<prompt> Upper covering layer of cochlear duct isBasilar membraneTectorial membraneStria vascularisVestibular membrane  <response>: Reissners membrane - between Scala vestibuli Scala media. Basilar membrane - between scala media Scala tympani Tectorial membrane - covers the hair cells. Stria vascularis gives the endolymph which is ultrafiltrate of blood. 