The digestive system breaks down food into smaller molecules that can be absorbed and used by the body. It consists of the mouth, esophagus, stomach, small intestine, large intestine, rectum, and anus. Food is mechanically and chemically broken down at each stage as it moves through the system. The mouth chews food, the stomach churns and adds acid, and the intestines further break down food with enzymes before nutrients are absorbed and waste is eliminated.