Flashcards in Liver Physiology Deck (12)
What is the blood supply to the liver?
30% Hepatic artery
70% Portal vein
What major veins drain into the portal vein?
Superior mesenteric vein and splenic vein
What are the major cell types of the liver?
Lipocytes (Stellate cells)
What are the functions of the liver? (Hint: DESPICES)
Drug metabolism and detoxification
Energy metabolism and substrate interconversion - (glucose, glycolysis, urea)
Synthesis of plasma proteins (albumin, fibrinogen, plasminogen)
Production of bile
Immune function - kupffer cells (phagocytosis)
Excretion of bilirubin
Storage of vit and min (A,D,E,K/ iron, copper)
How much bile does the liver produce per day? What does the gall bladder do?
0.7-1.2 L daily
Stores and concentrates bile
Liver secretes bile - drains into main bile duct
What is bile composed of? (Hint: Be Happy That Liver Creates Bile)
Bile salts (solubilise fat in SI)
HCO3- (neutralise acid in duodenum)
Bile pigments (bilirubin)
Are bile salts lost or recycled?
Released into SI
95% recycled - enterohepatic circulation - back to liver
5% lost in faeces
What are the main functions of bile salts?
Emulsification of dietary lipids (panc lipase can now access)
Elimination of cholesterol
Prevents cholesterol precipitations in the gall bladder (gall stones)
Absorption of vit D, E, A, K, iron, copper
What are the functions of cholesterol?
component of bile salts
precursor of steroid hormones
Where does cholesterol come from?
15% - diet
85% - synthesised
Transported in complexes with lipoproteins
How does the liver process cholesterol?
Synthesises chol from acetyl coA
Exports chol via circulatory system to body cells
Exports chol to liver for bile salt synthesis
Extracts excess chol from plasma
Export excess chol via liver into bile for excretion into faeces