The organ responsible for detecting linear acceleration within static equilibrium is the?

The organ responsible for detecting linear acceleration within static equilibrium is the?

• A. Utricle
• B. Semicircular canal
• C. Macula
• D. Saccule

Answer: (C)

Linear acceleration in static equilibrium is detected by the macula, the sensory epithelium inside the otolith organs. The macula sits within the utricle and saccule and contains hair cells whose stereocilia are embedded in an otolithic membrane seasoned with otoconia (tiny calcium carbonate crystals). When the head tilts or there is linear movement, inertia causes the otoconia to lag, bending the hair cell stereocilia. This changes the rate of neurotransmitter release and signals the vestibular nerve about the direction and amount of linear acceleration. The semicircular canals, by contrast, detect angular (rotational) movements, not linear acceleration, so they play a different role in balance.

Linear acceleration in static equilibrium is detected by the macula, the sensory epithelium inside the otolith organs. The macula sits within the utricle and saccule and contains hair cells whose stereocilia are embedded in an otolithic membrane seasoned with otoconia (tiny calcium carbonate crystals). When the head tilts or there is linear movement, inertia causes the otoconia to lag, bending the hair cell stereocilia. This changes the rate of neurotransmitter release and signals the vestibular nerve about the direction and amount of linear acceleration. The semicircular canals, by contrast, detect angular (rotational) movements, not linear acceleration, so they play a different role in balance.