Digestive Process :: essays research papers

Digestive change Digestive Process It is in the mouth, that the Thanksgiving feast begins its journey done the fabulous digestive system. It is here that the lips, cheeks and tongue, carefully position the provender that the odontiasis will chew. This chewing help breaks up the food, this universe a firearm of mechanical digestion. While the teeth grind up the turkey and pleasant-tasting stuffings, the salivary glands begin emitting enzymes, these enzymes being contained in saliva. This saliva helps to dissolve rough foods, and adds mucous secretion to make the foods solveage through the digestive system a little more speedy. The saliva also attacks dangerous microorganisms which go into the mouth. Saliva also contains an enzyme which helps to break master carbohydrates into sugars. As the food is being ground and coated with saliva, its passed over the taste buds, which in turn site messages to the brain. The brain uses this information to decide whether or not the f ood should be swallowed. The food is then gathered into a ball, called a bolus, and it is pushed down into the throat by way of the tongue. This bolus of Thanksgiving meal is then passed down the defile, the esophagus being a 24cm long tube which connects the pharynx and stomach. Lining the walls of the esophagus are rings of muscle which contract in waves, pushing the bolus down the length of the esophagus. At the base of the esophagus, where the esophagus and stomach join, a thick ring of muscle called a sphincter, is found. This sphincter acts like a valve, as it allows food to pass into the stomach but does not permit it to pass back up through the esophagus. The stomach, which is in the essence a fully grown muscle sack, contains three circumstancess of glands which produce gastric fluids. One set produces mucus which coats the food, making it slippery, and it protects the stomach walls from being digested by its own secretions. The second set of manufactures hydrochloric a cid, which aids in the break-down of foods. In conjuction with hydrochloric acid, pepsin, which aids in the break-down of protein into smaller polypeptides, begins the process of protein digestion. The stomachs muscular walls move around the food and mucus, mixing them with the gastric fluids produced. The food becomes a pasty substances referred to as chyme, after about 2 or 3 hours of grinding within the stomach.