Merck Manual

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The Cranial Nerves

The Cranial Nerves

Nerve

Function

Olfactory

Transmit smell

Optic

Necessary for vision; carry the sensory nerves for certain eye reflexes

Oculomotor

Carry motor neurons that control most of the muscles of the eye

Trochlear

Carry motor neurons that control other muscles of the eye

Trigeminal

Include 3 main branches: the motor nerve to the muscles of the jaw, sensory nerves to the mouth and nasal cavity, and sensory nerves that carry pain sensations from the cornea (the sensitive outermost part of the eyeball)

Abducent

Carry motor neurons that control other muscles of the eye

Facial

Control the muscles responsible for facial expression (ears, eyelids, nose, and mouth)

Vestibulocochlear

These nerves are divided into 2 parts: the cochlear nerve, which responds to sound; and the vestibular nerve, which functions to maintain posture and balance

Glossopharyngeal

Provide sensory and motor control of the throat and vocal chords

Vagus

Provide sensory and motor control for the major internal organs, including the heart and the digestive tract

Spinal accessory

Carry sensory and motor information for the muscles of the head and upper neck

Hypoglossal nerves

The motor nerves to the tongue