Fetal circulation Flashcards
1
Q
O2 in umbilical vein
A
PO2 ~ 30mmHg
80% saturated with O2
2
Q
3 shunts
A
1) ductus venosus into IVC
2) foramen ovale
3) ductus arteriosus (into descending aorta)
3
Q
Birth
A
Take a breath;
low resistance in pul vasculature;
high LA pressure so foramen ovale closes;
high O2 leads to low prostagladins, so ductus arteriosus closes.
4
Q
PDA: what closes and keeps it open
A
Indomethacin helps close PDA
Prostagladin E1 and E2 keeps PDA open
