In which part of the digestive system are fats emulsified?

Fats are emulsified primarily in the duodenum, which is the first section of the small intestine. This process is essential for the digestion and absorption of dietary fats. In the duodenum, bile salts produced by the liver and stored in the gallbladder are released into the digestive tract. These bile salts have both hydrophilic and hydrophobic properties, allowing them to surround fat globules and break them into smaller droplets. This emulsification increases the surface area of the fats, making them more accessible to pancreatic enzymes, particularly lipases, which are responsible for breaking down fats into fatty acids and glycerol.

The mouth and stomach do play roles in the digestion of food, including fats, but they do not emulsify fats to the same extent as the duodenum. In the mouth, fats may be mechanically broken down by chewing, but the chemical processes of emulsification are not initiated there. In the stomach, some fat digestion occurs, but it is primarily through the action of gastric juices rather than emulsification. The colon is involved in the absorption of water and electrolytes as well as the formation of feces, but it does not participate in the emulsification of fats. Thus, the duodenum is the key site