ESOPHAGUS

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

Contents

Functioning

Histology

Gastroesophageal junction

Etymology

Esophageal diseases and conditions

Additional images

References

External links

Functioning

Food is passed through the esophagus by using the process of peristalsis. Specifically, it connects the pharynx, which is the body cavity that is common to the digestive factory and respiratory system with the stomach, where the second stage of digestion is initiated.
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.

Histology

The layers of the esophagus are as follows:^[1]

★ ''mucosa''

★
★ nonkeratinized ''stratified squamous epithelium'': is rapidly turned over, and serves a protective effect due to the high volume transit of food, saliva and mucous.

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★ ''lamina propria'': sparse.

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★ ''muscularis mucosae'': smooth muscle
submucosa'': Contains the mucous secreting glands (esophageal glands), and connective structures termed papillae.

★ ''muscularis externa'' (or "muscularis propria"): composition varies in different parts of the esophagus, to correspond with the conscious control over swallowing in the upper portions and the autonomic control in the lower portions:

★
★ ''upper third, or superior part'': striated muscle

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★ ''middle third, smooth muscle and striated muscle,

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★ ''inferior third'': predominantly smooth muscle.

★ ''adventitia

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 sphincter, cardia or cardias, but is actually more of a stricture.

Etymology

It derives from Greek; hiοiσω -oeso, future tense of the verb φερω-to bring and from the verb έφαγον,-phagus, past tense of τρώγω-to eat.
The word "esophagus" is the result of the "o" being dropped from the oe (or œ) in "oesophagus".
This vowel does not exist in English but in most other Indoeuropean languages as œ, ö, or ø.
In mostly the rest of the non-US world, and according standard international latin and greek medical nomemclature, the spelling oesophagus (similarly œsophagus, ösofagus, or øsofagus) is used.

Esophageal diseases and conditions

Many people experience a burning sensation in their chest occasionally, caused by stomach acids refluxing into the esophagus, normally called 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.
The following are additional diseases and conditions that affect the esophagus:

★ Achalasia

★ Chagas disease

★ Caustic injury to the esophagus

★ Esophageal atresia and Tracheoesophageal fistula

★ Esophageal cancer

★ Esophageal web

★ Esophagitis

★ GERD

★ Hiatus hernia

★ Mallory-Weiss syndrome

★ Neurogenic dysphagia

★ Schatzki's ring

Additional images

References

1.
2.

External links

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