The mechanical and eleetromyographic activity of the pyloric antrum and duodenum of sheep has been studied both under resting conditions and while infusing various solutions to alter the chemical composition of the chyme.
Bursts of spike-type electrical activity, synchronized with the depolarization phase of slower potential variations, accompanied duodenal contractions. Both mechanical distension and chemical stimulation of the proximal duodenum influenced the electrical activity and led to changes in the frequency, duration and amplitude of contractions.