Alimentary Canal Function And Process

Running Head: GVT Task 2 GVT Task 2 Maureen O’Connor Western Governors University The mouth, pharynx, esophagus, stomach, small intestine consisting of the duodenum, jejunum, ileum, and large intestine consisting of the transverse colon, descending colon, ascending colon, cecum, sigmoid colon, rectum, vermiform appendix and anus are all part of the alimentary canal. The function of the alimentary canal is to provide nourishment. The teeth, tongue, gallbladder, salivary glands, liver and pancreas are considered to be accessory digestive organs.

These organs produce saliva (salivary glands), bile (gallbladder and liver) and digestive enzymes which contribute to the breakdown process of food. Mechanical digestion begins with the process of taking food into the mouth or ingestion and chewing it until it can be moved through the alimentary canal during the propulsion process. This process includes swallowing and in a series of muscle contractions and relaxation it is then moved from one organ to another.

Swallowing is performed in the pharynx while peristalsis occurs in the esophagus, stomach, small and large intestine. Breakdown of the food in the stomach, also called churning and in the small intestine are also part of the mechanical digestion process. When food leaves the stomach the process of chemical digestion begins. This is when carbohydrates, proteins, and lipids are broken down into simple sugars, amino acids, fatty acids and glycerol, otherwise known as chemical building blocks.

Enzymes are chiefly responsible for carrying out chemical digestion and are secreted in the central cavity of the alimentary canal. Digestive enzymes include salivary and pancreatic amylase, present in the mouth and small intestine, maltase and lactase which are also present in the small intestine and are involved with carbohydrate digestion. Pepsin which is present in the stomach and chymotrypsin present in the small intestine both involved with protein digestion. Aminopeptidase breaks down amino acids during protein digestion.

Finally pancreatic lipase is involved with fat digestion. Summary of Two Experiments An experiment performed in the Department of Food Sciences and Nutritional Health at Kyoto Prefectual University involved polylysine which had been used as a food additive in Japan for many years. The researchers were interested in how polylysine inhibited pancreatic lipase. They performed the experiment on rats and then measured the effect of the polylysine after the rats were fed a meal.

These measurements were taken after the rats had been administered fat emulsion with the polylysine and fat emulsion without polylysine. The results suggested that polylysine had the ability to inihibit pancreatic lipase in the small intestine and suppressed dietary fat absorption. A second experiment involved alpha-amylase inhibition from the white kidney bean and its effect on weight loss and blood glucose levels. Clinical studies in which subjects were given the white bean product and their after meal glucose levels were studied.

A group of subjects with diabetes were also given the white bean product and there was found to be a decrease in their after meal glucose levels. There were more clinical studies in which subjects were given varying doses of the white bean product along with amino acids with varying levels of dietary intake. The conclusion was that alpha-amylase inhibitor does have an effect on the absorption rate of carbohydrates and be a factor in weight management as well as type 2 diabetes mellitus control. Independent Experiment

Question|Independent Variable|Dependent Variable|Controlled Variable| What is the effect of digestive enzymes on peanut butter? |Kind of digestive enzyme added to peanut butter. |Change in consistency or texture of peanut butter after 1 hour. |Equal amount of peanut butter in each cup. | If I add pepsin and hydrochloric acid to peanut butter, this should cause a change in the consistency of the peanut butter after 1 hour. If I add lipase and hydrochloric acid to peanut butter this should cause a change in the consistency of the peanut butter after 1 hour.

The lining of the stomach secretes gastric juices including hydrochloric acid which dissolves food, pepsin which is a protein-splitting enzyme and lipase, a fat-dissolving enzyme. By adding the Biuret solution to identify the presence of protein to each cup containing peanut butter, enzymes and hydrochloric acid there should be a change in color to pink or purple. Data Table 1 Cup #|Contents| 1|Peanut Butter| 2|Peanut Butter & Pepsin| 3|Peanut Butter + Pepsin + HCl| 4|Peanut Butter + Lipase| 5|Peanut Butter + Lipase+ HCl|

Results Data Table Cup #|Contents|Observations| 1|Peanut Butter|| 2|Peanut Butter & Pepsin|| 3|Peanut Butter + Pepsin + HCl|| 4|Peanut Butter + Lipase|| 5|Peanut Butter + Lipase+ HCl|| Summary of Results and Conclusion Pepsin and hydrochloric acid are present in the stomach glands and responsible for breaking down protein to the building block stage to become amino acids. The absorption of protein then occurs and amino acids enter capillary blood via villi and subsequently transported via the hepatic portal vein to the liver.

Although lipase is present in the stomach it is not very effective because the stomach is a strongly acid environment. The majority of fat digestion happens in the small intestine although it needs bile from the liver to break it down into glycerol and fatty acids. Once that occurs the fatty acids enter the lacteals of the villi for transportation via lymphatic transportation to the thoracic duct. Glycerol and fatty acids (small-chain) are transported via the hepatic portal vein to the liver.