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Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
The lacrimal duct open at the
assistant
The correct answer is  *Nasolacrimal duct is a membranous passage of 18mm long. *It begins at the lower end of lacrimal sac, runs downwards, backward and laterally, and opens into the inferior meatus of nose. *A fold of mucous membrane called the valve of Hasner forms an imperfect valve at the lower end of the duct. <img src=" /> Ref: BDC. vol3,sixth edition pg 76.