During anatomy lab, a medical student notes a fibrous band that runs on the visceral surface of the liver. It is attached on one end to the inferior vena cava and on the other end to the left branch of the portal vein. In the embryo, this structure corresponds to the
a. Ductus venosus
b. Ligamentum teres
c. Ligamentum venosum
d. Umbilical arteries
The Correct option is A
Explanation with High Yield Facts:
This question could have tricked you if you didn't catch the key words, "in the embryo." If you read the question too quickly and thought you were going to be asked to identify the structure described, you probably chose choice C (ligamentum venosum), since that is indeed the structure in question.
However, in the embryo, this fibrous band is actually the ductus venosus. The ductus venosus is an embryonic vessel that allows blood to bypass the fetal liver; this prevents the depletion of oxygen and nutrient-rich blood in the hepatic sinusoids. The embryonic umbilical vein (choice E) actually becomes the fibrous ligamentum teres (choice B). The ligamentum teres is located in the free margin of the falciform ligament. The embryonic umbilical arteries (choice D) become the medial umbilical ligaments.
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