Final answer:
The hair cells in the organ of Corti within our inner ear react to sound waves by bending their stereocilia, causing the hair cells to depolarize and send auditory signals to the brain.
Step-by-step explanation:
Auditory Receptor Cells in the Inner Ear
The auditory receptor cells you're asking about are the hair cells that are situated within the organ of Corti, located in the cochlea of the inner ear. These cells are critical for the process of hearing as they transform mechanical sound vibrations into electrical signals that our brain can interpret. The organ of Corti contains two types of hair cells: inner hair cells and outer hair cells. The inner hair cells are primarily responsible for auditory transduction and exist in a single row consisting of about 3,500 cells. The outer hair cells, which are more numerous with around 12,000 cells, are arranged in three or four rows and serve to fine-tune the precision of sound.
The basilar membrane supports the organ of Corti and vibrates in response to sound waves moving through the cochlear fluid. These vibrations cause a relative motion between the basilar membrane and the tectorial membrane, which in turn, causes bending of the hair cells' stereocilia. The stereocilia are linked by protein fibers, which open ion channels when they bend, leading to hair cell depolarization and the initiation of auditory nerve signals.
Each hair cell has stereocilia that vary in height and are arranged from the tallest to the shortest. They are tethered to one another so that when they bend in response to sound vibrations, the resulting tension opens ion channels. When sound waves are absent, the stereocilia remain slightly depolarized due to residual tension on the tethering fibers, maintaining the readiness of the hair cells to respond to sound.