What is Bile, Its Properties, Secretion, Storage And Composition
What is Bile – It is a fluid that is made excretes from the liver and it is stored in the gallbladder. It helps in digestion and breaks down the fats into fatty acids, that can be taken into the body through digestive tract.
Properties:
There are following properties. These are:
- Volume : 800 to 1200 mL/day
- Reaction : Alkaline
- pH : 8 to 8.6
- Specific gravity : 1.010 to 1.011
- Color : Golden Yellow or Green
Composition:
It contains 97.6% of water and 2.4% of solids. Solids include organic and inorganic substances. These are:
- Organic Substances:
- Bile Salts
- Bile Pigments
- Cholesterol
- Fatty Acids
- Lecithin
- Mucin
- Inorganic Substances:
- Sodium
- Calcium
- Potassium
- Chloride
- Bicarbonate
Secretion:
It is secreted by hepatocytes. The initial bile secreted by hepatocytes contains large quantity of bile acids, bile pigments, cholesterol, lecithin and fatty acids. From hepatocytes, it is released into canaliculi. From here, it passes through small ducts and hepatic ducts and reaches the common hepatic duct. From common hepatic duct, it is diverted either directly into the intestine or into the gallbladder.
Sodium, bicarbonate and water are added to bile when it passes through the ducts. These substances are secreted by the epithelial cells of the ducts. Addition of sodium, bicarbonate and water increases its total quantity.
Storage:
Most of its quantity from liver enters the gallbladder, where is stored. It is released from gallbladder into the intestine, whenever it is required. When it is stored in gallbladder.
It undergoes many changes both in quality and quantity such as:
- Volume is decreased because of absorption of a large amount of water and electrolytes (except calcium and potassium).
- Concentration of salts, pigments, cholesterol, fatty acids and lecithin is increased because of absorption of water and electrolytes.
- The pH is decreased slightly.
- Specific gravity is increased.
- Mucin is added to it.