nervous input

• enteric nervous system

  GI system's gut brain

  • made of enteric neurons and has more than spinal cord
  • big nerve supply that controls mobility
• intrinsic nerve plexuses: Submucosal nerve plexus

  regulates smooth muscles and glands in mucosa
• intrinsic nerve plexuses: Myenteric nerve plexus

  controls GI tract mobility
• short reflexes

  are initiated by gut brain

  respond to what's going on in the GI tract
• long reflexes

  respond to stimuli inside or outside the GI tract like from the autonomic system
• parasympathetic enhances the digestive process

  sympathetic inhibits the digestive system
• what is digestive system provoked by:

  receptors that are found in walls of GI that detect: stretch, changes in osmolarity and pH, and presence of substrate and end products of digestion
• effectors can activate:

  smooth muscle to mix and move lumen contents

  activate or inactivate glands that secrete hormones or digestive juices
• intrinsic controls(short reflexes)


  take place in enteric nervous system, inside the GI tract
• extrinsic controls (long reflexes)

  autonomic system so outside of the GI tract
• hormonal controls

  hormones are secreted from cells of target or outside of target organs that can contract or secrete