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Encyclopedia > Peristalsis
A time-space diagram of a peristaltic wave after a water swallow. High pressure values are red, zero pressure is blue-green. The ridge in the upper part of the picture is the high pressure of the upper esophageal sphincter which only opens for a short time to let water pass.
A time-space diagram of a peristaltic wave after a water swallow. High pressure values are red, zero pressure is blue-green. The ridge in the upper part of the picture is the high pressure of the upper esophageal sphincter which only opens for a short time to let water pass.

Peristalsis is the rhythmic contraction of smooth muscles to propel contents through the digestive tract. The word is derived from New Latin and comes from the Greek peristaltikos, peristaltic, from peristellein, "to wrap around," and stellein, "to place." Image File history File links Question_book-3. ... Image File history File links Peristaltic. ... Image File history File links Peristaltic. ... New Latin (or Neo-Latin) is a post-medieval version of Latin, now used primarily in International Scientific Vocabulary cladistics and systematics. ...


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 and gastrointestinal tract and chyme in the stomach) along the gastrointestinal tract. Peristaltic movement is initiated by circular smooth muscles contracting behind the chewed material to prevent it from moving back into the mouth, followed by a contraction of longitudinal smooth muscles which pushes the digested food forward. Gut redirects here. ... Smooth muscle Layers of Esophageal Wall: 1. ... Look up bolus in Wiktionary, the free dictionary. ... The esophagus or oesophagus (see American and British English 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. ... Chyme, also known as Chymus is the liquid substance found in the stomach before passing through the pyloric valve and entering the duodenum. ... In anatomy, the stomach is a bean-shaped hollow muscular organ of the gastrointestinal tract involved in the second phase of digestion, following mastication. ...

Contents

In the esophagus

After food is chewed into a bolus, it is swallowed to move it into the esophagus. Smooth muscles will contract behind the bolus to prevent it from being squeezed back onto the mouth, then rhythmic, unidirectional waves of contractions will work to rapidly force the food into the stomach. This process works in one direction only and its sole purpose is to move food from the mouth into the stomach. For the Bush song, see Swallowed (song). ...


In the esophagus, two types of peristalsis occur.

A simplified image showing Peristalsis
  • First, there is a primary peristaltic wave; once the bolus enters the esophagus during swallowing. The primary peristaltic wave forces the bolus down the esophagus and into the stomach in a wave lasting about 8-9 seconds. The wave travels down to the stomach even if the bolus of food descends at a greater rate than the wave itself, and will continue even if for some reason the bolus gets stuck further up the esophagus.
  • In the event that the bolus gets stuck or moves slower than the primary peristaltic wave (as can happen when it is poorly lubricated), stretch receptors in the esophageal lining are stimulated and a local reflex response causes a secondary peristaltic wave around the bolus, forcing it further down the esophagus, and these secondary waves will continue indefinitely until the bolus enters the stomach.

For the Bush song, see Swallowed (song). ...

In the small intestine

Once processed and digested by the stomach, the milky chyme is squeezed through the pyloric valve into the small intestine. Once past the stomach a typical peristaltic wave will only last for a few seconds, traveling at only a few centimeters per second. Its primary purpose is to mix the chyme in the intestine rather than to move it forward in the intestine. Through this process of mixing and continued digestion and absorption of nutrients, the chyme gradually works its way through the small intestine to the large intestine. From Greek pylorus; pyl- = gate, -orus = guard. ... In biology the small intestine is the part of the gastrointestinal tract (gut) between the stomach and the large intestine and includes the duodenum, jejunum, and ileum. ... The large intestine, an organ which is now more commonly referred to by its Greek name, the colon, is the last part of the digestive system: the final stage of the alimentary canal in vertebrate animals. ...


During vomiting the propulsion of food up the esophagus and out the mouth comes from contraction of the abdominal muscles; peristalsis does not reverse in the esophagus. Heaving redirects here. ... The human abdomen (from the Latin word meaning belly) is the part of the body between the pelvis and the thorax. ...


As opposed to the more continuous peristalsis of the small intestines, fecal contents are propelled into the large intestine by periodic mass movements. These mass movements occur one to three times per day in the large intestines and colon, and help propel the contents from the large intestine through the colon to the rectum. Horse feces Feces, faeces, or fæces (see spelling differences) is a waste product from an animals digestive tract expelled through the anus (or cloaca) during defecation. ...


See also

Linear peristaltic pump Linear peristaltic pump A peristaltic pump is a type of positive displacement pump used for pumping a variety of fluids. ...

External links

  • Interactive 3D display of swallow waves at menne-biomed.de
  • MeSH Peristalsis
  • Physiology at MCG 6/6ch3/s6ch3_9
  • Overview at colostate.edu
Medical Subject Headings (MeSH) is a huge controlled vocabulary (or metadata system) for the purpose of indexing journal articles and books in the life sciences. ... In 1828 the Medical Academy of Georgia was chartered by the state of Georgia with plans to offer a single course of lectures leading to a bachelors degree. ... what was here was sick and improperly spelled. ... Human Physiology is the science of the mechanical, physical, and biochemical functions of humans in good health, their organs, and the cells of which they are composed. ... Gastrointestinal physiology is a branch of human physiology addressing the physical function of the gastrointestinal system. ... The enteric nervous system (ENS) is an interdependent part of the autonomic nervous system. ... The nerves of the small intestines are derived from the plexuses of sympathetic nerves around the superior mesenteric artery. ... Part of the enteric nervous system, Auerbachs plexus exists between the longitudinal and circular layers of muscle in the gastrointestinal tract and provides motor innervation to both layers and secretomotor innervation to the mucosa. ... A gastric chief cell (or peptic cell, or gastric zymogenic cell) is a cell in the stomach that releases pepsinogen and rennin. ... Pepsin is a digestive protease (EC 3. ... Human parietal cells - stomach Parietal cells (also called oxyntic cells) are the stomach epithelium cells which secrete gastric acid and intrinsic factor. ... Gastric acid is, together with several enzymes and the intrinsic factor, one of the main secretions of the stomach. ... Intrinsic factor is a glycoprotein produced by the parietal cells of the stomach. ... Goblet cells are glandular simple columnar epithelial cells whose sole function is to secrete mucus. ... Mucus cells. ... In medicine, the G cell is a type of cell in the stomach that secrets gastrin. ... In humans, gastrin is a hormone that stimulates secretion of gastric acid by the stomach. ... Delta cells are somatostatin producing cells. ... Somatostatin is a hormone. ... Enterochromaffin-like cells or ECL cells are a type of neuroendocrine cells found in the gastric mucosa beneath the epithelium, particularly in the vicinity of parietal cells. ... This article or section does not cite any references or sources. ... An enterogastrone is a substance in the lower gastrointestinal tract which opposes the caudad (or forward) motion of the contents of chyme when exposed to lipids. ... Cholecystokinin (from Greek chole, bile; cysto, sac; kinin, move; hence, move the bile-sac (gall bladder)) is a peptide hormone of the gastrointestinal system responsible for stimulating the digestion of fat and protein. ... Gastric inhibitory polypeptide (GIP) is a member of the secretin family of hormones. ... S cells are cells which release secretin, found in the jejunum and duodenum. ... Secretin is a peptide hormone produced in the S cells of the duodenum. ... Brunners glands are submucosal glands located throughout the duodenum. ... paneth cells Paneth cells provide host defense against microbes in the small intestine. ... Enterocyte is a type of epithelial cell of the superficial layer of the small and large intestine tissue. ... For the band, see Saliva (band). ... Bile (or gall) is a bitter, yellow or green alkaline fluid secreted by hepatocytes from the liver of most vertebrates. ... Intestinal juice (succus entericus) refers to the clear to pale yellow watery secretions from the glands lining the small intestine walls. ... Gastric juice is a strong acidic liquid, pH 1 to 3, which is close to being colourless. ... Pancreatic juice is a juice produced by the pancreas. ... For the Bush song, see Swallowed (song). ... Heaving redirects here. ... The Interstitial cell of Cajal (ICC) is a type of cell found in the gastrointestinal tract. ... Migrating motor complexes are waves of activity which sweep through the intestines in a regular cycle during fastening state. ... Borborygmus (plural borborygmi) is the rumbling sound produced by the movement of gas through the intestines of animals. ... The gastrocolic reflex or gastrocolic response is one of a number of physiological reflexes controlling the motility, or peristalsis, of the gastrointestinal tract. ... Segmentation contractions (or movements) are a type of gastric motility. ... Anatomy of the anus and rectum For the death metal band Defecation, see Defecation (band). ...

  Results from FactBites:
 
MedlinePlus Medical Encyclopedia: Peristalsis (237 words)
Peristalsis is a series of organized muscle contractions that occur throughout the digestive tract.
Peristalsis is also seen in the tubular organs that connect the kidneys to the bladder.
Peristalsis is an automatic and important process that moves food through the digestive system.
MedFriendly.com: Peristalsis (712 words)
Peristalsis is a series of wavelike, coordinated contractions and relaxations of a tube-like structure in the body that forces the contents of the tubes onwards.
Peristalsis also occurs in the esophagus, which is the natural tube in the body that food travels down to enter the stomach.
A strong, sustained wave of peristalsis occurs in the colon two or three times a day (usually after a meal), which forces the waste material into the last part of the large intestine (the rectum) and prompts the urge to poop.
  More results at FactBites »

 
 

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