<prompt> Valve of Rosenmuller is located atCystic ductOpening of nasolacrimal ductJunction of lacrimal sac and canaliculusAmpulla of vater  <response>: A fold of mucous membrane found at the junction between the common canaliculus and the lacrimal sac. It is not strictly a valve because fluids can be blown back to emerge at the puncta. It is not always fully developed. ref -medscape.com 