FE FE Hemodynamics & Blood Flow 1 — Questions and Answers
Question 1: Which vessel carries the most oxygenated blood from the placenta to the fetus?
- Umbilical artery
- Umbilical vein (Correct answer)
- Ductus venosus
- Portal vein
Correct answer: Umbilical vein
The umbilical vein carries oxygenated blood from the placenta to the fetal liver and heart.
Question 2: The ductus venosus shunts blood from the umbilical vein directly to which structure?
- Right atrium
- Left atrium
- Inferior vena cava (Correct answer)
- Portal sinus
Correct answer: Inferior vena cava
The ductus venosus connects the umbilical vein to the inferior vena cava, bypassing the hepatic circulation.
Question 3: In fetal circulation, the foramen ovale allows blood to shunt from which chamber to which chamber?
- Left atrium to right atrium
- Right atrium to left atrium (Correct answer)
- Right ventricle to left ventricle
- Left ventricle to right ventricle
Correct answer: Right atrium to left atrium
The foramen ovale allows oxygenated blood from the right atrium to pass into the left atrium, bypassing the pulmonary circulation.
Question 4: Which fetal shunt connects the main pulmonary artery to the descending aorta?
- Foramen ovale
- Ductus venosus
- Ductus arteriosus (Correct answer)
- Aortic isthmus
Correct answer: Ductus arteriosus
The ductus arteriosus connects the main pulmonary artery to the descending aorta, allowing most right ventricular output to bypass the lungs.
Question 5: What percentage of combined cardiac output does the right ventricle contribute in the normal fetus?
- 30%
- 45%
- 55% (Correct answer)
- 70%
Correct answer: 55%
The fetal right ventricle contributes approximately 55% of combined cardiac output, making it the dominant ventricle in utero.
Question 6: In the normal fetus, pulmonary vascular resistance is:
- Lower than systemic vascular resistance
- Equal to systemic vascular resistance
- Higher than systemic vascular resistance (Correct answer)
- Absent due to non-functional lungs
Correct answer: Higher than systemic vascular resistance
Fetal pulmonary vascular resistance is high due to fluid-filled lungs and hypoxic vasoconstriction, directing blood away from the pulmonary circulation.
FE FE Hemodynamics & Blood Flow 1
Which vessel carries the most oxygenated blood from the placenta to the fetus?