The digestive tract, also known as the alimentary canal or gastrointestinal tract, is a long muscular tube that extends from the mouth to the anus. In an adult human, the digestive tract is about 9 meters long and consists of the pharynx, esophagus, stomach, small intestine, and large intestine. The primary function of the digestive tract is to process food from the time it is ingested to the time the waste material is eliminated.