A mucous membrane is a thin tissue which lines the canals, cavities and the inside of hollow organs which communicate externally by different appertures.
Mucous membranes secrete a mucus, viscid, gummy secretion, analogous to vegetable mucilage.
It is albuminous, like the white of an egg. The mucus preserves the membranes and keeps them moist, a condition suitable for the performance of their functions. The mucus coating on the mucous membrane of the stomach prvents the stomach from self-digestion. Mucous membranes are well supplied with arteries, veins, lymphatics and nerves. In the acute stage of inflammation, the mucous membrane is at first dry and swollen.