2007-01-25 03:23:07 · 4 answers · asked by ladytiger6969 1 in Science & Mathematics ➔ Medicine
There is a ductus arteriosus that allows some of the blood to bypass the pulmonary circulation by permitting flow from the pulmonary artery to the aorta, as well as a foramen ovale, which allows blood to flow from the right to left atrium. There is also a ductus venosus for blood to bypass the liver.
2007-01-25 15:56:37 · answer #1 · answered by Stephanie S 2 · 0⤊ 0⤋
The blood from the placenta enters 1. the umbilical vein and passes through 2. the porta hepatis into the inferior vena cava. The blood then flows into the right atrium where this column of blood is mainly flowing from the right to the left and mostly passes through the 3. foramen ovale into the left atrium and through the mitral valve into the left ventricle and out the aortic valve to the ascending aorta. Most of this blood flow (the more oxygen rich) flows to the upper body including the brain. Blood returns from the upper body by way of the superior vena cava and is flowing mainly from top to bottom when it enters right atrium and this column of flow mainly passes into the tricuspid valve into the right ventricle. The blood leaves the right ventricle by way of the pulmonary valve into the pulmonary artery. Since the lungs are not expanded, the great majority of the flow passes through the 4. ductus arteriosis into the descending aorta (serving the lower body) and out the 5. umbilical arteries to the placenta.
2007-01-25 12:00:22 · answer #2 · answered by a simple man 6 · 0⤊ 0⤋
The Umbilical cord, A ductus arteriosus and a foramen ovale. and a ductus venosus
2007-01-25 03:32:07 · answer #3 · answered by Queen-o-the-Damned 3 · 2⤊ 0⤋
umbilical cord which is connected to the mother's circulation
2007-01-25 03:55:23 · answer #4 · answered by Anonymous · 0⤊ 1⤋