A membrane lining all body passages that communicate with the air, such as the respiratory and alimentary tracts, and having cells and associated glands that secrete mucus. Also called mucosa粘膜：一种能分泌粘液的膜，附于身体内与外界相通的腔道上，如消化道和呼吸道，有能分泌粘液的细胞和相关的腺 也作 mucosa