Which structure is primarily responsible for the internal segmentation of the liver?

The hepatic veins play a crucial role in the internal segmentation of the liver by facilitating the drainage of blood from the liver lobules into the inferior vena cava. Each hepatic vein collects blood from the central veins of the liver's functional units, known as lobules. These lobules are the structural units of the liver, where various metabolic processes occur, and they are separated by connective tissue septa. The hepatic veins, along with their positioning, essentially form boundaries that segment the liver into distinct anatomical and functional regions. This segmentation allows for efficient blood flow and proper functioning of hepatic tissue.

In contrast, the other structures listed do not perform the same internal segmentation function. The coronary ligament is a fold of peritoneum that anchors the liver to the diaphragm but does not segment the liver internally. The portal vein is responsible for supplying blood containing nutrients from the gastrointestinal tract to the liver but does not contribute to anatomical segmentation. The falciform ligament primarily serves to attach the liver to the anterior abdominal wall and the diaphragm, rather than serving a functional role in the liver’s internal structure.