Major Components of the Gastrointestinal System and Their Role in Digestion

The gastrointestinal (GI) system includes the GI tract and accessory organs that aid digestion. All components play a key role in the process of digestion, in order to provide the nutrients necessary to maintain normal body function. The entire digestive tract extends from mouth to anus in a continuous manner, which includes the esophagus, stomach, small intestine and large intestine (Figure 1.1). Accessory organs located outside of the GI tract include salivary glands, the pancreas, and the biliary system, which includes the liver, gallbladder, and bile ducts (Figure 1.1).