Which structures detect linear acceleration within the vestibular system?

Which structures detect linear acceleration within the vestibular system?

• A. Otolith organs detect angular acceleration.
• B. Otolith organs (utricle and saccule) detect linear acceleration and head tilt.
• C. Semicircular canals detect linear acceleration.
• D. Cochlea detects linear acceleration.

Answer: (B)

Linear acceleration is detected by the otolith organs in the vestibular system—the utricle and saccule. They have hair cells embedded in a gelatinous layer topped with otoliths (calcium carbonate crystals). When the head moves in a straight line or tilts, the inertia of the otoliths causes this layer to lag behind the hair cells, bending their stereocilia and triggering neural signals that convey motion and head position relative to gravity. The utricle is oriented to sense horizontal movements; the saccule detects vertical movements. The semicircular canals, by contrast, respond to angular (rotational) acceleration, while the cochlea handles hearing and not acceleration.

Linear acceleration is detected by the otolith organs in the vestibular system—the utricle and saccule. They have hair cells embedded in a gelatinous layer topped with otoliths (calcium carbonate crystals). When the head moves in a straight line or tilts, the inertia of the otoliths causes this layer to lag behind the hair cells, bending their stereocilia and triggering neural signals that convey motion and head position relative to gravity. The utricle is oriented to sense horizontal movements; the saccule detects vertical movements. The semicircular canals, by contrast, respond to angular (rotational) acceleration, while the cochlea handles hearing and not acceleration.