The sublingual glands are rarely affected. Salivary stones generally form when mucous sludge combines with calcium hydroxylapatite and deposits within the salivary ducts. While some stones can be seen ...

These spines are very small and closely-packed and end in a fleshy tip covered in mucus glands. They are also strongly ciliated along their shaft. In the living animal (above) the bands show up ...

Tears are made up of three layers: a mucous, watery, and oily layer, each of which comes together from separate glands. When the gland that produces the oily layer doesn't function properly ...