<prompt> Endolymphatic duct connects which structure?Scala media to subdural spaceScala vestibule to aqueduct of cochleaScala tympani to aqueduct of cochleaScala tympani to subdural space  <response>: Endolymphatic duct - It is a pa of membranous labyrinth Scala mediaIt is formed by union of saccule and utricleIt connects scala media to subdural spaceIts terminal pa is dilated to form the endolymphatic sacEndolymphatic sac lies between the two layers of dura on the posterior surface of petrous boneSurgical impoance - Endolymphatic sac is exposed for drainage or shunt operation in Menieres disease 