submucosa mucosa http://upload.wikimedia.org/wikipedia/commons/4/4e/Ens.png http://upload.wikimedia.org/wikipedia/en/thumb/4/4e/Ens.png/200px-Ens.png A lining of mostly endodermal origin, covered in epithelium, which is involved in absorption and secretion. They line various body cavities that are exposed to the external environment and internal organs. It is at several places continuous with skin: at the nostrils, the lips, the ears, the genital area, and the anus. The sticky, thick fluid secreted by the mucous membranes and gland is termed mucus. The term mucous membrane refers to where they are found in the body and not every mucous membrane secretes mucus[WP]. mucous membrane UMLS:C0026724 SCTID:361693009 NCIT:C13166 AEO:0000199 MESH:D009092 EV:0100382 uberon UBERON:0000344 region of mucosa CALOHA:TS-2031 tunica mucosa BTO:0000886 galen:Mucosa FMA has mucosa vs region of mucosa; these are subtypes of Mucosa: Mucosa of gallbladder, tongue, .... The following are subtypes of Region of mucosa: Mucosa of zone of stomach, trachea, bronchus, dorsum of tongue.... Depends on whether the covered area is an organ or organ component. Uberon does not regard organ vs organ component as crucial distinction and thus collapses these into a single class deliberately FMA:85355 FMA:85358 GAID:297 mucosal region mucosa of organ mucosa of organ part organ mucosa EHDAA2_RETIRED:0003234 mucosal Wikipedia:Mucous_membrane organ component layer