Which two vestibular structures work together to detect head rotation and linear acceleration?

• A. Cochlea and semicircular canals
• B. Otoliths and semicircular canals
• C. Otoliths and cochlea
• D. Malleus and incus

Answer: (B)

Rotational movement and linear acceleration come from separate parts of the vestibular system that work together to give the brain a full sense of head motion. The semicircular canals detect head rotation by sensing angular velocity through movement of endolymph when you turn your head. The otolith organs (utricle and saccule) detect linear acceleration and head position relative to gravity via the shifting of their otolith crystals, which bends the hair cells in the otolithic membrane. By combining signals from these two sensors, the brain can determine both how you’re rotating and how you’re moving linearly, which supports gaze stabilization and balance. The cochlea handles hearing, and the malleus and incus are auditory ossicles, not vestibular sensors.