Revision as of 16:46, 11 November 2020 by Travis(talk | contribs)(Created page with "<div class="WPC-editableContent"><table width="100%"><tr><td><div class="WPC-edit-area"><b>Fetal Circulation </b><br/><br/><b>The fetus</b><br/><ul><li>Has blood that is oxyge...")
Has blood that is oxygenated in the placenta rather than in the lungs.
Has three shunts that partially bypass the lungs and liver.
Foramen ovale
Is an opening in the septum secundum.
Usually closes functionally at birth, but with anatomic closure occurring later.
Shunts blood from the right atrium to the left atrium, partially bypassing the lungs (pulmonary circulation).
Ductus arteriosus
Is derived from the sixth aortic arch and connects the bifurcation of the pulmonary trunk.
Closes functionally soon after birth, with anatomic closure requiring several weeks.
Becomes the ligamentum arteriosum, which connects the left pulmonary artery (at its origin from the pulmonary trunk) to the concavity of the arch of the aorta.
Shunts blood from the pulmonary trunk to the aorta, partially bypassing the lungs (pulmonary circulation
Ductus venosus
Shunts oxygenated blood from the umbilical vein (returning from the placenta) to the IVC, partially bypassing the liver (portal circulation).
Joins the left branch of the portal vein to the IVC and is obliterated to become the ligamentum venosum after birth.
Umbilical arteries
Carry blood to the placenta for reoxygenation before birth.
Become medial umbilical ligaments after birth, after their distal parts have atrophied.
Umbilical veins
Carry highly oxygenated blood from the placenta to the fetus.
Consists of the right vein, which is obliterated during the embryonic period, and the left vein, which is obliterated to form the ligamentum teres hepatis after birth.
