Vitelline circulation

Gray's anatomy image 22

Gray's anatomy image 458

Vitelline circulation refers to the system of blood vessels that is associated with the yolk sac of a developing embryo. This circulatory system is crucial during the early stages of embryonic development, providing nutrients and oxygen to the growing embryo before the establishment of the placental circulation.

Development

The vitelline circulation begins to form during the third week of embryonic development. The yolk sac, which is an extra-embryonic membrane, is connected to the midgut of the embryo via the vitelline duct. Blood islands, which are clusters of hemangioblasts, form within the yolk sac and give rise to the vitelline blood vessels.

Vitelline Arteries and Veins

The vitelline circulation consists of vitelline arteries and veins:

• Vitelline arteries arise from the dorsal aorta and supply blood to the yolk sac.
• Vitelline veins return nutrient-rich blood from the yolk sac to the sinus venosus of the developing heart.

Function

The primary function of the vitelline circulation is to transport nutrients from the yolk sac to the embryo. This system is essential for the survival and growth of the embryo during the early stages of development, before the placenta becomes fully functional.

Transformation

As the embryo continues to develop, the vitelline circulation undergoes significant changes. The vitelline arteries contribute to the formation of the celiac artery, superior mesenteric artery, and inferior mesenteric artery. The vitelline veins contribute to the formation of the portal vein and the hepatic sinusoids.

Clinical Significance

Abnormalities in the development of the vitelline circulation can lead to congenital anomalies such as Meckel's diverticulum, which is a remnant of the vitelline duct. Other potential issues include malformations of the portal vein and associated structures.

Related Pages

• Embryonic development
• Yolk sac
• Placental circulation
• Vitelline duct
• Portal vein
• Meckel's diverticulum