In the mouth, stomach, and small intestine, the mucosa contains tiny glands that produce juices to help digest food. There are also two solid digestive organs, the liver and the pancreas, which produce juices that reach the intestine through small tubes.In addition, parts of other organ systems (for instance, nerves and blood) play a major role in the digestive system.igestion is the process by which food and drink are broken down into their smallest parts so that the body can use them to build and nourish cells and to provide energy. The digestive system is a series of hollow organs joined in a long, twisting tube from the mouth to the anus.