✔ Fetal circulatory systemFrom placenta to Umbilical vein(O2 rich blood)ductus venosus (정맥관) → bypass the liver → right side of heartThe foramen ovale : allows to go from right to left atrium(우심방->좌심장)Then to the left ventricle and out the aorta . As a result the blood with the most O2 gets to the brain.[ key point : 폐가 아닌 태반!! ]아기 필수 순환구조 : foramen ovale / ductus arteriosusFetal HR : 110-160bpm..