The esophagus is the muscular tube that carries food and drink from the mouth to the stomach. Dr. Jerman, can you tell us more about the esophagus?
Sure, Dr. Mansfield. When a person swallows, food from the mouth pushes into the esophagus through a ringlike bundle of muscles called the upper esophageal sphincter, or UES. The UES is under voluntary or conscious control and works in conjunction with the uvula, which covers the airway during the act of swallowing.
Layers of muscle in the walls of the esophagus then contract and relax to move the food down toward the stomach. This movement, which resembles an ocean wave traveling through the esophagus, is called peristalsis.
As food approaches the lower esophageal sphincter, or LES, the muscles relax and allow food to pass into the stomach. Unlike the UES, the muscles of the LES are not under voluntary or conscious control.