Nerve Supply of Head & Neck

Functional classifications of cranial nerves

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Olfactory nerve

CN I; smell.

Exit of olfactory nerve

Cribiform plate of ethmoid bone.

Optic nerve

CN II; vision.

Exit of optic nerve

Optic canal.

Oculomotor nerve

CN III; innervates superior rectus, inferior rectus, medial rectus, inferior oblique.

Trochlea nerve

CN IV; innervates superior oblique muscle.

Abducens nerve

CN VI; innervates lateral rectus.

Exit of oculomotor, trochlear and abducens nerve

Superior orbital fissure.

Trigeminal nerve

CN V (opthalmic, maxillary, mandibular n.); major general sensory nerve of head.

Opthalmic nerve of CN V

Innervates anterior scalp; exits through superior orbital fissure.

Maxillary nerve of CN V

Innervates skin of upper face; exits through foramen rotundum.

Mandibular nerve of CN V

Innervates skin of lower face; exits through foramen ovale.

Facial nerve

CN VII; sensory to part of external ear.

Exit of Facial nerve

Internal acoustic meatus to them stylomastoid foramen.

Vestibulocochlear nerve

CN VIII; balance and hearing (does not exit skull).

Structures of middle ear

Auditory ossicles (malleus, incus, stapes).

Function of middle ear

Auditory ossicles transmit vibrations of tympanic membrane to internal ear.

Structures of internal ear

Vestibule

Cochlea

x2 sacs (utricle and saccule)

x3 semicircular canals

Semicircular duct

Function of internal ear

Sensory receptors to enable balance and hearing.

Glossopharyngeal nerve

CN IX; taste to posterior 1/3 tongue.

Vagus nerve

CN X; sensory innervation to larynx.

Accessory nerve

CN XI; innervates trapezius.

Exit of vagus, glossopharyngeal, accessory nerve

Jugular foramen.

Hypoglossal nerve

CN XII; innervates all tongue.

Exit of hypoglossal nerve

Hypoglossal canal.