Digestive System

VIBS 443/602

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

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

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