The gastrointestinal system, or digestive tract, is actually a long tube that extends from the mouth to the anus. This body system is responsible for digesting foods to provide energy for the body. Digestion begins in the mouth with the mechanical breakdown by the teeth and with chemicals in the saliva, called enzymes, that break down carbohydrates. The food is then transferred to the stomach, where gastric juices further break down the food. Food may remain in the stomach for up to six hours until it is completely liquefied. After the stomach, the food moves into the small intestine. Once in the small intestine enzymes from the pancreas and bile from the liver break down the food for absorption. The large intestine serves to remove excess liquid so waste can be excreted from the body.
