The membranous labyrinth partitions the bony labyrinth of the cochlea into three chambers-the perilymphatic scala vestibuli and scala tympani; and the endolymphatic scala media. These fluids also extend into the vestibular labyrinth Vestibular Apical turn membrane Tectorial membrane Middle turn Vestibular duct Modiolus (scala vestibuli- contaIns From perilymph) Cochlear duct scala media- contains Basal endolymph) turn Organ of Corti Tympanic F。e tympani membrane s contains To round perilymph) window Temporal bone Spiral ganglion (petrous portion) Cochlear nerve Vestibulocochlear nerve(N VIll)The membranous labyrinth partitions the bony labyrinth of the cochlea into three chambers – the perilymphatic scala vestibuli and scala tympani; and the endolymphatic scala media. These fluids also extend into the vestibular labyrinth