<prompt> Endolymph is secreted byStria vascularisBasilar membraneCochlear ductHensen cell  <response>: - Vestibule is the central chainberQ. All three semicircular canals SCCs form 23rd of a circle and are set at right 90deg anglesQ to each other. 3 SCCs have only 5 openingsQ into the vestibule. Anterior posterior SCCs are veical and lateral SCC is horizontalQ.Apex of conical modiolus of cochlea axis of TM is directed anterolaterally inferiorlyQ. Hollow spiral canal around it makes 2.5 212 turnsQ with basal turn having biggest radiusQ.- Endolymph is secreted by secretory cells of stria vascularis of cochleaQ dark cells in utricle. 