(trā'kē-ō-ē-sof-ā'jē-ăl fōldz) A pair of longitudinal folds in the laryngotracheal diverticulum that unite to form a tracheoesophageal septum, which divides the diverticulum into the esophagus and the laryngotracheal tube. Synonym(s): transesophageal folds, transesophageal ridges.