Esophageal sphincter
Encyclopedia
The term esophageal sphincter refers to one of two sphincter
s that are part of the esophagus
:
Sphincter
A sphincter is an anatomical structure, or a circular muscle, that normally maintains constriction of a natural body passage or orifice and which relaxes as required by normal physiological functioning...
s that are part of the esophagus
Esophagus
The esophagus 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...
:
- lower esophageal sphincter (also called cardiac sphincter or gastroesophageal sphincter) which leads into the cardiaCardiaThe cardia is the anatomical term for the part of the stomach attached to the esophagus. The cardia begins immediately distal to the z-line of the gastroesophageal junction, where the squamous epithelium of the esophagus gives way to the columnar epithelium of the gastrointestinal tract.Just...
. - upper esophageal sphincterUpper esophageal sphincterThe upper esophageal sphincter refers to the superior portion of the esophagus.Unlike the lower esophageal sphincter, it consists of striated muscle and yet, is not under conscious control. Opening of the UES is triggered by the swallow reflex...
(also called pharyngoesophageal sphincter) within the hypopharynxHypopharynxIn human anatomy, the hypopharynx is the bottom part of the pharynx, and is the part of the throat that connects to the esophagus....