endolymphatic duct endolymphatic duct from the posterior wall of the saccule a canal, the endolymphatic duct, is given off; this duct is joined by the ductus utriculosaccularis, and then passes along the aquaeductus vestibuli and ends in a blind pouch (endolymphatic sac) on the posterior surface of the petrous portion of the temporal bone, where it is in contact with the dura mater. endolymphatic ductthe membranous labyrinth. (ductus endolymphaticus labeled at bottom center.)endolymphatic duct is #6, and is labeled at top center.detailsidentifierslatinductus endolymphaticusmeshd004711ta98a15.3.03.079ta27006fma61246anatomical terminology disorders of the endolymphatic duct include meniere's disease and enlarged vestibular aqueduct. additional images transverse section through head of fetal sheep, in the region of the labyrinth. x 30. transverse section of a human semicircular canal and duct