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Digestive System Digestive System VIBS 443/602 esophagus stomach intestine OBJECTIVES TO UNDERSTAND THE GENERAL ORGANIZATION OF ORGANS OF THE DIGESTIVE SYSTEM AND HOW THEY FUNCTION TO OBTAIN METABOLITES NECESSARY FOR GROWTH AND ENERGY FOR THE BODY, YET MAINTAIN A BARRIER BETWEEN THE ENVIRONMENT AND THE INTERNAL MILIEU OF THE BODY Digestive tract functions as part of the First of Defense against infections •FIRST LINE - PHYSICAL BARRIER – SKIN - STRATUM CORIUM – HCL IN STOMACH – MUCUS IN INTESTINES reak the cycle of transmission OBJECTIVES continued TO IDENTIFY AND DISCRIBE FUNCTIONS OF CELLULAR STRUCTURES, CELLS, AND GROUPS OF CELLS IN THE DIGESTIVE SYSTEM FUNCTION OF the G.I. TRACT MOVEMENT OF FOOD SECRETION OF DIGESTIVE JUICES ABSORPTION OF DIGESTED FOODS, WATER, AND ELECTROLYTES serosa Esophagus serosa Small intestine Esophagus Esophagus Proximal Distal region region More skeletal muscle and more smooth muscle 137 437 cardioesophageal junaion 140 Cardia stomach 145 Fundic stomach 145 145 Fundic stomach 243 Fundic stomach, monkey (PAS) 244 Surface mucus cells of Fundic stomach, rabbit (toluidine blue) 244 Mucus neck cells Fundic stomach, rabbit (toluidine blue) EM 16 • Granules of surface mucous cells • Mitochondria • Nuclei 244 • Lumen EM 15 • Nucleus of parietal cell • Mitochondrion • Canaliculi of parietal cell • Mucous granule of mucous neck cell • Fibroblast EM 15 Parietal cell produces 1. HCl 2. Bicarbonate 3. Intrinsic factor for vitamin B12 absorption by gut needed in red blood cell formation EM 14 • Large granules of chief cell • Granules of an argentaffin cell • Lamina propria • Nuclei 244 EM 14 • Large granules of chief cell • Granules of an argentaffin cell • Lamina propria • Nuclei EM 14 • Large granules of chief cell • Granules of an argentaffin cell • Lamina propria • Nuclei Pyloric stomach, monkey (PAS) 141 147 Pyloroduodenal junction, baboon Next time we will continue with the intestines Digestive System VIBS 443/602 Continued esophagus stomach intestine • Next time Possible unique features of this course • Guest lectures (protein evolution, clinical) • Great/approachable support staff • Friendly learning environment/handouts • EM/cell biology/functional approach • Conferences for application of content/”W” course • Thought creating questions • Timely return of tests results/goes over answers/copies of previous tests • Useful information to future career goals • Humorous lectures/helpful interactions • World travels pictures/adventures Digestive System VIBS 443/602 Continued esophagus stomach intestine Digestive System con’t 152 Duodenum 146 Duodenum, monkey Intestinal villus 1. Brush border 2. Lymphocyte 3. Lamina propria 4. Capillary Intestinal villus 1. Central lacteal 2. Intestinal absorptive cell 3. Brush border 447 4. Blood capillary 5. macrophage EM 17 Basal portion of intestinal absorptive cell 1. Plasma cell 2. Lymphocyte 3. Smooth muscle 4. Intestinal absorptive cell 5. Macrophage 6. Lumen of capillary 7. Pericyte of capillary EM 17 Basal portion of intestinal absorptive cell 1. Plasma cell 2. Lymphocyte 3. Smooth muscle 4. Intestinal absorptive cell 5. Macrophage 6. Lumen of capillary 7. Pericyte of capillary EM 17 Basal portion of intestinal absorptive cell 1. Plasma cell 2. Lymphocyte 3. Smooth muscle 4. Intestinal absorptive cell 5. Macrophage 6. Lumen of capillary 7. Pericyte of capillary 249 Ileum, monkey (PAS) EM 4. Apical portion of intestinal absorptive cell 1. Microvilli of brush border 2. Droplets of goblet cell 3. Terminal web 4. Lipid in SER 5. lumen Basal portion of intestinal absorptive cell 1. Mitochondria 2. Nuclei of intestinal absorptive cell 3. Smooth muscle of muscularis mucosa 4. Basal lamina EM 4b EM 4c Paneth cells and argentaffin cells, jejunum 1. Apical granules of Paneth cells 2. Goblet cell 3. Argentaffin cell with basal granules 148 4. Intestinal absorptive cell 32409 Rat intestine 148 Ileum 250 argentaffin cells of Ileum, monkey 250 goblet cells of Ileum, monkey 153 Large intestine or Colon, monkey Human appendix 204 32412 Summary Saw HOW organs FUNCTION TO OBTAIN METABOLITES NECESSARY FOR GROWTH AND ENERGY FOR THE BODY, YET MAINTAIN A BARRIER BETWEEN THE ENVIRONMENT AND THE INTERNAL MILIEU OF THE BODY • Physical barrier to infection • Immune system interface • Specialization for digestion and absorption and cleaning blood of toxins ingested Summary Next time .
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