Vitelline duct
4472292
219919382
2008-06-17T13:29:55Z
Uwe Gille
211241
+de, es removed (describes yolk sac)
{{Infobox Embryology |
Name = {{PAGENAME}} |
Latin = |
GraySubject = 10 |
GrayPage = 54 |
Image = Gray30.png |
Caption = [[Fetus]] of about eight weeks, enclosed in the [[amnion]]. (Vitelline duct labeled at lower right.) |
Image2 = Gray982.png |
Caption2 = Sketches in profile of two stages in the development of the human digestive tube. (Vitelline duct labeled on bottom image.) |
System = |
CarnegieStage = |
Days = 28 |
Precursor = [[midgut]], [[yolk sac]] |
GivesRiseTo = |
MeshName = Vitelline+Duct |
MeshNumber = A16.254.891 |
DorlandsPre = |
DorlandsSuf = |
}}
At the end of the fourth week the [[yolk-sac]] presents the appearance of a small pear-shaped vesicle (umbilical vesicle) opening into the digestive tube by a long narrow tube, the '''vitelline duct''', also known as the omphalomesenteric duct.
The vesicle can be seen in the [[after-birth]] as a small, somewhat oval-shaped body whose diameter varies from 1 mm. to 5 mm.; it is situated between the [[amnion]] and the [[chorion]] and may lie on or at a varying distance from the [[placenta]].
As a rule the duct undergoes complete obliteration during the seventh week, but in about two per cent of cases its proximal part persists as a diverticulum from the [[small intestine]], [[Meckel's diverticulum]], which is situated about two feet above the [[ileocecal junction]], and may be attached by a fibrous cord to the abdominal wall at the [[umbilicus]].
Sometimes a narrowing of the [[lumen]] of the [[ileum]] is seen opposite the site of attachment of the duct.
==Additional images==
<gallery>
Image:Gray983.png|Front view of two successive stages in the development of the digestive tube.
</gallery>
==External links==
* {{eMedicineDictionary|yolk+stalk}}
{{Embryology}}[[Category:Embryology]]
[[de:Dottergang]]