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., channel for eating (oiso-, akin to oísein, fut. inf. of phérein to carry + -phagos eating); r. ME ysophagus < ML]

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Muscular tube that conveys food by peristalsis from the pharynx to the stomach.

Both ends are closed off by sphincters (muscular constrictions), which relax to let food through and close to keep it from backing up. Disorders include ulceration and bleeding, heartburn from stomach acid, achalasia (failure of one or both sphincters to open), and muscle spasms. Scleroderma may involve the esophagus.

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also spelled  oesophagus 
 relatively straight muscular tube through which food passes from the pharynx to the stomach. The esophagus can contract or expand to allow for the passage of food. Anatomically, it lies behind the trachea and heart and in front of the spinal column; it passes through the muscular diaphragm before entering the stomach. Both ends of the esophagus are closed off by muscular constrictions known as sphincters; at the anterior, or upper, end is the upper esophageal sphincter, and at the distal, or lower, end is the lower esophageal sphincter.

      The upper esophageal sphincter is composed of circular muscle tissue and remains closed most of the time. Food entering the pharynx relaxes this sphincter and passes through it into the esophagus; the sphincter immediately closes to prevent food from backing up. Contractions of the muscles in the esophageal wall ( peristalsis) move the food down the esophageal tube. The food is pushed ahead of the peristaltic wave until it reaches the lower esophageal sphincter, which opens, allowing food to pass into the stomach, and then closes to prevent the stomach's gastric juices and contents from entering the esophagus.

      Disorders of the esophagus include ulceration and bleeding; heartburn, caused by gastric juices in the esophagus; achalasia, an inability to swallow or to pass food from the esophagus to the stomach, caused by destruction of the nerve endings in the walls of the esophagus; scleroderma, a collagen disease; and spasms of the esophageal muscles.

      In some vertebrates the esophagus is not merely a tubular connection between the pharynx and the stomach but rather may serve as a storage reservoir or an ancillary digestive organ. In many birds, for example, an expanded region of the esophagus anterior to the stomach forms a thin-walled crop, which is the bird's principal organ for the temporary storage of food. Some birds use the crop to carry food to their young. ruminant mammals, such as the cow, are often said to have four “stomachs.” Actually, the first three of these chambers (rumen, reticulum, and omasum) are thought to be derived from the esophagus. Vast numbers of bacteria and protozoans live in the rumen and reticulum. When food enters these chambers, the microbes begin to digest and ferment it, breaking down not only protein, starch, and fats but cellulose as well. The larger, coarser material is periodically regurgitated as the cud, and after further chewing the cud is reswallowed. Slowly the products of microbial action, and some of the microbes themselves, move into the cow's true stomach and intestine, where further digestion and absorption take place. Since the cow, like other mammals, has no cellulose-digesting enzymes of its own, it relies upon the digestive activity of these symbiotic microbes in its digestive tract. Much of the cellulose in the cow's herbivorous diet, which otherwise would have no nutritive value, is thereby made available to the cow.

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Universalium. 2010.

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Look at other dictionaries:

  • 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 — Gullet redirects here. For the African sailboat, see Gulet. For the Dutch soccer coach, see Ruud Gullit. Weasand redirects here. For other meanings, see Weasand (disambiguation). Esophagus Head and neck …   Wikipedia

  • 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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