The Esophagus
Narrow Areas of the Esophageal Lumen
The esophagus is narrowed at three sites: at the beginning, behind
the cricoid cartilage of the larynx; where the left bronchus and the arch of
the aorta cross the front of the esophagus; and where the esophagus enters the
stomach. These three sites may offer resistance to the passage of a tube down
the esophagus into the stomach .
Achalasia of the Cardia (Esophagogastric Junction)
The cause of achalasia is unknown, but it is associated with
a degeneration of the Auerbach’s plexus (parasympathetic plexus) in the wall of
the esophagus. The primary site of the disorder may be in the innervation of
the cardioesophageal sphincter by the vagus nerves. difficulty in swallowing (Dysphagia)
and regurgitation are common symptoms that are later accompanied by proximal
dilatation and distal narrowing of the esophagus.
Bleeding Esophageal Varices
At the lower third of the esophagus is an important portal– systemic
venous anastomosis. Here, the esophageal tributaries of the left gastric vein
(which drains into the portal vein) anastomose with the esophageal tributaries
of the azygos veins (systemic veins). Should the portal vein become obstructed,
as, for example, in cirrhosis of the liver, portal hypertension develops,
resulting in dilatation and varicosity of the portal–systemic anastomoses.
Varicosed esophageal veins may rupture, causing severe vomiting of blood
(hematemesis
Gastroesophageal Reflux Disease
Gastroesophageal reflux disease is the most common gastrointestinal
disorder seen in outpatient clinics. It consists of a reflux of acid stomach
contents into the esophagus producing the symptoms of heartburn on at least two
occasions per week. If the reflux continues, the esophageal mucous membrane becomes
inflammed. Later, if the condition persists, the lining of the esophagus
changes from squamous epithelium to columnar epitheliuim, and there is a risk
of the development of adenocarcinoma at the lower end of the esophagus. The
causes of this disease include failure of the lower esophageal sphincter,
hiatus hernia of the diaphragm, and abdominal obesity.
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