Duodenum
Duodenum | |
---|---|
vagus[1] | |
Identifiers | |
MeSH | D004386 |
TA98 | A05.6.02.001 |
TA2 | 2944 |
FMA | 7206 |
Anatomical terminology] |
Major parts of the |
Gastrointestinal tract |
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The duodenum is the first section of the
In humans, the duodenum is a hollow jointed tube about 25–38 centimetres (10–15 inches) long connecting the stomach to the middle part of the small intestine.[4][5] It begins with the duodenal bulb and ends at the suspensory muscle of duodenum.[6] Duodenum can be divided into four parts: the first (superior), the second (descending), the third (transverse) and the fourth (ascending) parts.[5]
Overview
The duodenum is the first section of the
In humans, the duodenum is a C-shaped hollow jointed tube, 25–38 centimetres (10–15 inches) in length, lying adjacent to the
Parts
The first part, or superior part, of the duodenum is a continuation from the
Relations:[citation needed]
- Anterior
- Gallbladder
- Quadrate lobe of liver
- Posterior
- Bile duct
- Gastroduodenal artery
- Portal vein
- Inferior vena cava
- Head of pancreas
- Superior
- Neck of gallbladder
- Hepatoduodenal ligament (lesser omentum)
- Inferior
- Neck of pancreas
- Greater omentum
- Head of pancreas
The second part, or descending part, of the duodenum begins at the superior duodenal flexure. It goes
The
The third part, or horizontal part or inferior part of the duodenum is 10~12 cm in length. It begins at the inferior duodenal flexure and passes transversely to the left, passing in front of the
The fourth part, or ascending part, of the duodenum passes upward, joining with the jejunum at the duodenojejunal flexure. The fourth part of the duodenum is at the vertebral level L3, and may pass directly on top, or slightly to the left, of the aorta.[9]: 274
Blood supply
The duodenum receives arterial blood from two different sources. The transition between these sources is important as it demarcates the foregut from the midgut. Proximal to the 2nd part of the duodenum (approximately at the major duodenal papilla – where the bile duct enters) the arterial supply is from the gastroduodenal artery and its branch the superior pancreaticoduodenal artery. Distal to this point (the midgut) the arterial supply is from the superior mesenteric artery (SMA), and its branch the inferior pancreaticoduodenal artery supplies the 3rd and 4th sections. The
The venous drainage of the duodenum follows the arteries. Ultimately these veins drain into the portal system, either directly or indirectly through the splenic or superior mesenteric vein and then to portal vein.
Lymphatic drainage
The
Histology
Under
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Dog Duodenum 100X
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Duodenum with amyloid deposition in lamina propria
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Section of duodenum of cat. X 60
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Duodenum with brush border (microvillus)
Variation
The duodenum's close anatomical association with the pancreas creates differences in function based on the position and orientation of the organs. The congenital abnormality, annular pancreas, causes a portion of the pancreas to encircle the duodenum. In an extramural annular pancreas, the pancreatic duct encircles the duodenum which results in gastrointestinal obstruction. An intramural annular pancreas is characterized by pancreatic tissue that is fused with the duodenal wall, causing duodenal ulceration.[12]
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Gene and protein expression
About 20,000 protein coding genes are expressed in human cells and 70% of these genes are expressed in the normal duodenum.[13][14] Some 300 of these genes are more specifically expressed in the duodenum with very few genes expressed only in the duodenum. The corresponding specific proteins are expressed in the duodenal mucosa, and many of these are also expressed in the small intestine, such as alanine aminopeptidase, a digestive enzyme, angiotensin-converting enzyme, involved in controlling blood pressure, and RBP2, a protein involved in the uptake of vitamin A.[15]
Function
The duodenum is largely responsible for the breakdown of food in the small intestine, using
The villi of the duodenum have a leafy-looking appearance, which is a histologically identifiable structure. Brunner's glands, which secrete mucus, are only found in the duodenum. The duodenum wall consists of a very thin layer of cells that form the muscularis mucosae.
Clinical significance
Ulceration
Ulcers of the duodenum commonly occur because of infection by the bacteria
Celiac disease
The
Cancer
Duodenal cancer is a cancer in the first section of the small intestine. Cancer of the duodenum is relatively rare compared to
Inflammation
Inflammation of the duodenum is referred to as duodenitis. There are multiple known causes.[21] Celiac disease and inflammatory bowel disease are two of the known causes.[22]
Etymology
The name duodenum is
Many languages retain a similar etymology for this word. For example, German Zwölffingerdarm, Dutch Twaalfvingerige darm and Turkish Oniki parmak bağırsağı.
Additional images
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Sections of the small intestine
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The celiac artery and its branches; the stomach has been raised and the peritoneum removed
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Superior and inferior duodenal fossæ
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Duodenojejunal fossa
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The pancreas and duodenum from behind
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Transverse section through the middle of the first lumbar vertebra, showing the relations of the pancreas
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The pancreatic duct
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Region of pancreas
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Duodenum
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Duodenum
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Duodenum
See also
- Pancreas
- Choledochoduodenostomy - a surgical procedure to create a connection between the common bile duct (CBD) and an alternative portion of the duodenum.
References
- ^ Nosek, Thomas M. "Section 6/6ch2/s6ch2_30". Essentials of Human Physiology. Archived from the original on 2016-03-24.
- ISBN 978-0-521-15255-6.
- ^ "NCI Dictionary of Cancer Terms". National Cancer Institute. Retrieved 2022-06-07.
The first part of the small intestine. It connects to the stomach. The duodenum helps to further digest food coming from the stomach. It absorbs nutrients (vitamins, minerals, carbohydrates, fats, proteins) and water from food so they can be used by the body.
- ^ "Duodenum: MedlinePlus Medical Encyclopedia". MedlinePlus. Retrieved 2022-06-07.
It is located between the stomach and the middle part of the small intestine. After foods mix with stomach acid, they move into the duodenum, where they mix with bile from the gallbladder and digestive juices from the pancreas.
- ^ ISSN 0942-5373.
duodenum is a C-shaped hollow organ forming an incomplete circle around the head of the pancreas. ...it is normally examined as part of the upper gastrointestinal tract.
- PMID 21557825.
- ^
Guillaume, Jean; Praxis Publishing; Sadasivam Kaushik; Pierre Bergot; Robert Metailler (2001). Nutrition and Feeding of Fish and Crustaceans. Springer. p. 31. ISBN 978-1-85233-241-9. Retrieved 2009-01-09.
- PMID 12547225.
- ^ ISBN 978-0-8089-2306-0.
- ISBN 978-93-5059-122-2.
- ISBN 978-0-443-06850-8.
- PMID 23264525.
- ^ "The human proteome in duodenum - The Human Protein Atlas". www.proteinatlas.org. Retrieved 2017-09-26.
- S2CID 802377.
- S2CID 21302849.
- ^ Smith, Margaret E. The Digestive System.
- ISBN 978-0-7020-3085-7.
- PMID 24917550.
- ^ Fagniez, Pierre-Louis; Rotman, Nelly (2001). Malignant tumors of the duodenum. Zuckschwerdt.
- ^ https://www.cancer.gov/publications/dictionaries/cancer-terms/def/adenocarcinoma.
{{cite web}}
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(help) - PMID 16679353.
- PMID 26252915.
- ^ "duodenum - Origin and meaning of duodenum by Online Etymology Dictionary". www.etymonline.com.
External links
- Duodenum at the Human Protein Atlas
- duodenum at The Anatomy Lesson by Wesley Norman (Georgetown University)