The swallowing apparatus consists of the pharynx, upper esophageal (cricopharyngeal) sphincter, the body of the esophagus, and the lower esophageal sphincter (LES). The upper third of the esophagus and the structures proximal to it are composed of skeletal muscle; the distal esophagus and LES are composed of smooth muscle. These components work as an integrated system that transports material from the mouth to the stomach and prevents its reflux into the esophagus. Physical obstruction or disorders that interfere with motor function (esophageal motility disorders Esophageal Motility Disorders Esophageal motility disorders involve dysfunction of the esophagus that causes symptoms such as dysphagia, heartburn, and chest pain. (See also Overview of Esophageal and Swallowing Disorders... read more ) can affect the system.
The patient’s history suggests the diagnosis almost 80% of the time. The only physical findings in esophageal disorders are cervical and supraclavicular lymphadenopathy caused by metastasis, swellings in the neck caused by large pharyngeal diverticula or thyromegaly, white plaques in the posterior oropharynx caused by Candida infection, and prolonged swallowing time (the time from the act of swallowing to the sound of the bolus of fluid and air entering the stomach—normally ≤ 12 seconds—heard by auscultation with the stethoscope over the epigastrium). Watching the patient swallow may help diagnose aspiration or nasal regurgitation. Most esophageal disorders require specific tests for diagnosis.
Esophageal and swallowing disorders include the following:
(See also Esophageal Cancer Esophageal Cancer The most common malignant tumor in the proximal two thirds of the esophagus is squamous cell carcinoma; adenocarcinoma is the most common in the distal one third. Symptoms are progressive dysphagia... read more and see Esophageal Atresia Esophageal Atresia Esophageal atresia is incomplete formation of the esophagus, frequently associated with tracheoesophageal fistula. Diagnosis is suspected by failure to pass a nasogastric or orogastric tube... read more .)