Master Small Intestine Digestion with Picmonic for Pre-Health

Small intestine digestion occurs in the duodenum, the first section of the small intestine. The epithelial cells are lined with microvilli, which is called the "brush border" region. There are many enzymes there that assist with digestion, and the brush border is a region of absorption later in the small intestine. The pancreas exocrine cells release enzymes that help with digestion through a duct that connects the pancreas and gallbladder to the duodenum. The pancreas also releases bicarbonate through the duct that helps neutralize the acidic chyme entering from the stomach. In addition, the small intestine Goblet cells secrete mucus into the duodenum which helps protect the endothelial cells from that acidic environment. Some of the enzymes located in the brush border help activate pancreatic and intestinal enzymes. One of the brush border enzymes, enterokinase, activates pancreatic trypsin. Trypsin then activates chymotrypsin and other pancreatic digestive enzymes. Trypsin and chymotrypsin digest proteins. The gallbladder release bile, which is made in the liver, through a duct into the duodenum. Bile emulsifies fats and makes them soluble which allows fat-digesting enzymes to function. One fat-digesting enzyme is pancreatic lipase, which breaks down lipids into free fatty acids. The other pancreatic enzymes are amylase, which breaks down carbohydrates into simple sugars (a process beginning in the mouth), and pancreatic nucleases which break down DNA/RNA into sugar, phosphate, and the bases.