Relation between Gut Motility and Innervation in Man

Abstract

Various factors combine to produce regional differences in the motility of the human gastrointestinal tract. Important contributions are made by the intrinsic nerves, and there is now evidence for four types of fibres, which include cholinergic and nor-adrenergic nerves, inhibitory fibres which are non-adrenergic, and excitatory fibres which are non-cholinergic. Studies using drugs or electric impulses to stimulate nerves demonstrate a relatively weak intrinsic cholinergic innervation of the stomach, an organ which relies substantially on extrinsic vagal fibres. There is strong excitatory innervation in the small intestine, but predominantly inhibitory innervation in the colon. These patterns of nerve distribution correlate with regional differences in behaviour and function of the gut.