Final answer:
The liver has two primary lobes, both essential for its metabolic functions, but often also includes two secondary lobes. It is anchored in the body by ligaments and performs its functions through hepatocytes in hepatic lobules.
Step-by-step explanation:
The human liver is a vital organ with a complex structure, crucial for various metabolic processes. It has two primary lobes: the larger right lobe and the smaller left lobe. Anatomically, some experts may additionally describe the existence of an inferior quadrate lobe and a posterior caudate lobe within the right lobe, but these are secondary lobes defined by internal liver features rather than external divisions.
The liver's connection to the body is maintained by five peritoneal folds known as ligaments, which play a role in securing the liver in place within the abdominal cavity. Among these ligaments are the falciform ligament and the ligamentum teres hepatis, both remnants of the umbilical vein in fetal circulation, that separate the right and left lobes anteriorly. The liver's metabolic functionality is further supported by its smallest functional units, the hepatic lobules, which are composed of hepatic cells or hepatocytes.
Hepatocytes account for around 80 percent of the liver's volume and are integral to the organ's secretory, metabolic, and endocrine functions. The hepatic lobules are structured around a central vein, from which plates of hepatocytes radiate outward, forming a hexagonal arrangement that is a hallmark of the liver's histology.