Introduction to Liver Functions

Study Notes

The liver is the largest solid organ in the body, with a substantial reserve capacity.
It receives blood from both the hepatic artery and portal vein (dual blood supply).
Bilary ducts carry bile from the liver to the gallbladder.
Lymph vessels are also present in the liver.
Approximately 60% of liver cells are hepatocytes (functional cells). Other cells include Kupffer cells, endothelial cells, and stellate cells.
The liver is capable of regeneration.

Metabolic: The liver is involved in the metabolism of carbohydrates, fats, and proteins.
Synthesis: It produces proteins (such as albumin), various enzymes, clotting factors, and complement proteins.
Storage: The liver stores glycogen, triglycerides (TGs), iron, copper, and fat-soluble vitamins (A, D, and B12).
Detoxification: It detoxifies foreign substances like drugs and endogenous substances such as ammonia.
Bile Production: Bile salts, bile pigments, and cholesterol are the key components of bile produced by the liver.

Hepatocyte Damage: Raised levels of ALT and AST, along with conjugated bilirubin, indicate liver cell damage.
Biliary Damage/Obstruction: Raised ALP, GGT, and conjugated bilirubin levels suggest issues with the bile duct system.
Synthetic Function: Assessment includes albumin, protein, urea, prothrombin time, and unconjugated bilirubin levels.
Synthetic Function (Continued): Raised lipids (cholesterol, triglycerides) can indicate issues with fat metabolism.
Excretion/Detoxification: Bilirubin, ammonia, and drug metabolites are measured to assess the liver's excretory and detoxification functions.