Esophagus

Esophagus
Esophagus
Illu01 head neck.jpg
Head and neck.
BauchOrgane wn.png
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) is an organ in vertebrates which consists of a muscular tube through which food passes from the pharynx to the stomach. During swallowing, food passes from the mouth through the pharynx into the esophagus and travels via peristalsis to the stomach. The word esophagus is derived from the Latin œsophagus, which derives from the Greek word oisophagos , 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 posterior mediastinum in thorax and enters abdomen through a hole in the diaphragm at the level of the tenth thoracic vertebrae (T10). It is usually about 25–30 cm long depending on individual height. It is divided into cervical, thoracic and abdominal parts. Due to the inferior pharyngeal constrictor muscle, the entry to the esophagus opens only when swallowing or vomiting.

Contents

Histology

Course of the esophagus (anterior view), showing it passing posteriorly to the trachea and the heart.

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

Esophageal constrictions

Normally, the esophagus has three anatomic constrictions at the following levels;[3][4]

  • At the esophageal inlet, where the pharynx joins the esophagus, behind the cricoid cartilage (14-16 cm from the incisor teeth).
  • Where its anterior surface is crossed by the aortic arch and the left bronchus (25-27 cm from the incisor teeth).
  • Where it pierces the diaphragm (36-38 cm from the incisor teeth).

The distances from the incisor teeth are important as is useful for diagnostic endoscopic procedures.

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, it actually better resembles a structure.

In much of the gastrointestinal tract, smooth muscles contract in sequence to produce a peristaltic wave which forces a ball of food (called a bolus) while in the esophagus. In humans, peristalsis is found in the contraction of smooth muscles to propel contents through the digestive tract.

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 esophagus effectively runs from the pharynx directly to the intestine, and is therefore somewhat longer.[5]

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.[5]

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

See also

Additional images

References

  1. ^ Physiology at MCG 6/6ch2/s6ch2_30
  2. ^ Histology at BU 10801loa
  3. ^ Snell, Richard (2007). Clinical anatomy by regions. Lippincott Williams & Wilkins. p. 129. ISBN 9780781764049. http://books.google.com/books?id=7SZWRe2OBlgC&pg=PA129. 
  4. ^ Schünke, Michael; Schulte, Erik; Schumacher, Udo; Ross, Lawrence; Lamperti, Edward (2006). Atlas of anatomy: neck and internal organs. Thieme. p. 70. ISBN 9781588904430. http://books.google.com/books?id=n0jqG0Lv2CAC&pg=PA70. 
  5. ^ 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


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  • Esophagus — E*soph a*gus, n. [NL., fr. Gr. o isofa gos; root of o i sw which is used as future of fe rein to bear, carry (cf. Skr. v[=i] to go, drive) + fagei^n to eat.] (Anat.) That part of the alimentary canal between the pharynx and the stomach; the… …   The Collaborative International Dictionary of English

  • esophagus — late 14c., from Gk. oisophagos gullet, lit. what carries and eats, from oisein, fut. inf. of pherein to carry (see INFER (Cf. infer)) + phagos, from phagein to eat (see PHAGOUS (Cf. phagous)). Related: Esophageal …   Etymology dictionary

  • esophagus — (Brit. oesophagus) ► NOUN (pl. esophagi or esophaguses) ▪ the part of the alimentary canal which connects the throat to the stomach. DERIVATIVES esophageal adjective. ORIGIN Greek oisophagos …   English terms dictionary

  • esophagus — [i säf′ə gəs, ēsäf′ə gəs] n. pl. esophagi [i säf′əjī΄] [altered (after ML) < ME ysophagus, OFr ysofague < ML oesophagus < Gr oisophagos, lit., passage for food < oisein, fut. inf. of pherein, to carry (see BEAR1) + phagein, to eat:… …   English World dictionary

  • esophagus — /i sof euh geuhs, ee sof /, n., pl. esophagi / juy , guy /. Anat., Zool. a muscular passage connecting the mouth or pharynx with the stomach in invertebrate and vertebrate animals; gullet. [1350 1400; < NL oesophagus < Gk oisophágos gullet, lit …   Universalium

  • Esophagus — The esophagus, part of the digestive tract, is a tube that connects the throat with the stomach. It lies between the trachea (windpipe) and the spine. In an adult, the esophagus is about 10 inches long. When a person swallows, the muscular walls… …   Medical dictionary

  • esophagus — Anterior part of alimentary canal between pharynx or mouth and stomach or stomodeum. (Syn. oesophagus) [Moore and McCormick, 1969]. (Order Cladocera): Relatively short and narrow anterior section of digestive tract. From mouth, esophagus curves… …   Crustacea glossary

  • esophagus — e•soph•a•gus [[t]ɪˈsɒf ə gəs, iˈsɒf [/t]] n. pl. gi [[t] ˌdʒaɪ, ˌgaɪ[/t]] anat. a muscular tube for the passage of food from the pharynx to the stomach; gullet • Etymology: 1350–1400; < ML isophagus, esophagus < Gk oisophágos gullet …   From formal English to slang

  • Esophagus — stemplė statusas T sritis virškinimo aparatas atitikmenys: lot. Esophagus; Oesophagus ryšiai: platesnis terminas – virškinimo aparatas siauresnis terminas – adventicija siauresnis terminas – gūžys siauresnis terminas – išilginis sluoksnis… …   Paukščių anatomijos terminai

  • Esophagus — stemplė statusas T sritis gyvūnų anatomija, gyvūnų morfologija atitikmenys: lot. Esophagus; Oesophagus ryšiai: platesnis terminas – kaklas …   Veterinarinės anatomijos, histologijos ir embriologijos terminai

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