Endolymph is rich in ?

Ans. is 'd' i.e., K+Fluid in inner ear There are two main fluids in the inner ear : -(i) Perilymph (ii) EndolymphPerilymphIt resembles ECF and is rich in Nu+ ions. It fills the space between bony and the membranous labyrinth, i.e., Scala vestibuli and scala tympani. It communicates with CSF through the aqueduct of Cochlea which opens into the scala tympani near the round window. Therefore It closely resembles CSF. It is formed by : -i) It is a filterate of blood serum and is formed by capillaries of the spiral ligament.ii) It is a direct continuation of CSF and reaches the labyrinth aqueduct of cochlea.EndolymphIt fills the entire membranous labyrinth including scala media (cochlear duct). It resembles intracellular fluid, being rich in IC 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).