The esophagus is the hollow tube that leads from the throat (pharynx) to the stomach. Food does not just fall through the esophagus into the stomach. The walls of the esophagus propel food to the stomach 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 diaphragm (4) and lower esophageal sphincter (5) and moves into the stomach. |
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 close so that food and stomach acid do not flow back up the esophagus from the stomach to the mouth. During swallowing, the sphincters open so food can pass to the stomach.
With aging, the strength of esophageal contractions and the pressure in the sphincters decrease. This condition makes older people more prone to backflow of acid from the stomach (gastroesophageal reflux or 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.
How the Esophagus Works
Esophageal and swallowing disorders include the following:
- Abnormal propulsion of food
- Dysphagia lusoria
- Eosinophilic esophagitis
- Esophageal laceration (Mallory-Weiss syndrome)
- Esophageal pouches (diverticula)
- Esophageal ruptures
- Esophageal spasm
- Esophageal webs
- Gastroesophageal reflux disease (GERD)
- Hiatus hernia
- Infection of the esophagus
- Injuries of the esophagus
- Lower esophageal ring
- Obstructions of the esophagus
- Propulsion disorders of the throat
Difficulty swallowing (dysphagia) can result from many of these esophageal disorders but also from problems with the nervous system.
In another esophageal disorder, called esophageal varices, the veins at the lower end of the esophagus become dilated and bleed easily.
Credits: Merck Manuals