The American encyclopedia and dictionary of ophthalmology Edited by Casey AWood, assisted by a large staff of collaborators . has no outlet, liesbehind and a little above the ligamentum palpebrsE mediale, the en-tire sac completely filling a groove in the lachrymal bone in whichit rests. The epithelium of its lining mucous membrane is of thecylindroid variety, and is continuous with that lining the nasal duct. The n-asal duct is directly continuous with the lachrymal sac. Itis about 21 mm. long, and -4 to 6 mm. wide, but by no means uniformin its diameter. There is a slight constriction where
The American encyclopedia and dictionary of ophthalmology Edited by Casey AWood, assisted by a large staff of collaborators . has no outlet, liesbehind and a little above the ligamentum palpebrsE mediale, the en-tire sac completely filling a groove in the lachrymal bone in whichit rests. The epithelium of its lining mucous membrane is of thecylindroid variety, and is continuous with that lining the nasal duct. The n-asal duct is directly continuous with the lachrymal sac. Itis about 21 mm. long, and -4 to 6 mm. wide, but by no means uniformin its diameter. There is a slight constriction where it joins the sac,and a somewhat expanded orifice where it enters the nose; its nar-rowest portion being about the middle. Regurgitation from the nasal 352 ANATOMY (GROSS) OF THE HUMAN EYE cavity is prevented by a fold of mucous membrane—the plica lachry-nialis, or valve of Hasner—situated at the opening of the duct intothe inferior meatus just underneath the attachment of the anteriorthird of the inferior turbinate bone; also by irregular folds of mucousmembrane forming imperfect valves along the course of the m n r s 0 ^f Orifices of Nasal Duct and Accessory Air Chambers of Nose. a, Frontal sinus; b, Twine in infundibulum; c, Middle turbinal (cut) ; d, Orificesof anterior ethmoidal cells; e, Bulla ethmoidalis; f, Orifices of posterior ethmoidalcells in superior meatus; g, Superior turbinal (cut); h, Twine in orifice of sphe-noidal cell; i, Sphenoidal cell; j, Diaphragmia sellge; k, Ca^alm sellse; 1, Hiatussemilunaris; m, Twine in nasal duct; n, Additional orifice of antrum of High-more; p, Middle turbinal (cut); q, Middle meatus; r, Inferior turbinal; s,Inferior meatus; t, Orifice of Eustachian tube. The epithelium is ciliated. The direction of the nasal duct is down-ward, outward, and backward; it is enclosed in a canal formed by thelachrymal, superior maxillary, and inferior turbinate bones. The mucous membrane lining the sac and the nasal duct is attachedto the s
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectophthalmology, bookye
