Q. From the lumen to the external surface what are the tissues that form the digestive tube wall?
From the internal surface to the external surface, the digestive tube wall is made of submucosa (connective tissue beneath the mucous membrane and where blood and lymphatic vessels and neural fibers are located), mucosa (epithelial tissue responsible for the intestinal absorption), muscle layers (smooth muscle tissue, two layers, one interior circular and other exterior longitudinal, structures responsible for the peristaltic movement), serous membrane (associated epithelial and connective tissue forming the external surface of the organ). In the bowels the serous membrane prolongs to form the mesentery a serosa that encloses blood vessels and supports the bowels within the abdominal cavity.