Anatomy and Physiology of Vestibular System

A comprehensive understanding of vestibular anatomy and physiology is essential to interpreting and treating vestibular disorders. The otolithic organs and semicircular canals are the major components of the vestibular system. Each contains hair cells, mechanosensory cells responsible for converting mechanical signals produced by the body into electrical signals. Each hair cell produces a resting discharge rate. This rate can be increased or decreased as a result of head motion, with the magnitude of change dependent on the direction and strength of the motion. These signals are sent to the vestibulocochlear nerve which interprets and integrates the information with input from other sensory organs. The main role of the vestibular system is to maintain balance and detect angular and linear acceleration. Angular acceleration is detected by the semicircular canal via interpretation of endolymph flow caused by head movement. Linear acceleration is detected by the otolith organs through gravity-dependent otoconia movement. This article serves as a review for the structure and function of the major vestibular organs. This review contains, 9 figures, 1 table, and 8 references  Keywords: Vestibular physiology, Hair cells, Otolith organs, Macule, Semicircular canals, Ampulla, Crista, Vestibulocochlear nerve, Angular acceleration, Linear acceleration