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Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Fundamentals of Anatomy & Physiology SIXTH EDITION Frederic H. Martini PowerPoint.

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Presentation on theme: "Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Fundamentals of Anatomy & Physiology SIXTH EDITION Frederic H. Martini PowerPoint."— Presentation transcript:

1 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Fundamentals of Anatomy & Physiology SIXTH EDITION Frederic H. Martini PowerPoint ® Lecture Slide Presentation prepared by Dr. Kathleen A. Ireland, Biology Instructor, Seabury Hall, Maui, Hawaii Chapter 24, part 1 The Digestive System

2 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Learning Objectives Identify the organs of the digestive system and their major functions Outline the mechanisms that regulate digestion Describe the anatomy of the organs and accessory organs of the digestive system Discuss the functions of the major structures and regions of the digestive system and discuss the regulation of their activities

3 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Learning Objectives Explain the significance of the large intestine in the absorption of nutrients Describe the events involved in the digestion of organic and inorganic nutrients Summarize the effects of the aging process on the digestive system

4 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings SECTION 24-1 The Digestive System

5 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings The muscular digestive tract Various accessory organs The Digestive system includes:

6 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24.1 Figure 24.1 The Components of the Digestive System

7 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Ingestion Mechanical processing Digestion Secretion Absorption Excretion Functions of the digestive system

8 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Mesenteries Sheets of serous membranes that support portions of the digestive tract Greater omentum lies anterior to abdominal viscera Provides padding, protection, insulation, and energy reserves Lesser omentum The digestive system organs and the peritoneum

9 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24.2 Mesenteries Figure 24.2a

10 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24.2 Mesenteries Figure 24.2b

11 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24.2 Mesenteries Figure 24.2c

12 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24.2 Mesenteries Figure 24.2d

13 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Mucosa lines digestive tract (mucous epithelium) Moistened by glandular secretions Lamina propria and epithelium form mucosa Submucosa Layer of dense irregular connective tissue Histological organization of the digestive tract

14 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Muscularis externa Smooth muscle arranged in circular and longitudinal layers adventitia Serosa Serous membrane covering most of the muscularis externa Histological organization of the digestive tract

15 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24.3 The Structure of the Digestive Tract Figure 24.3

16 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Visceral smooth muscle shows rhythmic cycles of activity Pacemaker cells Peristalsis Waves that move a bolus Segmentation Churn and fragment a bolus Movement of digestive materials

17 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24.4 Peristalsis Figure 24.4

18 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Movement of materials along the digestive tract is controlled by: Neural mechanisms Parasympathetic and local reflexes Hormonal mechanisms Enhance or inhibit smooth muscle contraction Local mechanisms Coordinate response to changes in pH or chemical stimuli Control of the digestive system

19 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24.5 The Regulation of Digestive Activities Figure 24.5

20 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings SECTION 24-2 The Oral Cavity

21 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Its functions include: Analysis of material before swallowing Mechanical processing by the teeth, tongue, and palatal surfaces Lubrication Limited digestion The mouth opens into the oral or buccal cavity

22 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Lined by oral mucosa Roof of cavity = hard and soft palates Floor of cavity = tongue Uvula guards opening to pharynx Oral cavity

23 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24.6 The Oral Cavity Figure 24.6a, b

24 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings primary functions include: Mechanical processing Assistance in chewing and swallowing Sensory analysis by touch, temperature, and taste receptors The tongue

25 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Extrinsic and intrinsic tongue muscles Innervated by the hypoglossal nerve Tongue movements involve

26 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Parotid, sublingual, and submandibular Saliva watery solution electrolytes, buffers, glycoproteins, antibodies, enzymes Functions include: Lubrication, moistening, and dissolving Initiation of digestion of complex carbohydrates Salivary glands (three pairs) Animation: Mastication Flythrough PLAY

27 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24.7 The Salivary Glands Figure 24.7a, b

28 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Function in mastication of bolus Contact of occlusal surfaces Contain three layers Enamel covering crown Dentin forms basic structure Root coated with cementum Periodontal ligaments hold teeth in alveoli Teeth

29 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings 20 primary teeth AKA deciduous teeth 32 teeth of secondary dentition Eruption of teeth

30 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24.8 Teeth Figure 24.8a, b

31 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24.9 Primary and Secondary Teeth Figure 24.9a, b

32 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings SECTION 24-3 The Pharynx

33 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Common passageway for food, liquids, and air Lined with stratified squamous epithelium Pharyngeal muscles assist in swallowing Pharyngeal constrictor muscles Palatal muscles The pharynx

34 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings SECTION 24-4 The Esophagus

35 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Carries solids and liquids from the pharynx to the stomach Passes through esophageal hiatus in diaphragm The wall of the esophagus contains mucosal, submucosal, and muscularis layers The esophagus

36 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Distinctive features of the esophageal wall include Nonkeratinized, stratified squamous epithelium Folded mucosa and submucosa Mucous secretions by esophageal glands A muscularis with both smooth and skeletal muscle portions Lacks serosa Anchored by an adventitia Histology of the esophagus

37 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure The Esophagus Figure 24.10a-c

38 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Buccal phase Pharyngeal phase Esophageal phase Swallowing (deglutition)

39 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure The Swallowing Process Figure 24.11a-h

40 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings SECTION 24-5 The Stomach

41 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Bulk storage of undigested food Mechanical breakdown of food Disruption of chemical bonds via acids and enzymes Production of intrinsic factor Functions of the stomach

42 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Cardia – superior, medial portion Fundus – portion superior to stomach- esophageal junction Body – area between the fundus and the curve of the J Pylorus – antrum and pyloric canal adjacent to the duodenum Anatomy of the stomach

43 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Phloric Sphincter Guards exit from stomach Rugae Ridges and folds in relaxed stomach Stomach anatomy

44 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure The Stomach Figure 24.12b

45 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Gastric glands Parietal cells Intrinsic factor, and HCl Chief cells Pepsinogen Pyloric glands Mucous secretion containing several hormones Enteroendocrine cells G cells secrete gastrin D cells secrete somatostatin Histology of the stomach

46 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure The Stomach Lining Figure 24.13a, b

47 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure The Stomach Lining Figure 24.13c, d

48 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure Figure The Secretions of Hydrochloric Acid

49 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Cephalic phase prepares stomach to receive ingested material Gastric phase begins with the arrival of food in the stomach Neural, hormonal, and local responses Intestinal phase controls the rate of gastric emptying Regulation of gastric activity

50 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24.15a Figure The Phases of Gastric Secretion

51 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24.15b Figure The Phases of Gastric Secretion

52 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24.15c Figure The Phases of Gastric Secretion

53 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Preliminary digestion of proteins Pepsin Permits digestion of carbohydrates Very little absorption of nutrients Some drugs, however, are absorbed Digestion and absorption in the stomach

54 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings SECTION 24-6 The Small Intestine and Associated Glandular Organs

55 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Important digestive and absorptive functions Secretions and buffers provided by pancreas, liver, gall bladder Three subdivisions: Duodenum Jejunum Ileum Ileocecal sphincter Transition between small and large intestine Small intestine

56 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24.16a Figure Regions of the Small Intestine

57 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Plicae Transverse folds of the intestinal lining Villi Fingerlike projections of the mucosa Lacteals Terminal lymphatic in villus Intestinal glands Lined by enteroendocrine, goblet and stem cells Histology of the small intestine

58 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24.17a Figure The Intestinal Wall

59 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24.17b, c Figure The Intestinal Wall

60 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24.17d, e Figure The Intestinal Wall

61 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Moisten chyme Help buffer acids Maintain digestive material in solution Intestinal juices

62 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Duodenal glands (Brunner’s glands) produce mucus, buffers, urogastrone Ileum aggregated lymphoid nodules (Peyer’s patches) Small Intestine

63 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Peristalsis Segmentation Gastroenteric reflexes Initiated by stretch receptors in stomach Gastroileal reflex Triggers relaxation of ileocecal valve Intestinal movements

64 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Pancreatic duct penetrates duodenal wall Endocrine functions Insulin and glucagons Exocrine functions Majority of pancreatic secretions Pancreatic juice secreted into small intestine Carbohydrases Lipases Nucleases Proteolytic enzymes The pancreas

65 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24.18a-c Figure The Pancreas

66 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Performs metabolic and hematological regulation and produces bile Histological organization Lobules containing single-cell thick plates of hepatocytes Lobules unite to form common hepatic duct Duct meets cystic duct to form common bile duct The liver

67 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24.19a Figure The Anatomy of the Liver

68 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24.19b, c Figure The Anatomy of the Liver

69 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Liver lobule is the basic functional unit of the liver Hepatocytes form irregular plates arranged in spoke-like fashion Bile canaliculi carry bile to bile ductules Bile ductules lead to portal areas

70 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24.20a, b Figure Liver Histology

71 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Hollow, pear-shaped organ Stores, modifies and concentrates bile The gallbladder Animation: Accessory Organ PLAY

72 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24.21a, b Figure The Gallbladder

73 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Neural and hormonal mechanisms coordinate glands GI activity stimulated by parasympathetic innervation Inhibited by sympathetic innervation Enterogastric, gastroenteric and gastroileal reflexes coordinate stomach and intestines Coordination secretion and absorption

74 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure The Activities of Major Digestive Tract Hormones Figure 24.22

75 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings SECTION 24-7 The Large Intestine

76 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Reabsorb water and compact material into feces Absorb vitamins produced by bacteria Store fecal matter prior to defecation Functions of the large intestine

77 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Ascending Transverse Descending Sigmoid The four areas of the colon are:

78 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24.23a Figure The Large Intestine

79 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24.23b, c Figure The Large Intestine

80 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Last portion of the digestive tract Terminates at the anal canal Internal and external anal sphincters The rectum

81 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Absence of villi Presence of goblet cells Deep intestinal glands Histology of the large intestine

82 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Reabsorption in the large intestine includes: Water Vitamins – K, biotin, and B 5 Organic wastes – urobilinogens and sterobilinogens Bile salts Toxins Mass movements of material through colon and rectum Defecation reflex triggered by distention of rectal walls Physiology of the large intestine

83 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure Figure The Defecation Reflex

84 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings SECTION 24-8 Digestion and Absorption

85 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Disassembles organic food into smaller fragments Hydrolyzes carbohydrates, proteins, lipids and nucleic acids for absorption Processing and absorption of nutrients

86 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Begins in the mouth Salivary and pancreatic enzymes Disaccharides and trisaccharides Brush border enzymes Monosaccharides Absorption of monosaccharides occurs across the intestinal epithelia Carbohydrate digestion and absorption

87 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Lipid digestion utilizes lingual and pancreatic lipases Bile salts improve chemical digestion by emulsifying lipid drops Lipid-bile salt complexes called micelles are formed Micelles diffuse into intestinal epithelia which release lipids into the blood as chylomicrons Lipid digestion and absorption

88 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Low pH destroys tertiary and quaternary structure Enzymes used include pepsin, trypsin, chymotrypsin, and elastase Liberated amino acids are absorbed Protein digestion and absorption

89 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Water Nearly all that is ingested is reabsorbed via osmosis Ions Absorbed via diffusion, cotransport, and active transport Vitamins Water soluble vitamins are absorbed by diffusion Fat soluble vitamins are absorbed as part of micelles Vitamin B 12 requires intrinsic factor Absorption

90 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure Digestive Secretion and Absorption of Water Figure 24.27

91 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure Ion and Vitamin Absorption by the Digestive Tract Figure 24.28

92 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings The organs of the digestive system and their major functions The mechanisms that regulate digestion The anatomy of the organs and accessory organs of the digestive system The functions of the major structures and regions of the digestive system and the regulation of their activities You should now be familiar with:

93 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings The significance of the large intestine in the absorption of nutrients The events involved in the digestion of organic and inorganic nutrients You should now be familiar with:


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