Figure 1: Vestibular signals from the labyrinth are transferred to the vestibular nuclei (VN) through the vestibular afferents. Several pathways connect VN to other areas: signals can be transmitted: 1) to contralateral VN, 2) to the abducens nucleus (ABD) to produce the vestibulo-ocular reflex, 3) to higher brain centers to provide information about spatial orientation, or 4) to the spinal cord motor neurons that produce reflexes to stabilize posture.
The vestibular system is comprised of two types of sensors: the two otolith organs (the saccule and utricle), which sense linear acceleration (i.e., gravity and translational movements), and the three semicircular canals, which sense angular acceleration in three planes. The receptor cells of the otoliths and semicircular canals send signals through the vestibular nerve fibers to the neural structures that control eye movements , posture, and balance (Fig. 1 ).