When you eat, food passes from the throat to the stomach through the esophagus. A ring of muscle fibers in the lower esophagus prevents swallowed food from moving back up. These muscle fibers are called the lower esophageal sphincter
Explanation: As a person swallows, food moves from the mouth to the throat, also called the pharynx. The upper esophageal sphincter opens so that food can enter the esophagus, where waves of muscular contractions, called peristalsis, propel the food downward to the stomach.
