How many membranes are found in epithelium ? Give a brief account on each of them



There are three major types of membranes underlying a sheet of epithelium :
(1) Mucous membrane : They line the internal surface of organs where passageways lead to the outside of the body. It secretes mucus to moisten and lubricate the membrane
(2) Serous membrane : They line the closed internal body cavities and cover the surfaces of the organs in these cavities. The serous membranes covering the lungs are called pleura and the membrane covering the heart are called pericardium.
(3) Cutaneous membrane : The cutaneous membrane constitutes an organ of the integumentary system.