ABSTRACT
THE OESOPHAGUS The abdominal oesophagus, about 3 cm long, enters the abdomen to the left of the midline through the right crus of the diaphragm to join the stomach at the cardiac orifice (Fig. 6.2). The fibres of the right crus form a sling around the oesophagus. At the gastro-oesophageal junction (cardia), or just above it, the oesophageal lining of stratified squamous epithelium
changes to columnar epithelium, and this lines the whole of the remainder of the gastrointestinal tract. The junction between the two different epithelial linings is normally 40 cm from the incisors and is readily recognizable endoscopically (Fig. 6.2). The oesophagus lies between the diaphragm posteriorly and the liver anteriorly, covered anterolaterally by peritoneum. Gastric vessels and nerves lie in its walls. Reflux of gastric contents is normally prevented by the lower oesophageal sphincter and the oblique angle of entry of the oesophagus into the stomach, as well as the positive abdominal pressure that compresses the walls of the intra-abdominal oesophagus.
