Obstetric and Gynecological Nursing - The Carter Center

nutrients. It has a branch which joins the portal vein and
supplies the liver.
The ductus vensous (from a vein to a vein) connects the
umblica vein to the inferior venacava. At this point the blood
mixes with deoxygenated blood returning from the lower parts
of the body. Thus the blood throughout the body is at best
partially oxygenated.
The foramen ovale (oval opening) is a temporary opening
between the atria which allows the majority of blood entering
from the inferior vencava to pass across into the left atrium.
The reason for this diversion is that the blood does not need
to pass through the lungs since it is already oxygenated.
The ductus arteriosus (from an artery to an artery) leads
from the bifuraction of the pulmonary artery to the descending
aorta, entering it just beyond the point where the subclavian
and carotid arteries leave.
The hypogastric arteries branch off from the internal iliac
arteries and become umbilical arteries when they enter the
umblical cord. They return blood to the placenta. This is the
only vessel inthe fetus which carries unmixed blood.
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