Liver

About the Liver

The liver is the largest internal organ, weighing approximately 1.5 kg in adults, located in the right upper quadrant beneath the diaphragm. It performs hundreds of distinct functions and has remarkable regenerative capacity, regrowing from 25 percent of its mass. The functional unit is the hepatic lobule, with hepatocytes arranged in plates radiating from the central vein. Portal triads carry portal venous blood nutrient rich from intestines, hepatic arterial blood oxygen rich, and bile ducts. The liver metabolizes carbohydrates glycogen storage, gluconeogenesis, lipids lipoprotein synthesis, cholesterol metabolism, and proteins albumin, clotting factors all except factor VIII, complement. It detoxifies drugs and toxins via phase I cytochrome P450 and phase II conjugation reactions. Bile production 600 to 1,000 mL daily emulsifies fats in the duodenum. Bilirubin from heme breakdown is conjugated and excreted in bile. Kupffer cells are resident macrophages. The liver stores vitamins A, D, B12, K and iron as ferritin. Cirrhosis replaces functional tissue with scar tissue, causing portal hypertension, ascites, varices, and hepatic encephalopathy.