Which system is responsible for balance and coordinating movements of the eyes, head, and body?

• A. Motor system
• B. Sensory system
• C. Vestibular system
• D. Cerebellar system

Answer: (C)

Balance and the coordination of eye, head, and body movements come from the vestibular system. Located in the inner ear, it detects head motion and gravity: the semicircular canals sense rotational movement, while the otolith organs sense linear acceleration and head position relative to gravity. This information is relayed to brainstem and cerebellar circuits to produce rapid compensatory actions, such as the vestibulo-ocular reflex that stabilizes gaze when the head moves, and postural adjustments that help keep you balanced. The motor system governs how movements are executed, the sensory system covers broad input gathering, and the cerebellar system fine-tunes coordination, but the vestibular system is the primary detector that drives these balance- and gaze-stabilizing responses.