Which vestibular structure is primarily responsible for sensing angular acceleration in three perpendicular axes?

• A. Otolith Organs
• B. Semicircular Canal
• C. Visual System
• D. Cochlea

Answer: (B)

The semicircular canals are designed to sense angular motion in three perpendicular directions. Each canal is oriented along a different axis (roughly corresponding to yaw, pitch, and roll) and contains endolymph that resists sudden movement. When the head rotates, the endolymph lags and pushes on the cupula within the ampulla, bending the hair cells and producing neural signals that encode angular velocity and acceleration. Having three canals in orthogonal planes lets the system detect rotation about any axis.

Otolith organs detect linear acceleration and head inclination relative to gravity, not rotation. The cochlea handles hearing, not balance.