The Digestive System

The Digestive System Why is it that 1 in 3 people perhaps even more regularly battles some kind of digestion problems? Understanding how the digestive system works will help to understand why digestive problems are so common. The digestive system is more than stomach and intestines. It is a system of organs that turns food into energy and is one of the most important functions the body performs. There are many reasons that cause so many people to suffer with digestive problems. Three of the most common reasons are the lack of knowledge of how the digestive system works, poor nutrition and undiagnosed medical conditions. Lack of knowledge of how the digestive system works is one of the many reasons that cause digestive problems. The digestive system is uniquely constructed to perform its specialized function of turning food into the energy and extracting nutrients necessary to sustain life. It does this by breaking down food into its basic nutrients, which include vitamins and minerals, fats, carbohydrates, proteins and water, before transporting them to the small intestine, where most of the nutrients are absorbed into the body. The digestive system takes place in the alimentary canal, a tube that runs from the mouth to the anus and includes the esophagus, stomach, small intestine, and large intestine, colon and rectum. The liver and pancreas also contribute to digestion, but are not part of the alimentary canal. Digestion begins in the mouth, where chemical and mechanical digestion occurs. Food inters the mouth and is chewed by the teeth, turned over and mixed with saliva by the tongue. The sensations of smell and taste from the food sets up reflexes which stimulate the salivary glands, saliva is produced by the salivary glands and is released into the mouth. Saliva begins to break down the food, moistening it and making it easier to swallow and contains a digestive enzyme called amylase which breaks down the carbohydrates (starches and sugars). One of the most important functions of the mouth is chewing. Chewing breaks the food into pieces and allows food to be mashed into a soft mass that is easier to swallow and digest later. Movements by the tongue and the mouth push the food to the back of the throat for it to be swallowed. A flexible flap called the epiglottis closes over the trachea to ensure that food enters the esophagus and not the wind pipe to prevent choking. Once the food is swallowed, it enters the esophagus, a muscular tube that is located between the throat and the stomach. Food is moved by peristalsis which pushes the food down through the esophagus to the stomach. The stomach is the widest part of the alimentary canal and acts as a reservoir for the food where it may remain for between 2 and 6 hours. The stomach has 3 main functions: to store the swallowed food and liquid; to mix up the food with various hormones, enzymes, including pepsinogen which begins the digestion of protein, hydrochloric acid, and other chemicals; and to slowly empty its contents into the small intestine. The wall of the stomach is impermeable to most substances, although it does absorb some water, electrolytes, certain drugs, and alcohol. At regular intervals a circular muscle at the lower end of the stomach, the pylorus opens allowing small amounts of food, now known as chyme to enter the small intestine. Most digestion and absorption of food occurs in the small intestine. The small intestine consists of 3 parts: the duodenum, the jejunum, and the ileum. The small intestine has 2 important functions. First, the digestive process is completed here by enzymes and other substances made by intestinal cells, the pancreas, and the liver. Second, the small intestine absorbs the nutrients from the digestive process. The inner wall of the small intestine is covered by millions of tiny finger like projections called villi. The villi are covered with tinier projections called microvilli. The combination of the two allows absorption of nutrients to occur. Undigested material travels next to the large intestine. The large intestine is to remove water and salts from the undigested material and to form solid waste that can be excreted. Bacteria in the large intestine help to break down the undigested materials. The remaining contents of the large intestine are moved toward the rectum where feces are stored until they leave the body through the anus. The anus is the last part of the digestive tract. Accessory digestive organs which include the pancreas, liver and gall ladder are not part of the digestive tract or also known as the alimentary canal, but play an important role in the digestive process. The pancreas produces enzymes that help digest proteins, fats and carbohydrates it also makes sodium bicarbonate which neutralizes stomach acid. The liver produces bile, which helps the body absorb fat and it also regulates substances in the blood cells. The gallbladder store s bile until it is needed. The enzymes and bile produced by these organs move through ducts into the small intestine where they help breakdown food. The nutrients from the small intestine travel through the blood to the liver, which help process the nutrients. Digestive problems results from poor nutrition. Good nutrition is essential for maintaining proper functioning of the body systems especially the digestive system. Eating a well-balanced, nutritious diet and maintaining a healthy lifestyle are the best ways to prevent digestive problems and diseases (Lipski, 2005). The kinds and amounts of food a person eats and how the digestive system processes that food plays key roles in maintaining good health and preventing common digestive problems. Since the digestive system is responsible for breaking down food into nutrients that can be absorbed by the body and used for fuel, growth and cell repair. Good nutrition is essential for maintaining proper functions of the body systems. Generally, health experts recommend eating fiber to help prevent constipation and diarrhea. Reduce fats and oils which can slow down digestion. They also suggest drinking plenty of water which helps lubricate food waste so that it passes more easily through the alimentary canal, it helps soften stool which may prevent constipation. Water also helps dissolve minerals, vitamins and other nutrients, there by facilitating their absorption by the body’s tissues. Good nutrition is not only essential for maintaining proper function of the body systems it is also essential for maintaining homeostasis of the body systems. The body needs good nutrition for the body systems to properly function correctly. The digestive system does assist with homeostasis however; it can not accomplish it alone. All organs systems work together to maintain homeostasis. The digestive system provides the nutrients needed for the circulatory system. As the food moves through the stages of digestion (mechanical, peristalsis, chemical) it is broken down into simple water-soluble molecules that can cross cell membranes. Since the circulatory system is the transportation system of the body it transports wastes, gases, hormones, electrolytes and nutrients from good nutrition to and from the body cells. It also transports water to and from the tissues. So as these molecular-sized, water soluble particles pass through the cell membranes of cells in the digestive tract and pass through the walls of capillaries the nutrients are picked up by the blood for transport. Blood in the capillaries carries the nutrients to all the cells in the body. Red blood cells, White blood cells, and Platelets and Plasma all help to maintain homeostasis. Red blood cells transport oxygen and hydrogen ions throughout the body. White blood cells fights infections and platelets assist in blood clotting and the plasma transports the blood cells. None of these things can function without the nutrients supplied by the digestive system. Blood also maintains homeostasis of water, electrolytes and body temperature all by getting the nutrients necessary to function from the digestive system. The digestive system needs good nutrition to keep it functioning properly and all organs systems working together properly to maintain homeostasis. Undiagnosed medial conditions will cause digestive problems if left untreated and is one of the most common reasons that so many people suffer with digestive problems. Nearly everyone suffers from heartburn and indigestion now and then and these might be normal side effects of digestion, but when they occur often it might be signs of a problem and should have medical attention. Seeking medical attention or being seen by a medical doctor will help to establish if the heartburn or indigestion are from normal side effects of digestion or whether any mechanical factor such as a hiatal hernia or even silent ulcers of the esophagus, stomach, or duodenum maybe causing the digestive problems. A hiatal hernia and silent ulcers if left untreated could turn into a serious problem which can cause bleeding, pain, scarring and difficulty in swallowing and can cause a chronic condition with complications. Treatment of heart burn and prevention of its complications are almost always medical, not surgical procedures these days; and, if followed faithfully are very effective. Peptic ulcers is another serious problem that many people have and do not even know it, one might mistaken them for heartburn, indigestion and nausea. The pain and discomfort comes and goes and sometimes lasting for days or even weeks. An ulcer can be treated by medication and usually takes about eight weeks to completely heal. If left untreated it can cause internal bleeding and more severe damage that might need surgical repair (Monroe, 2000). The digestive system is a complex system. There is a lot of information that we know about this system and so much more that is still unknown. For example, for many years the American Heart Association has recommended taking aspirin to prevent heart attacks and strokes. Now, there appears to be a downside to taking a low dosage of aspirin daily. According to research taking a daily aspirin can cause serious problems in the digestive system. Research shows that people who take aspirin are at risk for excess gastro-intestinal bleeding or ulcers that perforate. So the question is does the risk balance the benefit? Through research they have found out that there are three factors that particularly affect developing gastro-intestinal complications they are the increased risk, male gender and ulcer history. All of those things are doubled when a person takes a daily low dose aspirin and the complications can be serious including death. In fact five to ten percent of people with these complications will die from it. Research has proven that the thing that is in aspirin that causes these problems is the same thing that prevents heart disease and the same prostaglandin changes are the ones that somehow enhance the probability of developing gastrointestinal irritation that can lead to bleeding, that can lead to perforation. So research has taught us that there is a high risk of developing gastro-intestinal complications including bleeding or ulcers that perforate, with the use of a low daily dosage of aspirin especially in the male gender and in those with a past history of ulcers. Through this research we still do not understand why the risk is much higher for the male gender than the female gender, that mystery is still unknown. Reasons that cause so many people to suffer with digestive problems are the lack of knowledge of how the digestive system works, poor nutrition and undiagnosed medical conditions. The most obvious solution to maintaining good health and preventing digestive problems would be getting to know the digestive tract and understanding how it works, maintaining a healthy diet and lifestyle and seek medical attention instead of letting the digestive problem turn into something much worse. The Digestive System The human body consists of number of organ systems which work collectively to execute functions of the body. The three most important human organ systems are circulatory, digestive and endocrine system. The main function of the digestive system is to process food in such a way that the energy molecules are absorbed by the body and the residues are left out. The physiological processes which are required for the digestive system are absorption, digestion, motility, secretion and excretion (Margaret E. Smith, 2001) Digestive System: Digestive system helps the body to maintain stability, equilibrium or balance.Digestive system contributes in homeostatic regulation of the body. The body would suffer if there is no regular supply of energy and nutrients from digestive system. The digestive system helps in absorption of ions, vitamins, organic substances and water that is necessary to the body. When the food is chewed and swallowed, the food is broken down in the digestive tract to very sm all nutrient molecules which can be easy to enter into the villi of small intestine. (Rebecca L. Johnson, 2004) Digestive enzymes are formed by the pancreas and the digestive tract.Besides this, the liver produces bile which is stored in the gall bladder to digest the fats. By the use of hepatic portal vein, blood passes from smaller intestine to the liver i. e. , in to the circulatory system. The liver is the vital organ of homeostasis and it monitors the blood. The liver produces urea by breaking down toxic substances like alcohol and other drugs. After eating, the liver stores glucose as glycogen and produces plasma proteins. Liver keeps the blood glucose concentration constant by releasing glucose in between eating. This is how the digestive system works along with the other systems which include circulatory system.Organs in the Digestive system: There are several organs in the digestive system. The digestive system can be divided in to two systems. They are upper gastrointestin al tract and lower gastrointestinal tract. The upper gastrointestinal tract consists of several organs like mouth, oral cavity, pharynx, esophagus and stomach. The lower gastrointestinal tract consists of small intestine, ileum, large intestine, anus and rectum. (Cheryl Jakab, 2007) The functions of some important organs include Oral Cavity: The oral cavity or the mouth is the first part of the digestive system. It accepts food by way of ingestion.Here, the food will be broken in to smaller pieces and get mixed with saliva. Saliva helps as lubrication for the food particles. The oral cavity consists of different parts which are helpful in the digestive system. They are tongue and teeth. Small Intestine: The small intestine is about 35 millimeteres in length and grayish purple in color. The small intestine is the longer intestine which is six to seven meters long. The small intestine has the general structure of the GI tract. The small intestine consists of exocrine cells in the muco sa which secretes peptidase, mucus, maltase, sucrose, lipase, maltase and enterokinase.Endocrine cells secrete secretin and cholecystokinin. The process of digestion is completed by the small intestine. It absorbs the nutrients and sends the residue to large intestine. The gall bladder, liver and pancreas are important organs in the digestive system which is closely related to the small intestine. Small intestine is divided in to duodenum, jejunum and ileum. The small intestine helps in several functions such as hormone secretion, intestinal juice secretion, ninety percent absorption, forward propulsion of contents and it is the major site of digestion.Rectum: The rectum can be found in the lowest portion of the large intestine which connects to the anus and it is a muscular tube like structure. The waste is stored here and permits expulsion when pressure on the rectal walls is caused. Anus: The anus is formed by the surface layers of the body, skin and the intestine. The anus is th e opening at the end of the digestive tract through which the waste matter is ejected from the body. There are many diseases which are caused due to the improper functioning of the digestive system. The most specific disease is the Ulcer.Ulcer is the disorder caused in the upper digestive tract. Ulcer can be developed in the duodenum, lower part of the esophagus and in jejunum. There are many causes for ulcer. Some of them include certain medications, infection and disorders caused by the over secretion of stomach juices. The symptoms of gastric ulcer include weight loss, feeling heart burn and indigestion and gastrointestinal bleeding. Most of the patients suffering from ulcer suffer from bleeding which results in vomiting blood, anemia or blood through rectum.