Abstract
Abstract: :
Purpose:It is said that a lot of mucosal valves in the human nasolacrimal duct form a baffle that prevents the counterflow of the air from the nasal cavity. However, a recent anatomical study (Kurihashi et al, Int Opthalomol 1991) indicated that no apparent valves were found in the human nasolacrimal ducts. The present study was carried out in order to verify their results. Methods:The donated adult Japanese cadavers were used for this study. The nasolacrimal ducts were isolated with the surrounded tissues and examined histologically. In some specimens, after washing out the nasolacrimal ducts, corrosion casts of the ducts were prepared. Results:In the present sudy, remarkable musocal folds were found in the luminal surface of the human nasolacrimal duct. The fold ran spirally the entire course of the duct. However, the apparent valves were not found at the opening of the duct into the nasal cavity. Conclusions:Helical membranous folds, which were found in the luminal surface of the human nasolacrimal duct, might play a role in the prevention of the counterflow of the air from the nasal cavity.
Keywords: anatomy • lacrimal gland