Which structure contains hair cells that transduce mechanical vibrations into neural signals?

Which structure contains hair cells that transduce mechanical vibrations into neural signals?

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

Answer: (B)

Organ of Corti houses the hair cells that transduce mechanical energy into neural signals. Inside the cochlea, sound vibrations cause the basilar membrane to move, bending the stereocilia of inner and outer hair cells. This deflection opens mechanically gated ion channels, creating receptor potentials and triggering neurotransmitter release onto the adjacent auditory nerve fibers. The resulting action potentials travel through the auditory pathway to be interpreted as sound. The semicircular canals, in contrast, are part of the vestibular system and detect head rotation, not airborne sounds. The tympanic membrane (eardrum) vibrates in response to sound and helps transfer energy to the ossicles, but it does not itself transduce vibrations into neural signals. The Eustachian tube mainly equalizes middle-ear pressure and isn’t involved in auditory transduction.

Organ of Corti houses the hair cells that transduce mechanical energy into neural signals. Inside the cochlea, sound vibrations cause the basilar membrane to move, bending the stereocilia of inner and outer hair cells. This deflection opens mechanically gated ion channels, creating receptor potentials and triggering neurotransmitter release onto the adjacent auditory nerve fibers. The resulting action potentials travel through the auditory pathway to be interpreted as sound.

The semicircular canals, in contrast, are part of the vestibular system and detect head rotation, not airborne sounds. The tympanic membrane (eardrum) vibrates in response to sound and helps transfer energy to the ossicles, but it does not itself transduce vibrations into neural signals. The Eustachian tube mainly equalizes middle-ear pressure and isn’t involved in auditory transduction.