Which of the following structures is embedded within the otolithic membrane of the vestibular system?

• A. Cochlear duct
• B. Semicircular canal ampullae
• C. Hair cell nuclei
• D. Otoliths (calcium carbonate crystals)

Answer: (D)

Verified step by step guidance

1. Understand the vestibular system: The vestibular system is responsible for maintaining balance and spatial orientation. It includes structures such as the semicircular canals, the utricle, and the saccule.
2. Learn about the otolithic membrane: The otolithic membrane is a gelatinous structure located in the utricle and saccule of the vestibular system. It plays a key role in detecting linear acceleration and head position relative to gravity.
3. Identify the components of the otolithic membrane: Embedded within the otolithic membrane are otoliths, which are small calcium carbonate crystals. These crystals add weight to the membrane, enhancing its sensitivity to movement.
4. Clarify the role of otoliths: Otoliths interact with hair cells in the utricle and saccule. When the head moves, the otolithic membrane shifts, bending the hair cell stereocilia and triggering nerve signals to the brain.
5. Eliminate incorrect options: The cochlear duct is part of the auditory system, not the vestibular system. The semicircular canal ampullae detect rotational movement, not linear acceleration. Hair cell nuclei are part of the hair cells but are not embedded in the otolithic membrane. The correct answer is otoliths.