Digesting_Kfc

Digesting KFC Form the second you start chewing on all those potato strips, the chicken pot pie, the pecan pie, and drinking all 32oz of that soda, you are beginning the digestion process. When food enters the mouth it is partly broken down by the process of chewing and by the salivary enzymes. These enzymes are produced by the salivary glands and break down starches into smaller maltose molecules. Many of the starches from the potato strips, pecan pie, and chicken pot pie with be broken down in the mouth. The sugars from the soda do not get a chance to be broken down in the mouth because it only spends a short time in the mouth before being swallowed. After being chewed and swallowed, the food passes the epiglottis and larynx, and then enters the esophagus. Food in the esophagus is called bolus. The esophagus is a long tube that runs from the mouth to the stomach. It uses rhythmic, wave-like muscle movements called peristalsis to force food from the throat into the stomach. Before food enters the stomach it passes the lower esophageal sphincter. Once the delicious KFC enters the stomach, the stomach secretes gastric juices from the gastric gland. The gastric gland has three types of cells. Mucus cells secrete mucus which protects the lining of the stomach, chief cells chief cells secrete pepsinogen which is the inactive form of pepsin, and the parietal cells secrete hydrochloric acid. Gastrin stimulates the gastric juices, which are made up of a mixture of digestive enzymes and Hydrochloric acid. The mixture of food and gastric juices in the stomach is called chyme. The stomach can also physically break down chyme by using its muscles to churn its contents. The HCL has a pH of about 2, and it acidity denatures the proteins the hold the food together. The enzyme pepsin also helps break down proteins in the stomach. The many of the proteins found in the chicken pot pie, potato wedges and the pecan pie will be denatured in the stomach. Depending on the type of food you eat it can remain in the stomach for 2-6 hours. Once the chyme is soft enough it passes the pyloric sphincter and then enters the small intestine. The first 25cm of the small intestine is called the duodenum. The duodenum continues to break down proteins, starches and nucleotides with various enzymes. Proteases and amino peptides break down proteins, maltase and lactase break down disaccharides, and phosphatases digests nucleotides. The duodenum is also a major crossroad in digestion. Chemicals, hormones, and enzymes from the liver, gallbladder and pancreas meet in the duodenum. As the 84 grams of fat pass through the fatty acids stimulate CCK. CCK stimulates the release of enzymes from the pancreas, and bile from the gallbladder to break down the fats. The liver detoxifies the blood and, produces bile which is stores in the gallbladder. Secretin and CCK inhibit acid secretion in the stomach which slows digestion. Secretin stimulates the pancreas to release sodium bicarbonate which neutralizes the chyme as it enters the small intestine. If the chyme was to keep its acidity it would burn through the small intestines. It also stimulates the liver to secrete bile. As the chyme passes further down the small intestine it is absorbed by the “finger like projections” called villi. The villi increase the surface area of the intestine so nutrient absorption is more efficient. Small molecules like disaccharides can be absorbed through the capillary walls, but fatty acids and other lipids must take a different path. The fats are coated with chylomicrons and are brought to lacteals in the core of the villi and break down more slowly. The nutrients that diffuse through the capillary walls enter the hepatic portal and are brought directly to the liver. From there the nutrients can be detoxified and equally distributed to the rest of the body. The further down the small intestine the food travels the less nutrients there are. When it reaches the large intestine are very few nutrients left. In the large intestine, 90% of the water, and some electrolytes like sodium are removed from the food. Many bacteria (like E. coli and Klebsiella) in the large intestine help in the digestion process. The first part of the large intestine is called the cecum (the appendix is connected to the cecum). Food then travels upward in the ascending colon, then travels across the abdomen in the transverse colon, goes back down the other side of the body in the descending colon, and then through the sigmoid colon. Feces are the waste products of digestion, and they become increasingly solid as they move down the colon. It takes from 12-24 hours for material to travel the length of the colon, and it moves by peristalsis. Solid waste is then stored in the rectum until it is excreted through the anus.