Source:http://linkedlifedata.com/resource/umls/id/C3203348
NCI: The upper part of the gastrointestinal tract that includes the esophagus, stomach, and duodenum. (NCI),MSH: The segment of GASTROINTESTINAL TRACT that includes the ESOPHAGUS; the STOMACH; and the DUODENUM.,NCI: The upper part of the gastrointestinal tract that includes the esophagus, stomach, and duodenum.