The Structure, Function, and Conditions of the Esophagus

The esophagus is the hollow, muscular tube that carries food and liquids from the throat to the stomach. The esophagus runs through the middle of the chest cavity, an area known as the mediastinum and has two sphincters that control opening and closing. The primary function of the esophagus is to transport food from the mouth to the stomach. Acid reflux is a very common condition that affects the esophagus, with cancer of the esophagus increasing at the current time.

Structure 

The esophagus begins at the throat (pharynx) and travels to the stomach, passing through the diaphragm en route. The length is usually around 25 cm (9 to 10 inches) in adults. It passes behind the trachea (windpipe) and in front of the spine.

There are two sphincters (areas that can be opened and closed) in the esophagus.

• The upper esophageal sphincter (UES) is under voluntary as well as involuntary control. It functions to prevent food and liquids from entering the windpipe (trachea), in other words, prevents food from "going down the wrong way" (aspirating). The IUS can be opened and closed consciously, as during burping, swallowing, and vomiting.
• The lower esophageal sphincter (LES) is not under conscious control and works to prevent stomach acid from traveling into the esophagus. Alcohol, as well as several types of prescription medications, can cause relaxation of the LES leading to reflux.

Function

The esophagus serves to pass food and liquids from the mouth down to the stomach. This is accomplished by periodic contractions (peristalsis) instead of gravity. With vomiting, these contractions are reversed, allowing stomach contents to be returned to the mouth to spit out.

Medical Conditions 

There are many medical conditions which can occur in the esophagus. Some of these include:

Gastroesophageal Reflux (GERD)

Gastroesophageal reflux (GERD) often leads to the burning people experience as "heartburn." While chronic heartburn has been considered primarily a nuisance syndrome by many, it can be an important risk factor for one type of esophageal cancer.

Esophagitis

Esophagitis or inflammation of the esophagus can occur as a result of acid reflux, from infections, and not uncommonly from radiation therapy to the chest.

Motility Disorders

There are a few conditions in which the normal motion of the esophagus, peristalsis, is disrupted in some way. Nutcracker esophagus is a type of esophageal spasm characterized by coordinated spasms of the esophagus that lead to difficulty swallowing. Jackhammer esophagus is a condition in which extremely intense and long-lasting spasms affect the esophagus.

Barrett's Esophagus

Barrett's esophagus is a "precancerous" change in the tissue lining the esophagus, often caused by long-standing GERD. If you have had chronic GERD with symptoms of heartburn, your healthcare provider may recommend a test to evaluate for Barrett's esophagus. If changes are noted, further treatment may be considered to reduce the risk of developing esophageal cancer in the future.

Esophageal Cancer

Esophageal cancer is cancer that generally has a poor prognosis, and even when curable, can be very challenging. There are two major types. Squamous cell esophageal cancer is thought to be often related to a history of heavy smoking and drinking. The other type, esophageal adenocarcinoma, is oftentimes found in people with longstanding heartburn.

Mallory-Weiss Tears

Mallory-Weiss tears are deep tears of the esophagus which sometimes occur with violent vomiting.

Perforated Esophagus

A perforated esophagus is a condition in which a hole is formed in the esophagus and is a medical emergency. It may occur due to procedures (such as endoscopy), trauma (such as a gunshot), from swallowing caustic materials or sharp objects, or due to conditions that cause thinning of the esophageal wall.

Esophageal Varices

Esophageal varices are essentially "varicose veins" involving the veins of the esophagus which become dilated most commonly with cirrhosis of the liver.

Achalasia

Achalasia is a condition in which the lower esophagus does not relax, preventing food from passing into the stomach.

Signs and Symptoms of Esophageal Disorders

Symptoms of disorders of the esophagus can overlap with those of many other structures nearby. These may include:

Heartburn

A symptom many people are all to familiar with, most people experience heartburn at some time.

Dysphagia

Dysphagia, or difficulty swallowing can arise in two different ways. It may be due to difficulty in transferring food or liquids from the mouth into the upper esophagus (oropharyngeal dysphagia), or due to problems with transport of food through the length of the esophagus (esophageal dysphagia).

Oropharyngeal dysphagia often causes symptoms such as drooling, a dry mouth, or a seeming inability to be able to initiate swallowing.

Esophageal dysphagia, in contrast, causes symptoms somewhat later as food doesn't feel like it's passing through the esophagus well. Symptoms can be worse with solid food (such as when an obstruction is present), or equally difficult with solids and liquids (such as with motility disorders).

Odynophagia

Odynophagia is term that means pain with swallowing, and is usually described as a sharp pain behind the sternum. It can be caused by swallowing toxic materials that burn the esophagus or by infections.

Chest Pain

Non-specific chest pain can occur with many esophageal disorders, and can be difficult to distingush from a number of other medical conditions.

Diagnostic Tests

A number of different tests may be done to evaluate the esophagus. These include:

Upper GI Series

This is a series of X-rays that is taken, usually after a patient swallows a solution containing barium.

Upper GI Endoscopy

In endoscopy, a tube is passed through the mouth directly into the esophagus, allowing a healthcare provider to directly visualize the esophagus. If abnormalities are noted, a biopsy may be done through the scope using special instruments.

pH Monitoring

In pH monitoring, a probe is placed in the esophagus in order to get a continuous reading of the pH in the esophagus.

Manometry

Manometry is a test that is commonly done to evaluate motility disorders of the esophagus. Contractions of the musculature of the esophagus can be monitored.

A Word From Verywell

The esophagus is a vital structure that is needed in order to transport food to our stomachs, and many people don't realize its importance unless faced with one of the conditions above. Fortunately, several of these conditions are very preventable by avoiding smoking, minimizing alcohol consumption, and maintaining a healthy weight.