Tube that connects the pharynx to the stomach. In mammals, the oesophagus connects the buccal cavity with the stomach. The stratified squamous non-keratinised epithelium lining the buccal cavity is continued through the pharynx down into the oesophagus. The lowest part of the oesophagus (ca. 2 cm) is lined with gastric mucosa and covered by peritoneum. The main body of the oesophagus is lined with small, simple mucous glands. Each gland opens into the lumen by a long duct which pierces the muscularis mucosae (Wilson and Washington, 1989). A sphincter is situated at the point where the oesophagus enters the stomach to prevent gastro-oesophageal reflux, i.e. to prevent acidic gastric contents from reaching stratified epithelia of the oesophagus, where they can cause inflammation and irritation (Wilson and Washington, 1989; Brown et al., 1993).