Exchange Question and answers
verified to pass 2025/2026
In fetal circulation, the blood circulating to the placenta to pick up oxygen is in (parallel/series) to the
blood going to the rest of the body. - correct answer ✔parallel - O2 rich blood from placenta mixes
from O2 poor blood from the rest of the body of the fetus
(T/F) Maternal blood gets mixed into fetal circulation. - correct answer ✔False. The maternal and fetal
blood come into close enough proximity to each other in the placental microcirculation to allow
exchange of gases and nutrients, but blood is never exchanged.
What supplies the fetal placenta with blood? - correct answer ✔two umbilical arteries off the fetal
internal iliac
What supplies the maternal placenta with blood? - correct answer ✔200 endometrial spiral arteries
What drains the fetal placenta? - correct answer ✔single umbilican vein
What drains the maternal placenta? - correct answer ✔endometrial veins
Where does the exchange of solutes (and gases) occur between maternal and fetal blood? - correct
answer ✔fetal placental veilli surrounded by a maternal blood reservoir
Contrast maternal blood flow (in L/min) and fetal blood flow. - correct answer ✔maternal: 1 L/min
fetal: 600 mL/min
, Contrast O2 extraction of placenta and rest of mother's body. - correct answer ✔Placenta: venous
blood returns with 70%
rest of body: venous blood returns with 75%
Placenta is slightly higher.
Which process is utilized for the transfer of oxygen from maternal to fetal blood? - correct answer
✔diffusion via partial pressure gradient (like adult lung)
Why is O2 diffusion worse in the placenta than in the lung? - correct answer ✔longer distances to
travel to red blood cells in the fetus than the mother and lung
Where is PO2 the highest in fetal circulation? - correct answer ✔fetal umbilical venous blood
What is the PO2 of maternal arterial blood? - correct answer ✔95 mmHg
What is the PO2 of maternal venous blood? - correct answer ✔35 mmHg (70% sat and blue)
What is the PO2 of fetal umbilical arterial blood? - correct answer ✔22 mmHg (58% sat)
What is the PO2 of fetal umbilical venous blood? - correct answer ✔30 mmHg (80% sat)
The fetal umbilical venous blood returning from the placenta has a _____ PO2 and ______ saturation
than the maternal venous blood returning from the placenta. - correct answer ✔lower; higher
Maternal and fetal blood never reach equilibrium (same PO2), but more of the fetal hemoglobin is
saturated than that of the returning venous blood from the mother. This is due to *fetal hemoglobin has