The 12 Cranial Nerves. Name, Number, Composition, Function (Biol 320)

Olfactory nerve

CN I

Composition: Sensory

Function: smell; runs from nasal mucosa to olfactory bulbs

Optic nerve

CN II

Composition: Sensory

Function: vision; brain tract

Oculomotor nerve

CN III

Composition: Motor

Function: moves 4 of 6 eye muscles (inferior oblique, medial rectus, inferior rectus & superior rectus)

Trochlear nerve

CN IV

Composition: Motor

Function: innervates the eye muscles that loops through a pulley-shaped ligament

Trigeminal nerve

CN V

Composition: Motor & Sensory

Function: Supplies sensory fibers to face & motor fibers to chewing muscles; 3 branches & largest cranial nerve

Abducens nerve

CN VI

Composition: Motor

Function: Controls lateral rectus & extrinsic muscles that abduct the eyeball (turns eyeball laterally)

Facial nerve

CN VII

Composition: Motor & Sensory

Function: Facial expression

Vestibulocochlear nerve

CN VIII

Composition: Sensory

Function: Hearing & Balance

Glossopharyngeal nerve

CN IX

Composition: Motor & Sensory

Function: Primarily sensory to the throat

Vagus nerve

CN X

Composition: Motor & Sensory

Function: Supplies motor/sensory fibers to the organs of the thorax and abdomen

Spinal Accessory nerve

CN XI

Composition: Motor

Function: supplies motor to sternocleidomastoid and trapeizus muscles

Hypoglossal nerve

CN XII

Composition: Motor

Function: Innervates tongue-moving muscles; runs inferior to tongue