(Solved): In the fetal circulation: The foramen ovale divides the left and right ventricles. Blood flows in a ...

In the fetal circulation: The foramen ovale divides the left and right ventricles. Blood flows in an identical path to that observed in the circulation of an "adult". There are two umbilical veins and one umbilical artery. Over \( 90 \% \) of the blood passes through the kidneys via the ductus venosus The foramen ovale allows oxygenated blood to bypass the pulmonary circulation The blood vessel labelled \( A \) in the photograph below is: A venule An arteriole An artery A capillary A vein In the fetal circulation as blood moves from the placenta to the aorta, it can pass through the following structures. Which order is correct? (1) right atrium (2) Aorta (3) Liver (4) Ductus arteriosus (5) umbilical vein (6) Inferior vena cava (7) Right ventricle (8) Pulmonary trunk \[ 5-3-6-1-7-2-4-8 \] \[ 5-6-3-8-1-7-2-4 \] \[ 3-5-6-1-8-7-4-2 \] \[ 5-3-6-1-7-8-4-2 \] In general, in an adult mammal, arteries can be distinguished from veins because: Veins have thicker walls than arteries. Arteries often collapse whereas veins retain their cylindrical shape in fixed histological sections. The tunica media layer is thicker in veins. Arteries typically contain valves to prevent backflow of blood. Veins have a larger lumen than arteries.