Vestibular system

Article By:

Highstein, Stephen M. Washington University, St. Louis, Missouri.

Last reviewed:January 2021

DOI:https://doi.org/10.1036/1097-8542.757803

The system that subserves the bodily functions of balance and equilibrium. The vestibular system accomplishes this by assessing head and body movement and position in space, generating a neural code representing this information, and distributing this code to appropriate sites located throughout the central nervous system. The centrifugal flow of information begins at sensory hair cells located within the peripheral vestibular labyrinth. These hair cells synapse chemically with primary vestibular afferent nerve fibers, causing them to fire with a frequency code of action potentials that include the parameters of head motion and position. These vestibular afferents, in turn, enter the brain and terminate within the vestibular nuclei and cerebellum. Information carried by the firing patterns of these afferents is combined within these central structures with incoming sensory information from the visual, somatosensory, cognitive, and visceral systems to compute a central representation of head and body position in space. This representation is called the gravito-inortial vector and is an important quantity that the central nervous system employs to achieve balance and equilibrium. See also: Brain; Nervous system (vertebrate); Postural equilibrium

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