What is the function of the macula in static equilibrium?

What is the function of the macula in static equilibrium?

• A. It senses linear acceleration
• B. It senses angular acceleration
• C. It transduces sound
• D. It detects pressure changes

Answer: (A)

Static equilibrium relies on detecting gravity direction and linear motion. The macula, found in the vestibule (utricle and saccule), has hair cells with stereocilia and a kinocilium embedded in an otolithic membrane studded with otolith crystals. When you tilt your head or experience linear acceleration, the heavier otoliths lag slightly due to inertia, bending the hair cell stereocilia. This bending changes neurotransmitter release and sends signals through the vestibular nerve, informing the brain about head position in space. Angular acceleration is sensed by the semicircular canals, not the macula. Hearing involves the cochlea, and pressure changes are not the macula’s role.

Static equilibrium relies on detecting gravity direction and linear motion. The macula, found in the vestibule (utricle and saccule), has hair cells with stereocilia and a kinocilium embedded in an otolithic membrane studded with otolith crystals. When you tilt your head or experience linear acceleration, the heavier otoliths lag slightly due to inertia, bending the hair cell stereocilia. This bending changes neurotransmitter release and sends signals through the vestibular nerve, informing the brain about head position in space. Angular acceleration is sensed by the semicircular canals, not the macula. Hearing involves the cochlea, and pressure changes are not the macula’s role.