Fig 4

The Scheme of the Anti-Reflux Gastroesophageal Complex. A The gastroesophageal complex consists of the esophageal stump, pseudo-gastric fornix, and lower mediastinum. During periods of resting, a one-way valve maintains pressure in the lower esophagus. The pseudo-gastric fornix acts as a food reservoir, relieving pressure. B During episodes of increased intragastric pressure, such as vomiting, the enlarged pseudo-gastric fornix creates a high-pressure zone by pushing against the esophagus (indicated by black arrows). The narrow space of the lower mediastinum reinforces this effect. Thus, the gastroesophageal complex functions as a self-adjusting anti-reflux system.