Leber

Leber refers to the liver, a large glandular organ essential to metabolism, detoxification and digestion. In humans it lies largely in the upper right quadrant of the abdomen, beneath the diaphragm, and typically weighs about 1.2 to 1.5 kilograms. The liver is divided into right and left lobes, with smaller caudate and quadrate lobes. Its functional units are hepatic lobules centered on a central vein; at the corners of each lobule lies the portal triad, consisting of the portal vein, hepatic artery and bile duct. Blood from the portal vein and hepatic artery flows through sinusoids that mix nutrients and oxygen before draining into central veins and then the hepatic veins to the inferior vena cava. Bile is produced by hepatocytes, flows through bile canaliculi into bile ducts, and is conducted to the gallbladder or duodenum as needed.

Functions include carbohydrate, lipid and protein metabolism; regulation of blood glucose through glycogen storage and gluconeogenesis; detoxification and drug metabolism via cytochrome P450 enzymes; bile formation for fat emulsification; and storage of vitamins and minerals, iron, copper, and vitamin A, D and B12. The liver also contributes to immune function through resident macrophages (Kupffer cells) and other immune cells. It has a remarkable regenerative capacity, capable of restoring tissue after injury or partial resection.

Clinical relevance: liver diseases include hepatitis, fatty liver disease, cirrhosis and hepatocellular carcinoma. Evaluation relies on liver function tests and imaging. The liver’s central role in metabolism and detoxification makes it a focal organ in physiology and medicine.