Which part detects angular acceleration?

• A. Semicircular canals detect angular acceleration
• B. Otolith organs detect angular acceleration
• C. Cochlea detects angular acceleration
• D. Visual cortex detects angular acceleration

Answer: (A)

The semicircular canals detect angular acceleration. They are arranged in three perpendicular planes and filled with endolymph fluid. When the head starts or stops rotating, the inertia of the endolymph causes it to lag behind the canal wall, bending the cupula and deflecting the hair cells. This transduction signals a change in rotational velocity to the brain. Once rotation becomes constant, the endolymph catches up and deflection subsides, so the canal mainly responds to changes in rotation—the angular acceleration or deceleration. In contrast, the otolith organs sense linear acceleration and head position relative to gravity, the cochlea handles hearing, and the visual cortex processes visual information.