Hair cells extend into which gelatinous mass?

Hair cells extend into which gelatinous mass?

• A. Bone
• B. Water
• C. Gelatinous mass
• D. Air

Answer: (C)

Hair cells in the vestibular system extend into a gelatinous mass, which is the structure that transduces motion into neural signals. In the semicircular canals, this gelatinous mass is the cupula inside the ampulla; when the head rotates, the flow of endolymph pushes on the cupula and bends the hair-cell stereocilia. This bending changes the receptor potential and sends information about angular acceleration to the brain. The other options don’t fit because bone, water, or air are not the structures that hair cells extend into. For context, another part of the vestibular system features a different gelatinous layer called the otolithic membrane in the otolith organs, which also interacts with hair cells to detect linear acceleration.

Hair cells in the vestibular system extend into a gelatinous mass, which is the structure that transduces motion into neural signals. In the semicircular canals, this gelatinous mass is the cupula inside the ampulla; when the head rotates, the flow of endolymph pushes on the cupula and bends the hair-cell stereocilia. This bending changes the receptor potential and sends information about angular acceleration to the brain. The other options don’t fit because bone, water, or air are not the structures that hair cells extend into. For context, another part of the vestibular system features a different gelatinous layer called the otolithic membrane in the otolith organs, which also interacts with hair cells to detect linear acceleration.