The prolonged prothrombin time seen in severe liver disease

Briefly explain the prolonged prothrombin time seen in severe liver disease 

 PT is the time taken to form a clot via extrinsic and common pathways
 prolonged PT indicates that extrinsic or common pathway or both are impaired
 In chronic liver disease liver functions are impaired
 liver produces most of the clotting factors
 Fibrinogen, factors II VII IX X are produced in liver
 Bile salts are produced in the liver and secreted via bile to GIT which are important in
 fat digestion
 and absorption
 Fat soluble vitamins are absorbed with digested fat
 So in liver disease absorption of vitamins A,D,E,K is impaired
 Vitamin K is important in gamma carboxylation of
 factors II VII IX X
 liver is responsible for the clearance of tissue plasminogen activator
 in liver disease due to
 less production of clotting factors
 lack of gamma carboxylation of factors II VII IX X
 decreased clearance of TPA
 PT is prolonged