To install click the Add extension button. That's it.

The source code for the WIKI 2 extension is being checked by specialists of the Mozilla Foundation, Google, and Apple. You could also do it yourself at any point in time.

4,5
Kelly Slayton
Congratulations on this excellent venture… what a great idea!
Alexander Grigorievskiy
I use WIKI 2 every day and almost forgot how the original Wikipedia looks like.
What we do. Every page goes through several hundred of perfecting techniques; in live mode. Quite the same Wikipedia. Just better.
.
Leo
Newton
Brights
Milds

From Wikipedia, the free encyclopedia

Pylorus
Gray1050.png
Inside of the stomach (pylorus labeled at center left)
Details
Identifiers
LatinPylorus
MeSHD011708
TAA05.5.01.017
FMA14581
Anatomical terminology

The pylorus (/pˈlɔːrəs/ or /pɪˈlrəs/), 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]

YouTube Encyclopedic

  • 1/5
    Views:
    117 254
    6 458
    9 916
    18 933
    39 266
  • ✪ Hypertrophic pyloric stenosis - causes, symptoms, diagnosis, treatment, pathology
  • ✪ Hypertrophic Pyloric Stenosis – Surgery | Lecturio
  • ✪ SURGERY Congenital Hypertrophic Pyloric Stenosis , Surgery Lectures
  • ✪ Pyloric Ultrasound
  • ✪ Pyloric Stenosis

Transcription

With hypertrophic pyloric stenosis, hypertrophy refers to an increase in size, pyloric refers to the pylorus which is the tissue between the stomach and the duodenum, and stenosis means narrowing, so hypertrophic pyloric stenosis, or HPS, is a congenital condition where a baby’s pylorus grows in size such that it narrows the tiny opening between the stomach and the duodenum. The pylorus itself has two parts to it, the pyloric antrum, which connects to the body of the stomach, and the pyloric canal, which connects to the duodenum. At the end of the pyloric canal you’ve got the pyloric sphincter, which is a ring of smooth muscle that contracts and acts like a valve, letting food pass down into the duodenum, but not go back up into the stomach. In HPS, babies are born with a normal pylorus, but within a few weeks after birth, the smooth muscle of the pyloric antrum begins to undergo hypertrophy and hyperplasia, meaning an increase in the size of each cell as well as an increase in the overall number of cells, respectively. This causes the pyloric antrum to nearly double in size. This thick and muscular antrum obstructs the pathway of food, which makes it harder for food to leave the stomach and enter the small intestine. Clinically the enlarged pylorus can be felt as an “olive” in the right upper quadrant or epigastric region of the abdomen, which is just above the umbilicus. Also, there’s normally contraction and relaxation of the smooth muscle lining the stomach, a process called peristalsis. Obstruction from HPS can cause the stomach smooth muscle to have to work much harder to push food through, and sometimes there can even be hypertrophy of those muscles, which can result in peristalsis that can be felt or seen. If food can’t pass through the pylorus, it quickly starts to build up to the point where it has nowhere to go, which can lead to vomiting. This usually happens around 2-6 weeks, and can get more intense over time, until it ultimately starts causing projectile vomiting, called that because the vomit literally launches out of a child’s mouth. The vomit is also non-bilious, meaning it doesn’t contain bile, which makes sense, since bile secretion happens after the pyloric sphincter in the duodenum. This vomiting leads to loss of stomach acid, which leads to dehydration, as well as loss of hydrochloric acid, which depletes the body’s chloride and leads to hypochloremia—low chloride in the blood. Also, due to having a lowered blood volume from dehydration, the kidneys retain salt and excrete potassium, which results in hypokalemia—low potassium in the blood. Hypokalemia results in a movement of potassium out of cells and hydrogen ions into cells, as well as secretion of hydrogen ions and reabsorption of bicarbonate ions in the kidneys. These effects all tend to decrease the acidity of the blood, in other words increase the blood’s pH, resulting in metabolic alkalosis. The precise cause of HPS isn’t known, but likely involves genetic and environmental factors. For example it’s more likely among infant boys, and more common among first born children. It has also been associated with exposure to macrolide antibiotics. Now, the diagnosis of HPS is usually based on identifying serious vomiting in an infant that’s a few weeks old, and feeling a small mass, or an “olive”, or begin able to see stomach peristalsis on a physical exam. At that point, an ultrasound or other imaging studies like an X-ray can be used to confirm the disease. In addition, lab studies will classically show hypochloremic, hypokalemic metabolic alkalosis. Treatment typically Initially involves good hydration and ensuring good electrolyte balance, but the definitive treatment is a pyloromyotomy, also known as Ramstedt’s procedure, where the muscle of the pylorus are cut and separated, allowing food to pass through more easily. Alright, as a quick recap, hypertrophic pyloric stenosis is a congenital condition where a newborn’s pylorus undergoes hyperplasia and hypertrophy, leading to obstruction of the pyloric valve which causes vomiting (that might be projectile), as well as dehydration and metabolic alkalosis. Thanks for watching, you can help support us by donating on patreon, or subscribing to our channel, or telling your friends about us on social media.

Contents

Structure

Diagram from cancer.gov:* 1. Body of stomach* 2. Fundus* 3. Anterior wall* 4. Greater curvature* 5. Lesser curvature* 6. Cardia* 9. Pyloric sphincter* 10. Pyloric antrum* 11. Pyloric canal* 12. Angular incisure* 13. Gastric canal* 14. 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

The pyloric antrum is the initial portion of the pylorus. 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 digestion by peristaltic contraction of the prepyloric sphincter; it is demarcated, sometimes, from the pyloric canal by a slight groove.

Canal

The 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 valve, is a strong ring of smooth muscle at the end of the pyloric canal which lets food pass from the stomach to the duodenum. It controls the outflow of gastric contents into the duodenum.[6] It receives sympathetic innervation from the celiac ganglion.

Histology

Microscopic cross-section of the pylorus.
Microscopic cross-section of the pylorus.

Under microscopy, the pylorus contains numerous glands, including gastric pits, which constitute about half the depth of the pyloric mucosa. They consist of two or three short closed tubes opening into a common duct or mouth. These tubes are wavy, and are about one-half the length of the duct. The duct is lined by columnar cells, continuous with the epithelium lining the surface of the mucous membrane of the stomach, the tubes by shorter and more cubical cell which are finely granular. The glands contain mucus cells and G cells that secrete gastrin.[7]

The pylorus also contains scattered parietal cells and neuroendocrine cells. These endocrine cells including D cells, which release somatostatin.[8] (Somatostatin is responsible for shutting off acid secretion. There is a second hormone-sensitive population near the fundus.) Unstriated muscles which are entirely involuntary are located in 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. This tube is called a gastroduodenostomy.

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

See also

References

  1. ^ Harper, Douglas. "Pylorus". Etymology Online. Retrieved 27 March 2014.
  2. ^ Drake, Richard L.; Vogl, Wayne; Tibbitts, Adam W.M. Mitchell; illustrations by Richard; Richardson, Paul (2005). Gray's anatomy for students. Philadelphia: Elsevier/Churchill Livingstone. p. 272. ISBN 978-0-8089-2306-0.
  3. ^ University of Illinois Medical Center:Health Library Archived 2012-04-26 at the Wayback Machine
  4. ^ Rohrschneider, WK; Mittnacht, H; Darge, K; Tröger, J (June 1998). "Pyloric muscle in asymptomatic infants: sonographic evaluation and discrimination from idiopathic hypertrophic pyloric stenosis". Pediatric radiology. 28 (6): 429–34. doi:10.1007/s002470050377. PMID 9634457.
  5. ^ Lin, Hsien-Ping; Lin, Yu-Chiang; Kuo, Chen-Yun (2015). "Adult idiopathic hypertrophic pyloric stenosis". Journal of the Formosan Medical Association. 114 (7): 659–662. doi:10.1016/j.jfma.2012.07.001. ISSN 0929-6646.
  6. ^ Snell, Richard S. (2008). Clinical Anatomy by Regions. Lippincott Williams & Wilkins. p. 220. 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. ^ Deakin, Barbara Young ... [et al.]; drawings by Philip J. (2006). Wheater's functional histology : a text and colour atlas (5th ed.). [Edinburgh?]: Churchill Livingstone/Elsevier. p. 273. ISBN 978-0-443-068-508.
  9. ^ Clayden, Tom Lissauer, Graham (2007). Illustrated textbook of paediatrics (3rd ed.). Edinburgh; New York: Mosby/Elsevier. pp. 207–208. ISBN 9780723433972.
  10. ^ Chen, ZM; Scudiere, JR; Abraham, SC; Montgomery, E (2009). "Pyloric gland adenoma: an entity distinct from gastric foveolar type adenoma". Am J Surg Pathol. 33 (2): 186–193. doi:10.1097/PAS.0b013e31817d7ff4. PMID 18830123.

External links

This page was last edited on 23 August 2019, at 08:29
Basis of this page is in Wikipedia. Text is available under the CC BY-SA 3.0 Unported License. Non-text media are available under their specified licenses. Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc. WIKI 2 is an independent company and has no affiliation with Wikimedia Foundation.