1 Digestive Diseases Chapter 31 Doctors who specialize in gastroenterology see patients with digestive problems.

2 Introduction  Digestion  The mechanical and chemical breakdown of foods into forms that your body cells can absorb  The organs of the digestive system carry out digestion.  Two categories  Those of the alimentary canal  The accessory organs

3 Alimentary Canal  Mucosa - absorbs nutrients  Submucosa - carry away absorbed nutrients  Muscular layer - move materials through the canal  Serosa - secretes serous fluid to keep the outside of the canal moist and prevent it from sticking to other organs.  Length of the entire canal is about 9 meters (29 feet)

4 Mouth, Teeth, Tongue, and Salivary Glands  Mouth takes in food and reduces its size through chewing  Salivary glands - saliva (spit) contains an enzyme that will break down carbohydrates  Teeth act to decrease the size of food particles and different types of teeth are adapted to handle food in different ways

5 Apply Your Knowledge What is the purpose of the serosa?

6 Answer Apply Your Knowledge - Answer Serosa - secretes serous fluid to keep the outside of the alimentary canal moist and prevent it from sticking to other organs. What is the purpose of the serosa?

7 Pharynx The throat - long, muscular structure that extends from the area behind the nose to the esophagus  Nasopharynx  Oropharynx  Laryngopharynx The throat - long, muscular structure that extends from the area behind the nose to the esophagus  Nasopharynx  Oropharynx  Laryngopharynx  Acts to connect the nasal cavity with the oral cavity for breathing through the nose  Acts to push food into the esophagus  Acts to connect the nasal cavity with the oral cavity for breathing through the nose  Acts to push food into the esophagus

8 Swallowing Process An involuntary automatic response (reflex) 1. Soft palate raises causing the uvula to cover the opening between the nasal cavity and oral cavity 2. Epiglottis covers the opening of the larynx An involuntary automatic response (reflex) 1. Soft palate raises causing the uvula to cover the opening between the nasal cavity and oral cavity 2. Epiglottis covers the opening of the larynx

9 Swallowing Process (cont.) 3.Muscles in the pharynx contract, forcing food toward the esophagus 4.Esophagus opens 5.Food is pushed into the esophagus by the muscles of the pharynx 3.Muscles in the pharynx contract, forcing food toward the esophagus 4.Esophagus opens 5.Food is pushed into the esophagus by the muscles of the pharynx

10 Esophagus  Esophagus is a muscular tube about 25 cm long that connects the pharynx to the stomach  Esophageal sphincter controls the movement of food into the stomach  Opens and closes to allow or prevent movement of substances out of a tube  Esophagus is a muscular tube about 25 cm long that connects the pharynx to the stomach  Esophageal sphincter controls the movement of food into the stomach  Opens and closes to allow or prevent movement of substances out of a tube

11 Stomach  Below the diaphragm in the upper left region of the abdominal cavity  It functions to receive food from the esophagus  Mix food with gastric juice (secretions of the stomach lining)  Start protein digestion  Move food into the small intestine  Below the diaphragm in the upper left region of the abdominal cavity  It functions to receive food from the esophagus  Mix food with gastric juice (secretions of the stomach lining)  Start protein digestion  Move food into the small intestine Click for Larger View

12 Stomach (cont.)

13 Stomach Secretions When a person smells, tastes, or sees appetizing food, the parasympathetic nervous system stimulates the gastric glands to secrete their products. Gastrin Gastrin - made by the stomach, also stimulates gastric glands to become active. Chief cells Chief cells - secrete pepsinogen, which becomes pepsin in the presence of acid. Pepsin digests proteins. When a person smells, tastes, or sees appetizing food, the parasympathetic nervous system stimulates the gastric glands to secrete their products. Gastrin Gastrin - made by the stomach, also stimulates gastric glands to become active. Chief cells Chief cells - secrete pepsinogen, which becomes pepsin in the presence of acid. Pepsin digests proteins.

14 Stomach Secretions (cont.) Parietal cells –  secrete hydrochloric acid, that convert pepsinogen to pepsin.  secrete intrinsic factor, which is necessary for vitamin B 12 absorption. Parietal cells –  secrete hydrochloric acid, that convert pepsinogen to pepsin.  secrete intrinsic factor, which is necessary for vitamin B 12 absorption.

15 Small Intestine  Small intestine is a tubular organ that extends from the stomach to the large intestine  Carries out most digestion in the body and is responsible for absorbing most of the nutrients into the bloodstream  Small intestine is a tubular organ that extends from the stomach to the large intestine  Carries out most digestion in the body and is responsible for absorbing most of the nutrients into the bloodstream

16 Small Intestine - Secretions  Peptidases - enzymes that digest proteins.  Intestinal lipase - an enzyme that digests fats  Sucrase, maltase, and lactase - Digest sugars.  Peptidases - enzymes that digest proteins.  Intestinal lipase - an enzyme that digests fats  Sucrase, maltase, and lactase - Digest sugars.  If a person cannot produce lactase, he will not be able to digest lactose, which is the sugar in dairy products - lactose intolerance

17 Apply Your Knowledge Your patients states that she is lactose intolerant. What does that mean?

18 Answer Apply Your Knowledge - Answer She cannot produce lactase and cannot digest lactose, which is the sugar in dairy products; thus, she is lactose intolerant. Your patient states that she is lactose intolerant. What does that mean?

19 Pancreas  Pancreatic amylase - digests carbohydrates  Pancreatic lipase - digests lipids  Nucleases - digests nucleic acids  Trypsin, chymotrypsin, and carboxypeptidase - digest proteins  Pancreas is located behind the stomach.  Pancreatic acinar cells produce pancreatic juice.  Pancreatic juice contains the following enzymes:

20 Liver  Reddish-brown in color  Large organ that fills most of the upper right abdominal quadrant  Has a large right lobe and a small left lobe - separated into smaller divisions called hepatic lobules. Hepatic lobules contain macrophages that destroy bacteria and viruses in the blood  Stores vitamins and iron  Reddish-brown in color  Large organ that fills most of the upper right abdominal quadrant  Has a large right lobe and a small left lobe - separated into smaller divisions called hepatic lobules. Hepatic lobules contain macrophages that destroy bacteria and viruses in the blood  Stores vitamins and iron

21 Liver (cont.)  Each hepatic lobule contains many cells called hepatocytes  Process the nutrients in blood and make bile, which is used in the digestion of fats  Bile leaves the liver through the hepatic duct  Each hepatic lobule contains many cells called hepatocytes  Process the nutrients in blood and make bile, which is used in the digestion of fats  Bile leaves the liver through the hepatic duct

22 Gallbladder  Small sac-like structure located beneath the liver  Only function is to store bile  Cholecystokinin causes the gallbladder to release bile Gallbladder

23 Large Intestine  Large intestine extends from the ileum of the small intestine to where it opens to the outside world as the anus

24 Large Intestine (cont.)  Lining of the large intestine - secretes mucus to aid in the movement of substances  Large intestine absorbs water and a few electrolytes from chyme; the left over forms feces

25 The Absorption of Nutrients  Nutrients are defined as necessary food substances and are absorbed in the small intestine  Carbohydrate  Proteins  Lipids  Vitamins  Minerals  Water

26 Apply Your Knowledge Why can a person live without their gallbladder?

27 Answer Apply Your Knowledge - Answer It’s only purpose is to store bile. As long as a person is still making bile in the liver, they can still digest fats. Why can a person live without their gallbladder?

28 Diseases and Disorders of the Digestive System  Appendicitis - an inflammation of the appendix  Causes  Blockage of appendix with feces  Blockage of appendix with tumor  Treatments  Surgery to remove appendix  Antibiotics to prevent infection Signs and symptoms – lack of appetite, pain in and around the navel area or in the abdomen, nausea, slight fever, pain in the right leg, and increased white blood cell content

29 Diseases and Disorders of the Digestive System  Cirrhosis  Cirrhosis - a long lasting liver disease in which normal liver tissue is replaced with nonfunctional scar tissue, patients can appear jaundiced.  Causes - Excessive alcohol consumption  Hepatitis C infection  Hepatitis B infection  Treatment - Liver transplant  Lifestyle changes  Stop medications  Stop use of alcohol

30 Diseases and Disorders of the Digestive System (cont.)  Celiac Disease - defined as inflammation of the large intestine  Causes – It’s a malabsorptive disorder. An allergic reaction to gluten, a protein present in most grains. The villi and microvilli of the small intestine are destroyed therefore preventing the absorption of nutrients.  Treatments  Gluten free diet Normal villi Celiac Disease villi

31  Cholecystitis - Inflammation of gallbladder.  Causes –Gallstones. They can block the bile duct causing pain in the shoulder blades and digestive disorders and jaundice. Small ones may pass on their own, large ones surgically removed.  Treatment:  Surgical removal of gallbladder = Cholecystectomy Diseases and Disorders of the Digestive System (cont.)

32  Crohn’s disease - a common type of inflammatory bowel disease and is an autoimmune disorder that typically affects the end of the small intestine. There is a chronic inflammation of the intestines, ulcers in the intestines, rectal bleeding, and weight loss and fever.  Causes - this is an autoimmune disorder.  Treatment  Medications to reduce inflammation  Antibiotics  Surgery to remove affected part of intestine  Changes in diet Diseases and Disorders of the Digestive System (cont.)

33  Diverticulitis - inflammation of diverticuli in the intestine. Diverticuli are abnormal dilations in the intestinal wall  Causes – mostly unknown. Lack of fiber in diet and bacterial infection of the diverticuli.  Signs  Abdominal pain  Constipation  Diarrhea & nausea  Fever  Blood in feces  High white blood cell count Diseases and Disorders of the Digestive System (cont.)

34  Gastritis  Gastritis - an inflammation of the stomach lining  Causes - bacteria or viruses, some medications, alcohol, spicy foods, excessive eating poisons, and stress.  Symptoms – diarrhea and dehydration  Treatment  Cook food properly to kill bacteria/viruses  Avoid foods/medications that irritate stomach linings  Begin acid reducing medications Diseases and Disorders of the Digestive System (cont.)

35  Heartburn - called gastroesophageal reflux disease (GERD) - occurs when stomach acids are pushed into the esophagus  Causes – acid reflux, alcohol, some foods, defective esophageal sphincter, pregnancy, obesity, hiatal hernia, and repeated vomiting.  Treatment  Diet changes -avoid chocolate and peppermint, coffee, citrus, fried or fatty foods, tomato products  Reduce alcohol consumption, smoking  Reducing weight  Medications, antacids  Not lying down after meal Diseases and Disorders of the Digestive System (cont.)

36  Hemorrhoids  Hemorrhoids - varicose veins of the rectum or anus  Causes – constipation, excessive straining during bowel movements, liver disease, pregnancy, and obesity.  Treatment  Eating high fiber  Stool softeners  Medications  Surgery Diseases and Disorders of the Digestive System (cont.)

37  Hepatitis  Hepatitis A - inflammation of the liver.  Causes - bacteria, viruses, parasites, immune disorders, the use of alcohol and drugs, and overdose of acetaminophen. Spread through contaminated food or H 2 O.  Treatment  Avoid drugs and alcohol  Prescribed medications  Prevention: Vaccination Diseases and Disorders of the Digestive System (cont.)

38  Ulcer-  Ulcer- Sore or lesion that forms in the mucosal lining of the stomach or in the duodenum. Symptoms include burning pain in abdomen, between meals and early morning, may be relieved by eating or taking antacids. Diagnosis by x-ray, presence of bacteria  Causes - Bacteria is primary cause and lifestyle factors: cigarette smoking, alcohol, stress, certain drugs.  Treatment -  Treatment - H 2 blockers (drugs) that block release of histamine Diseases and Disorders of the Digestive System (cont.)

What Digestive Disorder does Kenny have? Poor Kenny! 39

40 Apply Your Knowledge Your patient has been diagnosed with Crohn’s disease. What is the usual treatment for this disease?

41 Answer Apply Your Knowledge - Answer Treatment for Crohn’s disease includes medications to reduce inflammation, antibiotics, surgery to remove affected part of intestine and/or changes in diet Your patient has been diagnosed with Crohn’s disease. What is the usual treatment for this disease?

Test Your Grey Matter:  Using your power point, text book or the internet as a reference answer the following questions: Kenny is jaundiced. What could have caused this? The medical term that means inflammation of the mucous membrane lining of the stomach and intestines is: When small quantities of stomach acid are regurgitated into the esophagus, the resulting condition is called: Eating proper foods such as cereals, fruits, vegetables, and drinking plenty of fluids can help avoid what condition? The medical term that means surgical removal of the gallbladder is: It is recommended that all healthcare workers be vaccinated for what disease? Hemorrhoids are caused by? A condition in which a sore or lesion forms in the mucosal lining of the stomachs called? 42