Table of Contents
Structure and functional units of the Liver
The liver is a complex organ and consists of various structural and functional units that work together to perform its vital functions. The primary structural and functional units of the liver are called Hepatic Lobules.
Hepatic lobules are small, hexagonal-shaped units that form the structural organisation of the liver. Each lobule is about 1-2 millimetres in diameter and consists of several different regions.
At each corner of the hepatic lobule is a portal triad consisting of three main structures-
- Hepatic artery– It supplies the liver with oxygenated blood.
- Portal vein- It transports nutrient-rich blood from the digestive organs to the liver.
- Bile duct- This duct collects and transports bile produced by hepatocytes (liver cells) out of the liver.
Sinusoids are thin-walled, leaky blood vessels that run between rows of hepatocytes within the hepatic lobules. They receive blood from the portal vein and hepatic artery and facilitate the exchange of nutrients, oxygen and waste products between the blood and the hepatocytes.
Hepatocytes are the primary functional cells of the liver. They are arranged in a radial pattern around the central vein of each liver lobule. These cells perform numerous vital functions, including-
- Detoxification of harmful substances and drugs.
- Metabolism of nutrients such as carbohydrates, fats and proteins.
- Production of bile, which aids in the digestion and absorption of fats.
- Synthesis of various plasma proteins, including albumin and clotting factors.
- Storage of vitamins, minerals and glycogen.
Kupffer cells are specialised macrophages found in the sinusoids of the liver. They play a crucial role in the liver’s immune defence by removing bacteria, debris and foreign particles from the blood.
Bile canaliculi are small ducts located between adjacent hepatocytes. They collect the bile produced by the hepatocytes and transport it to the bile ducts in the portal triads.
The central vein is located in the centre of each hepatic lobule and collects deoxygenated blood and drains it from the liver.