Duodenum

The “C-shaped,” fixed part of the small intestine is called the duodenum. The duodenum is separated from the stomach by the pyloric sphincter which opens to allow chyme to move from the stomach to the duodenum. In the duodenum, chyme is mixed with pancreatic juices in an alkaline solution rich in bicarbonate that neutralizes the acidity of chyme and acts as a buffer.

Pancreatic juices also contain several digestive enzymes, which are mixed with bile from the liver and gallbladder, as well as digestive juices from gland cells of the intestinal wall itself. These digestive juices break down the food particles in the chyme into glucose, triglycerides, and amino acids. Some chemical digestion of food takes place in the duodenum as well as absorption of fatty acids.