Which structure houses the hair cells responsible for transducing mechanical vibrations into neural signals?

Which structure houses the hair cells responsible for transducing mechanical vibrations into neural signals?

• A. Semicircular canals
• B. Organ of Corti
• C. Tympanic membrane
• D. Eustachian tube

Answer: (B)

Transduction of sound into neural signals happens in the organ of Corti, the sensory epithelium located on the basilar membrane inside the cochlea. This is where hair cells, especially the inner hair cells, convert mechanical vibrations from sound into electrical signals. When the basilar membrane moves in response to sound, the stereocilia on these hair cells bend against the overlying tectorial membrane, opening mechanically gated ion channels. This lets ions flow, depolarizes the cell, and triggers neurotransmitter release onto the auditory nerve fibers, sending signals to the brain. The other options don’t perform this transduction. Semicircular canals detect rotational head movement for balance. The tympanic membrane (eardrum) vibrates in response to sound but does not transduce it into neural signals. The Eustachian tube helps equalize middle-ear pressure.

Transduction of sound into neural signals happens in the organ of Corti, the sensory epithelium located on the basilar membrane inside the cochlea. This is where hair cells, especially the inner hair cells, convert mechanical vibrations from sound into electrical signals. When the basilar membrane moves in response to sound, the stereocilia on these hair cells bend against the overlying tectorial membrane, opening mechanically gated ion channels. This lets ions flow, depolarizes the cell, and triggers neurotransmitter release onto the auditory nerve fibers, sending signals to the brain.

The other options don’t perform this transduction. Semicircular canals detect rotational head movement for balance. The tympanic membrane (eardrum) vibrates in response to sound but does not transduce it into neural signals. The Eustachian tube helps equalize middle-ear pressure.