Bile is a digestive juice that is secreted by the liver and stored in the gallbladder. It has two important functions :
- Assists with fat digestion and absorption in the gut.
- Is a means for the body to excrete waste products from the blood.
Bile does not contain enzymes like other secretions from the gastrointestinal tract. Instead it has bile salts (acids) which can :
- Emulsify fats and break it down into small particles. This is a detergent-like action of bile.
- Helps the body absorb the breakdown products of fat in the gut. Bile salts bind with lipids to form micelles. This is then absorbed through the intestinal mucosa.
The other important function of bile is that it contains waste products from hemoglobin break down. This is known as bilirubin and is normally formed by the body as it gets rid of old red blood cells which are rich in hemoglobin. Bile also carries excess cholesterol out of the body and ‘dumps’ it into the gastrointestinal tract where it can be passed out with other waste matter.