Uberon definition : A long narrow tube that joins the yolk-sac to the midgut lumen of the developing fetus.;
Uberon related term : ductus vitellinus; embryonic yolk stalk; yolk-stalk; omphalomesenteric duct; yolk duct;
Uberon Development note : In humans, it appears at the end of the fourth week, when the yolk-sac presents the
appearance of a small pear-shaped vesicle (the umbilical vesicle). The vesicle can
be seen in the afterbirth 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. Generally, the duct fully obliterates
(narrows and disappears) during the seventh week, but a failure of the duct to close
is termed a vitelline fistula. This results in discharge of meconium from the umbilicus.
About two per cent of fetuses exhibit a type of vitelline fistula characterized by
persistence of the proximal part of the vitelline duct as a diverticulum protruding
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;
Automatic exact mappings (from CISMeF team)