Neural Reflex Modulation of Intestinal Epithelial Transport
The mucosal lining of the gastrointestinal tract, for example, is provided with an extensive nervous supply from the enteric nervous system (ENS). This chapter reviews present knowledge of the physiology and pathophysiology of the ENS in the intestines with regard to epithelial transport. It describes the extrinsic nervous control of the intestinal epithelium. The ENS represents one of the major parts of the autonomic nervous system (ANS). This was recognized by Langley in his classical monograph from 1921, in which the autonomic nervous system (ANS) was divided into three major parts: the sympathetic, the parasympathetic, and the enteric nervous systems. Excitatory postsynaptic potentials (EPSP) denote a depolarization of the membrane potential, which, if large enough, may trigger an action potential. The fast type (fEPSP) in the ENS is generally believed to be mediated via the action of acetylcholine on the postsynaptic membrane via a nicotinic receptor. Slow inhibitory postsynaptic potentials can be evoked by extrinsic or intrinsic nerves.