1. NA or other NANC 5HT 3 - ACh + - + 5HT 4 5HT 1or2 5-HT + + + ACh Enk +  ,, - - DA - D2 PERISTALTIC REFLEX Proximal Contraction Distal Relaxation WATER EXCRETION

2. NA or other ACh + - Water Excretion Motility ACh + X

3. + Motility Don’t forget hormone actions esp. motilin, somatostatin

4. ACh + DA - D2

5. ACh + DA - D2 METOCLOPRAMIDE X

6. + 5HT 4 ACh NANC 5HT 3 - ACh + 5-HT + + PERISTALTIC REFLEX Proximal Contraction Distal Relaxation

7. + 5HT 4 ACh + CISAPRIDE TEGASEROD (5HT 4 agonists)

8. NANC 5HT 3 - ACh + 5-HT + ONDANSETRON ALOSETRON (5HT 3 antagonists) X INCREASED CONTRACTION BUT DECREASED MOTILITY!

9. ACh + Enk ,, - -

10. ACh + Enk NA or other - 5HT 1or2 5-HT + Enk +  ,, - - + inhibition of 5-HT mediating segmentation (not shown)

11. NA or other ACh + - 5HT 1or2 5-HT +  ,, DIPHENOXYLATE LOPERAMIDE

12. NA or other NANC 5HT 3 - ACh + - + 5HT 4 5HT 1or2 5-HT + + + ACh Enk +  ,, - - DA - D2 METOCLOPRAMIDE is a DA antagonis that acts as cholinomimetics to increase motility DIPHENOXYLATE & LOPERAMIDE are opioids that decrease motility and reduce secretion CISAPRIDE and TEGASEROD are 5Ht4 agonist s that increase motility The “SETRONS”are 5Ht3 antagonist s that inhibit peristalsis ALVIMOPAN and METHYLNALTREXONE are opioid receptor antagonists that increase motility and increase secretion