MODULATION OF PUMPING FUNCTION OF GASTRIC BODY AND ANTROPYLORIC CONTRACTIONS

Gastric and antropyloric phasic contractions control transpyloric puls atile flow, the major mechanism of gastric emptying. Both the occurren ce and patterning of phasic gastric contractions are highly modulated by intestinal feedback mechanisms, with resultant variation in gastric emptying. The observed patterns of these contractions can only be pla usibly explained by the action of neural influences on gastric motilit y. These influences derive from several mechanisms driven by intestina l feedback, central nervous system controls, and higher centers, with transmission of signals via intrinsic enteric pathways and extrinsic n erves. It is suggested that the occurrence and patterning of gastric p hasic contractions depend on the spatial specificity and local modulat ion of the intensity of neural stimulation of gastric muscle. The resu ltant strength of contraction determines the occurrence and timing of lumen occlusion relative to adjacent regions. The timing of lumen occl usion in adjacent regions may be the major determinant of mechanical o utcome.