What is basic functional unit of the liver?

The basic functional unit of the liver is the hepatic lobule. It is a hexagonal-shaped structure composed of hepatocytes (liver cells) arranged in a radial manner around a central vein. The hepatic lobules are separated by connective tissue septa that contain portal triads, which are composed of branches of the hepatic artery, portal vein, and bile duct.

The hepatic lobules are the functional units of the liver, where various metabolic processes occur. The hepatocytes in the hepatic lobules perform multiple functions, including:

1. Metabolism of Carbohydrates: Hepatocytes are involved in the metabolism of carbohydrates. They take up glucose from the portal vein and convert it into glycogen through the process of glycogenesis. When blood glucose levels drop, hepatocytes can break down glycogen into glucose and release it into the bloodstream through a process called glycogenolysis.

2. Metabolism of Fats: Hepatocytes play a crucial role in lipid metabolism. They take up fatty acids from the portal vein and convert them into triglycerides, which are stored as lipid droplets within the cytoplasm. Hepatocytes can also synthesize cholesterol and various lipoproteins.

3. Metabolism of Proteins: Hepatocytes are involved in the metabolism of proteins. They synthesize various plasma proteins, including albumin, clotting factors, and lipoproteins. They also detoxify and degrade certain amino acids.

4. Detoxification: Hepatocytes have specialized enzymes that detoxify various harmful substances, such as drugs, toxins, and metabolic waste products. These substances are modified into forms that can be excreted by the body.

5. Bile Production: Hepatocytes secrete bile, which is essential for the digestion and absorption of fats. Bile is composed of bile salts, phospholipids, cholesterol, and bilirubin (a breakdown product of hemoglobin). Bile is stored in the gallbladder and released into the small intestine when needed.

6. Storage: Hepatocytes serve as a storage site for various substances, including glycogen, vitamins (such as vitamins A, D, B12), and minerals (such as iron and copper). These stored substances can be released when the body requires them.

Overall, the hepatic lobules and hepatocytes are the fundamental units of liver function, carrying out numerous vital metabolic processes that are crucial for the body's overall health and well-being.