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

serosa

Small intestine

Esophagus

Esophagus

Esophagus

Proximal

region

Distal

region

More skeletal muscle and more smooth muscle

137

437 cardioesophageal junaion

140

Cardia stomach

Fundic stomach 145

145

Fundic stomach 145

Fundic stomach, monkey (PAS)

243

Surface mucus cells of Fundic stomach,

rabbit (toluidine blue)

244

Mucus neck cells Fundic stomach,

rabbit (toluidine blue)

244

EM 16

• Granules of surface mucous

cells

• Mitochondria

• Nuclei

• Lumen

244

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

Pyloroduodenal junction, baboon

147

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

Duodenum 152

Duodenum, monkey 146

Intestinal villus

1. Brush border

2. Lymphocyte

3. Lamina propria

4. Capillary

Intestinal villus

1. Central lacteal

2. Intestinal absorptive cell

3. Brush border

4. Blood capillary

5. macrophage

447

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

Ileum, monkey (PAS)

249

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

4. Intestinal absorptive cell

148

32409

Rat intestine

Ileum 148

argentaffin cells of Ileum, monkey

250

goblet cells of Ileum, monkey 250

Large intestine or Colon, monkey 153

204

Human appendix

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