Bile, crucial for digestion and absorption, is composed of approximately seven key components. These are:
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Water (97-98%): The primary component, acting as a solvent for the other constituents.
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Bile Salts (0.7%): Essential for emulsifying fats, aiding in their digestion and absorption in the small intestine. Examples include sodium taurocholate and sodium glycocholate.
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Bilirubin (0.2%): A waste product from the breakdown of heme, giving bile its characteristic color. It's eventually excreted in feces.
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Fats (0.51%):
- Cholesterol: A lipid that is both synthesized in the liver and obtained from the diet. Bile is a primary route for cholesterol excretion.
- Fatty Acids: Contribute to the lipid composition of bile.
- Lecithin (Phosphatidylcholine): A phospholipid that helps solubilize cholesterol in bile, preventing gallstone formation.
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Inorganic Salts (200 meq/L): Electrolytes such as sodium, chloride, bicarbonate, and potassium contribute to maintaining the correct pH and osmotic balance.
In summary, bile is a complex mixture of water, bile salts, bilirubin, cholesterol, fatty acids, lecithin, and inorganic salts, each playing a vital role in digestion, waste removal, and overall liver function.
