The liver is the largest internal organ in the adult human body.
Located mainly in the upper-right part of the abdomen, the liver performs hundreds of important functions. It processes nutrients absorbed from the digestive tract, produces bile, stores glycogen and certain vitamins, makes many blood proteins, and helps break down drugs and toxins. It also contributes to immune defence through specialised cells in its blood channels.
The liver receives blood from two major sources: the hepatic artery supplies oxygen-rich blood, while the portal vein brings nutrient-rich blood from the digestive organs. Its tissue is organised into microscopic lobules, with hepatocytes carrying out much of its metabolic work. The liver can regenerate a substantial amount of lost tissue, although severe or repeated damage can lead to fibrosis and cirrhosis. The skin is larger overall by surface area and is often called the largest organ, but the liver is the largest internal organ.