In this video I discuss what bile is, and its main functions in fat digestion, red blood cell recycling, and cholesterol removal.
Transcript
What is bile? Bile is a digestive juice that is produced in the liver and stored in the gallbladder. Bile’s major function is that it is involved with fat digestion and absorption in the intestinal tract.
So let’s take a very basic look at how this happens.
Here we have Jayson, and he has just eaten a meal, and part of that meal contained some fat. And fat does not dissolve in water, so this means his body has to digest it in a different way than it would protein or carbohydrates.
As fat moves through the digestive system, it mainly remains clumped together. When fat reaches the small intestine it basically is large fat droplets. And this is where bile does its job.
Bile is released into the small intestine, and it is able to mix with the large fat droplets. Bile contains bile salts, which allow it to emulsify the fat, or break it down into smaller droplets.
Next, the enzyme pancreatic lipase comes in and breaks the fat into free fatty acids and monoglycerides. These free fatty acids and monoglycerides are now small enough to pass through the epithelial cell layer that covers the villi.
Villi are tiny finger like projections that cover the interior of the small intestinal wall. Inside these villi are blood capillaries and lymph capillaries.
Here fats are absorbed into the lymph capillary and transported to the liver by way of the lymphatic duct and circulatory system.
So, as you can see, bile has a very important role in fat digestion and absorption. But bile does a couple of other things. It helps remove a substance called bilirubin, which is made when the body breaks down old blood cells. Bile also helps remove cholesterol, as some cholesterol is converted to bile acids and eliminated in bile in feces.
Timestamps
0:00 What is bile?
0:16 Example of how bile works
1:35 Other functions of bile