Digestive System Research Paper

The digestive system is made up of the gastrointestinal (GI) tract and the liver, pancreas, and gallbladder. The GI tract is a series of hollow organs joined in a long, twisting tube from the mouth to the anus. The hollow organs that make up the GI tract are the mouth, esophagus, stomach, small intestine, large intestine (which includes the rectum) and anus.5 Food enters the mouth and passes to the anus through the hollow organs of the GI tract. The liver, pancreas, and gallbladder are the solid organs of the digestive system. The digestive system helps the body digest food. The large, hollow organs of the GI tract contain a layer of muscle that enables their walls to move. The movement of organ walls, known as peristalsis, propels food and liquid through the GI tract and mixes the contents within each organ.

When a person swallows, food is pushed into the esophagus and the muscular tube carries the food and liquids from the mouth to the stomach.5 Once swallowing begins, it becomes involuntary and proceeds under the control of the esophagus and brain. The lower esophageal sphincter, a ring-like muscle at the junction of the esophagus and stomach, controls the passage of food and liquid between the esophagus and stomach. As food approaches the closed sphincter, the muscle relaxes and lets food pass through to the stomach. Stomach. The stomach stores swallowed food and liquid, mixes the food and liquid with digestive juice it produces, and slowly empties its contents, called chyme, into the small intestine. The muscle of the upper part of the stomach relaxes to accept large volumes of swallowed material from the