Inner ear contain endolymph and perilymph. Which of the following structure of the inner ear produces endolymph?: (A) Is a filtrate of blood serum, (B) Is secreted by Stria vascularis, (C) Is secreted by Basilar membrane, (D) Is secreted by Hair cells
Answer is B. Endolymph fills the entire membranous labyrinth and resembles intracellular fluid, being rich in K ions. It is secreted by the secretory cells of the stria vascularis of the cochlea and by the dark cells (present in the utricle and near the ampullated ends of semicircular ducts).