CCMA Training Notes: Digestive/Gastrointestinal System

  • Gastrointestinal system  

  • Anatomy  

  • Gastrointestinal Tract: Is divided into the...  

  • Upper GI Tract 

  • Oral Cavity: The structures of the oral cavity including the lips, soft and hard palate, uvula, tongue, soft tissues, dental arches, teeth primary and permanent dentition, and salivary glands secreting saliva.  

  • Pharynx: Is the passageway for both respiration and diagestion. It plays a role in deglutiton, or swallowing. The epiglottis covers the entrance to the trachea so that food and liquids do not enter in to the airway.  

  • Esophagus: Is a long muscular tube that serves to the stomach. The lower esphageal spincter serves as a gateway between the esophagus and stomach and relaxes during swallowing so that food can enter the stomach  

  • Stomach: This sac-like organ receives food from the esophagus for diagestion. 

  • Lower GI Tract 

  • Small Intestine: This tube extends from the end of the pyloric sphincter of the stomach to the large intestine. It is divided into the duodenum, the jejunum, and the ileum.  

  • Long Intestine: This tube extends from the end of the small intestine to anus. The major divisions are the cecum, colon, rectum, and anus. 

  • Accessory Organs 

  • Liver: This large organ removes toxins from the blood and helps turn food into fuel and nutrients.  

  • Gallbladder: This pear-shaped organ is located under the liver and conncets via small ducts. It stores bile formed by the liver.  

  • Pancreas: This soft, oblong gland is located behind the stomach. It secretes pancreatic juices to aid diagestion which it secretes into the panvcreatic duct, into the bile duct, and into the duodenum.  

  • Physiology 

  • The Gastrointestinal System:  

  • Digestion: Is the process by which complex foods are broken down into nutrients in forms the body can use. Nutrients are substances necessary for normal functioning of the body and include:  

  • Carbohydrates  

  • Fats  

  • Proteins  

  • Vitamins  

  • Minerals  

  • Water  

  • Metabolism: Refers to all the processes involved in the body’s use of nutrients. It includes anabolism, or the building up of body cells and substances from nutrients. It also includes catabolism, or the breaking down of body cells or substances, releasing energy and carbon dioxide.  

  • Absorption: Is the process by which completely digested nutrients are transported to cells throughout the body.  

  • Mastication: Is the technical term for chewing, breaking food down into smaller pieces and mixing it with saliva. It prepares to swallow.  

  • Deglutition: Is the technical term for swallowing.  

  • Peristalsis: Is the series of wave-like contractions of smooth muscles in a single direction that moves the food forward into the digestive system.  

  • Work of Specific Organs:  

  • Stomach: Secretes gastric juices that contain hydrochloric acid and digestive enzymes to break down food. The nutrients resulting in this breakdown enter the bloodstream through the walls of the stomach. The food that has been ingested is now referred to as chyme.  

  • Small Intestine: The chyme is moved into the small intestine by peristalsis. In the duodenum, chyme is mixed with pancreatic juices and bile from the pancreas and liver/gall bladder, respectively. These emulsify fat so that the nutrients can be absorbed by the body. The jejunum secretes digestive enzymes to continue digestion. The ileum is a site for absorption of nutrients into the bloodstream so they can be carried to the body tissues.  

  • Large Intestine: The role of the large intestine is to receive the waste products of digestion and store them until they can be eliminated. Food waste enters the large intestine. Excess water is reabsorbed back into the body leaving the waste, referred to as faces. The large intestine contains gut microflora to help break down organic waste material producing gas.  

  • Defecation: refers to the evacuation or emptying of the large intestine through the rectum and anus.  

  • Liver: Secretes bile to help emulsify (breakdown) fats.  

  • Pancreas: Secretes digestive juices to help break down proteins and carbohydrates. 

  • Common Diseases and Disorders 

  • Oral Cavity Disorders:  

  • Aphthous ulcers: These are also called canker sores or mouth ulcers. They are gray-white pits with a red border in the mouth tissue often associated with stress, certain types of foods, or fever.  

  • Cheilosis: This is a disorder of the lips. Crack-like sores appear at the corners of the mouth.  

  • Herpes labialis: This is commonly called a fever blister or cold sore and is caused by the oral herpes simplex virus type 1 (HSV-1). The virus causes a blister-like sore on the lips and facial tissue surrounding the mouth.   

  • Oral thrush: This is a fungal infection of the oral area causing symptoms of creamy white lesions on the tongue or inner cheeks most commonly in infants, older adults with weakened immune systems, or those taking a lot of antibiotics.  

  • Xerostomia: This condition is commonly called dry mouth. It is caused by the lack of saliva by the salivary glands because of medications or radiation.  

  • Cleft Palate: This condition results from a failure of the palate to close during the early development of the fetus creating an opening that may involve th upper lip, hard palate, and/or soft palate.  

  • Dental Diseases and Disorders:  

  • Bruxism: this refers to involutary grinding or clenching of the teeth usually occurring during sleep. It is often associated with stress.  

  • Dental caries: This is commonly known as tooth decay or a cavity. It refers to an infectious disease caused by bacteria that destroys the dentin and enamel of the tooth.  

  • Dental plague: This refers to soft deposits in areas of the teeth near the gums and between the teeth. It consists of bacteria and bacteria by-products and leads to dental caries.  

  • Halitosis: This is commonly referred to as bad breath and refers to an unpleasant odor in the mouth. It is commonly caused by dental diseases or a respiratory or gastric disorder.  

  • Periodontal disease: This condition is commonly called periodontitis and refers to an inflammation of the tissues surrounding the teeth eventually involving the gums and bones.  

  • Gingivitis: This is the earliest stage of periodontal disease and refers to an inflammation of the gums.  

  • Disorders of the Esophagus:  

  • Dysphagia: Refers to difficulty in swallowing.  

  • Eosinophilic Esophagitis: This is a chronic immune system disease where eosinophils, one type of white blood cell) build up in the esophagus. It is a result of an allergy to certain foods. 

  • GERD: Refers to gastroesophageal reflux disease and this is upward flow of acid from the stomach into the esophagus.  

  • Esophageal Structure: This results from scar tissue or other dmage of the sophagus causing swallowing difficulties.  

  • Pyrosis: This is commonly called heartburn and refers to a burning sensation caused by the return of acidic stomach contents into the esophagus.  

  • Esophageal varices: This refers to an enlarged and swollen vein at the lower end of the esophagus.  

  • Hiatal hernia: This is an anatomical abnormality where a portion of the stomach protrudes upward into the chest through an opening in the diaphragm.  

  • Disorders of the Stomach:  

  • Gastritis: This refers to the inflammation of the stomach lining caused by bacteria.  

  • Gastroenteritis: This refers to an inflammation of the mucous membrane lining of the stomach and intestines.  

  • Gastroparesis: This refers to a condition in which the muscles in the stomach slow down and work poorly or not work at all. This prevents the stomach from emptying normally.  

  • Gastrorrhea: This refers to the excessive secretion of gastric juice or mucus in the stomach.  

  • Peptic ulcers: This refers to sores that affect the mucous membranes of the digestive system.  

  • Gastric ulcer: Is a peptic ulcer in the stomach.  

  • Nutritional Disorders:  

  • Anorexia: Refers to an eating disorder characterized by an abnormally low body weight and overwhelming fear of and obsession about gaining weight. Patients have a distorted perception of their own weight.  

  • Bulimia: This emotional disorder involves distortion of body image and obsession with losing weight. Patients experience bouts of overeating followed by depression and self-induced vomiting, purging, or fasting.  

  • Dehydration: Refers to fluid loss that exceeds the fluid intake disrupting the body’s normal electrolyte balance.  

  • Cachexia: Refers to physical waste due to loss of weight and muscle mass. This condition is commonly a result of advanced cancer or AIDS.  

  • Malnutrition: This refers to a lack of proper food or nutrients because of a shortage of food or poor eating habits. It can also be caused by the inability of the body to digest, absorb, or distribute nutrients.  

  • Malabsorption: This condition is when the small intestine cannot absorb nutrients from food as it passes through the digestive tract.  

  • Obesity: Refers to an excessive accumulation of fat in the body. It is diagnosed when individuals are more than 20% of established weight standards based on height, age, and gender.  

  • Indigestion and Vomiting:  

  • Dyspepsia: Refers to indigestion, or pain or discomfort in digestion.  

  • Emesis: This is a term for vomiting, or the reflex ejection of the stomach contents outward through the mouth.  

  • Hematemesis: Refers to vomiting blood.  

  • Hyperemesis: Refers to an extreme, persistent vomiting causing a risk for hydration.  

  • Nausea: Refers to the urge to vomit.  

  • Regurgitation: Refers to the return of swallowed food back into the mouth 

  • Eructation: This is the act of belching or raising gas orally from the stomach.  

  • Aerophagia: This refers to the excessive swallowing of air while eating or drinking. It is the common cause of gas in the stomach.  

  • Intestinal Disorders:  

  • Celiac disease: This is a hereditary autoimmune disorder leading to a severe reaction to foods containing gluten, a type of protein found in grains.  

  • Gluten intolerance: This condition is typically caused by an allergy to wheat.  

  • Food Allergy: This immune system reaction occurs after eating a certain food.  

  • Lactose Intolerance: This is the inability to digest dairy products because of the absence of the enzyme lactase needed to metabolize the sugar, lactose, found in milk and dairy products.  

  • Diverticulosis: This is the chronic presence of an abnormal number of diverticula in the colon  

  • Diverticulitis: Sometimes develops into diverticulitis which is the inflammation of infection of one or more diverticulum in the colon.  

  • Enteritis: Refers to an inflammation of the small intestine caused by eating or drinking something contaminated with a pathogen, typically viral or bacterial.  

  • Ischemic colitis: Occurs when a part of the large intestine is partially or completely deprived of blood leading to inflammation and permanent damage in that area.  

  • lleus: refers to the partial or complete blockage of the small or large intestine.  

  • Irritable Bowel Syndrome (IBS): This common condition leads to intermittent cramping and abdominal pain. Patients may experience constipation or diarrhea.  

  • Inflammatory Bowel Disease (IBD): This condition is caused by inflammation and swelling in the intestines. Both ulcerative colitis and Crohn’s disease are inflammatory bowel diseases.  

  • Ulcerative colitis: This chronic condition causes episodes of inflammation in the rectum and large intestine causing ulcers and irritation.  

  • Intestinal obstructions: Refers to a partial or complete blockage of the small or large intestine caused by a physical obstruction.  

  • Inguinal Hernia: Refers to the protrusion of a small loop of bowel through a weak place in the lower abdominal wall or groin.  

  • Dysentery: This is a bacterial infection spread through food or water contaminated with human feces.  

  • E. coli: This infection is caused by the bacterium Escherichia coli, transmitted through contaminated foods that have not been adequately cooked.  

  • Anorectal Disorders:  

  • Bowel incontinence: Refers to the inability to control the exertion of feces.  

  • Constipation: Refers to having a bowel movement fewer than three times per week. Stools are usually hard, dry, small, and difficult to eliminate.  

  • Diarrhea: Refers to an abnormally frequent flow of loose or watery stools that can lead to dehydration.  

  • Hemorrhoids: These occur when a cluster of veins, muscles, and tissues slip near or through an anal opening.  

  • Disorders of the Liver:  

  • Ascites: Refers to an abnormal accumulation of serous fluid in the peritoneal cavity resulting in severe liver disease creating pressure on the liver’s blood vessels.  

  • Hepatomegaly: Refers to an abnormally large liver.  

  • Jaundice: Refers to a yellow discoloration in the skin, mucous membranes, and eyes caused by abnormally large amounts of bilirubin.  

  • Hepatitis: Refers to an inflammation of the liver typically caused by viral infection.  

  • Cirrhosis: Refers to a chronic degenerative disease of the liver.  

  • Nonalcoholic fatty liver disease: NAFLD refers to the accumulation of fat in the liver of people who do not drink large amounts of alcohol.  

  • Disorders of the Gallbladder:  

  • Cholangitis: Refers to an acute inflammation of the bile duct characterized by pain in the right upper quadrant of the abdomen, fever, and jaundice.  

  • Cholecystitis: Refers to the inflammation of the gallbladder. Patients often experience gallstones that block the flow of the bile.  

  • Gallstones: These are termed cholelith and refer to a hard deposit formed in the gallbladder and  

  • Cholelithiasis: This refers to the presence of gallstones in the gallbladder or bile ducts.  The condition can lead to complications such as pancreatitis or cholangitis if left untreated.