What does the cochlea primarily do?

What does the cochlea primarily do?

• A. Regulates fluid balance in the inner ear.
• B. Converts mechanical motion into neural signals.
• C. Produces ear wax.
• D. Transmits sound waves to the tympanic membrane.

Answer: (B)

The cochlea’s main role is to convert mechanical energy from sound into neural signals. When sound causes the basilar membrane to vibrate, the hair cells in the organ of Corti bend their stereocilia. This mechanical deflection opens ion channels, leading to hair cell depolarization and the release of neurotransmitter onto afferent auditory neurons. The resulting electrical signals travel through the auditory nerve to the brain. The cochlea also encodes pitch through tonotopy, with different frequencies activating different parts along its length. Other choices refer to functions of different structures: producing earwax, which is done by glands in the ear canal; transmitting sound to the tympanic membrane by the outer and middle ear; and fluid balance involving other inner ear components, not the cochlea’s transduction role.

The cochlea’s main role is to convert mechanical energy from sound into neural signals. When sound causes the basilar membrane to vibrate, the hair cells in the organ of Corti bend their stereocilia. This mechanical deflection opens ion channels, leading to hair cell depolarization and the release of neurotransmitter onto afferent auditory neurons. The resulting electrical signals travel through the auditory nerve to the brain. The cochlea also encodes pitch through tonotopy, with different frequencies activating different parts along its length. Other choices refer to functions of different structures: producing earwax, which is done by glands in the ear canal; transmitting sound to the tympanic membrane by the outer and middle ear; and fluid balance involving other inner ear components, not the cochlea’s transduction role.