Nutrient Supply

• The liver plays an important role in regulating the levels of nutrients in the bloodstream
• Nutrients absorbed by the small intestine are transported by the hepatic portal vein to the liver for metabolism
• The liver converts nutrients into forms that can be stored or used and mediates their transport to various tissues
• Nutrients stored within the liver include glycogen, iron, vitamin A, and vitamin D
• Carbohydrate Metabolism:

  • Excess glucose in the bloodstream is stored as glycogen in the liver
  • When blood glucose levels drop, the liver breaks down glycogen into glucose and exports it to body tissues
  • When hepatic glycogen reserves are exhausted, the liver synthesizes glucose from other sources like fats
• Protein Metabolism:

  • Amino acids cannot be stored and must be broken down when in excess
  • The liver removes the amine group through deamination and converts it into urea, which is excreted in urine
  • The liver can synthesize non-essential amino acids from surplus stock via transamination
• Fat Metabolism:

  • The liver converts excess carbohydrates and proteins into fatty acids and triglycerides
  • It synthesizes phospholipids and cholesterol
  • LDL transports cholesterol to cells, while HDL transports excess cholesterol back to the liver
  • Surplus cholesterol is converted into bile salts by the liver for elimination from the body
• Low-density lipoprotein (LDL) is considered 'bad' as it raises blood cholesterol levels, while high-density lipoprotein (HDL) is 'good' as it lowers cholesterol levels
• The liver's role in the transport of lipids is crucial for maintaining lipid balance in the body