Where are the maculae located and what is their role in vestibular function?

• A. Otoliths are located in the utricle and saccule; maculae detect linear accelerations and head tilt via otoliths overlying maculae.
• B. Maculae are located in the cochlea; they detect sound.
• C. Maculae are located in the semicircular canals; they detect angular velocity.
• D. Maculae are located in the vestibulocochlear nerve; they transmit auditory signals.

Answer: (A)

Maculae are the sensory patches that line the otolith organs of the inner ear—the utricle and saccule. Their purpose is to sense linear motion and head position relative to gravity. They sit beneath a gelatinous layer that contains otoliths, tiny calcium crystals. When you move in a straight line or tilt your head, gravity causes these crystals to tug on the gelatin and bend the hair cells of the macula. This bending converts mechanical movement into neural signals that travel via the vestibular nerve to the brain, providing information about linear acceleration and tilt.

This data is essential for balance and stabilizing gaze, working alongside the semicircular canals, which detect angular (rotational) motion. The cochlea is involved in hearing, and the vestibulocochlear nerve transmits these sensory signals rather than housing the sensory cells themselves.