A Bench to Bedside Primer Frontiers in Physiology is sponsored by the American Physiological Society (APS) and the National Center for Research Resources Science Education Partnership Award (NCRR SEPA, R25 RR025127) at the National Institutes of Health (NIH). Note: The lesson plans and opinions in this report are those of the authors and do not necessarily reflect the opinions of any of the supporting institutions or the editors. Appropriate citation: Eldridge-Sandbo, Mary Bench to Bedside Primer: Gastrointestinal Physiology and Appendicitis (APS Archive of Teaching Resources Item #5978). [Online]. Bethesda, MD: American Physiological Society, 2011. http://www.apsarchive.org/my/submit9.cfm?submissionID=5978 Editor’s notes: This four-page “primer” (a booklet of basic principles) highlights a scientific interest of the teacher producing it in ONE of three physiology topics: cardiovascular (CV), renal (REN), or gastrointestinal (GI) physiology. This primer should be readable by middle to high school students or the general public to help inform them about the organ system, diseases that affect it, and basic and clinical research being done on it. This resource can be used as a sample of the primer a teacher wishes to have their students produce or as an educational tool to explain basic and clinical research. Website URLs listed in this resource were current as of publication, but may now be obsolete. If you know of a replacement URL, please suggest it in the resource’s “Comments” section. Errata Page follows this resource. Disclaimer: This activity was created by the author and reviewed by the American Physiological Society. Any interpretations, statements, or conclusions in this publication are those of the author and do not necessarily represent the views of either the American Physiological Society or the funding agencies supporting the professional development program in which the author participated. Frontiers in Physiology © The American Physiological Society www.frontiersinphys.org Permission is granted for workshop/classroom use with appropriate citation Errata Page What causes appendicitis? It is important to note that the cause of appendicitis is not known. Also, while appendicitis can follow an infection of the digestive tract, it is not "caused by an infection of the intestinal tract". Frontiers in Physiology © The American Physiological Society www.frontiersinphys.org Permission is granted for workshop/classroom use with appropriate citation Gastrointestinal (GI) Physiology When you swallow a bite of your favorite food, it is easy to think about taking another bite. It is easy to forget that each bite of food, which enters your mouth, begins a 30-hour, nine- meter long journey through muscles, acids, enzymes, and bacteria as it travels through the gastrointestinal (GI) tract of the digestive system. This journey is not exactly glamorous, but you cannot live without it because it provides your cells with the nutrients and energy they need to keep you alive. Organs of the GI tract: Mouth, Esophagus, Stomach, Small intestine, Large intestine Accessory organs: Pancreas, Liver, Gallbladder A summary… It all begins in the mouth, where food is chewed and moistened. Chemical digestion begins when salivary enzymes start carbohydrate digestion. When food is swallowed, it enters the esophagus, which is lined with muscles that contract in a wave-like motion called peristalsis to move the food into the stomach in less than 10 seconds! In the stomach, enzymes and acids begin protein digestion and muscular contractions transform the lump of food into a semi- liquid form known as chyme. Bit by bit, the chyme enters the upper part of the small intestine, called the duodenum, where bile, which is secreted by the gall gladder, helps break down fats and intestinal and pancreatic enzymes complete chemical digestion. The remainder of the small intestine is lined with tiny projections, called villi, which allow nutrients to be absorbed into the bloodstream and transported to the liver. The liver carries out many functions to be sure that nutrients are stored or released as needed in the correct form for the body. Once digestion and absorption are completed, the remaining, undigested food, called feces, and a lot of water enter the large intestine, which is home to many harmless bacteria. The bacteria digest, produce some vitamins, and help protect against disease-causing bacteria! Finally, water is sent back http://commons.wikimedia.org/wiki/File:Digestive_system_diagram.edit.svg to the blood stream and the feces is stored in the lowest portion of the large intestine, called the rectum, until it is sent out of the body through the anus. References • WebMD Digestive Disorders Health System: http://www.webmd.com/digestive- disorders/digestive-system • National Geographic. The Digestive System: http://science.nationalgeographic.com/science/health-and-human-body/human- body/digestive-system-article.html • U.S. Department of Health and Human Services. National Institutes of Health. National Digestive Diseases Information Clearninghouse. Your Digestive System and How it Works: http://digestive.niddk.nih.gov/ddiseases/pubs/yrdd/index.aspx Appendicitis What is the appendix? The appendix is a tube measuring about seven centimeters in length located at the point where the small intestine meets the large intestine. If this structure has a function in humans, it has not been discovered yet. It is known that people can live normal lives without an appendix. This structure is technically known as the vermiform appendix. What is appendicitis? When the appendix becomes inflamed, it is called appendicitis. The inflammation can lead to infection, which, if not treated, can lead to a rupture, or bursting of the appendix. What causes appendicitis? The appendix can become inflamed when it is blocked by something in the digestive tract, or when the digestive tract becomes infected. What are the symptoms of appendicitis? Pain in the abdomen is one of the most common symptoms of appendicitis. Sometimes, the pain is more localized on the right side. Other symptoms include nausea, vomiting, changes in bowl movements, and fever. What is the treatment for appendicitis? The routine treatment for appendicitis is an appendectomy, which is the surgical removal of the appendix. There are several different forms of this surgery, depending on the patient and severity of infection. This is one of the most common emergency surgeries in the United States. The goal of the surgery is to remove the appendix before it ruptures because a ruptured appendix can spread infection throughout the abdominal cavity. Surgery is usually followed with antibiotics in order to treat infection. Who is at risk for appendicitis? Anyone can get appendicitis, but family history could increase the risk of this problem. Children, younger than two, and adults, older than 70, are at a greater risk for a ruptured appendix. Can appendicitis be prevented? Current resources report no prevention for appendicitis, but a diet with fiber can help things move most efficiently through the digestive tract, which can prevent a blockage that could lead to appendicitis. References: PubMedHealth National Center for Biotechnology Information, U.S. National Library of Medicine:http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001302/ WebMD:http://www.webmd.com/digestive-disorders/digestive-diseases-appendicitis University of Maryland Medical Center: http://www.umm.edu/altmed/articles/appendicitis- 000014.htm Recent Research Related to Appendicitis Appendicitis is nearly always treated by the surgical removal of the appendix (Vans et al., 2011). Over the years, however, research has explored the effectiveness of treating appendicitis with antibiotics. Potential benefits to this non-surgical approach include avoiding surgical risks and reducing financial costs. (Liu, Ahanchi, Pisaneschi, Lin, & Walter, 2007). At this point, there are conflicting results as to whether antibiotic treatment is a beneficial alternative to surgery for patients with acute appendectomy without other symptoms or complications (Vans et al., 2011). A 2007 study in Chicago compared the results of 151 patients whose acute appendicitis was treated with traditional surgery were compared to 19 patients with similar symptoms who were treated with antibiotics (Liu et al., 2007). The results of this study were that antibiotic treatment was equally safe as an emergency appendectomy (Liu et al., 2007). A more recent study in Korea studied 107 patients, with symptoms of acute appendicitis, who were first treated with antibiotics (Park et al., 2011). Of the 107 patients, 97 were successfully treated with antibiotics (Park et al., 2011). These results led Park et al., (2011) to conclude that antibiotic treatment is not only equally effective to surgery, but eliminates the risks associated with surgery. Not all research investigating the effectiveness of antibiotic therapy compared to surgical removal of the appendix has come to the same conclusion. Vons et al. (2011) conducted a larger, randomized study consisting of 243 patients. Nearly half of the patients received antibiotic treatment, while the other half underwent an appendectomy (Vons et al., 2011). The authors of this study explained that their research was the first one that randomized their patients after appendicitis had been diagnosed (Vons et al., 2011). They concluded that antibiotic treatment was not as effective as surgery and recommended that appendectomy was still the best way to treat this