Gastrointestinal function

The extrinsic autonomic nervous system is critically involved in modulating the reflex and local control of secretion, absorption, digestion, motility, and sensation in the gastrointestinal tract, both during fasting and postprandially. In general, the craniosacral parasympathetic nervous system is excitatory (e.g., secretion, peristalsis) and the thoracolumbar sympathetic supply is mostly inhibitory (e.g., proabsorptive and inhibition of motility with stimulation of sphincters). While intrinsic neural and local paracrine control can sustain most gastrointestinal functions, the extrinsic autonomic nervous system provides additional input to the highly integrated digestive system.