Functions of the Liver

Functions of the Liver

• Major functions include metabolism regulation, hematological functions, bile synthesis, protein synthesis, and filtration of particulates.

Metabolism Regulation

• Absorbs nutrients and toxins from blood
• Maintains blood organic nutrient levels, especially glucose
• Stores fat-soluble vitamins (A, D, K, E) and iron

Hematological Functions

• Removes aged and damaged red blood cells
• Produces plasma proteins for blood osmotic balance
• Synthesizes clotting factors necessary for hemostasis

Bile Synthesis

• Produces bile salts essential for fat and fat-soluble vitamin absorption

Nutrient Homeostasis

• Manages glucose storage and synthesis, and cholesterol uptake
• Impairment leads to conditions like hypoglycemia and hypercholesterolemia

Filtration of Particulates

• Filters substances such as products from intestinal bacteria
• Impaired filtration can cause endotoxemia

Protein Synthesis

• Synthesizes key proteins including clotting factors and albumin
• Impairment results in excess bleeding and complications like ascites and fatty liver

Bio-activation and Detoxification

• Processes substances like bilirubin, ammonia, and xenobiotics
• impairments can cause jaundice and hyperammonemia-related coma

Formation of Bile and Biliary Secretion

• Involves bile acid-dependent uptake of dietary lipids and vitamins
• Impairment leads to fatty diarrhea, vitamin deficiencies, and gallstones

Glycogen Dynamics

• Liver removes glucose from blood for storage as glycogen (glycogenesis)
• When blood glucose levels drop, liver performs glycogenolysis and gluconeogenesis to restore balance

Liver Structure

• Contains functional structural units called lobules which include hepatocytes, sinusoids, and a central vein

Functional Unit (Lobule)

• Hepatocytes arranged around a central vein, resembling spokes of a wheel
• Sinusoids are the spaces between sheets of hepatocytes

Portal Triad

• Comprises three structures located between lobules: portal vein, bile duct, and hepatic artery

Zones of the Liver

• Divided into three zones based on oxygen supply: zones 1, 2, and 3.

Zone 1

• Located around portal tracts with high oxygen concentration from hepatic arteries

Zone 2

• Lies between zones 1 and 3

Zone 3

• Found around central veins with lower oxygen concentrations

Mechanisms of Liver Toxicity

• The liver is a primary target organ for toxins due to its extensive blood supply and "first pass" metabolism
• High concentrations of detoxifying enzymes (like P450s) can bioactivate toxins into more harmful metabolites

Results of Liver Toxicity

• Can lead to cell death, cholestasis, bile duct damage, sinusoidal disruption, fatty liver, fibrosis, cirrhosis, and tumors

Pathways of Cell Death

• Necrosis: Involves inflammation and affects groups of cells
• Apoptosis: Affects single cells and is characterized by lack of inflammation

Locations of Cell Death

• Can occur either widely throughout the liver or in specific zonal areas

Mechanisms of Cell Death

• Pathys of cell death determined by various stressors and toxicants affecting cellular integrity.

Dive into the vital roles of the liver in the body, including metabolism regulation, hematological functions, and bile synthesis. This quiz will test your knowledge on how the liver maintains nutrient balance and filters toxins. Explore the significance of liver functions and their impact on overall health.