- The growing fetus receives its oxygen from the mother so has no need for functioning lungs. The oxygenated blood enters the fetus through the umbilical vein and travels through the liver to the heart.
- Once the blood reaches the right heart, it is shunted directly into the left atrium for distribution through the aorta. There is a physiological opening between the atria, (foramen ovale) and a second vascular connection between the pulmonary artery and the aorta (ductus arteriosus), through which blood shunts.
- Soon after delivery, the lungs expand, the foramen ovale and ductus arteriosus close, and blood begins to circulate through the lungs to supply oxygen for the tissues. Failure to convert to neonatal circulation is known as persistent fetal circulation and must be treated.
30 x 40 = $395 + shipping
36 x 48 = $425 + shipping
Digital = $395