|
The esophagus is the hollow tube that leads from the throat (pharynx) to the stomach. The walls of the esophagus propel food to the stomach not by gravity, but by rhythmic waves of muscular contractions called peristalsis.
|
|
 | | |
|
How the Esophagus Works
|
 |
|
As a person swallows, food moves from the mouth to the throat, also called the pharynx (1). The upper esophageal sphincter opens (2) so that food can enter the esophagus, where waves of muscular contractions, called peristalsis, propel the food downward (3). The food then passes through the lower esophageal sphincter (4) and moves into the stomach (5).
|
|
Just below the junction of the throat and the esophagus is a band of muscle called the upper esophageal sphincter. Slightly above the junction of the esophagus and the stomach is another band of muscle called the lower esophageal sphincter. When the esophagus is not in use, these sphincters contract so that food and stomach acid do not flow up from the stomach to the mouth. During swallowing, the sphincters relax so food can pass to the stomach.
With aging, the strength of esophageal contractions and the tension in the sphincters decrease. This condition, called presbyesophagus, makes older people more prone to backflow of acid from the stomach (gastroesophageal reflux or GERD—see Peptic Disorders: Gastroesophageal Reflux (GERD)), especially when lying down after eating.
Two of the most common symptoms of esophageal disorders are dysphagia (an awareness of swallowing difficulty) and chest or back pain. Dysphagia and chest or back pain may occur in any esophageal disorder, the most serious of which is esophageal cancer.
The esophageal disorders discussed in this chapter are propulsion-related, infection-related, injury-related, or obstruction-related. In another esophageal disorder, called esophageal varices, the veins at the lower end of the esophagus become dilated and bleed easily (see Gastrointestinal Emergencies: Abdominal Abscesses and Manifestations of Liver Disease: Portal Hypertension).
Last full review/revision October 2007 by Michael C. DiMarino, MD
|
