Wall of the digestive tube is formed by four layers of tissue(inner to outer0 MUCOSA-type varies depending on GI location (toughened stratified or delicate and simple epithelium); muscus production. SUBMUCOSA-connective tissue layer MUSCULARIS-circular longitudinal and oblique (in stomach) layers of muscle important in GI motility *Peristalsis-"wavelike" movements pushes food down the tract *Segmentation-"back and forth"movement SEROSA-serous membrane that covers the outside of abdominal organs;it attaches the digestive tract to the wall of abdominoL pelvic cavity by forming folds called MESENTERIES