part_of part of part of develops from develops from ends during starts during trachea esophagus anterior foregut septum transient tracheoesophageal septum transient TES XAO:0005425 tracheoesophageal septum esophagotracheal septum xenopus_anatomy Temporary septum formed from epithelial tissue dividing the esophagus from the trachea. After mesenchymal invasion this gives rise to the permanent tissue separating the esophagus from the trachea. tracheoesophageal fold NF stage 39 NF stage 44