Digestion and Absorption of Food Nutrients - Article Example

Digestion and Absorption of Food Nutrients Student’s Name: Instructor’s Name: Course Code: Date of Submission: Part 1: Overview Digestion in the body of a human being is a very important function. This is because it involves the mechanical breakdown of food consumed and the absorption of the different nutrients contained in it to provide energy and protection as well as ensure proper growth and development of an individual. It’s through digestion and absorption of various meals that we expect to get what we need to grow and protect our bodies against diseases. Digestion starts at the point when food is put into the mouth through the stomach where its various nutrients are absorbed to the blood system while wastes are eliminated through various processes. Digestion and absorption is supported by the anatomy structures, the physiological process and provision of various secretions in form of enzymes (Mackenzie 2001). Anatomy of digestion and absorption Anatomy is described as the skeletal parts of the body that support the digestion and absorption of food nutrients. The digestive and absorption skeletal parts include the mouth, the pharynx, the esophagus, the cardiac opening, the stomach and the intestines. The mouth is composed of the tongue and the teeth which play a very initial role of breaking the food received into simpler units for further digestion and absorption. The salivary glands are also found in the mouth and they are important in secreting saliva that is used for digestion. Once the food has been digested, it’s then sent through the funnel-shaped opening called the pharynx which is part of the mouth (Wooldridge 2009). The food then goes through the esophagus which is a very elastic muscular opening and that connects with the stomach. Through the contraction and relaxation of the cardiac muscles, food is allowed to move through the stomach. The stomach is known to hold and facilitate further breaking of food. This process is supported by the breaking and relaxation of stomach muscular fibers. Finally, the intestines are known to play the final work of digesting and absorbing food nutrients and excreting the waste through the duodenum (Robbins and Burgess 2002). The physiological process of digestion and absorption Unlike the anatomy of digestion and absorption, the physiological process is characterized by the functioning of various parts of the digestive system in order to help the process of preparing various food nutrients for use by body cells. The physiological process of the digestion and absorption in human beings entails six activities which include ingestion, mechanical digestion, chemical digestion, movements, absorption and elimination (Mackenzie 2001). Secretions in digestion and absorption For appropriate digestion and absorption to take place, all involved body functions must be supportive of the process. However, important in digestion, is the production of various juices also referred to as solvents for dissolving food particles. At the mouth for instance, the saliva glands are stimulated to produce saliva to aid the breaking down of food particles into small particles. The saliva contains an enzyme that accelerates the chemical activities in the body. In the stomach, the digestive glands also produce the gastric juices and enzymes that contain hydrochloric acid (HCI), which is very important in digestion. The three main enzymes contained in the gastric juices secreted in the stomach include pepsin, lipase and rennin by Salyers and Whitt (2002). Digestion and absorption carbohydrates, proteins and fat Carbohydrates Digestion and absorption of carbohydrates ends at the intestines when the polysaccharides are broken down into monosaccharides like glucose, galactose and fructose. These sugars are absorbed into the bloodstream through the diffusion process (Kong and Singh 2008). Protein The proteins are broken down both in the stomach and the intestines. The proteins in the stomach are broken down into peptides by pepsin. In the intestines the proteins are broken down by pancreatic and chemotrypsin. The fragments are digested into free amino acids which are then absorbed into the blood system through the process of secondary active transport and diffusion as well as endo-and exocytosis (Mackenzie 2001). Fats The digestion of fats takes place in the intestines and in the process monoglyceride and two other fatty acids are produced. The free fatty acids are absorbed through the process of diffusion (Salyers and Whitt 2002). Digestion of vitamins, minerals and electrolytes Vitamins The digestion of vitamins in the body of the human being is depended on the type of food consumed and its digestion is normally done in the intestines. The process of absorption of common vitamins is done by diffusion as found by Kong and Singh (2008). Minerals Various minerals are contained in different types of food consumed and its digestion starts from the mouth. However, much of the many of the minerals get absorbed in the intestines. The absorption of calcium for instance takes place in the duodenum (Brown and Ferruzzi 2004). Electrolytes The electrolytes in the body such as bicarbonate, sodium and potassium as well as chlorides get digested in the intestines where they get absorbed through the process of diffusion and active transport (Wardlaw and Kessel 2002). Part 2 Chicken sandwich containing: wholemeal bread; margarine; and chicken breast. Macronutrients refer to those nutrients that are required in large quantities in the body of a human being for adequate energy supply. Nutrients are very important for growth and metabolism as well as other body functions. Macronutrients are classified into three broad categories namely carbohydrates, proteins and fats. Given the case of chicken sandwich that contains wholemeal bread, margarine and chicken breast, the three contents can be classified accordingly based on their source (Mackenzie 2001). Wholemeal In this case the wholemeal contained in the chicken sandwich can be traced to the source of grains that are used to prepare bread and that are less processed. This therefore can be classified into carbohydrates. The use of less refined carbohydrates in the chicken sandwich is to make sure that as much vitamins as possible are sustained (Kong, and Singh 2008). As identified earlier, digestion of every meal starts from the mouth through the stomach and the intestine. However, with the process of absorption, better part of the nutrients contained in the food is absorbed in the intestines in form of galactose, glucose and fructose. After absorption galactose and fructose are converted into glucose in the liver and then discharged into bloodstream (Brown and Ferruzzi 2004). Margarine Margarine used in preparing the chicken sandwich represents the fats macronutrients. This is because fats are characterized by their complex that comprises fatty acids and glycerol. Fats in the body of a human being are very necessary in that they are necessary for growth and provision of energy (Mackenzie 2001). Fats are known to be the slowest form of energy food of energy but most-efficient type of food. The digestion of fats in the body is not easy with aquatic environment and therefore in most cases the process of emulsification is important in breaking various fat molecules. The fats contained in the margarine are expected to be absorbed into the blood in form of tiny micelles from the intestines by fingerlike projections known as microvilli (Brown and Ferruzzi 2004). Chicken breast In the sandwich, the protein macronutrients are represented by the chicken breast. This is because of its source. Chicken breast is part of an animal meat and it’s known to have large quantities of proteins. Proteins exist in small units but very complex amino acids. Because of their complexity, protein molecules are very hard to break and take quite sometime. In the body proteins are required for maintenance and replacement of various body tissues and functions. Much of the proteins is digested and absorbed in the intestines through the secondary active transport (Wardlaw and Kessel 2002). Part 3 Implications of lactose intolerance Luctose intolerance can be described as a situation whereby an individual is not able to break or digest the sugars found in various foods that are made from milk and other related products. The implication of this scenario is that one is likely to do away with those products that contain the sugar in order to avoid the problem of being lactose intolerant. In other cases, the situation may force one to reduce on the consumption of the related products and which is intolerant to. This is to mean that affected person is likely to suffer health-wise for not using certain foods. The nutrients that the person suffering from this problem is likely to miss include calcium, vitamin D and potassium as well as protein. All these nutrients are very essential for a person’s health. This therefore will force one to source for other alternatives to compensate for missed food nutrients (Wardlaw and Kessel 2002). Condition and symptoms The condition of the person suffering from lactose intolerance is likely to present various characteristics if lactose is not broken down into galactose and glucose and therefore escapes digestion in the small intestines thereby going through the caecum and colon a place where it gets fermented by microflora. Because of this fermentation condition, fatty acids and lactic acids as well as gasses namely carbon dioxide, hydrogen and methane are likely to be formed. The end result of this condition is increased diarrhea as a result of advanced osmotic value in the intestinal contents. The other conditions associated with lactose intolerance include bloating, flatulence and formation of intestinal cramps (Kong and Singh 2008). Management of lactose intolerance condition As identified earlier, the person is lactose intolerant is likely to avoid completely the use of milk products that are high in lactose content and therefore becoming a victim of lack of important body nutrients like calcium, vitamin D and protein as well as potassium. To help manage this condition alternatives have to be sought. First and foremost in case of calcium deficiency, the person may opt for low-luctose products that available. Supplements and other fortified cereals may be good substitutes of dairy products (Salyers and Whitt 2002). Other examples of natural foods with calcium include tofu, canned salmon, spinach, soya beans, collard greens and many more. The alternative sources of vitamin D include salmon, tuna fish, beef, egg yolks, beef liver, mackerel and sardines. Supplements of vitamin D can also be taken. Finally, proteins and potassium can be sourced from various sources. Protein is readily available in meat, beans, eggs, nuts, legumes and soya beans. Potassium on the other hand is plenty in fruits and vegetables and also in grains and other fortified fruits (Brown and Ferruzzi 2004). References Brown, M. and Ferruzzi, M. (2004). Carotenoid bioavailability is higher from salads ingested with full-fat than with fat-reduced salad dressings as measured with electrochemical detection, 80(14), p. 396–403. Kong, F and Singh, R (2008). "Disintegration of solid foods in human stomach", J. Food Sci., 73 (5), 67–80. Mackenzie, B. (2001). Physiology - Skeletal System [WWW] Available from: http://www.brianmac.co.uk/physiol.htm [Accessed 18/6/2012] Robbins, G. and Burgess, S. (2002). A Wellness Way of Life, 5th edn. New York: McGraw- Hill. Salyers, A. and Whitt, D. (2002). Bacterial Pathogenesis: A Molecular Approach, 2nd ed., Washington, D.C.: ASM Press. Wardlaw, G. and Kessel, M. (2002). Perspectives in Nutrition, 5th edn. New York: McGraw-Hill. Wooldridge, K. (2009). Bacterial Secreted Proteins: Secretory Mechanisms and Role in Pathogenesis. New York: Caister Academic Press. Appendix Read More