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