The Enterogastric reflex is one of three extrinsic reflexes of the Gastrointestinal Tract. The reflex is stimulated by the presence of acid levels in the duodenum at a pH of 3-4 or in the stomach at a pH of 1.5. Upon stimulation of the reflex, the release of gastrin from G-cells in the antrum of the stomach is shut off. This in turn inhibits gastric motility and secretion of gastric acid (HCl). In addition to the Enterogastric reflex, the other two extrinsic reflexes of the Gastrointestinal Tract include the Gastrocolic reflex and the Colonoileal reflex.