esophagus

[Middle English isophagus, from Medieval Latin ēsophagus, from Greek oisophagos, arbitrary medical coinage perhaps from ois-, future tense stem of pherein, to carry + -phagos, food (unattested sense) (from phagein, to eat).]

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A section of the alimentary canal that is interposed between the pharynx and the stomach. Because of divergent specializations in the various vertebrates, the esophagus cannot be described in general terms and is not always distinguishable.

In humans it is a tube running the full length of the neck and the thorax, held in its position ventral to the vertebral centra by a tunica adventitia of loose connective tissue. It has an inner lining of folded mucous membrane with an exceptionally thick lamina propria, a submucosa of elastic and collagenous connective tissue, and two layers of muscle. The musculature is striated in the anterior third of its length, unstriated in the posterior third, and variably intermixed in the middle. It is supplied with autonomic nerve fibers.

Although normally collapsed, the human esophagus is capable of considerable distension during the rapid passage of swallowed material, under which condition the folds of mucous membrane and lamina propria are temporarily smoothed out. Numerous microscopic esophageal glands open into the lumen, extending their compound tubules out into the submucosa.

In humans the transition from the esophagus to the stomach occurs quite abruptly at the diaphragm. The pharynx narrows posteriorly like a funnel and the foregut may thereupon enlarge, but much of what appears to be stomach may have an esophageal character histologically. See also Digestive system.

Oesophagus (esophagus), from the Greek for gullet, refers to the muscular tube, with a mucus-secreting lining, that leads from the mouth via the pharynx, down through the neck and the thorax, and through the diaphragm to the stomach. In the neck it lies behind the air passages — the lower end of the larynx and the upper part of the trachea. In the thorax, it continues behind the trachea and the heart, to pass into the abdominal cavity through a gap in the muscle of the diaphragm; less than an inch below this, it opens into the stomach. When swallowing occurs, food is pushed into the top of the oesophagus, and is then propelled onwards by waves of circular muscle relaxation below it and of contraction above it: the peristalsis that occurs throughout the gut. This process can if necessary defeat gravity; food, and even liquids, can be swallowed even standing on one's head, though clearly this is not generally attempted except as a remarkable demonstration. Muscle encircling the oesophagus at the top and bottom provides sphincters that, respectively, prevent air being sucked in during inhalation, and regurgitation of stomach contents.

— Stuart Judge

See alimentary system; swallowing.

The muscular canal, about 25 cm long, extending from the pharynx to the stomach.

The muscular tube that connects the mouth to the stomach and serves as a passageway for food. (See digestive system.)

The musculomembranous passage extending from the pharynx to the stomach, consisting of an outer fibrous coat, a muscular layer (all striated in dogs and ruminants, plus some smooth muscle in cats, pigs and horses), a submucous layer, and an inner mucous membrane. Each end is equipped with a functional sphincter although these are not distinct anatomically.

• redundant e. — a ventral esophageal deviation at the thoracic inlet. Seen on x-rays, mainly in brachycephalic dogs.

"Gullet" redirects here. For the Turkish sailboat, see Gulet. For the Dutch football coach, see Ruud Gullit.

"Weasand" redirects here. For other meanings, see Weasand (disambiguation).

This article needs additional citations for verification. Please help improve this article by adding reliable references. Unsourced material may be challenged and removed. (December 2007)

Esophagus
Head and neck.
Digestive organs. (Esophagus is #1)
Latin	œsophagus
Gray's	subject #245 1144
Artery	esophageal arteries
Vein	esophageal veins
Nerve	celiac ganglia, vagus[1]
Precursor	Foregut
MeSH	oesophagus
Dorlands/Elsevier	Esophagus

The esophagus or oesophagus (see spelling differences), sometimes known as the gullet, is an organ in vertebrates which consists of a muscular tube through which food passes from the pharynx to the stomach. The word esophagus is derived from the Latin œsophagus, which derives from the Greek word oisophagos (οισοφάγος), lit. "entrance for eating." In humans the esophagus is continuous with the laryngeal part of the pharynx at the level of the C6 vertebra. The esophagus passes through a hole in the diaphragm at the level of the tenth thoracic vertebrae (T10). It is usually about 25–30 cm long and connects the mouth to the stomach. It is divided into abdominal parts.

Contents 1 Histology 2 Gastroesophageal junction 3 In other animals 4 See also 5 Additional images 6 References 7 External links

Histology

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

• mucosa (mucus)
  • nonkeratinized stratified squamous epithelium: is rapidly turned over, and serves a protective effect due to the high volume transit of food, saliva and mucus.
  • 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, 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 sphincter, cardia or cardias, although it is actually better resembles a stricture.

In other animals

In most fish, the esophagus is extremely short, primarily due to the length of the pharynx (which is associated with the gills). However, some fish, including lampreys, chimaeras, and lungfish, have no true stomach, so that the oesophagus effectively runs from the pharynx directly to the intestine, and is therefore somewhat longer.^[3]

In tetrapods, the pharynx is much shorter, and the esophagus correspondingly longer, than in fish. In amphibians, sharks and rays, the esophageal epithelium is ciliated, helping to wash food along, in addition to the action of muscular peristalsis. In the majority of vertebrates, the esophagus is simply a connecting tube, but in birds, it is extended towards the lower end to form a crop for storing food before it enters the true stomach.^[3]

A structure with the same name is often found in invertebrates, including molluscs and arthropods, connecting the oral cavity with the stomach.

See also

• Esophageal disease

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.	Esophagus	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.
Microscopic shot of a cross section of human gastroesophageal junction wall.

References

1. ^ Physiology at MCG 6/6ch2/s6ch2_30
2. ^ Histology at BU 10801loa
3. ^ ^{a b} Romer, Alfred Sherwood; Parsons, Thomas S. (1977). The Vertebrate Body. Philadelphia, PA: Holt-Saunders International. pp. 344-345. ISBN 0-03-910284-X. 

External links

Look up esophagus in Wiktionary, the free dictionary.

• Virtual Slidebox at Univ. Iowa Slide 449

v • d • e Anatomy of torso, digestive system: Gastrointestinal tract, excluding mouth (TA A05.3-7, GA 11.1141) Upper GI Hypo- pharynx Piriform sinus spaces: Peripharyngeal space (Retropharyngeal space, Parapharyngeal space) · Retrovisceral space (Retropharyngeal space, Danger space) · Prevertebral space Pterygomandibular raphe · Pharyngeal raphe · Buccopharyngeal fascia · Pharyngobasilar fascia Pharyngeal muscles Esophagus UES, LES Stomach Gastric rugae · gastric pits · cardia/gland · fundus/gland · pylorus/gland · pyloric antrum · pyloric canal · greater curvature · lesser curvature · angular incisure Lower GI Intestine: small Duodenum (Suspensory muscle, Major duodenal papilla, Minor duodenal papilla, Duodenal cap) • Duodenojejunal flexure • Jejunum • Ileum (Terminal ileum) • Ileocecal valve continuous (intestinal villus, crypts of Lieberkühn, circular folds) Intestine: large Vermiform appendix • Cecum • Colon (ascending colon, hepatic flexure, transverse colon, splenic flexure, descending colon, sigmoid colon) continuous (taenia coli, haustra, epiploic appendix) Termination Rectum: Houston valve • rectal ampulla • pectinate line Anal canal: anal valves • anal sinuses • anal columns • Hilton's white line Anus: Sphincter ani internus muscle • Sphincter ani externus muscle Lymph GALT: Peyer's patches (M cells) digestive system navs: anat of tract,glands,perit,diaphragm/physio/dev, noncongen/congen/congen of d+w/neoplasia, symptoms+signs/eponymous, proc

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Dansk (Danish)
n. - spiserør, øsofagus

Nederlands (Dutch)
slokdarm

Français (French)
n. - ¯sophage

Deutsch (German)
n. - Ösophagus, Speiseröhre

Ελληνική (Greek)
n. - οισοφάγος

Italiano (Italian)
esofago

Português (Portuguese)
n. - esôfago (m) (Anat.)

Русский (Russian)
пищевод

Español (Spanish)
n. - esófago

Svenska (Swedish)
n. - matstrupe

中文（简体）(Chinese (Simplified))
食道

中文（繁體）(Chinese (Traditional))
n. - 食道

한국어 (Korean)
n. - 식도

日本語 (Japanese)
n. - 食道

العربيه (Arabic)
‏(الاسم) المرئ‏

עברית (Hebrew)
n. - ‮ושט‬

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