Vestibular System

A common experience of childhood is spinning in circles and then stopping and feeling the world and oneself to be turning. These after-sensations are the result of stimulation of receptors in the vestibular system, or labyrinth, of the inner ear that are differentially specialized for the detection of angular and linear acceleration. On either side of the head, there are three semicircular canals embedded in the temporal bones, orthogonally oriented in relation to one another, and also two otolith organs. These are the receptor mechanisms that detect angular and linear acceleration, respectively. They are illustrated in Figure 1. When a head movement is made in or near the plane of rotation of a semicircular canal, the endolymph fluid within the canal lags and “displaces” a ...