Final answer:
Within the cochlea, the hair cells of the basilar membrane have stereocilia embedded in the tectorial membrane, which is which is crucial for the process of hearing.
Step-by-step explanation:
The hair cells of the basilar membrane within the cochlea have stereocilia that are embedded in the tectorial membrane. These hair cells are situated in the organ of Corti and are vital for hearing.
The inner hair cells, which serve as the primary auditory receptors, have their stereocilia extending into the lower surface of the tectorial membrane, while the outer hair cells, which are more numerous and assist in fine-tuning sound waves, have stereocilia that attach directly to the tectorial membrane.
When sound-induced vibrations cause the basilar membrane to move, the resultant sliding of the tectorial membrane across the stereocilia bends them. This bending creates tension in protein fibers, called tip links, that connect the stereocilia.
If the stereocilia bend towards the tallest member of their array, it causes ion channels to open, leading to depolarization of the hair cell membrane, which triggers nerve impulses in the cochlear nerve. Conversely, bending towards the shortest stereocilia causes the channels to close, stopping the nerve impulses.