What structure separates the left lobe of the liver from the right lobe?

The falciform ligament is the structure that separates the left lobe of the liver from the right lobe. This ligament is a double layer of peritoneum that extends from the liver to the anterior abdominal wall and diaphragm, anchoring the liver in place and playing a role in the division of the liver into its anatomical lobes. It runs along the midline of the liver, effectively indicating the boundary between the left and right lobes.

The round ligament, also known as the ligamentum teres, is a remnant of the obliterated umbilical vein and is found within the free edge of the falciform ligament, but it does not serve as the primary separator of the liver lobes. The coronary ligament is associated with the attachment of the liver to the diaphragm but does not separate the lobes. The ligamentum venosum, which is a remnant of the ductus venosus, also does not act as a separating structure between the liver lobes but rather marks the division between the caudate lobe and the left lobe. Thus, the falciform ligament's role is specifically related to the separation of the left and right lobes of the liver.