Vestibular System

The vestibular system is phylogenetically one of the oldest sensory systems. Its sensory organs detect angular and linear motion of the head relative to space, as well as gravitational forces. The vestibular system generates reflexes in response to head movements to both stabilize the visual axis (gaze) and maintain head and body posture, and is also necessary for our sense of self-motion and orientation in space. In contrast to importance of vision or audition in our daily lives, which can easily be understood by simply shutting our eyes or plugging our ears, the significance of vestibular function is more difficult to appreciate. When the system is functioning normally, we are usually unaware of a distinct sensation arising from vestibular inputs. This is because vestibular signals are integrated with visual, proprioceptive and other sensory information to provide a sense of motion. The critical role played by the vestibular system in everyday life becomes obvious once it has been compromised. For this reason, clinical studies have provided important insights into function of the vestibular system.