Medical assisting Administrative and clinical procedures (5e) Chapter 33 The digestive system

After completing chapter 33, you will be able to: Describe the organs of the alimentary canal and their functions; explain the functions of the digestive system’s accessory organs; identify the nutrients absorbed by the digestive system and where they are absorbed; describe the causes, signs and symptoms, and treatments of various common diseases and disorders of the digestive system.

CHAPTER 33 The Digestive System 33-2 Learning Outcomes (cont.) 33.1 Describe the organs of the alimentary canal and their functions 33.2 Explain the functions of the digestive system’s accessory organs 33-3 Learning Outcomes (cont.) 33.3 Identify the nutrients absorbed by the digestive system and where they are absorbed 33.4 Describe the causes, signs and symptoms, and treatments of various common diseases and disorders of the digestive system 33-4 Introduction • Digestion – mechanical and chemical breakdown of foods • Organs of digestion – Alimentary canal organs form a pathway extending from the mouth to the anus – Accessory organs 33-5 Characteristics of the Alimentary Canal • Mucosa – Epithelial tissue – Secretes enzymes and mucus – Absorbs nutrients • Submucosa – loose connective tissue, blood vessels, glands, and nerves 33-6 Characteristics of the Alimentary Canal • Muscular layer – Smooth muscle – Contracts to move materials through the canal • Serosa or peritoneum – Visceral peritoneum – Parietal peritoneum 33-7 Characteristics of the Alimentary Canal (cont.) • Movements – Churning ~ mixes substances – Peristalsis ~ moves substances 33-8 The Mouth • Buccal cavity • Mechanical digestion • Starts chemical digestion • Cheeks – hold food in mouth • Lips – judge temperature of food The Mouth 33-9 The Mouth (cont.) • Tongue – Mixes and holds food between teeth – Contains taste buds – Lingual frenulum – Lingual tonsils • Palate – Hard palate – Soft palate – Uvula • Lymphatic tissue – Palatine tonsils – Pharyngeal tonsils or adenoids The Mouth 33-11 The Mouth (cont.) • Salivary glands – Cells • Serous – watery fluid and amylase • Mucous – Parotid gland – Submandibular gland – Sublingual gland 33-43 The Absorption of Nutrients (cont.) • Lipids – Used to make energy when glucose levels are low – Triglycerides • Most abundant • Excess stored in adipose tissue – Cholesterol – essential for cell growth and function 33-44 The Absorption of Nutrients (cont.) • Vitamins – Fat-soluble – Water-soluble • Protein – Requirements vary – Used for growth and tissue repair • Minerals – Found in bones and teeth – Used to make enzymes, cell membranes, and proteins 33-45 Apply Your Knowledge True or False: ANSWER: T Carbohydrates are starches, simple sugars, and cellulose _ liver F Excess glucose is stored in the gallbladder as glycogen _ most F Triglycerides are the least abundant lipids _ T Linoleic acid is an essential fatty acid _ fat-soluble F A, D, E and K are water-soluble vitamins _ T Minerals are used by cells to make enzymes _ 33-46 Aging and the Digestive System • Decreased – Motility – Absorption – Ability to detoxify blood • More likely to develop ulcers and cancers • Sense of taste altered • Dietary changes due to – Isolation – Depression 33-47 Common Diseases and Disorders Disease/Disorder Description Appendicitis Inflammation of the appendix; can be life-threatening if not treated promptly Cirrhosis Chronic liver disease; normal tissue is replaced with nonfunctional scar tissue Cholelithiasis (gall Hard deposits of cholesterol or stones) bilirubin in the gall bladder 33-48 Common Diseases and Disorders Disease/Disorder Description Colitis Inflammation of the large intestine; can be acute or chronic Colorectal cancer Arises from lining of rectum or colon; curable if treated early Constipation Difficult defecation Crohn’s disease Inflammatory bowel disease; typically effects small intestine 33-49 Common Diseases and Disorders (cont.) Disease/Disorder Description Diarrhea Watery and frequent feces; usually self-limiting Diverticulitis Inflammation of diverticula Diverticulosis – diverticula with no inflammation Gastritis Inflammation of the stomach lining; “upset stomach” 33-50 Common Diseases and Disorders (cont.) Disease/Disorder Description Heartburn Gastroesophageal reflux disease (GERD); stomach acids push into esophagus Hemorrhoids Hepatitis Varicose veins of rectum or anus Inflammation of the liver; various types Hiatal hernia Portion of stomach protrudes into the chest through an opening in the diaphragm 33-51 Common Diseases and Disorders (cont.) Disease/Disorder Description Inguinal hernia Portion of large intestine protrudes in the inguinal canal (where thigh and trunk meet) or, in males, into the scrotum Oral cancer Usually involves the lips or tongue but can occur anywhere in the mouth; tends to spread rapidly 33-52 Common Diseases and Disorders (cont.) Disease/Disorder Description Pancreatic cancer Fourth leading cause of cancer deaths in the U.S Stomach cancer Commonly in cardiac portion of the stomach; occurs more frequently in Japan, Chili, and Iceland Stomach ulcers Breakdown in lining of the stomach 33-53 Apply Your Knowledge Matching: ANSWER: E Inflammation of the large intestine _ A Heartburn D Inflammatory bowel disease _ B Hemorrhoids F Watery and frequent feces _ C Difficult defecation _ C Constipation G Inflammation of the stomach lining _ E Colitis D Crohn’s disease H Inflammation of pouches in the intestinal wall F Diarrhea _ A GERD _ G Gastritis B Varicose veins of rectum _ H Diverticulitis 33-54 In Summary 33.1 The pathway of food through the alimentary canal starts with the mouth continues through the pharynx, esophagus, stomach, small intestine, large intestine, and anal canal and 33-55 In Summary (cont.) 33.2 The accessory organs to the digestive system include the liver, gallbladder, and pancreas 33.3 Nutrients absorbed by the body include carbohydrates, proteins, lipids, vitamins, minerals, and water Most of the absorption takes place in the small intestine 33-56 In Summary (cont.) 33.4 There are many common diseases and disorders of the digestive system with varied signs, symptoms, and treatments 33-57 End of Chapter 33 Take all that is given whether wealth, love or language; nothing comes by mistake and with good digestion all can be turned to health ~ George Herbert .. .33- 2 Learning Outcomes (cont.) 33. 1 Describe the organs of the alimentary canal and their functions 33. 2 Explain the functions of the digestive system s accessory organs 33- 3 Learning... (cont.) 33. 3 Identify the nutrients absorbed by the digestive system and where they are absorbed 33. 4 Describe the causes, signs and symptoms, and treatments of various common diseases and disorders... or adenoids The Mouth 33- 11 The Mouth (cont.) • Salivary glands – Cells • Serous – watery fluid and amylase • Mucous – Parotid gland – Submandibular gland – Sublingual gland 33- 12 The Mouth (cont.)