The Vessels Practice MCQ's - The Cardiovascular System (II): The Vasculature

The correct answer is "ligamentum venosum." In the adult, the ductus venosus, which is a blood vessel that connects the umbilical vein to the inferior vena cava in the fetus, becomes the ligamentum venosum. This transformation occurs after birth when the ductus venosus is no longer needed for fetal circulation. The ligamentum venosum is a fibrous band that helps to stabilize the liver and is a remnant of the fetal circulation.

In the 8th week LEFT BRACHIOCEPHALIC VEIN forms

The left brachiocephalic vein functions to shunt systemic blood from the left to right side

It develops from an anastomoses between left and right anterior cardinal veins when the caudal part of the left anterior cardinal vein degenerates

The course of the adult recurrent laryngeal nerves differs on the two sides due to differences in the transformation of the sixth aortic arch arteries. The left recurrent laryngeal nerve hooks around the ligamentum arteriosum, while the right recurrent laryngeal nerve hooks around the right pulmonary artery. This is because of the specific anatomical structures present on each side of the body.

Coarctation of the aorta is the correct answer because it is the only arterial malformation listed that has a better prognosis (higher chance of survival) if the infant has another defect known as patent ductus arteriosus. Patent ductus arteriosus is a condition where a blood vessel called the ductus arteriosus, which is supposed to close shortly after birth, remains open. In infants with coarctation of the aorta, the presence of patent ductus arteriosus allows for better blood flow and circulation, improving the prognosis compared to the other listed arterial malformations.

FOURTH AORTIC ARCH
Left side becomes arch of aorta (link to later diagram on formation of aorta as a whole)

Right side becomes right subclavian artery (proximal segment of)

The ductus venosus receives blood from the umbilical vein. During fetal development, the umbilical vein carries oxygenated blood from the placenta to the fetus. The blood then enters the liver through the ductus venosus, bypassing the hepatic circulation. This allows the majority of oxygenated blood to be directed towards the fetal heart and brain. After birth, the ductus venosus closes and becomes a ligament known as the ligamentum venosum.

The superior vena cava is formed by the fusion of the right anterior cardinal vein and the right common cardinal vein. These embryological vessels give rise to the superior vena cava, which is responsible for draining blood from the head and neck.

The correct answer is sinous venosus. The sinous venosus is a primitive structure in the embryonic heart that receives blood from the common cardinal vein. It is responsible for directing the blood flow into the right atrium. The left atrium receives blood from the pulmonary veins, not the sinous venosus. The pulmonary artery and ductus arteriosus are not directly connected to the right atrium.

Ductus venosus forms in liver – fetal shunt to bypass liver sinusoids; shunt connects hepatocardiac channel with left umbilical vein (definitive umbilical vein

During fetal development, the vasculature undergoes extensive remodeling. The left umbilical vein is the correct answer because it does not degenerate during this process. The left vitelline vein, right dorsal aorta, right umbilical vein, and fifth aortic arch arteries all undergo degeneration and remodeling as part of normal fetal development.