Medical Emergencies · single question
A patient with a long history of reflux is found to have oesophageal dysplasia. Which sphincter is most directly implicated?
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Correct answer: D. Lower oesophageal (cardiac) sphincter
- A. The upper oesophageal sphincter guards against aspiration from the pharynx into the oesophagus. It is not the barrier that fails in reflux disease.
- B. The pyloric sphincter controls gastric emptying into the duodenum — downstream of the problem.
- C. The sphincter of Oddi regulates bile and pancreatic secretions into the duodenum and has no role in oesophageal reflux.
- D. CORRECT. The LOWER OESOPHAGEAL SPHINCTER (also called the cardiac sphincter) is the functional valve at the gastro-oesophageal junction. When it becomes incompetent, gastric acid refluxes into the distal oesophagus; chronic exposure drives metaplasia (Barrett oesophagus) and then dysplasia, the precursor of oesophageal adenocarcinoma. It is also the reason GORD patients show palatal erosion of the maxillary teeth.
Note: Dental relevance: patients with chronic GORD show erosion on the palatal surfaces of maxillary teeth. Advise against brushing immediately after a reflux episode.
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