Small intestine in rabbits
The chyme passes into the small intestine from the stomach. Flow into the small intestine is regulated by the pyloric sphincter. The small intestine is the place where the majority of digestion and absorption of nutrients occurs. The small intestine can be divided into three sections – duodenum, jejunum, and ileum. The duodenum is the first section and is the site of most digestion. Buffers are secreted from the pancreas into the small intestine to increase the pH to a more neutral level, as the stomach acids would make the digested food have a low pH level. In addition, a variety of enzymes are secreted by and into the small intestine to break down the food. These include proteolytic, lipolytic (fat digesting), and amylolytic (starch digesting) enzymes. The jejunum is the middle section of the small intestine. Many nutrients, such as amino acids, fatty acids, and glucose, are absorbed here. The last section of the small intestine is the ileum. In the ileum, the remaining digested nutrients are absorbed, as well as the B vitamins.
