Final answer:
The ligamentum teres hepatis resides within the falciform ligament of the liver, marking the boundary between the right and left lobes, and is a remnant of the fetal umbilical vein.
Step-by-step explanation:
The ligamentum teres hepatis is located within the falciform ligament, anchoring the liver to the anterior abdominal wall and inferior border of the diaphragm. It runs from the umbilicus to the liver's inferior surface, delineating the left and the right lobes of the liver. The embryological structure it is a remnant of is the umbilical vein, which in the fetus carries oxygenated blood from the placenta to the growing fetus. After birth, this blood vessel becomes obliterated and turns into the fibrous structure known as the ligamentum teres hepatis.