Meckel's diverticulum pathophysiology: Difference between revisions
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==Overview== | ==Overview== | ||
The [[vitelline duct]] or the [[Vitelline duct|omphalomesenteric duct]] is the connection between the [[midgut]] and the [[yolk sac]] responsible for providing [[nutrition]] to the [[midgut]], during [[Fetus|fetal]] development. The [[vitelline duct]] subsequently undergoes involution,in the period between the fifth and the sixth weeks of [[gestation]] while the [[Intestinal|intestinal loop]] is rapidly pulled into the [[abdominal cavity]]. Failure of [[Duct (anatomy)|duct]] involution may lead to persistence of the proximal portion of [[Vitelline duct|omphalomesenteric duct]], which may be referred to as the Meckel's diverticulum. The Meckel’s diverticulum is a true [[diverticulum]] (comprising of all layers of [[Small intestine|intestinal wall]] i.e. [[Mucous membrane|mucosa]], [[submucosa]] and [[Muscularis externa|muscularis propria]]). It arises from the antimesenteric border of the [[ileum]] and extends into the [[umbilical cord]]. The blood supply comes from the [[Vitelline arteries|vitelline artery]], which is a branch of the [[Superior mesenteric artery|Superior Mesenteric Artery (SMA)]], prone to torsion, [[ischemia]], [[infarction]] and [[obstruction]]. The [[diverticulum]] may contain [[Ectopic|ectopic tissue]] due to the presence of a [[Pluripotency|pluripotent cell]] lining, faulty association between [[Endoderm|endodermal]] and [[Neural crest|neural crest cells]] and absence of inhibitory effect of the [[mesoderm]] on the local [[endoderm]]. | |||
Failure of duct involution may lead to persistence of the omphalomesenteric duct | |||
Meckel’s diverticulum | |||
==Pathophysiology== | ==Pathophysiology== | ||
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*** Arises from the antimesenteric border of the [[ileum]], extends into the [[umbilical cord]] | *** Arises from the antimesenteric border of the [[ileum]], extends into the [[umbilical cord]] | ||
*** Supplied by the [[Vitelline arteries|vitelline artery]], branch of the [[Superior mesenteric artery|Superior Mesenteric Artery (SMA)]], prone to torsion and subsequent [[ischemia]], [[infarction]] and [[obstruction]] | *** Supplied by the [[Vitelline arteries|vitelline artery]], branch of the [[Superior mesenteric artery|Superior Mesenteric Artery (SMA)]], prone to torsion and subsequent [[ischemia]], [[infarction]] and [[obstruction]] | ||
*** | *** May contain [[Ectopic|ectopic tissue]] due to the following reasons: | ||
**** Presence of a [[Pluripotency|pluripotent cell]] lining | **** Presence of a [[Pluripotency|pluripotent cell]] lining | ||
**** Faulty association between [[Endoderm|endodermal]] and [[Neural crest|neural crest cells]] | **** Faulty association between [[Endoderm|endodermal]] and [[Neural crest|neural crest cells]] | ||
Revision as of 17:25, 5 January 2018
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Sudarshana Datta, MD [2]
Overview
The vitelline duct or the omphalomesenteric duct is the connection between the midgut and the yolk sac responsible for providing nutrition to the midgut, during fetal development. The vitelline duct subsequently undergoes involution,in the period between the fifth and the sixth weeks of gestation while the intestinal loop is rapidly pulled into the abdominal cavity. Failure of duct involution may lead to persistence of the proximal portion of omphalomesenteric duct, which may be referred to as the Meckel's diverticulum. The Meckel’s diverticulum is a true diverticulum (comprising of all layers of intestinal wall i.e. mucosa, submucosa and muscularis propria). It arises from the antimesenteric border of the ileum and extends into the umbilical cord. The blood supply comes from the vitelline artery, which is a branch of the Superior Mesenteric Artery (SMA), prone to torsion, ischemia, infarction and obstruction. The diverticulum may contain ectopic tissue due to the presence of a pluripotent cell lining, faulty association between endodermal and neural crest cells and absence of inhibitory effect of the mesoderm on the local endoderm.
Pathophysiology
- During embryonic life, the vitelline duct or the omphalomesenteric duct is the connection between the midgut and the yolk sac responsible for providing nutrition to the midgut.
- In the period between the fifth and the sixth weeks of gestation, the vitelline duct involutes and disappears, while the bowel is rapidly pulled into the abdominal cavity.
- Failure of duct involution may lead to persistence of the omphalomesenteric duct with variable morphology:
- Vitelline fistulae draining through the umbilicus
- Vitelline cysts
- Fibrous bands connecting the umbilicus to the diverticulum that may twist to cause intestinal obstruction
- Meckel’s diverticulum:
- True diverticulum (comprising of all layers of intestinal wall i.e. mucosa, submucosa and muscularis propria)
- Arises from the antimesenteric border of the ileum, extends into the umbilical cord
- Supplied by the vitelline artery, branch of the Superior Mesenteric Artery (SMA), prone to torsion and subsequent ischemia, infarction and obstruction
- May contain ectopic tissue due to the following reasons:
- Presence of a pluripotent cell lining
- Faulty association between endodermal and neural crest cells
- Absence of inhibitory effect of the mesoderm on the local endoderm may also be responsible
- Types of ectopic tissue: