Digestion is the mechanical and chemical breakdown of foods into nutrients that cell membranes can absorb. The organs of the digestive system carry out these processes. The digestive system consists of the alimentary canal, which extends from the mouth to the anus, and several accessory organs, which release secretions into the canal. The alimentary canal includes the mouth, pharynx, esophagus, stomach, small intestine, large intestine, and anal canal; the accessory organs include the salivary glands, liver, gallbladder, and pancreas.