NationMaster - Encyclopedia: Duodenum

In anatomy of the digestive system, the duodenum is a hollow jointed tube about 25-30 cm long connecting the stomach to the jejunum. It is the first and shortest part of the small intestine and it is where most chemical digestion takes place. It begins with the duodenal bulb and ends at the ligament of Treitz. The name duodenum is from the Latin duodenum digitorum, twelve fingers' breadths. Image File history File links BauchOrgane_wn. ... Image File history File linksMetadata Illu_small_intestine. ... Section of an artery For other uses, see Artery (disambiguation). ... The inferior pancreaticoduodenal artery is given off from the superior mesenteric or from its first intestinal branch, opposite the upper border of the inferior part of the duodenum. ... The superior pancreaticoduodenal artery descends between the contiguous margins of the duodenum and pancreas. ... In the circulatory system, a vein is a blood vessel that carries blood toward the heart. ... The pancreaticoduodenal veins accompany their corresponding arteries; the lower of the two frequently joins the right gastroepiploic vein. ... Nerves (yellow) Nerves redirects here. ... The Celiac Ganglia (semilunar ganglia) are two large irregularly shaped masses having the appearance of lymph glands and placed one on either side of the middle line in front of the crura of the diaphragm close to the suprarenal glands, that on the right side being placed behind the inferior... The vagus nerve is tenth of twelve paired cranial nerves and is the only nerve that starts in the brainstem (somewhere in the medulla oblongata) and extends all the way down past the head, right down to the abdomen. ... This article or section is in need of attention from an expert on the subject. ... The foregut is the anterior part of the alimentary canal, from the mouth to the intestine, or to the entrance of the bile duct. ... The midgut is the portion of the embryo from which most of the intestines are derived. ... 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. ... Elseviers logo. ... Human heart and lungs, from an older edition of Grays Anatomy. ... what was here was sick and improperly spelled. ... In anatomy, the stomach is a bean-shaped hollow muscular organ of the gastrointestinal tract involved in the second phase of digestion, following mastication. ... Diagram of the Human Intestine In anatomy of the digestive system, the jejunum is the central of the three divisions of the small intestine and lies between the duodenum and the ileum. ... 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 Duodenal bulb is the portion of the duodenum which is closest to the stomach. ... It has been suggested that Treitz ligament be merged into this article or section. ... For other uses, see Latin (disambiguation). ...

Function

The duodenum is largely responsible for the breakdown of food in the small intestine. Brunner's glands, which secrete mucus, are found in the duodenum. The duodenum wall is composed of a very thin layer of cells that form the muscularis mucosae. The duodenum is almost entirely retroperitoneal. The pH in the duodenum is approximately six. Brunners glands are submucosal glands located throughout the duodenum. ... Mucus is a slippery secretion of the lining of the mucous membranes in the body. ... Section of mucous membrane of human rectum. ... Retroperitoneal is an anatomical term that refers to the relationship of the contents of the abdominal cavity to the peritoneal space. ... For other uses, see PH (disambiguation). ...

Sections

The duodenum is divided into four sections for the purposes of description. The first three sections form a "C" shape.

First part

The first (superior) part begins as a continuation of the duodenal end of the pylorus. From here it passes laterally (right), superiorly and posteriorly, for approximately 5 cm, before making a sharp curve inferiorly into the superior duodenal flexure (the end of the superior part). It is intraperitoneal. From Greek pylorus; pyl- = gate, -orus = guard. ... In higher vertebrates, the peritoneum is the serous membrane that forms the lining of the abdominal cavity - it covers most of the intra-abdominal organs. ...

Second part

The second (descending) part of the duodenum begins at the superior duodenal flexure. It passes inferiorly to the lower border of vertebral body L3, before making a sharp turn medially into the inferior duodenal flexure (the end of the descending part).

The pancreatic duct and common bile duct enter the descending duodenum, commonly known together as the hepatopancreatic duct (or pancreatic duct in the United States), through the major duodenal papilla. This part of the duodenum also contains the minor duodenal papilla, the entrance for the accessory pancreatic duct. The junction between the embryological foregut and midgut lies just below the major duodenal papilla. A duct joining the pancreas to the bile duct to supply pancreatic juice which aid in digestion provided by the exocrine pancreas. ... Bile, which is synthesized in the liver, is carried to the right and left hepatic ducts, which converge to form the common hepatic duct. ... The pancreatic duct, or duct of Wirsung, is a duct joining the pancreas to the bile duct to supply pancreatic juices which aid in digestion provided by the exocrine pancreas. Most people have one pancreatic duct, which joins the biliary tract just prior to the ampulla of Vater. ... A duct joining the pancreas to the bile duct to supply pancreatic juice which aid in digestion provided by the exocrine pancreas. ... A papilla (plural: papillae) can be: A small projection, such as a nipplelike projection on the skin, at the base of a hair or the root of a feather; the base of a new tooth. ... The pancreatic duct, or Duct of Wirsung, is a duct joining the pancreas to the bile duct to apply pancreatic juice which aid in digestion provided by the exocrine pancreas. Most people have one pancreatic duct, which joins the biliary tract just prior to the ampulla of Vater. ... The foregut is the anterior part of the alimentary canal, from the mouth to the intestine, or to the entrance of the bile duct. ... The midgut is the portion of the embryo from which most of the intestines are derived. ...

Third part

The third (inferior/horizontal) part of the duodenum begins at the inferior duodenal flexure and passes transversely to the left, crossing the inferior vena cava, aorta and the vertebral column. This article may be too technical for most readers to understand. ... The aorta (generally pronounced [eÉªËˆÉ”ËtÉ™] or ay-orta) is the largest artery in the human body, originating from the left ventricle of the heart and bringing oxygenated blood to all parts of the body in the systemic circulation. ... The vertebral column seen from the side Different regions (curvatures) of the vertebral column The vertebral column (backbone or spine) is a column of vertebrae situated in the dorsal aspect of the abdomen. ...

Fourth part

The fourth (ascending) part passes superiorly, either anterior to, or to the right of, the aorta, until it reaches the inferior border of the body of the pancreas. Then, it curves anteriorly and terminates at the duodenojejunal flexure where it joins the jejunum. The duodenojejunal flexure is surrounded by a peritoneal fold containing muscle fibres: the ligament of Treitz. The pancreas is a gland organ in the digestive and endocrine systems of vertebrates. ... The ascending portion of the duodenum ascends on the left side of the aorta, as far as the level of the upper border of the second lumbar vertebra, where it turns abruptly forward to become the jejunum, forming the duodenojejunal flexure. ... Diagram of the Human Intestine In anatomy of the digestive system, the jejunum is the central of the three divisions of the small intestine and lies between the duodenum and the ileum. ... It has been suggested that Treitz ligament be merged into this article or section. ...

Additional images

References

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. ...

External links

Category: Digestive system 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. ... The cecum or caecum (from the Latin caecus meaning blind) is a pouch connected to the ascending colon of the large intestine and the ileum. ... It has been suggested that this article or section be merged with Large intestine. ... In anatomy of the digestive system, the colon or large intestine or large bowel is the part of the intestine from the cecum to the rectum. ... A colic flexure is a flexure (a bend) in the colon. ... In anatomy of the digestive system, the colon is the part of the intestine from the cecum to the rectum. ... Grays Fig. ... The Descending Colon passes downward through the left hypochondriac and lumbar regions along the lateral border of the left kidney. ... The sigmoid colon is the part of the large intestine after the descending colon and before the rectum. ... The rectum (from the Latin rectum intestinum, meaning straight intestine) is the final straight portion of the large intestine in some mammals, and the gut in others, terminating in the anus. ... Although the term rectum means straight, the human rectum is not. ... The rectum is about 12 cm. ... The pectinate line (anocutaneous line, dentate line, anal verge, anorectal junction) is a line which marks the end of the rectum and the beginning of the anal canal. ... The anal canal is the terminal part of the large intestine. ... The rectal sinuses, end in small valve-like folds, termed anal valves, which join together the lower ends of the rectal columns. ... The rectal columns are separated from one another by furrows, or rectal sinuses, which end below in small valve-like folds, termed anal valves. ... The lumen of the anal canal presents, in its upper half, a number of vertical folds, produced by an infolding of the mucous membrane and some of the muscular tissue. ... This article is about the bodily orifice. ... The Sphincter ani internus muscle is a muscle of the human body. ... The Sphincter ani externus muscle is a muscle of the human body. ... Overview About 70% of the bodys immune system is found in the digestive tract. ... Peyers patches are secondary lymphoid organs, named after the 17th-century Swiss anatomist Johann Conrad Peyer. ... M cells (or Microfold cells) are cells found in the follicle-associated epithelium of the Peyers patch that have the unique ability to sample antigen from the lumen of the small intestine and deliver it via transcytosis to antigen presenting cells and lymphocytes located in a unique pocket-like... Intestinal villi (singular: villus) are tiny, finger-like structures that protrude from the wall of the intestine and have additional extensions called microvilli (singular: microvillus) which protrude from epithelial cells lining villi. ... The crypts of LieberkÃ¼hn are glands found in the epithelial lining of the small intestine. ... The circular folds (valves of Kerkring) are large valvular flaps projecting into the lumen of the bowel. ... The Taenia Coli are three separate longitudinal ribbons of smooth muscle on the outside of the ascending, transverse, descending and sigmoid colons. ... The haustra of the colon are the small pouches caused by sacculation, which give the colon its segmented appearance. ... The epiploic appendices (or epiploic appendages) are small pouches of the peritoneum filled with fat and situated along the colon and upper part of the rectum. ...

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