Components of the Gastrointestinal System
The digestive tract, gastrointestinal (GI) tract, or alimentary tract (see Figure 11.1) is a long tube, about9 meters (29.5 ft) long in the cadaver. The tract begins at the oral cavity, continues through the pharynx and esophagus to reach the stomach. The stomach opensinto the small intestine, where most absorption oc-curs. From the small intestine, the food moves into the large intestine and, finally, to the rectum (also part ofthe large intestine) and anus. The teeth, tongue, sali-vary glands, liver, gallbladder, and pancreasareconsidered accessory digestive organs. The teeth help to break down the food, and the tongue helps taste, chew, and swallow. The other organs do not come in direct contact with the food; however, they help digest the food chemically by the enzymes they secrete and convey to the lumen by ducts.