Innervation of the GI tract 3. Intrinsic(enteric)nerve plexuses Located in the submucosa(submucosal or Meissner's plexus) and between circular and longitudinal muscle layers (myenteric or Auerbach's plexus) Excitatory- Acetylcholine, Control Substance P Inhibitory -VIP, nitric oxide Motility -Myenteric plexus d Secretion-Submucosal plexus- Excitatory-Acetylcholine through release of neurotransmitters 2020 Innervation of the GI tract 3. Intrinsic (enteric) nerve plexuses Located in the submucosa (submucosal or Meissner’s plexus) and between circular and longitudinal muscle layers (myenteric or Auerbach’s plexus) Control Motility - Myenteric plexus Secretion - Submucosal plexus through release of neurotransmitters Excitatory - Acetylcholine, Substance P Inhibitory - VIP, nitric oxide Excitatory - Acetylcholine