In mammals, it is composed of large number of interconnected ganglia that are arranged into two concentric rings embedded throughout the gut wall, beginning in the esophagus and ending in the anus.

[1] A large number of organs derived from the developing foregut also receive input from the vagus nerve, which also works in tandem with the ENS to control gastrointestinal function.

[2] The expanding dorsal stomach wall then rotates the on its transverse plane, pulling its caudal portion upward and forcing the upper duodenum into a C shape.

In the adult, these connective structures of omentum and mesentery form the peritoneum, and act as an insulating and protective layer while also supplying organs with blood and lymph vessels as well as nerves.

[3] Recent research has suggested that most foregut malformations are due to defects in these signalling pathways, with sonic hedgehog gene knockout mice showing phenotypes similar to those seen in patients with esophageal atresia/stenosis, tracheo-esophageal fistula, and respiratory tract anomalies.