Lacrimal canaliculi

Lacrimal canaliculi
The lacrimal apparatus. Right side.
Latin	canaliculus lacrimalis
Gray's	subject #227 1028

The lacrimal canaliculi, also known as the lacrimal canals or lacrimal ducts, are the small channels in each eyelid that commence at minute orifices, termed puncta lacrimalia, on the summits of the papillae lacrimales, seen on the margins of the lids at the lateral extremity of the lacus lacrimalis.

• The superior duct, the smaller and shorter of the two, at first ascends, and then bends at an acute angle, and passes medialward and downward to the lacrimal sac.

• The inferior duct at first descends, and then runs almost horizontally to the lacrimal sac.

At the angles they are dilated into ampullæ. Microscopically, they are lined by nonkeratinizing stratified squamous epithelium surrounded by fibrous tissue.

Outside the latter is a layer of striped muscle, continuous with the lacrimal part of the Orbicularis oculi; at the base of each lacrimal papilla the muscular fibers are circularly arranged and form a kind of sphincter.

Clinical significance

Canaliculitis is an inflammation of the canaliculus.^[1]

See also

• Lacrimal apparatus
• canaliculus

References

1. ^ Handbook of Ocular Disease Management - Molluscum Contagiosum

External links

• lacrimal+canaliculus at eMedicine Dictionary

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This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained herein may be outdated.