1. Liver Functions
27-Apr-19
Liver Functions

2. Functional Anatomy Liver is the largest solid viscera
1.5 kg
Important for regulation of energy metabolism
Stores Carbohydrate (Glycogen)
Regulate composition of blood
Secretes bile
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Liver Functions

3. Structure Liver is made up of plates or sheets of cells
Separated by sinusoids
Lined by reticulo-endothelial cells
Tunneled by portal tracts and hepatic central vein
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Liver Functions

4. Structure The portal tracts consist of Branches of portal vein
Hepatic artery
Small bile duct
Lymph duct
Blood flows from these portal tract into central vein
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Liver Functions

5. Structure Bile excreted by hepatic cells Into canaliculi
Flows into bile duct
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Liver Functions

6. Blood flow through the liver
Zone 1
Zone 3
Zone 2
Press=5 mm Hg PO2 = 30 mm Hg 60 – 65% Sat with O2
Press =10 mmHg PO2 = 60mm Hg, 80 – 90% Sat with O2
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Liver Functions

7. Blood Supply Portal blood flow is Liver O2 extraction
Approx 1.5 liters/min (about 25% CO)
70% from portal vein
30% from hepatic artery
Hepatic artery provides 50% of O2 supply
Liver O2 extraction
55 ml/min
27-Apr-19
Liver Functions

8. Functions of Liver Synthetic Detoxification various substances
Plasma proteins
Clotting factors
Fibrinogen, prothrombin, factors V, VII, IX, X, XIII
Fibrinolytic factors
Bile salts
Detoxification various substances
Hydroxylation, oxidation
Responsible for metabolism of drugs
27-Apr-19
Liver Functions

9. Functions Conjugation Conversion into glucoronide or sulphate
Bilirubin,
Steroid hormones
Detoxification of drugs and foreign substances
Oxidation, reduction, demythylation
Followed by conjugation
Makes substances water soluble
Excreted by kidneys
27-Apr-19
Liver Functions

10. Functions Storage function Metabolic functions
Glycogen , vitamins A,D,E,K
Vit. B12 (1- 3 yrs)
Metabolic functions
Liver as a regulator of energy metabolism
Carbohydrates, fats and protein
27-Apr-19
Liver Functions

11. Metabolic Functions Carbohydrates Storage of glycogen
Glucose Glycogen
Coversion of Galactose to Glucose
Gluconeogenesis
Lactate
Amino acids Glucose
Glycerol
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Liver Functions

12. Functions Maintain normal blood glucose concentration
Glucose can be converted
Glycogen
Fatty acids
5 carbon sugars
Amino acids
H2O, CO2 and ATP
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Liver Functions

13. Fat Metabolism - oxidation of FFA Acetocetic acid
Formation of lipoproteins
Formation of cholesterol and phopholipids
For cell membrane formation
Bile formation
Cholesterol is precursor for some hormones
Conversion of dietary sugars & AA
Fatty acids
27-Apr-19
Liver Functions

14. Protein Metabolism Synthesis of Enzymes Plasma proteins
Essential for hepatocyte function
Plasma proteins
Transport proteins (albumin, transferrin, ceruloplasmin, haptoglobulin)
Other proteins (clotting factors, complement factors)
Acute phase reactant proteins
27-Apr-19
Liver Functions

15. Protein Metabolism Deamination of amino acids Before they can be
Used for energy
Converted into carbohydrates or fat
Formation of UREA
Removal of ammonia
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Liver Functions