The muscular tube that connects the back of the mouth to the top of the stomach that carries food from the mouth to the stomach. The upper third of the esophagus is usually referred to as the proximal esophagus, or cervical esophagus. The middle third of the esophagus may be referred to as the thoracic esophagus. The lower third of the esophagus is usually referenced as the distal esophagus.