Vestibular System

The inner ear balance organs and their brain connections

Overview

The vestibular system detects head movement and orientation relative to gravity. Its sensors sit in the inner ear alongside the cochlea: three semicircular canals respond to rotation, and two otolith organs, the utricle and saccule, respond to linear acceleration and head tilt. Signals travel through the vestibular nerve to brainstem nuclei and the cerebellum, which combine them with vision and body position sense. Key reflexes include the vestibulo ocular reflex, which keeps vision steady during head movement, and vestibulospinal reflexes that maintain posture. Disorders cause vertigo, imbalance, and visual blurring.