The duodenum is the first, and shortest, section of the small intestine. This means that it is the first place that the partially digested food, called chyme, passes after it leaves the stomach. In humans, the duodenum is about 25-38 cm (10-15 in.) long and connects the stomach and the jejunum, which is the middle section of the small intestine. Let’s take a closer look at the function of the duodenum.
What is the function of the duodenum?
The duodenum is where most of the chemical digestion takes place in the body. This means that bile and digestive enzymes are used to break down the protein, fats and carbohydrates into simpler substances that can be used by the body. These substances that assist in chemical digestion come from the liver and gallbladder, in the form of bile, as well as from the pancreas, in the form of digestive enzymes. The duodenum is also responsible for regulating the rate of emptying from the stomach via hormones. Hormones are also responsible for releasing the digestive enzymes when they are needed for digestion.
Did you know?
Although the bile does not actually digest fats it plays a very important role in breaking them down. The bile salts coat the fat droplets, which stops them from rejoining other fats and increases the surface area for the enzyme pancreatic lipase to break them down.
When a patient with type 2 diabetes has gastric bypass surgery, which bypasses the duodenum, they have an 80% chance of being cured of the disease. It is hoped that further research into the reason that this happens will lead to a cure for the disease.