Digestive System Structures, Functions & Disorders (HU40 Health Science I)

3.01 Structures, Functions and Disorders of the Digestive System HU40 Health Science I Functions of the Digestive System Physical breakdown of food Chemical digestion of food—breaking food down into end products of fat, carbohydrates and protein Absorption of nutrients Elimin...

3.01 Structures, Functions and Disorders of the Digestive System HU40 Health Science I Functions of the Digestive System Physical breakdown of food Chemical digestion of food—breaking food down into end products of fat, carbohydrates and protein Absorption of nutrients Elimination of waste products of digestion Digestive Tract Also know as: Gastrointestinal Tract GI Tract Alimentary Canal Approximately 30 foot tube from mouth to the anus Structures of the Digestive System Primary Structures: Mouth (buccal cavity) Pharynx--throat Esophagus Stomach Small Intestine Large Intestine Accessory Organs: Salivary glands Pancreas Liver Gallbladder Mouth Where food enters digestive system The roof of the mouth is formed by the hard palate and soft palate Tongue assists to mix food with saliva Taste buds are contained in papillae of tongue Tongue and palate assist to move food into pharynx Uvula-flap hands off soft palate and prevents food from going up into nasal cavity during swallowing Teeth Gingiva (gums)—support and protect the teeth Deciduous teeth (baby teeth)-20 Permanent teeth—32 teeth Mastication (chewing)— aids in mechanical digestion Salivary Glands 3 main pairs: parotid, sublingual, and submandibular Produces saliva which moistens the mouth and other parts of the digestive system Begins the breakdown of carbohydrates with Pharynx Commonly known as the throat Muscular tube connected to the posterior mouth Serves as a passageway for food from the mouth to the esophagus Esophagus Hollow tube connecting the pharynx to the stomach Walls of the esophagus propel food to the stomach by rhythmic waves called peristalsis  Stomach Muscular sac that stores food to allow time for digestion esophag Hydrochloric acid and digestive enzymes us continue digestion that began in the mouth Peristalsis moves food into small intestine Body Cardiac sphincter: circular muscle that controls passage of food from esophagus into stomach Pyloric sphincter: circular muscle that controls the passage of food from the stomach into the duodenum Rugae: folds in the mucous lining of the stomach that allow the stomach to stretch  Small Intestine Divided into 3 segments: Duodenum: first segment, curves around pancreas, 12” long Jejunum: middle section, 8 ft. long Ileum: final portion, 10-12 feet long Most absorption takes place in the small intestine Digested food passes into bloodstream and on to body cells Anything not digested passes on to large intestine Pancreas Located behind stomach Serves as both exocrine and endocrine gland Exocrine function – secretes digestive enzymes Also has endocrine function - secretes insulin to control blood sugar levels  Liver Located below the diaphragm, upper right quadrant Connected to gallbladder and small intestine by ducts Produces and stores glucose in the form of GLYCOGEN Detoxifies alcohol, drugs and other harmful substances Manufacture blood proteins Manufactures bile Store Vitamins A, D and B complex Gallbladder Small green organ, inferior surface of the liver Stores and concentrates bile until needed by the body When fatty foods digested, bile released by  Large Intestine Approx 2” in diameter Also called the colon CECUM – lower right portion of large intestine APPENDIX is finger-like projection off cecum RECTUM – last portion of large intestine ANUS – external opening CHYME – semi-liquid food (the state food is in when it reaches the large intestine) Water balance regulated—large amounts of water reabsorbed  Processes of Digestion Physical Digestion (aka mechanical digestion): Food is broken into smaller pieces—this occurs in the mouth with chewing of food and in the stomach with churning of food. Peristalsis is part of the process Chemical Digestion: Secretion of enzymes throughout the digestive tract break the chemical bonds of food, making it small enough to digest Absorption: Nutrients are absorbed in the small intestine. Water is reabsorbed as needed in the large intestine. Elimination: Undigested material, along with water, bacteria, cellulose and fats become feces (also known as stool). Feces is eliminated through defecation (aka bowel Electrolytes and Vitamins Sodium is actively absorbed in the large intestine Potassium is either absorbed or secreted based on the levels of potassium in the body Vitamin K and B vitamins, including biotin, are produced by bacteria in the large intestine These vitamins are then Common Disorders of the Digestive System Cholecystitis: Inflammation of the gallbladder Cholelithiasis: gallstones Cholecystectomy: surgical removal of the gallbladder Constipation: Infrequent bowel movements with hard, dry feces. Treated with diet high in fiber,  Cirrhosis Chronic, progressive disease of the liver Normal tissue replaced by fibrous connective tissue 75% of cases are caused by excessive alcohol consumption Tylenol abuse can lead to Cirrhosis  Gastroenteritis/Diarrhea Inflammation of the mucous membrane lining of the stomach and the intestines Commonly caused by a virus Symptoms—vomiting and diarrhea for 24-36 hours Common complication is dehydration Diarrhea—frequent, loose stools Gastroesophageal Reflux Disease (GERD) Occurs when acid and stomach contents regurgitate up into the esophagus May cause heartburn May cause sour or bitter taste in mouth Can cause difficulty swallowing Treated by avoiding chocolate, peppermint, coffee, citrus, and fatty/fried foods, stopping smoking, taking antacids, and not lying down within 2-3 hours of eating Hiatal Hernia Condition in which the upper part of your stomach bulges through an opening in your diaphragm More common after the age of 50 Higher risk with obesity or smoking Treatments include eating small meals, avoiding certain foods, not smoking or drinking alcohol, and losing weight Doctor may prescribe antacids or other medications Hepatitis Inflammation of the liver Hepatitis A: spread through contaminated food or water Hepatitis B and Hepatitis C: caused by a virus. Spread through blood and body fluids. Use universal precautions to avoid Irritable Bowel Syndrome Disorder that affects the large intestine Signs and symptoms include cramping, abdominal pain, bloating, gas, and diarrhea or constipation, or both. Chronic condition that requires long term management More common in women Peptic Ulcers Sore or lesion in mucosal lining of the stomach Gastric ulcers in stomach Duodenal ulcers in duodenum Primary cause: H Pylori bacteria Contributing life style factors: smoking, alcohol, stress, certain drugs Symptoms: burning pain in abdomen between meals and early morning—may be relieved by eating or taking antacids Diagnosis: x-ray, blood test Treatment: H2 blockers—drugs that block the release of histamine  Resources File:Digestive system without labels.svg. (2018, March 18). Wikimedia Commons, the free media repository. Retrieved 20:32, May 29, 2020 from https://commons.wikimedia.org/w/index.php?title=File:Digestive_system_without_labels.svg&oldid=292655948. File:Blausen 0316 DigestiveSystem.png. (2020, May 9). Wikimedia Commons, the free media repository. Retrieved 20:37, May 29, 2020 from https://commons.wikimedia.org/w/index.php?title=File:Blausen_0316_DigestiveSystem.png&oldid=418238381 File:2401 Components of the Digestive System.jpg. (2017, November 25). Wikimedia Commons, the free media repository. Retrieved 20:41, May 29, 2020 from https://commons.wikimedia.org/w/index.php?title=File:2401_Components_of_the_Digestive_System.jpg&oldid=269243805. File:Blausen 0780 SalivaryGlands.png. (2020, April 25). Wikimedia Commons, the free media repository. Retrieved 20:59, May 29, 2020 from https://commons.wikimedia.org/w/index.php?title=File:Blausen_0780_SalivaryGlands.png&oldid=414704326. File:2305 Divisions of the Pharynx.jpg. (2017, November 25). Wikimedia Commons, the free media repository. Retrieved 21:07, May 29, 2020 from https://commons.wikimedia.org/w/index.php?title=File:2305_Divisions_of_the_Pharynx.jpg&oldid=269243785. File:Digestive system simplified.svg. (2016, June 24). Wikimedia Commons, the free media repository. Retrieved 21:27, May 29, 2020 from https://commons.wikimedia.org/w/index.php?title=File:Digestive_system_simplified.svg&oldid=199807682. File:Blausen 0817 SmallIntestine Anatomy.png. (2020, May 9). Wikimedia Commons, the free media repository. Retrieved 21:29, May 29, 2020 from https://commons.wikimedia.org/w/index.php?title=File:Blausen_0817_SmallIntestine_Anatomy.png&oldid=418238438. File:Blausen 0699 PancreasAnatomy2.png. (2020, May 9). Wikimedia Commons, the free media repository. Retrieved 00:07, May 30, 2020 from https://commons.wikimedia.org/w/index.php?title=File:Blausen_0699_PancreasAnatomy2.png&oldid=418238435. File:Liver (organ).png. (2020, February 7). Wikimedia Commons, the free media repository. Retrieved 00:09, May 30, 2020 from https://commons.wikimedia.org/w/index.php?title=File:Liver_(organ).png&oldid=392720196 File:Gallbladder (organ).png. (2020, May 29). Wikimedia Commons, the free media repository. Retrieved 00:12, May 30, 2020 from https://commons.wikimedia.org/w/index.php?title=File:Gallbladder_(organ).png&oldid=422478726. File:Blausen 0604 LargeIntestine2.png. (2020, May 9). Wikimedia Commons, the free media repository. Retrieved 00:14, May 30, 2020 from https://commons.wikimedia.org/w/index.php?title=File:Blausen_0604_LargeIntestine2.png&oldid=418238430. File:Gallstones.png. (2019, June 21). Wikimedia Commons, the free media repository. Retrieved 00:24, May 30, 2020 from https://commons.wikimedia.org/w/index.php?title=File:Gallstones.png&oldid=355598143. File:Liver Cirrhosis.png. (2018, March 17). Wikimedia Commons, the free media repository. Retrieved 00:29, May 30, 2020 from https://commons.wikimedia.org/w/index.php?title=File:Liver_Cirrhosis.png&oldid=292501092.  Additional Resources File:Gastroenteritis.jpg. (2019, December 22). Wikimedia Commons, the free media repository. Retrieved 00:35, May 30, 2020 from https://commons.wikimedia.org/w/index.php?title=File:Gastroenteritis.jpg&oldid=382253741. File:GERD.png. (2018, March 17). Wikimedia Commons, the free media repository. Retrieved 00:39, May 30, 2020 from https://commons.wikimedia.org/w/index.php?title=File:GERD.png&oldid=292501388. File:Hiatal Hernia.png. (2018, March 17). Wikimedia Commons, the free media repository. Retrieved 00:41, May 30, 2020 from https://commons.wikimedia.org/w/index.php?title=File:Hiatal_Hernia.png&oldid=292501194. File:Irritable bowel syndrome.jpg. (2019, December 22). Wikimedia Commons, the free media repository. Retrieved 00:44, May 30, 2020 from https://commons.wikimedia.org/w/index.php?title=File:Irritable_bowel_syndrome.jpg&oldid=382253993 “Other images taken from Creative Commons with CCO license. No attribution required.” https://www.niddk.nih.gov/health-information/digestive-diseases/digestive-system-how-it-works https://www.medicinenet.com/the_digestion_process_organs_and_functions/article.htm https://medlineplus.gov/digestivesystem.html