Cardio2 Flashcards
Fetal erythropoiesis Fetal circulation Fetal-postnatal derivatives
Where does fetal erythropoiesis occur?
“Young Liver Synthesizes Blood”
Yolk sac (3-10 wk)
Liver (6 wk-birth)
Spleen (15-30 wk)
Bone Marrow (22 wk-adult)
Fetal hemoglobin =
alpha2gamma2
Adult hemoglobin =
alpha2beta2
Blood in umbilical vein has a PO2 = ___ and is = ____ saturated with O2
30 mmHg
80%
Umbilical arteries have ___ O2 saturation.
Low
3 important shunts in fetal circulation.
Ductus Venosus
Foramen Ovale
Ductus Arteriosus
Function of Ductus Venosus.
Blood entering fetus through the Umbilical Vein is conducted via the DV into the IVC
The ductus venosus allows for bypassing of what?
Hepatic circulation
Function of Foramen Ovale.
Most oxygenated blood reaching the heart via the IVC is diverted through the FO and pumped out the Aorta to the head and body
Function of Ductus Arteriosus.
Deoxygenated blood entering the RA from the SVC enters the RV, is expelled into the Pulmonary Artery, then through the DA into the descending Aorta
What happens when infant takes 1st breath at birth.
DEcrease Resistane in pulmonary vasculature
INcreased LA pressure vs. RA pressure
Foramen ovale CLOSES
What is the foramen ovale called once it closes?
Fossa Ovalis
What causes closure of the Ductus Arteriosus?
DEcreased Prostaglandins d/t INcreased O2
What drug helps close a Patent Ductus Arteriousus?
Indomethacin
What helps keep PDA open?
Prostaglandins E1 & E2
