What do the semicircular canals sense?

What do the semicircular canals sense?

• A. Head position
• B. Head movement
• C. Loudness
• D. Pressure

Answer: (B)

Rotational head movement is what the semicircular canals detect. Each canal is oriented in a different plane and contains hair cells in a structure called the ampulla. When the head turns, the endolymph fluid inside the canal lags due to inertia, bending the cupula and deflecting the hair cells. This changes the firing rate of the vestibular nerve, signaling angular acceleration and rotation to the brain to help maintain balance and gaze stability during movement. Static head position or orientation, on the other hand, is sensed mainly by the otolith organs (utricle and saccule) that detect linear acceleration and gravity. Loudness is processed by the auditory system in the cochlea, and pressure changes are not sensed by the semicircular canals.

Rotational head movement is what the semicircular canals detect. Each canal is oriented in a different plane and contains hair cells in a structure called the ampulla. When the head turns, the endolymph fluid inside the canal lags due to inertia, bending the cupula and deflecting the hair cells. This changes the firing rate of the vestibular nerve, signaling angular acceleration and rotation to the brain to help maintain balance and gaze stability during movement. Static head position or orientation, on the other hand, is sensed mainly by the otolith organs (utricle and saccule) that detect linear acceleration and gravity. Loudness is processed by the auditory system in the cochlea, and pressure changes are not sensed by the semicircular canals.