Umbilical artery Umbilical artery The umbilical artery is a paired artery (with one for each half of the body) that is found in the abdominal and pelvic regions. In the fetus, it extends into the umbilical cord. The umbilical arteries supply deoxygenated blood from the fetus to the placenta. Although this blood is typically referred to as deoxygenated, it is important to note that this blood is fetal systemic arterial blood and will have the same amount of oxygen and nutrients as blood distributed to the other fetal tissues. There are usually two umbilical arteries present together with one umbilical vein in
Umbilical ring vessels. Cranially it lies ventral to the umbilical vein and on each side extends into the tissue of the lateral pillars of the cord bounding the coelom. When the myotomic downgrowths reach the ventral aspect, their anterior portions (i.e. the sheaths of the recti muscles) become continuous with the tissue of the umbilical ring. Umbilical ring The umbilical ring is a dense fibrous ring surrounding the umbilicus at birth. At about the sixth week of embryological development, the midgut herniates through the umbilical ring; six weeks later it returns to the abdominal cavity and rotates around the superior mesenteric artery.