Digestion and diseases of Term Paper Example | Topics and Well Written Essays - 1250 words

Digestion and diseases of - Term Paper Example Digestion is a complex process involving mechanical and chemical processes. Different complex molecules in our food are treated differently by our digestive system, depending upon its composition such as fats, proteins, carbohydrates, vitamins and minerals etc. All these compounds are important as they provide source of energy, for protein making, for growth and for all the activities that we carry. The digestion starts from the mouth by chewing of food called mastication. A cephalic phase starts in which a signal is transferred to stomach lining to produce acid. The enzymes and saliva (produced by salivary glands for moistening the food) also enters the complex food particles. The starch and fats starts to breakdown right from the mouth due to saliva. The esophagus transfers the chewed food to the stomach, and this ineffective barrier may cause the acid in stomach to come up to the esophagus and cause a disease called gastro esophageal reflux disease (GERD) which is very common nowa days. The stomach consists of fundus, body and antrum. The gastric phase starts when food enters into a large body called stomach. Here, the proteins start to break down to form peptides and acidic conditions in stomach prevent the microorganisms for further contamination. The fundus lining in the stomach produce hydrochloric acid when as the food enter in the lining of stomach, and by this acid the de naturation of proteins occur. The pepsinogen becomes activated in the form of pepsin after the formation of hydrochloric acid. The gastric lipase further hydrolyzes the fats in the stomach. The anturm stabilizes the acid produced and is a site for the grinding action. Food passing through pyrolic sphincter to the small intestine is called chime, while passing through the pyrolic sphincter, small intestine simulates hormones secretin and cholecystokinin, further resulting in the release of pancreatic juice from pancreas. The food enters the small intestine that is extended and has incr eased surface area for absorption. It contains folding called plicae, villi and microvilli. The sucrose, maltase and lactose hydrolyze di sugars. In the region called duodenum, the bicarbonates mix with chime decreasing its acidity. The pancreatic juice also helps in digestion. Iron and calcium are taken in duodenum, while most minerals and vitamins are absorbed in jejunum. The starch also digested in duodenum and jejunum. The liver produces bile that solubilizes fat. The ileums being the final part of small intestine do the final digestion. At the end of this process, 90 percent of food is digested. The large intestine conserves the water and salts. The remaining fibers in large intestine may remain there for up to 3 days. After the whole process, the unwanted food is defecated outside the body, from colon to rectum and then out of the body. The intestines are the important part of gastro intestinal (G.I) tract because most of the absorption and digestion is done in intestines, so it has vital importance in our body. Intestines are divided into small intestine and large intestine. The anatomy tells us that from which cells, the small intestines are made up of and then discuss the physiological role played by intestines. Small intestine is that portion of intestine which is connected to stomach and food contents from stomach come into large intestine via small intestine. Here, absorption, mixing and digestion takes place. Small intestine