Source:http://linkedlifedata.com/resource/umls/id/C2753459
GO: An extracellular region part that consists of a protective layer of mucus secreted by epithelial cells lining tubular organs of the body such as the colon. Mucus is a viscous slimy secretion consisting of mucins and various inorganic salts dissolved in water, with suspended epithelial cells and leukocytes. [GOC:mah, GOC:mm2, PMID:18806221, PMID:19432394]