The umbilical vein carries
- A. deoxygenated blood from the fetus to the placenta
- B. oxygenated blood from the placenta to the fetus
- C. fetal urine to the placenta for disposal
- D. maternal blood directly into the fetal circulation
Explanation
The cord contains two arteries and one vein, and as always the vein is named for the direction of flow towards the heart, so it brings oxygen and nutrients from the placenta to the fetus. The umbilical arteries do the reverse, carrying deoxygenated blood loaded with waste to the placenta. Maternal and fetal blood remain in separate vessels throughout, exchanging only by diffusion across the placental barrier.