Figure 24-1 The Components of the Digestive System Major Subdivisions of the Digestive Tract Mouth Oral Cavity, Teeth, Tongue Mechanical processing, moistening, mixing with salivary secretions Pharynx Muscular propulsion of materials into the esophagus Esophagus Transport of materials to the stomach Stomach Chemical breakdown of materials by acid and enzymes; mechanical processing through muscular contractions Small Intestine Enzymatic digestion and absorption of water, organic substrates, vitamins, and ions Large Intestine p. 864 Enzymatic digestion and absorption of water, organic substrates, vitamins, and ions Anus 1

Figure 24-1 The Components of the Digestive System Accessory Organs of the Digestive System Salivary glands Secretion of lubricating fluid containing enzymes that break down carbohydrates Liver Secretion of bile (important for lipid digestion), storage of nutrients, many other vital functions Gallbladder Storage and concentration of bile Pancreas Exocrine cells secrete buffers and digestive enzymes; endocrine cells secrete hormones p. 864 2

Figure 24-2b Mesenteries Greater omentum (cut) Lesser omentum Transverse mesocolon Mesocolon of ascending and descending colons fused to posterior portion of the parietal peritoneum Transverse colon Ascending colon Mesentery proper (mesenterial sheet) Descending colon Small intestine Sigmoid colon A diagrammatic view of the organization of mesenteries in an adult. p. 866 3

p. 866 Figure 28-2c Mesenteries Falciform ligament Diaphragm Inferior vena cava Esophagus Coronary ligament of liver Pancreas Left kidney Right kidney Attachment of transverse mesocolon Duodenum Position of ascending colon Superior mesenteric artery and vein Position of descending colon Root of mesentery proper Attachment of sigmoid mesocolon Rectum Parietal peritoneum Urinary bladder p. 866 An anterior view of the empty peritoneal cavity, showing the attachment of mesenteries to the posterior body wall. 4

Figure 24-2d Mesenteries Falciform ligament Diaphragm Liver Lesser omentum Stomach Pancreas Transverse mesocolon Duodenum Transverse colon Mesentery proper Greater omentum Sigmoid mesocolon Parietal peritoneum Rectum Small intestine Urinary bladder Uterus p. 866 A sagittal section showing the mesenteries of an adult. Notice that the pancreas, duodenum, and rectum are retroperitoneal. 5

Figure 24-3 The Structure of the Digestive Tract Mesenteric artery and vein Plica circulares Mesentery Mucosa Submucosa Muscularis externa p. 867 Serosa (visceral peritoneum) 6

Figure 24-3 The Structure of the Digestive Tract Plica circulares Mucosal epithelium Mucosa Lamina propria Villi Mucosal glands Submucosal gland Muscularis mucosae Lymphatic vessel Mucosa Artery and vein Submucosa Submucosal plexus Muscularis externa Circular muscle layer p. 867 Serosa (visceral peritoneum) Myenteric plexus Longitudinal muscle layer 7

Figure 24-5 The Regulation of Digestive Activities Neural Control Mechanisms CNS Long reflex Myenteric plexus Short reflex Peristalsis and segmentation movements Stretch receptors, chemoreceptors Buffers, acids, enzymes released Secretory cells Hormonal Control Mechanisms Local Factors Via the bloodstream Enteroendocrine cells p. 869 Hormones released 8

Figure 24-6a The Oral Cavity Hard palate Soft palate Nasal cavity Palatoglossal arch Pharyngeal tonsil Opening of parotid duct Entrance to auditory tube Upper lip Nasopharynx Cheek Uvula Dorsum of tongue Palatine tonsil Fauces Lower lip Palatopharyngeal arch Gingiva Vestibule Oropharynx Lingual tonsil Body of tongue Epiglottis Hyoid bone Root of tongue Laryngopharynx p. 870 A sagittal section of the oral cavity 9

Figure 24-6b The Oral Cavity Hard palate Soft palate Fauces Uvula Palatoglossal arch Palatopharyngeal arch Palatine tonsil Tongue Lingual frenulum Gingiva Vestibule Openings of submandibular ducts p. 870 An anterior view of the oral cavity as seen through the open mouth 10

Figure 24-7a The Salivary Glands Openings of sublingual ducts Lingual frenulum Parotid salivary gland Parotid duct Opening of left submandibular duct Submandibular duct Sublingual salivary gland Submandibular salivary gland A lateral view, showing the relative positions of the salivary glands and ducts on the left side of the head. p. 872 11

Bicuspids (premolars) Figure 24-8b Teeth Incisors Cuspids (canines) Bicuspids (premolars) Molars Upper jaw Lower jaw The adult teeth from the right side of the upper and lower jaws. Figure 24-9a,b provides a view of the occlusal surfaces. p. 873 12

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p. 873 A diagrammatic section through a typical adult tooth. Enamel Figure 24-8a Teeth Enamel Crown Dentin Pulp cavity Gingiva Gingival sulcus Neck Cementum Periodontal ligament Root Root canal Bone of alveolus Apical foramen p. 873 Branches of alveolar vessels and nerve A diagrammatic section through a typical adult tooth. 14

© 2012 Pearson Education, Inc. Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings © 2012 Pearson Education, Inc.

© 2012 Pearson Education, Inc. Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

© 2012 Pearson Education, Inc. Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

© 2012 Pearson Education, Inc. http://www.youtube.com/watch?v=Q-n_Q0qKXzg&feature=related p. 868 Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

© 2012 Pearson Education, Inc. Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

© 2012 Pearson Education, Inc. Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Figure 24-13a The Stomach Lining Layers of the Stomach Wall Mucosa Gastric pit (opening to gastric gland) Mucous epithelium Lamina propria Muscularis mucosae Submucosa Artery and vein Muscularis externa Oblique muscle Circular muscle p. 880 Lymphatic vessel Longtudinal muscle Myenteric plexus Serosa Stomach wall 21

Figure 24-13b The Stomach Lining Lamina propria Gastric pit Mucous cells Neck Cells of Gastric Glands Parietal cells Gastric gland G cell Chief cells p. 880 Smooth muscle cell Gastric gland 22

© 2012 Pearson Education, Inc. Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings p. 884

© 2012 Pearson Education, Inc. Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings p. 884

© 2012 Pearson Education, Inc. Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings p. 885

© 2012 Pearson Education, Inc. Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings © 2012 Pearson Education, Inc.

© 2012 Pearson Education, Inc. Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings © 2012 Pearson Education, Inc.

Figure 24-17b The Intestinal Wall Villi Intestinal crypt Lymphoid nodule Lacteal Layers of the Small Intestine Submucosal artery and vein Mucosa Lymphatic vessel Muscularis mucosae Submucosal plexus Submucosa Circular layer of smooth muscle Muscularis externa Myenteric plexus Serosa Longitudinal layer of smooth muscle p. 887 The organization of the intestinal wall 28

© 2012 Pearson Education, Inc. Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

© 2012 Pearson Education, Inc. Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

© 2012 Pearson Education, Inc. Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

© 2012 Pearson Education, Inc. Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings p. 899

Figure 24-25a The Mucosa and Glands of the Colon Taenia coli Fatty appendices Haustrum Simple columnar epithelium Goblet cells Intestinal crypt Muscularis mucosae Submucosa Serosa Aggregated lymphoid nodule Longitudinal layer (taenia coli) Circular layer p. 901 Muscularis externa 33

Figure 24-25b The Mucosa and Glands of the Colon Simple columnar epithelium Goblet cells Intestinal crypt Muscularis mucosae Submucosa Serosa p. 901 The colon LM  114 34

Figure 24-28 Digestive Secretion and Absorption of Water Digestive Secretions Dietary Input Food and drink 2000 mL Saliva 1500 mL Gastric secretions 1500 mL 5000 mL Liver (bile) 1000 mL Pancreas (pancreatic juice) 1000 mL Water Reabsorption Intestinal secretions 2000 mL 9000 mL Small intestine reabsorbs 7800 mL 1200 mL Colonic mucous secretions 200 mL Colon reabsorbs 1250 mL 1400 mL p. 907 150 mL lost in feces 35