Balancing Act

The Vestibular System
The vestibular system is responsible for maintaining posture, balance, and spatial orientation. Part of the system is located in the inner ear. It also includes the vestibulocochlear nerve (the eighth cranial nerve) and certain parts of the brain that interpret the information the vestibulocochlear nerve receives.

The cerebellum is folded into many lobes and lies above and behind the pons. It receives sensory input from the spinal cord, motor input from the cortex and basal ganglia and position information from the vestibular system. The cerebellum then integrates this information and influences outgoing motor pathways from the brain to coordinate movements. To demonstrate this, reach out and touch a point in front of you, such as the computer monitor -- your hand makes one smooth motion. If your cerebellum were damaged, that same motion would be very jerky as your cortex initiated a series of small muscle contractions to home in on the target point. The cerebellum may also be involved in language (fine muscle contractions of the lips and larynx), as well as other cognitive functions.