The sensory receptors for rotational head movement are located in which structure?

The sensory receptors for rotational head movement are located in which structure?

• A. Utricle
• B. Saccule
• C. Ampulla
• D. Cochlea

Answer: (C)

Rotational head movement is detected by the semicircular canals, specifically in the ampullae at their ends. Each ampulla contains the crista ampullaris, a ridge of hair cells whose stereocilia are embedded in a gelatinous cupula. When you rotate your head, the endolymph inside the canal lags due to inertia and pushes against the cupula, bending the hair cells. This bending changes the rate of neurotransmitter release to the vestibular nerve, signaling angular acceleration to the brain. The utricle and saccule sense linear acceleration and head position relative to gravity, not rotation, and the cochlea is involved in hearing.

Rotational head movement is detected by the semicircular canals, specifically in the ampullae at their ends. Each ampulla contains the crista ampullaris, a ridge of hair cells whose stereocilia are embedded in a gelatinous cupula. When you rotate your head, the endolymph inside the canal lags due to inertia and pushes against the cupula, bending the hair cells. This bending changes the rate of neurotransmitter release to the vestibular nerve, signaling angular acceleration to the brain. The utricle and saccule sense linear acceleration and head position relative to gravity, not rotation, and the cochlea is involved in hearing.