Lobules of liver

Lobules of liver

The lobules of the liver are the functional units of the liver, an essential organ in the human body responsible for various metabolic, detoxification, and synthetic functions. Each lobule is a small, hexagonal structure composed of hepatocytes, the liver cells, and is the site where many of the liver's critical processes occur.

Structure

The liver lobules are hexagonal in shape and are organized around a central vein. Each lobule is made up of plates of hepatocytes that radiate outward from the central vein. Between these plates are the sinusoids, which are small blood vessels that allow blood to flow through the lobule. The sinusoids are lined with endothelial cells and Kupffer cells, which are specialized macrophages that play a role in the immune response.

At each corner of the hexagonal lobule is a portal triad, which consists of a branch of the hepatic artery, a branch of the portal vein, and a bile duct. The hepatic artery supplies oxygen-rich blood to the liver, while the portal vein carries nutrient-rich blood from the digestive organs. The bile duct collects bile produced by the hepatocytes and transports it to the gallbladder and small intestine.

Function

The primary functions of the liver lobules include:

• Metabolism: The hepatocytes within the lobules are responsible for the metabolism of carbohydrates, proteins, and fats. They also play a role in the storage of glycogen, vitamins, and minerals.
• Detoxification: The liver lobules detoxify various metabolites, drugs, and toxins, converting them into less harmful substances that can be excreted from the body.
• Synthesis: The liver synthesizes important proteins such as albumin, clotting factors, and complement proteins.
• Bile production: Hepatocytes produce bile, which is essential for the digestion and absorption of fats in the small intestine.

Clinical Significance

Damage to the liver lobules can lead to various liver diseases, such as cirrhosis, hepatitis, and liver cancer. Cirrhosis is characterized by the replacement of healthy liver tissue with scar tissue, which can impede the liver's ability to function properly. Hepatitis is an inflammation of the liver, often caused by viral infections, alcohol abuse, or autoimmune diseases. Liver cancer can arise from the hepatocytes (hepatocellular carcinoma) or from the bile ducts (cholangiocarcinoma).

See Also

• Liver
• Hepatocyte
• Portal triad
• Sinusoid (blood vessel)
• Kupffer cell
• Hepatic artery
• Portal vein
• Bile duct
• Cirrhosis
• Hepatitis
• Liver cancer