The duodenum facilitates the initial phase of digestion by regulating the emptying of food in the stomach into the small intestine, says Laparoscopic.md. As the first part of the small intestine, digestive enzymes released by the pancreas and bile from the gallbladder mix with the food and break it down, reports Seattle Children’s Hospital. To neutralize the acidity of food that enters the duodenum, the pancreas produces bicarbonate, states the International Foundation for Functional Gastrointestinal Disorders.
The duodenum’s main role is to engage in continuous breakdown of food into smaller particles that the body can absorb. The entry of chyme into the duodenum stimulates the release of secretin and cholecystokinin hormones by the cell walls of the duodenum, reports Laparoscopic.md. The hormones trigger the pancreas to secrete digestive enzymes, which neutralize the chyme and help break down carbohydrates, proteins and fats.
The gallbladder also releases bile so that the duodenum can digest and absorb fats, according to the Cleveland Clinic. The bile salts break down soluble vitamins A, D, E and K, reports the International Foundation for Functional Gastrointestinal Disorders. The cells of the duodenum absorb iron, vitamins A and B-1, glycerol and calcium, states Laparoscopic.md. The duodenum also absorbs fatty acids, amino acids, simple sugars and monoglycerides.