The organ containing hair cells that detect sound is located in which structure?

• A. Organ of Corti
• B. Basilar membrane
• C. Auditory cortex
• D. Cochlear nuclei in the brainstem

Answer: (A)

The hair cells that detect sound are housed in the Organ of Corti, the specialized sensory structure inside the cochlea. This organ sits on the basilar membrane and contains inner and outer hair cells that respond when their stereocilia bend in response to fluid motion triggered by the vibrating basilar membrane. The bending opens ion channels and converts mechanical energy into neural signals that travel via the auditory nerve. The other options refer to parts of the auditory pathway after transduction: the basilar membrane is the supporting surface under the Organ of Corti, while the auditory cortex and the brainstem cochlear nuclei are regions where sound is processed higher up in the brain.