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In the human embryo, the vitelline duct, also known as the vitellointestinal duct, [1] the yolk stalk, [1] the omphaloenteric duct, [1] or the omphalomesenteric duct, [1] is a long narrow tube that joins the yolk sac to the midgut lumen of the developing fetus. [2]
Blood is conveyed to the wall of the yolk sac by the primitive aorta and after circulating through a wide-meshed capillary plexus, is returned by the vitelline veins to the tubular heart of the embryo. This constitutes the vitelline circulation, which in humans serves as a location of haematopoiesis.
A Meckel's diverticulum, a true congenital diverticulum, is a slight bulge in the small intestine present at birth and a vestigial remnant of the vitelline duct.It is the most common malformation of the gastrointestinal tract and is present in approximately 2% of the population, [1] with males more frequently experiencing symptoms.
Vitelline circulation refers to the system of blood flowing from the embryo to the yolk sac and back again. The yolk-sac is situated on the ventral aspect of the embryo; it is lined by endoderm , outside of which is a layer of mesoderm .
Progressive expansion of the amnion from the umbilical ring (surrounding the roots of the vitelline duct and connecting stalk) creates a tube with a covering of amniotic membrane with allantois and umbilical vessels as its content and mesoderm of the connecting stalk as the ground substance.
This article incorporates text in the public domain from page 1213 of the 20th edition of Gray's Anatomy (1918) ^ "Urachus" . www.cancer.gov . 2 February 2011 .
The midgut forms the primary intestinal loop, from which originates the distal duodenum to the entrance of the bile duct. The loop continues to the junction of the proximal two-thirds of the transverse colon with the distal third. At its apex, the primary loop remains temporarily in open connection with the yolk sac through the vitelline duct.
The yolk sac remains connected to the gut tube via the vitelline duct. Usually, this structure regresses during development; in cases where it does not, it is known as Meckel's diverticulum. During fetal life, the primitive gut is gradually patterned into three segments: foregut, midgut, and hindgut. Although these terms are often used in ...