Frequency of the rhythmic contractions of the small intestine

Summary

Chronic experiments were performed on dogs with divided intestine at the level of Treitz ligament. A sharp decrease in the frequency of jejunal rhythmical contractions (by 25%) caudal to the site of division was noted. Following intestinal division between the pylorus and duodenum, and 3–4 weeks after the division of the duodenum (oral to the attachment of the pancreas) and placing end-to-end enteroenterostomies — normal frequency of rhythmical contractions was noted, distal to the site of division. Division of the duodenum 0.5 to 1 cm caudal to the attachment of the pancreas resulted in a sharp and stable decrease in the frequency of intestinal rhythmical contractions distal to the cut. The presence of an intestinal contraction automatic “pacemaker” is inferred, found in the intestinal portion directly adherent to the pancreas. The functioning of such a pacemaker explains the mechanism governing the extension of peristaltic contractions in the caudal direction.