Science Fair Project Encyclopedia
The esophagus (also spelled oesophagus/sophagus), or gullet is the muscular tube in vertebrates through which ingested food passes from the mouth area to the stomach. 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 junction between the esophagus and the stomach is not actually considered a valve, although it is sometimes called the cardiac valve, cardia or cardias, but is actually more of a stricture. 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 word "esophagus" is the result of the "o" being dropped from the typographic (oe) in "sophagus".
Esophageal diseases and conditions
The following are diseases and conditions that affect the esophagus:
- Bleeding varices
- Chagas disease
- Caustic injury to the esophagus
- Esophageal cancer
- Esophageal web
- Esophageal speech
- Esophageal spasm
- Esophageal stricture
- Mallory-Weiss syndrome
- Neurogenic dysphasia
- Plummer-Vinson syndrome
- Schatzki's ring
- Zenker's diverticulum
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