Not Medical Advice: That tube is called the esophagus. The esophagus is a narrow muscular tube connecting the throat (pharynx) with the stomach. The esophagus is around 8 inches long, and is lined by moist pink tissue called mucosa.
The esophagus runs behind the trachea and heart, and in front of the spine. Just before arriving at the stomach, the esophagus passes through the diaphragm.
The esophagus comprises three basic layers:
An outer layer of fibrous tissue.
A middle layer containing smoother muscle.
An inner membrane, which contains many tiny glands.
Get information, picture, conditions and more about esophagus at WebMD.