Sphincter of Oddi explained

Sphincter of Oddi
Latin:	m. sphincter ampullae
System:	Digestive system
Acronym:	SO
Location:	Surrounds the Major duodenal papilla
Function:	A circular muscle (sphincter) that controls the secretion of pancreatic juices and bile into the duodenum, and prevents reflux from the duodenum.

The sphincter of Oddi (also hepatopancreatic sphincter or Glisson's sphincter), abbreviated as SO, is a muscular valve that in some animals, including humans, controls the flow of bile and pancreatic juice out of the gallbladder and pancreas respectively through the ampulla of Vater into the second part of the duodenum. It is named after Ruggero Oddi.

Structure

The sphincter of Oddi is a circular muscle band (sphincter) that surrounds the major duodenal papilla.^[1]

Function

The sphincter regulates the secretion of pancreatic juice and bile into the duodenum.^[2] It also prevents reflux of duodenal contents into the ampulla of Vater.^[3] By preventing reflux of the contents of the duodenum, the sphincter of Oddi prevents the accumulation of particulate matter and sludge in the bile ducts, reducing the risk of cholangitis. The sphincter of Oddi also allows retrograde filling of the gallbladder.^[4]

The sphincter of Oddi is relaxed by the hormone cholecystokinin^{[5] [6]} via vasoactive intestinal peptide.^[7]

Clinical significance

See main article: sphincter of Oddi dysfunction. Pancreatitis can result from a failure of pancreatic secretions to drain properly. One possible cause of impaired drainage of pancreatic juice is blockage of the sphincter of Oddi. A common cause of blockage is a gallstone in the common bile duct.

Opiates may cause spasms of the sphincter of Oddi, leading to increased serum amylase levels.^[8]

History

The sphincter was described for the first time by Ruggero Oddi when he was a young student in 1887.^[9] This description followed extensive research into the physiology of dogs and detailed histological examinations of humans and many other species.^[10]

Other animals

In many mammals (including mice, guinea pigs, dogs, and opossums), the smooth muscle around the ampulla of Vater does not form a sphincter.^[11]

Further reading

• 19864708 . Physiology of the sphincter of Oddi--the present and the future?--Part 1 . 2000 . Ballal . M. A. . Saudi Journal of Gastroenterology . 6 . 3 . 129–46 . Sanford . P. A. .
• 19861760 . Physiology of the sphincter of Oddi: The present and the future?--Part 2 . 2001 . Ballal . M. A. . Saudi Journal of Gastroenterology . 7 . 1 . 6–21 . Sanford . P. A. .

Notes and References

1. Horiguchi. Shin-ichiro. Kamisawa. Terumi. 2010. Major Duodenal Papilla and Its Normal Anatomy. Digestive Surgery. en. 27. 2. 90–93. 10.1159/000288841. 20551649. 21666445. 1421-9883.
2. Horiguchi. Shin-ichiro. Kamisawa. Terumi. 2010. Major Duodenal Papilla and Its Normal Anatomy. Digestive Surgery. en. 27. 2. 90–93. 10.1159/000288841. 20551649. 21666445. 1421-9883.
3. Horiguchi. Shin-ichiro. Kamisawa. Terumi. 2010. Major Duodenal Papilla and Its Normal Anatomy. Digestive Surgery. en. 27. 2. 90–93. 10.1159/000288841. 20551649. 21666445. 1421-9883.
4. Book: Ahmed . Abdelwahab . Zuchelli . Toby . Anatomy, Abdomen and Pelvis, Sphincter of Oddi (Hepatopancreatic Sphincter) . 18 July 2022 . StatPearls Publishing . 19 February 2023 .
5. Book: BRS Physiology (Board Review Series). Costanzo L. March 2006. Lippincott Williams & Wilkins. 978-0781798761. 5th. 220.
6. Liddle. Rodger A.. 2003-01-01. CCK (Cholecystokinin). Encyclopedia of Endocrine Diseases. en. 485–489. 10.1016/B0-12-475570-4/00260-2. 9780124755703.
7. Wiley JW, O'Dorisio TM, Owyang C. June 1988. Vasoactive intestinal polypeptide mediates cholecystokinin-induced relaxation of the sphincter of Oddi. J. Clin. Invest.. 81. 6. 1920–4. 10.1172/JCI113539. 442644. 3384954.
8. Druart-Blazy A, Pariente A, Berthelemy P, Arotçarena R . The underestimated role of opiates in patients with suspected sphincter of Oddi dysfunction after cholecystectomy . Gastroenterol. Clin. Biol. . 29 . 12 . 1220–3 . December 2005 . 16518275 . 10.1016/s0399-8320(05)82204-3 .
9. Ono K, Hada R . Ruggero Oddi. To commemorate the centennial of his original article--"Di una speciale disposizione a sfintere allo sbocco del coledoco" . Jpn J Surg . 18 . 4 . 373–5 . July 1988 . 3050213 . 10.1007/bf02471459 . 30812172 .
10. Book: Yamada T. Textbook of Gastroenterology. 78. 2011-10-13. John Wiley & Sons. 978-1-4443-5941-1.
11. Higashiyama H, Sumitomo H, Ozawa A, Igarashi H, Tsunekawa N, Kurohmaru M, Kanai Y. February 2016. Anatomy of the Murine Hepatobiliary System: A Whole-Organ-Level Analysis Using a Transparency Method. The Anatomical Record. 299. 2. 161–72. 10.1002/ar.23287. 26559382. free.