<prompt> The following is true about nasolacrimal ductDirected downward, forward, and mediallyDirected downward, backward and laterallyDrains in posterior pa of inferior meatus18 cm in length  <response>: Ref BDC volume 3,6th edition pg 76 It begins at the lower end of the lacrimal sac, runs downwards, backwards and laterally, and opens into the inferior meatus of the nose. Nasolacrimal duct is a membranous passage 18mm long. Notes: A fold of mucous membrane called valve of Hasner forms an imperfect valve at the lower end of the duct. 