The<unk> , also known as the<unk>  canals or<unk>  ducts, are the small channels in each eyelid that commence at minute orifices, termed puncta<unk> ia, on the summits of the papillæ<unk> es, seen on the margins of the lids at the lateral extremity of the lacus<unk> is.
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<unk>  sac.
The inferior duct at first descends, and then runs almost horizontally to the<unk>  sac.
At the angles they are dilated into ampullæ; their walls are dense in structure and their mucous lining is covered by stratified squamous epithelium, placed on a basement membrane.
Outside the latter is a layer of striped muscle, continuous with the<unk>  part of the Orbicularis oculi; at the base of each<unk>  papilla the muscular fibers are circularly arranged and form a kind of sphincter.
Lacrimal canaliculi
Nasolacrimal duct
Lacrimal bone
Ear canal
Outer ear
Ranula
Cauliflower ear
Semicircular canal