by Sarah Parrish

Created on: April 26, 2009

There are twelve different nerve fiber bundles known as the "cranial nerves" that enter the brain, each with a specific name and function.

Olfactory nerve

The olfactory nerve is at the front of the brain and transmits the sense of smell. At the anterior end of the olfactory nerve is the olfactory bulb which sits just underneath the frontal lobe.

Optic nerve

The optic nerve connects to the eye at the anterior end and runs along the underside of the brain, at one point sending efferents to the contralateral side of the brain through a crossing called the optic chaisma or optic chiasm.

Oculomotor nerve

This nerve helps control the muscles that attach to the eye, helping to orient our vision.

Trochlear nerve

The trochlear nerve also innervates one of the eye muscles, inducing intortion of the eyeball.

Trigeminal nerve

The trigeminal nerve innervates the face and allows us to receive sensation and sensory input from the skin and muscle on our faces and also innervates muscles used in mastication (chewing).

Abducens nerve

The abducens nerve is yet another nerve innervating the eye. The abducens innervation allows the eyes to abduct.

Facial nerve

This nerve innervates the muscles of the face and allows us to form expressions, including motor control of facial muscles needed for anterior taste as well as salivary production.

Vestibulocochlear nerve

This nerve innervates the cochlea where we receive sound input as well as our sense of balance through the workings of the vestibular canals. This nerve is associated with hearing and balance as well as a sense of proprioception.

Glossopharyngeal nerve

This nerve controls taste on the most posterior third of the tongue providing us with a sense of taste, complementing the function of the facial nerve which innervates the other two thirds of the tongue.

Vagus nerve

The vagus controls throat muscles including those involved in swallowing and vocal acoustic production. The vagus also innervates viscera in the thorax and abdomen for the parasympathetic (non-emergency/non-fight-or-flight) system

Accessory nerve

The accessory nerve controls neck muscles including those involved in shrugging and head movement.

Hypoglossal nerve

The hypoglossal nerve innervates the tongue but rather than provide us with a sense of taste as the glossopharyngeal and facial nerves do, the hypoglossal nerve controls the movement of the tongue and therefore assists us not only with eating but also with forming words.

There are mnemonic devices for remembering the sequence of cranial nerves and the names. One of the most common mnemonic devices is the phrase "Ooh, Ooh, Ooh, To Touch And Feel Very Good Velvet, AH." The sequence of nerves (provided you can keep them in order within the first letter of the cranial nerve) is in the same sequence as the organization of the nerves as you go from the anterior to the posterior of the brain.

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