Broadly, the several neuron masses, ganglia, and nerve fibre plexus that lie in the walls of the intestinal tract, particularly the small intestine. They monitor and stimulate local muscle and glandular functions as well as blood supply, with little interface or control by the central nervous system or the autonomics. Each synapse away from the CNS gives greater autonomy, and these nerves only listen to God ... and food. This means the small intestine is relatively free of stress syndromes.