vestibular membrane of cochlear duct

A membrane inside the cochlea of the inner ear. It separates scala media from scala vestibuli. Together with the basilar membrane it creates a compartment in the cochlea filled with endolymph, which is important for the function of the organ of Corti. It primarily functions as a diffusion barrier, allowing nutrients to travel from the perilymph to the endolymph of the membranous labyrinth. Histologically, the membrane is composed of two layers of flattened epithelium, separated by a basal lamina. Its structure suggests that its function is transport of fluid and electrolytes.