Fatty liver (Steatosis) Definition: It is the accumulation of excessive amount of lipids more than 4% of the weight of the liver leading to liver cells replacement by fibrous tissues with subsequent liver cirrhosis. Causes of Fatty liver 1.Over feeding of fats. 2.Over feeding of carbohydrates. 3.Over mobilization of F.A from depot to liver. 4.Decreased oxidation of F.A. due to: A. Deficiency of pantothenic acid. B. Deficiency of carnitine. C. Increased NADH/NAD ratio as in alcoholism. 5. Decreased mobilization of fats from liver to blood. Definition: These are factors which facilitate transport of TAG from liver to be utilized by the tissues. These factors may be either: 1. Substances needed for phospholipid biosynthesis. 2. Substances needed for protein biosynthesis. 1. Substances needed for phospholipid biosynthesis. A. Essential F.A. B. Inositol. C. Choline D. Substances needed for choline biosynthesis as Methionine,Glycine betaine,Folic acid and Vit.B12 2. Substances needed for protein biosynthesis: A. Protein of high biological value. B. Essential a.a (e.g Methionine). C. Non-essential a.a (Serine). Antilipotropic Factors Definition: These are substances which inhibit mobilization of fats from the liver. Causes: 1. Substances Which inhibit phospholipid biosynthesis. 2. Substances Which inhibit protein biosynthesis. 1. Substances Which inhibit phospholipid biosynthesis as in over feeding of cholesterol, niacin and biotine. 2. Substances Which inhibit protein biosynthesis like carbon tetracholoride, choloroform, phosphorus, arsenic and ethionine