Perilymph communicates with subarachnoid space through:: (A) Ductus reunions, (B) Helicotrema, (C) Utriculosaccular duct, (D) Cochlear aqueduct
Answer is D. Ans: D (Cochlear aqueduct) Ref: Diseases of the Ear Nose and Throat by PL Dhingra 5th edn .2010.Page 12Explanation:* PerilymphComposition is like extracellular fluidLies between the bony and membranous labyrinthRich in Na+ ions* EndolymphFills the membranous labyrinth.It is rich in K~ ions.Composition is like intracellular fluid.Secreted by the stria vascularis of the crista and dark cells which are seen in the utricle and the ampullary ends of the semi circular canals.