 |
|
|
|
 |
|
|
Vitelline duct
| Vitelline duct |
|
|
| Fetus of about eight weeks, enclosed in the amnion. (Vitelline duct labeled at lower right.) |
|
|
| Sketches in profile of two stages in the development of the human digestive tube. (Vitelline duct labeled on bottom image.) |
| Gray's |
subject #10 54 |
| Days |
28 |
| Precursor |
midgut, yolk sac |
| MeSH |
Vitelline+Duct |
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
|
| |
|
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Vitelline_duct". A list of authors is available in Wikipedia.
|
|
|
|
|
|
Top