Esophagus

Esophagus

Digestive organs. (Esophagus is #1)
Latin	oesophagus
Gray's	subject #245 1144
Nerve	celiac ganglia, vagus^[1]
Precursor	Foregut
MeSH	Esophagus
Dorlands/Elsevier	e_16/12343479

The esophagus (also spelled oesophagus/œsophagus), or gullet is an organ in vertebrates which consists of a muscular tube through which 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.

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.

Histology

The layers of the esophagus are as follows:^[2]

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 into the stomach.
- lamina propria: sparse.
- 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
- middle third: a combination of smooth muscle and striated muscle,
- 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 valve, cardia or cardias, but is actually more of a stricture.

Etymology

The word "esophagus" is the result of the "o" being dropped from the oe (or œ) in "oesophagus". It derives from Greek; οiσω -oeso, future tense of the verb φερω-to bring and from the verb έφαγον,-phagus, past tense of τρώγω-to eat.

Esophageal diseases and conditions

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.

The following are additional diseases and conditions that affect the esophagus:

Additional images

H&E stain of biopsy of normal esophagus showing the stratified squamous cell epithelium	Layers of the esophagus.	Mid esophageal mass	Stomach
Accessory digestive system.	Organs of the digestive tract.	Section of the neck at about the level of the sixth cervical vertebra.	Transverse section of thorax, showing relations of pulmonary artery.
Sagittal section of nose mouth, pharynx, and larynx.	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.