The semicircular canals sense angular acceleration to help balance.

The semicircular canals sense angular acceleration to help balance.

• A. The cochlea is responsible for balance.
• B. The vestibule and cochlea regulate balance.
• C. The semicircular canals sense angular acceleration to help balance.
• D. The eustachian tube regulates balance.

Answer: (C)

The semicircular canals detect angular acceleration, which is rotation of the head, and this information helps maintain balance. Each canal is oriented in a different plane so the system senses rotation in three dimensions. Inside each canal, movement of the endolymph fluid during head rotation pushes on the cupula, bending the hair cells and changing their firing rate to the brain. This rapid signaling informs the brain about head velocity, supporting postural adjustments and stabilizing gaze through reflexes like the vestibulo-ocular reflex. The cochlea handles hearing, not balance; the vestibule (utricle and saccule) detects linear acceleration and gravity, contributing to balance but not angular rotation; and the Eustachian tube simply equalizes middle-ear pressure.

The semicircular canals detect angular acceleration, which is rotation of the head, and this information helps maintain balance. Each canal is oriented in a different plane so the system senses rotation in three dimensions. Inside each canal, movement of the endolymph fluid during head rotation pushes on the cupula, bending the hair cells and changing their firing rate to the brain. This rapid signaling informs the brain about head velocity, supporting postural adjustments and stabilizing gaze through reflexes like the vestibulo-ocular reflex. The cochlea handles hearing, not balance; the vestibule (utricle and saccule) detects linear acceleration and gravity, contributing to balance but not angular rotation; and the Eustachian tube simply equalizes middle-ear pressure.