Question

In the fetal circulation the oxygen content of blood in the 

A. Femoral artery is less than that in the brachial artery. 

B. Superior vena cava is higher than that in the inferior vena cava. 

C. Right ventricle is higher than that in the left ventricle. 

D. Pulmonary artery is higher than that in the pulmonary veins. 

E. Cerebral arteries is lower than in the maternal cerebral arteries.

Answer 1

A. True Due to deoxygenated pulmonary arterial blood passing through the ductus arteriosus to the descending aorta. 

B. False The IVC receives oxygenated blood from the placenta. 

C. False Deoxygenated SVC blood streams to the right ventricle while oxygenated IVC blood streams via the foramen ovale to the left ventricle. 

D. True Since the lungs are not ventilated, oxygen is lost rather than gained in its passage through the fetal lungs. 

E. True Umbilical venous blood is only about 80 per cent saturated with oxygen and fetal arterial oxygen levels cannot exceed this; fetal tissues are adapted to survive in relative hypoxia.