2. Four General Functions Ingestion Ingestion Digestion Digestion Absorption Absorption Excretion Excretion

3. Digestion The breaking down of food by both chemical and mechanical means into usable forms. The breaking down of food by both chemical and mechanical means into usable forms.

4. Types of Digestion Mechanical Digestion – Physically breaking down of food into smaller pieces: Mechanical Digestion – Physically breaking down of food into smaller pieces: -Grinding of teeth to soften food -Churning of food by smooth muscles to mix with digestive enzymes Chemical Digestion - series of catabolic reactions that break down large molecules into smaller molecules. Chemical Digestion - series of catabolic reactions that break down large molecules into smaller molecules.

5. Absorption The passage of digested food from the alimentary canal into the cardiovascular and lymphatic systems for transportation to body cells

6. Defecation (Excretion) The elimination of indigestible substances from the alimentary canal

7. Ingestion Taking food into the body (EATING)

8. Processes of the Digestive System Mastication – chewing Mastication – chewing Movement of skeletal muscles to close the mandible or jaw to help move the teeth break down food. Movement of skeletal muscles to close the mandible or jaw to help move the teeth break down food.

9. Maceration Muscular waves in the stomach which mix food with the gastric juice forming a liquid paste called chyme. Occurs in the stomach. Muscular waves in the stomach which mix food with the gastric juice forming a liquid paste called chyme. Occurs in the stomach.

10. Segmentation Short small mixing movements of the alimentary canal. Muscle contractions to mix the chyme with enzymes and other secretions. Some propulsion of the chyme also occurs. Short small mixing movements of the alimentary canal. Muscle contractions to mix the chyme with enzymes and other secretions. Some propulsion of the chyme also occurs.

11. Peristalsis Involuntary wave like smooth muscle contractions to propel food chime & wastes through the alimentary canal. Involuntary wave like smooth muscle contractions to propel food chime & wastes through the alimentary canal.

12. Haustral Churning Movement of wastes along the large intestine by the contraction of pouches (haustra). Slow, segmental churning helps to facilitate water reabsorption. Slow, segmental churning helps to facilitate water reabsorption.

13. Gastrointestinal Tract (Alimentary Canal) A continuous tube extending through the ventral cavity extending from the mouth to the anus A continuous tube extending through the ventral cavity extending from the mouth to the anus Organs of the Alimentary Canal Organs of the Alimentary Canal –mouth - pharynx - esophagus –stomach -small intestine - large intestine

14. Diagram of the Alimentary Canal

15. Accessory Organs Organs that help with digestion by secreting chemicals such as enzymes and bile. –salivary glands –liver –gallbladder - pancreas

16. Accessory Organs

17. Oral Cavity – The Mouth

18. Mouth (Oral or Buccal Cavity) Cheeks Cheeks Lips Lips Hard Palate Hard Palate Soft Palate Soft Palate –Uvula Tongue Tongue –Papillae –Lingual Frenulum

19. Salivary Glands Paired accessory structures that lie outside the oral cavity Paired accessory structures that lie outside the oral cavity Secrete their contents (saliva) into ducts that empty into the mouth Secrete their contents (saliva) into ducts that empty into the mouth Parotid Glands - underneath the ears Parotid Glands - underneath the ears Submandibular Glands - under the mandible Submandibular Glands - under the mandible Sublingual Glands - under the tongue Sublingual Glands - under the tongue

20. Salivary Glands Accessory structures of the digestive system Accessory structures of the digestive system Deciduous teeth (baby teeth) - 20 Deciduous teeth (baby teeth) - 20 Permanent teeth - 32 Permanent teeth - 32 Incisors (8) - 4 on top, 4 on bottom Incisors (8) - 4 on top, 4 on bottom –chisel shaped - front of mouth Canines (4) - 2 on top, 2 on bottom Canines (4) - 2 on top, 2 on bottom –sharp pointed tearing teeth Premolars (8) - 4 on top, 4 on bottom Premolars (8) - 4 on top, 4 on bottom Molars (12) - 6 on top, 6 on bottom Molars (12) - 6 on top, 6 on bottom –broad, flat, crushing teeth

21. Saliva and Salivary Amylase Salivary glands produce saliva which includes 99.5 % water, mucin, bicarbonate ions, and the enzyme, salivary amylase. Salivary glands produce saliva which includes 99.5 % water, mucin, bicarbonate ions, and the enzyme, salivary amylase. Salivary amylase helps to chemically break down starch into the disaccharide maltose. Salivary amylase helps to chemically break down starch into the disaccharide maltose.

22. Digestion in the Mouth Mechanical Digestion Mechanical Digestion –Chewing (Mastication) Tongue manipulates the food Tongue manipulates the food Teeth grind up the food and mix it with saliva Teeth grind up the food and mix it with saliva The result of mechanical digestion is a soft flexible mass of food called a bolus The result of mechanical digestion is a soft flexible mass of food called a bolus Chemical Digestion Chemical Digestion –Salivary amylase initiates the breakdown of carbohydrates –Only chemical digestion in the mouth

23. Digestion of Starch by Salivary Amylase Digestion of Starch by Salivary Amylase

24. Teeth

25. Tooth Structures

26. Anatomy of a Tooth Crown - exposed portion of the tooth above the gum line Crown - exposed portion of the tooth above the gum line Neck - constricted junction line in the tooth between the crown and the root Neck - constricted junction line in the tooth between the crown and the root Root - one to three projections of the tooth that are embedded in the sockets of the alveolar processes of the mandible and maxillae Root - one to three projections of the tooth that are embedded in the sockets of the alveolar processes of the mandible and maxillae

27. Anatomy of a Tooth Enamel - outermost portion of the tooth, protects the tooth from wear and tear Enamel - outermost portion of the tooth, protects the tooth from wear and tear –the hardest substance in the body Dentin - calcified connective tissue that gives the tooth its basic shape and rigidity Dentin - calcified connective tissue that gives the tooth its basic shape and rigidity Pulp – fleshy part of the tooth that is enclosed by the dentin. It contains the blood vessels and nerves. Pulp – fleshy part of the tooth that is enclosed by the dentin. It contains the blood vessels and nerves. Cementum - a bone-like substance that covers the dentin of the root Cementum - a bone-like substance that covers the dentin of the root

28. Anatomy of a Tooth Gingiva – the gums or epithelial tissue that help to protect the root of the tooth. Gingiva – the gums or epithelial tissue that help to protect the root of the tooth. Periodontal Ligament - dense fibrous connective tissue, anchor teeth in position. Serves as a shock absorber when chewing. Periodontal Ligament - dense fibrous connective tissue, anchor teeth in position. Serves as a shock absorber when chewing.

29. Anatomy of a Tooth Root Canal – the openings in the root that allows for the passage of blood vessels and nerves. Root Canal – the openings in the root that allows for the passage of blood vessels and nerves.

30. Processes of the Digestive System Deglutition – swallowing Deglutition – swallowing

31. Swallowing (Deglutition) Moving food from the mouth to the stomach Moving food from the mouth to the stomach Voluntary Stage - bolus is moved through the mouth into the oropharynx Voluntary Stage - bolus is moved through the mouth into the oropharynx Pharyngeal Stage - involuntary passage of the bolus through the pharynx and into the esophagus Pharyngeal Stage - involuntary passage of the bolus through the pharynx and into the esophagus Esophageal Stage - involuntary passage of the bolus through the esophagus and into the stomach Esophageal Stage - involuntary passage of the bolus through the esophagus and into the stomach

32. Pharynx Also called the throat. Also called the throat. Serves as a passageway for food and air. Serves as a passageway for food and air. Also helps in the formation of words. Also helps in the formation of words.

33. Esophagus About 10 inches long. Located posterior to the trachea. About 10 inches long. Located posterior to the trachea. Does not participate in digestive processes – transportation of the bolus to the stomach by peristaltic action. Moves food down into the stomach Does not participate in digestive processes – transportation of the bolus to the stomach by peristaltic action. Moves food down into the stomach –Esophageal hiatus - opening in the diaphragm for the esophagus –Joins the stomach at the cardiac opening.

34. Peristalsis

35. Lining of the Esophagus

36. Stomach J-shaped enlargement of the digestive tract located just below the diaphragm J-shaped enlargement of the digestive tract located just below the diaphragm Superior portion - continuation of the esophagus Superior portion - continuation of the esophagus Inferior portion empties into the duodenum through the pylorus. Inferior portion empties into the duodenum through the pylorus. Position and size of the stomach varies from individual to individual Position and size of the stomach varies from individual to individual

37. Histology of the Stomach Composed of the same four tissue types as the other structures of the alimentary canal Composed of the same four tissue types as the other structures of the alimentary canal When the stomach is empty the mucosa lie in large folds called rugae When the stomach is empty the mucosa lie in large folds called rugae Mucosa contains millions of tiny openings called gastric pits that open into gastric glands Mucosa contains millions of tiny openings called gastric pits that open into gastric glands –Secretes digestive enzymes and a fluid called gastric juice (2-3 liter per day)

38. Anatomy of the Stomach Cardiac Opening – where the stomach is connected to the esophagus. Is not a true sphincter as food can flow into and out of the stomach. Cardiac Opening – where the stomach is connected to the esophagus. Is not a true sphincter as food can flow into and out of the stomach. Fundus -The rounded superior part of the stomach that will expand. Acts as a temporary storage for food. Fundus -The rounded superior part of the stomach that will expand. Acts as a temporary storage for food. Body -The large central portion of the stomach below the fundus. Body -The large central portion of the stomach below the fundus. Pylorus- narrow, inferior region of stomach that connects it to the small intestine. Pylorus- narrow, inferior region of stomach that connects it to the small intestine.

39. Anatomy of the Stomach, p.2 Rugae - Folds of the stomach that allow for stretching with the intake of food. Rugae - Folds of the stomach that allow for stretching with the intake of food. Pyloric Sphincter – the one way valve between the stomach and the duodenum Pyloric Sphincter – the one way valve between the stomach and the duodenum (first part of the small intestine)

40. Anatomy of the Stomach

41. Stomach Structures

42. Secretory Cells of the Gastric Glands Chief Cells Chief Cells –Digestive enzymes –Pepsinogen activated by HCl and converted to –Pepsin which breaks down protein Parietal Cells Parietal Cells –HCl – Hydrochloric Acid Goblet Cells Goblet Cells –Secrete mucus to protect the stomach mucosa from the acidic environment

43. Histology of the Stomach

44. Gastric Gland

45. Mechanical Digestion in the Stomach Several minutes after food enters, the stomach generates mixing waves that churns the food inside - maceration Several minutes after food enters, the stomach generates mixing waves that churns the food inside - maceration Food mixes with gastric juices and is converted into a thin liquid called chyme Food mixes with gastric juices and is converted into a thin liquid called chyme

46. Chemical Digestion in the Stomach Cephalic Phase - reflexes initiated by sensory receptors in the head. Gastric juices are excreted. Cephalic Phase - reflexes initiated by sensory receptors in the head. Gastric juices are excreted. –sight-smell - taste -thought of food Gastric Phase - sensory receptors in the alimentary canal and stomach initiate nervous and hormonal chemical digestive processes Gastric Phase - sensory receptors in the alimentary canal and stomach initiate nervous and hormonal chemical digestive processes Intestinal Phase - secretion of stomach enzymes that removes nutrients from food Intestinal Phase - secretion of stomach enzymes that removes nutrients from food Can absorb water if dehydrated. Medication like aspirin, ethanol and caffeine. Can absorb water if dehydrated. Medication like aspirin, ethanol and caffeine.

47. Absorption in the Stomach Does not participate in the absorption of food molecules into the blood Does not participate in the absorption of food molecules into the blood However, can absorb some substances through the stomach wall However, can absorb some substances through the stomach wall –Water –Weak glucose concentrations –Electrolytes –Certain drugs (aspirin) –Alcohol

48. Small Intestine The next part of the alimentary canal. The next part of the alimentary canal. Divided into three sections – the duodenum, jejunum, and ileum. Divided into three sections – the duodenum, jejunum, and ileum. In the duodenum, chemical digestion is completed. In the duodenum, chemical digestion is completed. The majority of nutrients are absorbed in the jejunum and ileum. The majority of nutrients are absorbed in the jejunum and ileum.

49. The Small Intestine Duodenum - the beginning of the small intestine where it attaches to the stomach Duodenum - the beginning of the small intestine where it attaches to the stomach –First 6 inches Jejunum - the portion of the small intestine right after the duodenum Jejunum - the portion of the small intestine right after the duodenum –Normally about 8 ft. long Ileum - the final portion of the small intestine Ileum - the final portion of the small intestine –About 12 ft. long –Ileocecal valve

50. The Small Intestine

51. Chemical Digestion of the Small Intestine Complex series of chemical events that results in the breakdown of carbohydrates, fats, and proteins Complex series of chemical events that results in the breakdown of carbohydrates, fats, and proteins Result of the collective effort of pancreatic juice, bile, and intestinal juice which contain digestive enzymes Result of the collective effort of pancreatic juice, bile, and intestinal juice which contain digestive enzymes Results in absorption - passage of digested nutrients into the blood or lymph Results in absorption - passage of digested nutrients into the blood or lymph

52. Plicae Circulares

53. Modifictions of the Small Intestine Villi – Finger-like extensions of the mucosa to increase surface area for absorption of nutrients. Villi – Finger-like extensions of the mucosa to increase surface area for absorption of nutrients. Lacteal – lymphatic vessel for lipid absorption. Lacteal – lymphatic vessel for lipid absorption.

54. Villi in Duodenum

55. Absorption in the Small Intestine 90% of absorption takes place within the small intestine 90% of absorption takes place within the small intestine –Remaining 10% occurs in the stomach and large intestine Absorption of nutrients occurs through the villi by means of: Absorption of nutrients occurs through the villi by means of: –diffusion- facilitated diffusion –osmosis- active transport

56. Villi of Small Intestine

57. Villi with Lacteal

58. Small Intestine Absorption

59. Nutrient Absorption

60. Additional Components of the Small Intestine Intestinal Juice - slightly alkaline secretion (pH 7.6) secreted by intestinal glands Intestinal Juice - slightly alkaline secretion (pH 7.6) secreted by intestinal glands –rapidly absorbed by the villi and provides a mechanism for absorption of substances in chyme Peyer’s Patches - lymphatic glands of the small intestine Peyer’s Patches - lymphatic glands of the small intestine Brunner’s Glands - mucus secreting glands of the small intestine Brunner’s Glands - mucus secreting glands of the small intestine

61. Mechanical Digestion of the Small Intestine Segmentation - localized contraction of muscles of the small intestine in areas containing food Segmentation - localized contraction of muscles of the small intestine in areas containing food –Rate of about 12 - 16 contractions/minute –Sloshing of chyme back and forth within the intestinal lumen Peristalsis - rhythmical contraction of muscles of the small intestines that propels chyme through the intestinal tract Peristalsis - rhythmical contraction of muscles of the small intestines that propels chyme through the intestinal tract

62. Large Intestine The last part of the alimentary canal. The last part of the alimentary canal. Responsible for the absorption of water, compaction of feces, and the production of Vitamin K. Responsible for the absorption of water, compaction of feces, and the production of Vitamin K.

63. The Large Intestine About 1.5 m (5 ft) in length About 1.5 m (5 ft) in length Cecum - beginning of the large intestine Cecum - beginning of the large intestine –Vermiform appendix Colon - large tube-like portion of large intestine Colon - large tube-like portion of large intestine –Ascending colon - Transverse colon –Descending colon - Sigmoid colon Rectum Rectum Anal Canal Anal Canal Anus Anus

64. Functions of the Large Intestine Completion of absorption Completion of absorption Reabsorption of water Reabsorption of water Manufacture of certain vitamins (K) Manufacture of certain vitamins (K) Formation of feces Formation of feces Expulsion of feces from the body Expulsion of feces from the body

65. Histology of the Large Intestine Walls of the large intestine contain no villi or permanent circular folds in the mucosa layer Walls of the large intestine contain no villi or permanent circular folds in the mucosa layer Epithelial tissue layer contain numerous goblet cells (secretes mucus) Epithelial tissue layer contain numerous goblet cells (secretes mucus) Lubricates the colonic contents as it passes through the large intestine Lubricates the colonic contents as it passes through the large intestine

66. Haustra - series of characteristic pouch like structures that run the entire length of the colon Haustra - series of characteristic pouch like structures that run the entire length of the colon Taenia Coli - bands of smooth muscle that are arranged longitudinally along the length of the colon Taenia Coli - bands of smooth muscle that are arranged longitudinally along the length of the colon Anal Columns - parallel ridges of mucosa in the anal canal which reduces friction with feces during defecation Anal Columns - parallel ridges of mucosa in the anal canal which reduces friction with feces during defecation

67. Large Intestine Histology

68. Large Intestine Structures

69. Mechanical Digestion in the Large Intestine Haustral Churning - the relaxation and contraction of the individual segments of the colon Haustral Churning - the relaxation and contraction of the individual segments of the colon Peristalsis - rhythmical contraction of the colon that moves the contents along through the length of the colon Peristalsis - rhythmical contraction of the colon that moves the contents along through the length of the colon Mass Peristalsis - a strong peristaltic wave that begins about the middle of the transverse colon and drives the colonic contents into the rectum Mass Peristalsis - a strong peristaltic wave that begins about the middle of the transverse colon and drives the colonic contents into the rectum

70. Chemical Digestion in the Large Intestine Last stage of digestion Last stage of digestion Due to bacterial action in the large intestine Due to bacterial action in the large intestine Bacteria ferment any remaining carbohydrates and release hydrogen, carbon dioxide, and methane gas Bacteria ferment any remaining carbohydrates and release hydrogen, carbon dioxide, and methane gas Also converts any remaining proteins into amino acids Also converts any remaining proteins into amino acids Absorbs any remaining water and electrolytes Absorbs any remaining water and electrolytes

71. Feces Formation in the Large Intestine By the time chyme has remained in the large intestine for 3 - 10 hours it has become a solid or semi-solid and is known as feces By the time chyme has remained in the large intestine for 3 - 10 hours it has become a solid or semi-solid and is known as feces Consists of water, inorganic salts, sloughed off epithelial cells, products from bacterial decomposition, and indigestible parts of food Consists of water, inorganic salts, sloughed off epithelial cells, products from bacterial decomposition, and indigestible parts of food

72. Defecation The emptying of the rectum The emptying of the rectum Diarrhea - frequent defecation of liquid feces Diarrhea - frequent defecation of liquid feces Constipation - infrequent or difficult defecation Constipation - infrequent or difficult defecation

73. Diagram of Accessory Organs

74. Pancreas Oblong gland that lies posterior to the greater curvature of the stomach Oblong gland that lies posterior to the greater curvature of the stomach Connected by the pancreatic duct to the duodenum Connected by the pancreatic duct to the duodenum Composed of clusters of glandular epithelial cells. Composed of clusters of glandular epithelial cells. Pancreas is the only organ classified as both an endocrine AND an exocrine gland. Pancreas is the only organ classified as both an endocrine AND an exocrine gland.

75. Pancreas

76. Pancreas Two main types of Pancreatic Cells: Two main types of Pancreatic Cells: –Pancreatic Islets-Islets of Langerhans (1%) Hormones: insulin, glucagon, somatostatin Hormones: insulin, glucagon, somatostatin –Acini Cells (99%) Digestive pancreatic enzymes Digestive pancreatic enzymes

77. Pancreatic Juice Alkaline mixture of fluid and digestive enzymes from the acini cells Alkaline mixture of fluid and digestive enzymes from the acini cells Pancreatic digestive enzymes: Pancreatic digestive enzymes: –Pancreatic amylase - carbohydrate digestion –Pancreatic lipase - fat digestion –Chymotrypsin-Trypsin-Carboxypeptidase - protein digestion –Nucleases - nucleic acid digestion Regulated by the intestinal hormones secretin and cholecystokinin Regulated by the intestinal hormones secretin and cholecystokinin

78. Liver and Pancreas

79. Liver Located inferior to the diaphragm on the right side of the body Located inferior to the diaphragm on the right side of the body Largest organ of the abdominopelvic cavity Largest organ of the abdominopelvic cavity Weighs about 1.4 kgs (3 lbs) Weighs about 1.4 kgs (3 lbs) Completely covered by the peritoneum and a dense layer of connective tissue beneath the peritoneum Completely covered by the peritoneum and a dense layer of connective tissue beneath the peritoneum Responsible for MANY regulatory functions for the body. Responsible for MANY regulatory functions for the body.

80. Lobules of the Liver Smaller functional units of the liver Smaller functional units of the liver Hepatocytes in the lobules produce bile which is a yellowish, brownish, or olive green liquid (1 quart daily) Hepatocytes in the lobules produce bile which is a yellowish, brownish, or olive green liquid (1 quart daily) –Composed of bile salts and pigments, lecithin, and several ions –pH of 7.6 - 8.6 –Excretory product and digestive secretion –Assists in the breakdown of fat molecules (emulsification) –Principle bile pigment is bilirubin

81. Functions of the Liver Metabolism of carbohydrates, fats, and proteins Metabolism of carbohydrates, fats, and proteins Removal of drugs and hormones Removal of drugs and hormones Synthesis and excretion of bile Synthesis and excretion of bile Storage of vitamins, minerals, and food molecules Storage of vitamins, minerals, and food molecules Phagocytosis of old worn out red and white blood cells Phagocytosis of old worn out red and white blood cells Activation of Vitamin D Activation of Vitamin D Storage of glucose and glycogen Storage of glucose and glycogen

82. The Gallbladder A pear shaped sac about 7 - 10 cm long A pear shaped sac about 7 - 10 cm long Located on the inferior surface of the liver Located on the inferior surface of the liver Stores and concentrates bile until it is needed by the small intestine for the emulsification of fat Stores and concentrates bile until it is needed by the small intestine for the emulsification of fat

83. Gallbladder

84. Bile Pathway

85. Summary of Digestion Mouth Mouth –Ingestion –Mastication – form a bolus as food mixes with saliva. –Digestion of carbohydrates with amylase (starch to maltose) –Deglutition

86. Summary of Digestion Pharynx Pharynx –Peristalsis Esophagus Esophagus –Peristalsis

87. Summary of Digestion Stomach Stomach –Maceration and formation of chyme as the bolus mixes with gastric juices. –Digestion of proteins to dipeptides by the enzyme, pepsin. –Peristalsis continues

88. Summary of Digestion Small Intestine Small Intestine –Segmentation –Digestion of carbohydrates, lipids, and proteins is completed (mostly in the duodenum) –Nutrient absorption (mostly in the ileum and jejunum) –Peristalsis

89. Summary of Digestion Large Intestine Large Intestine –Peristalsis –Haustral churning –Absorption of some vitamins –Absorption of water –Formation and compaction of feces. –Excretion

90. Digestive System Diseases and Homeostatic Imbalances

91. Appendicitis Inflammation of the vermiform appendix Inflammation of the vermiform appendix Can be caused by an obstruction of the lumen of the appendix by fecal material, a foreign body, stenosis, kinking of the organ, or carcinoma Can be caused by an obstruction of the lumen of the appendix by fecal material, a foreign body, stenosis, kinking of the organ, or carcinoma

92. Cirrhosis of the Liver Distorted or scarred liver tissue due to chronic inflammation Distorted or scarred liver tissue due to chronic inflammation Commonly caused by hepatitis, chemical exposure, parasites, and alcoholism Commonly caused by hepatitis, chemical exposure, parasites, and alcoholism Symptoms include: jaundice, bleeding, edema, and increased sensitivity to drugs and chemicals Symptoms include: jaundice, bleeding, edema, and increased sensitivity to drugs and chemicals

93. Cirrhosis of the Liver

94. Effects of Cirrhosis

95. Colorectal Cancer –Can occur in all areas of the digestive system. 3rd most common cause of cancer for both males and females. Can be benign or malignant. –Overall mortality rate is over 60% –Factors contributing to colorectal cancer include genetic predisposition, diet high in fat, protein, insufficient dietary fiber, and low calcium and selenium in the diet

96. Colorectal Cancer

98. Gall Stones Crystallization of bile in the gallbladder Crystallization of bile in the gallbladder Medical Term -- Cholelithiasis Medical Term -- Cholelithiasis Can block the bile duct causing intense pain Can block the bile duct causing intense pain Usually treated with gall stone dissolving drugs, lithotripsy, or surgery Usually treated with gall stone dissolving drugs, lithotripsy, or surgery

99. Gallstones

100. Gallstones

101. Hepatitis Inflammation of the liver Inflammation of the liver Can be caused by viruses, drugs, and certain chemicals including steroids and alcohol Can be caused by viruses, drugs, and certain chemicals including steroids and alcohol Many different types of Hepatitis including: Many different types of Hepatitis including: –Hepatitis A (Infectious Hepatitis) –Hepatitis B (Serum Hepatitis)

103. Hepatitis A Infectious hepatitis Infectious hepatitis Caused by Hepatitis A virus Caused by Hepatitis A virus Spread by fecal contamination of food, clothing, toys, eating utensils, etc. Spread by fecal contamination of food, clothing, toys, eating utensils, etc. Generally a mild disease of children and young adults Generally a mild disease of children and young adults Characterized by anorexia, malaise, jaundice, nausea, diarrhea, fever, and chills Characterized by anorexia, malaise, jaundice, nausea, diarrhea, fever, and chills

104. Hepatitis B Serum hepatitis Serum hepatitis Caused by the Hepatitis B virus Caused by the Hepatitis B virus Transmitted by sexual contact, contaminated syringes, transfusion equipment, saliva, tears, and puncture wounds in the skin Transmitted by sexual contact, contaminated syringes, transfusion equipment, saliva, tears, and puncture wounds in the skin Can produce cirrhosis and possibly cancer of the liver Can produce cirrhosis and possibly cancer of the liver

105. Hepatitis

106. Obesity Clinically classified as obese if: Clinically classified as obese if: –Body Mass Index >30 –Females greater than 30% of normal body weight –Males greater than 20% of normal body weight

107. U.S. surgeon general has said obesity is a serious threat to the health of Americans U.S. surgeon general has said obesity is a serious threat to the health of Americans A serious risk factor for: A serious risk factor for: –Heart Disease - Diabetes –Hypertension - Cancers –Respiratory Disorders –Endocrine Disorders –Gastrointestinal Disorders –Urinary and Reproductive System Disorders

108. Obesity

109. Ulcers Crater like lesions that develop in the gastrointestinal tract Crater like lesions that develop in the gastrointestinal tract Gastric Ulcers ---> Stomach Gastric Ulcers ---> Stomach Duodenal Ulcers ---> Duodenum Duodenal Ulcers ---> Duodenum Commonly caused by hypersecretion of gastric juices and acids Commonly caused by hypersecretion of gastric juices and acids Contributing factors include: stress, cigarette smoking, certain foods, some medications, and bacterial infections Contributing factors include: stress, cigarette smoking, certain foods, some medications, and bacterial infections

110. Ulcers

111. Ulcers

112. Celiac Disease A digestive and autoimmune disorder that results in damage to the lining of the small intestine when foods with gluten are eaten. Gluten is a protein found in some grains. The damage to the intestine makes it hard for the body to absorb nutrients, especially fat, calcium, iron, and folate. A digestive and autoimmune disorder that results in damage to the lining of the small intestine when foods with gluten are eaten. Gluten is a protein found in some grains. The damage to the intestine makes it hard for the body to absorb nutrients, especially fat, calcium, iron, and folate.

113. Celiac Disease

115. Crohn’s Disase Crohn's disease is a chronic disease that causes inflammation—irritation or swelling—in the gastrointestinal (GI) tract. Crohn's disease is a chronic disease that causes inflammation—irritation or swelling—in the gastrointestinal (GI) tract. Most commonly, Crohn's affects the ileum of the small intestine and the beginning of the large intestine. Most commonly, Crohn's affects the ileum of the small intestine and the beginning of the large intestine.

116. Crohn’s Disease

118. Irritable Bowel Syndrome Irritable bowel syndrome commonly causes cramping, abdominal pain, bloating, gas, diarrhea and constipation. Irritable bowel syndrome commonly causes cramping, abdominal pain, bloating, gas, diarrhea and constipation. IBS is a chronic condition. IBS is a chronic condition. IBS does not cause changes in the tissues of the intestine. IBS does not cause changes in the tissues of the intestine.

119. Irritable Bowel Syndrome