Nerves of the Ear Region

Nerve: Cochlear
Origin: Division of vestibulocochlear nerve
Course: Traverses internal acoustic meatus, enters modiolus with spiral ganglia and peripheral processes in spiral lamina
Innervation: Spiral organ

Nerve: Posterior auricular
Origin: As first extracranial branch of facial nerve
Course: Passes posterior to ear, sending branch to occipital region
Innervation: Posterior auricular muscle and intrinsic auricular muscles, occipital belly of occipitofrontalis

Nerve: Tympanic
Origin: As first extracranial branch of glossopharyngeal nerve, from inferior glossopharyngeal ganglion
Course: Passes into tympanic canaliculus, enters tympanic cavity, ramifies on promontory of labyrinthine wall as tympanic plexus
Innervation: Otic ganglion for secretomotor innervation of parotid gland; mucosa of tympanic cavity, mastoid cells, and pharyngotympanic tube

Nerve: Vestibular
Origin: As a division of the vestibulocochlear nerve
Course: Traverses internal acoustic meatus to vestibular ganglion at fundus; branches pass to vestibule of bony labyrinth
Innervation: Cristae of ampullae of semicircular ducts, maculae of saccule and utricle

Nerve: Vestibulocochlear
Origin: Groove between pons and myelencephalon
Course: Traverses internal acoustic meatus, dividing into cochlear and vestibular nerve
Innervation: Spiral organ and cristae of ampullae of semicircular ducts, maculae of saccule and utricle