Anatomical Features of the Internal Ear

Neurovascular Supply to the Internal Ear

The internal ear, also known as the labyrinth, plays a critical role in auditory and vestibular functions. It is supplied by a complex network of neurovascular structures that ensure its functionality.

Blood Supply

The primary blood supply to the internal ear is provided by the labyrinthine artery, a branch of the anterior inferior cerebellar artery (AICA) or sometimes the basilar artery. The labyrinthine artery further divides into:

• Anterior vestibular artery – supplies the utricle, semicircular canals, and part of the vestibular nerve.
• Cochlear artery – supplies the cochlea and spiral ganglion.

Venous Drainage

Venous drainage of the internal ear occurs through the internal auditory veins, which drain into the inferior petrosal sinus or directly into the sigmoid sinus.

Nerve Supply

The innervation of the internal ear is primarily derived from the vestibulocochlear nerve (cranial nerve VIII). It consists of:

• Cochlear nerve – responsible for auditory processing.
• Vestibular nerve – divided into superior and inferior branches that innervate the vestibular apparatus.

Clinical Significance

Compromise in the neurovascular supply to the internal ear can lead to conditions such as labyrinthine ischemia, vertigo, and sensorineural hearing loss. Understanding this anatomy aids in diagnosing and managing inner ear disorders.