What is the function of the tectorial membrane?

What is the function of the tectorial membrane?

• A. It overlies the hair cells and participates in mechanotransduction.
• B. It forms the organ of Corti.
• C. It secretes endolymph.
• D. It vibrates independently of the basilar membrane.

Answer: (A)

The tectorial membrane functions as the gelatinous overlay that sits above the hair cells in the organ of Corti and enables mechanotransduction by interacting with the hair bundle. Its relationship with the outer hair cell stereocilia, which extend into it, means that when the basilar membrane moves in response to sound, there is shear between the basilar and tectorial membranes that deflect the stereocilia. This bending opens mechanosensitive ion channels, producing receptor potentials that initiate neural signals. It does not form the organ of Corti, and it does not secrete endolymph (that is done by the stria vascularis). It also does not vibrate independently of the basilar membrane; its motion is coupled to cochlear mechanics to produce the necessary hair-bundle deflections for transduction.

The tectorial membrane functions as the gelatinous overlay that sits above the hair cells in the organ of Corti and enables mechanotransduction by interacting with the hair bundle. Its relationship with the outer hair cell stereocilia, which extend into it, means that when the basilar membrane moves in response to sound, there is shear between the basilar and tectorial membranes that deflect the stereocilia. This bending opens mechanosensitive ion channels, producing receptor potentials that initiate neural signals.

It does not form the organ of Corti, and it does not secrete endolymph (that is done by the stria vascularis). It also does not vibrate independently of the basilar membrane; its motion is coupled to cochlear mechanics to produce the necessary hair-bundle deflections for transduction.