oesophageal

Oesophageal refers to the oesophagus, a muscular tube about 25 cm long that transports swallowed material from the pharynx to the stomach. It begins at the upper oesophageal sphincter near the cricoid cartilage and ends at the gastro-oesophageal junction just below the diaphragm. The wall consists of mucosa with non-keratinised stratified squamous epithelium, a submucosa, a muscularis externa with inner circular and outer longitudinal layers, and an adventitia (there is no serosa). Blood supply comes from several arteries along the course, with venous drainage to the azygos system and, in the distal segment, to the portal system via the left gastric vein. Lymphatic drainage runs to mediastinal and coeliac nodes. Innervation is predominantly vagal (parasympathetic) with additional sympathetic input; the enteric nervous system coordinates peristalsis.

Functionally, the oesophagus moves ingested material toward the stomach through coordinated peristaltic contractions. The upper and lower oesophageal sphincters regulate entry of food into the oesophagus and prevent reflux, aided by diaphragmatic support at the gastro-oesophageal junction.

Common clinical topics include oesophagitis from gastro-oesophageal reflux disease (GORD), infections, and pill-induced injury; Barrett’s oesophagus, a metaplastic change in the distal oesophagus associated with chronic reflux and increased risk of adenocarcinoma. Esophageal cancer arises as squamous cell carcinoma (more typical in the mid-upper oesophagus) or adenocarcinoma (distal, linked to Barrett’s). Motility disorders such as achalasia cause dysphagia and impaired relaxation of the lower oesophageal sphincter. Diagnosis relies on endoscopy with biopsy, imaging (barium swallow), manometry, and pH monitoring, with treatment ranging from acid suppression and dilation to surgery and oncologic therapy as indicated.