Low pH in the small intestine

Small intestinal fluid is secreted by the small intestinal glands in the small intestinal mucosa. Was weakly alkaline. Adults secrete about 1 to 3L per day. The small intestine fluid is secreted and absorbed, and this fluid communication provides a medium for the absorption of nutrients in the small intestine. In addition to water and electrolytes, the small intestine fluid also contains mucus, immune proteins and two enzymes: enterokinase (which can activate trypsinogen, see above) and small intestine amylase. It was thought that various other digestive enzymes were contained in the small intestine fluid, but it has been proved that other various digestive enzymes are not secreted from the small intestine glands, but exist in the small intestinal mucosal epithelial cells. They are several peptidases that break down peptides into amino acids and several monosaccharides that break down disaccharides into monosaccharides. After the nutrients are absorbed into the epithelial cells, these digestive enzymes continue to digest the nutrients. As the epithelial cells at the top of the villi fall off, these digestive enzymes enter the small intestinal fluid.