Pylorus

Source: Wikipedia, the free encyclopedia.
For the town of ancient Crete, see Pylorus (Crete).
Pylorus
Inside of the stomach (pylorus labeled at center left)
Details
Identifiers
Latinpylorus
MeSHD011708
TA98A05.5.01.017
TA22930
FMA14581
Anatomical terminology

The pylorus (/paɪˈlɔːrəs/ or /pɪˈloʊrəs/) pyloric region or pyloric part connects the stomach to the duodenum. The pylorus is considered as having two parts, the pyloric antrum (opening to the body of the stomach) and the pyloric canal (opening to the duodenum). The pyloric canal ends as the pyloric orifice, which marks the junction between the stomach and the duodenum. The orifice is surrounded by a sphincter, a band of muscle, called the pyloric sphincter. The word pylorus comes from Greek πυλωρός, via Latin. The word pylorus in Greek means "gatekeeper", related to "gate" (Greek: pyle) and is thus linguistically related to the word "pylon".[1]

Structure

Rugal folds

The pylorus is the furthest part of the stomach that connects to the duodenum. It is divided into two parts, the antrum, which connects to the body of the stomach, and the pyloric canal, which connects to the duodenum.[2]

Antrum

See also: Gastric antral vascular ectasia

The antrum also called the gastric antrum or the pyloric antrum is the initial portion of the pyloric region. It is near the bottom of the stomach, proximal to the pyloric sphincter, which separates the stomach and the duodenum. It may temporarily become partially or completely shut off from the remainder of the stomach during

demarcated
, sometimes, from the pyloric canal by a slight groove.

Canal

The pyloric canal (

Latin: canalis pyloricus) is the opening between the stomach and the duodenum.[3] The wall thickness of the pyloric canal is up to 3 millimeters (mm) in infants younger than 30 days,[4] and up to 8 mm in adults.[5]

Sphincter

The pyloric sphincter, or

celiac ganglion
.

Histology

Microscopic cross-section of the pylorus

Under

G cells that secrete gastrin.[7]

The pylorus also contains scattered

fundus
.) Unstriated muscles, which are entirely involuntary, are located at the pylorus.

Function

The pylorus is one component of the

gastrointestinal system. Food from the stomach, as chyme, passes through the pylorus to the duodenum
. The pylorus, through the pyloric sphincter, regulates entry of food from the stomach into the duodenum.

Clinical significance

In such conditions as stomach cancer, tumours may partly block the pyloric canal. A special tube can be implanted surgically to connect the stomach to the duodenum so as to facilitate the passage of food from one to the other. The surgery to place this tube is called a gastroduodenostomy.

Stenosis

Main article: Pyloric stenosis

Pyloric stenosis refers to a pylorus that is narrow. This is due to congenital hypertrophy of the pyloric sphincter. The lumen of the pylorus is narrower, and less food is able to pass through. This problem is often detected in the early weeks of life. When it is present, a newborn baby may projectile vomit after eating, but despite vomiting remain hungry. Pyloric stenosis may be managed by the insertion of a stent, or through surgical cutting of the pyloric sphincter, a pyloromyotomy.[9]

Other

  • Pyloric tumors
    • Pyloric gland adenoma[10]

Additional images

  • Stomach
    Stomach
  • Dissection showing the stomach and pylorus in a cadaver. The antrum of the pylorus is shown in green.
    Dissection showing the stomach and pylorus in a cadaver. The antrum of the pylorus is shown in green.

See also

This article uses anatomical terminology.

References

  1. ^ Harper, Douglas. "Pylorus". Etymology Online. Retrieved 27 March 2014.
  2. ISBN 978-0-8089-2306-0
    .
  3. ^ University of Illinois Medical Center:Health Library Archived 2012-04-26 at the Wayback Machine
  4. PMID 9634457
    .
  5. PMID 26154756
    .
  6. ISBN 978-0781764049
    .
  7. ^ Cardiac, fundus and pyloric regions of the stomach, Pyloric region. available from: http://histology.leeds.ac.uk/digestive/cardiac_pyloric.php (Last inspected April 16, 2017)
  8. ISBN 978-0-443-068-508
    .
  9. ISBN 9780723433972.{{cite book}}: CS1 maint: multiple names: authors list (link
    )
  10. PMID 18830123
    .

External links
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