What is the esophagus ?
The esophagus, a straight, collapsible tube about 25 centimeters long, is a food passageway from the pharynx to the stomach (see Figure 1). The esophagus begins at the base of the laryngopharynx and descends posterior to the trachea, passing through the mediastinum. It penetrates the diaphragm through an opening, the esophageal hiatus and is continuous with the stomach on the abdominal side of the diaphragm.
Mucous glands are scattered throughout the submucosa of the esophagus. Their secretions moisten and lubricate the tube’s inner lining.
Figure 1. Esophagus
Figure 2. Esophagus anatomy
Figure 3. Cross section view of the esophagus
Some of the smooth muscle just superior to the point where the esophagus joins the stomach has increased muscle tone, forming the lower esophageal sphincter (LES), or cardiac sphincter (Figures 4 and 5). This smooth muscle usually remains contracted. The sphincter closes the entrance to the stomach, preventing the stomach contents from regurgitating into the esophagus. When peristaltic waves in the esophagus reach the stomach, the sphincter temporarily relaxes and allows the swallowed food to enter.
Figure 4. Lower esophageal sphincter
Figure 5. lower esophageal sphincter (endoscopic view)
What does the esophagus do
The esophagus is the muscular tube that carries food, and liquids from your mouth to the stomach. You may not be aware of your esophagus until you swallow something too large, too hot, or too cold. You may also notice it when something is wrong. You may feel pain or have trouble swallowing.
The most common problem with the esophagus is GERD (gastroesophageal reflux disease). With gastroesophageal reflux disease (GERD), a muscle at the end of your esophagus does not close properly. This allows stomach contents to leak back, or reflux, into the esophagus and irritate it. Over time, gastroesophageal reflux disease (GERD) can cause damage to the esophagus.
Other problems include heartburn, cancer, and esophagitis. Doctors may use various tests to make a diagnosis. These include imaging tests, an upper endoscopy, and a biopsy.
Treatment depends on the problem. Some problems get better with over-the-counter medicines or changes in diet. Others may need prescription medicines or surgery.