Article: Esophagus

Esophagus
The position and relation of the esophagus in the cervical region and in the posterior mediastinum. Seen from behind.
Section of the human esophagus. Moderately magnified. The section is transverse and from near the middle of the gullet. a. Fibrous covering. b. Divided fibers of longitudinal muscular coat. c. Transverse muscular fibers. d. Submucous or areolar layer. e. Muscularis mucosae. f. Mucous membrane, with vessels and part of a lymphoid nodule. g. Stratified epithelial lining. h. Mucous gland. i. Gland duct. m’. Striated muscular fibers cut across.
Latin	oesophagus
Gray's	subject #245 1144
System
Precursor
MeSH	A03.556.875.500
Dorlands/Elsevier	e_16/12343479

The esophagus (also spelled oesophagus/œsophagus), or gullet is the muscular tube in vertebrates through which ingested food passes from the mouth area to the stomach. The esophagus is continuous with the laryngeal part of the pharynx at the level of the C6 vertebra.

Parts

The esophagus is histologically broken down into 3 parts.

• The superior portion consists primarily of striated muscle.
• The middle portion consists of mixed striated and smooth muscle.
• The inferior 1/3 consists primarily of smooth muscle.

Function

Food is passed through the esophagus by using the process of peristalsis. Specifically, in mammals, it connects the pharynx, which is the body cavity that is common to the digestive system and respiratory system behind the mouth (buccal cavity), with the stomach, where the second stage of digestion is initiated (the first stage of digestion is in the mouth, with teeth and tongue masticating food and mixing it with saliva).

The esophagus is lined with mucous membrane, and is more deeply lined with muscle that acts with peristaltic action to move swallowed food down to the stomach.

Gastroesophageal junction

The junction between the esophagus and the stomach (the gastroesophageal junction or GE junction) is not actually considered a valve, although it is sometimes called the cardiac valve, cardia or cardias, but is actually more of a stricture. Many people experience acid reflux, where stomach acid gets pushed up into the esophagus, causing a burning sensation, commonly termed heartburn. Extended exposure to heartburn may erode the lining of the esophagus, leading to a potentially cancerous condition called Barrett's Esophagus.

Some people also experience a sensation known as globus esophagus, where it feels as if a ball is lodged in the lower part of the esophagus.

Etymology

The word "esophagus" is the result of the "o" being dropped from the oe (or œ) in "oesophagus".

Esophageal diseases and conditions

The following are diseases and conditions that affect the esophagus:

• Achalasia
• Chagas disease
• Caustic injury to the esophagus
• Esophageal atresia and Tracheoesophageal fistula
• Esophageal cancer
• Esophageal spasm
• Esophageal speech
• Esophageal stricture
• Esophageal varices
• Esophageal web
• Esophagitis
• GERD
• Hiatus hernia
• Mallory-Weiss syndrome
• Neurogenic dysphasia
• Plummer-Vinson syndrome
• Schatzki's ring
• Zenker's diverticulum