KEY POINTS

1. An independent, intrinsic enteric nervous system lies within the wall of the gut.

2. The enteric nervous system contains receptors, sensory neurons, interneurons, and motor neurons.

3. The gut receives extrinsic innervation from the autonomic nervous system.

4. The gut contains afferent neurons that relay information to the central nervous system.

5. The gastrointestinal system has an intrinsic endocrine system.

6. The immune system participates in regulation of gastrointestinal activity.

7. The regulation of gastrointestinal function is integrated by the interaction of many regulatory molecules on multiple cell types in the gut.