Final answer:
The shearing force that bends the tips of the inner hair cells in response to movement of the basilar membrane arises from the linkage between the hair cells and the tectorial membrane.
Step-by-step explanation:
The shearing force that bends the tips of the inner hair cells in response to movement of the basilar membrane arises from the linkage between the hair cells and the tectorial membrane. When pressure waves created by sound vibrations move the basilar membrane in the cochlea, the tectorial membrane slides across the stereocilia, causing them to bend towards or away from the tallest member of each array. This bending opens ion channels in the hair cell membrane, triggering nerve impulses that are transmitted to the cochlear nerve.