata	Tongue movement	Speech problems, ipsilateral (single sided) movement of tongue and thick speech