Secondary peristalsis of the esophagus — a demonstration on a dog with a permanent esophageal fistula

Abstract

The peristalsis of the esophagus with which every one is familiar is that which follows an act of deglutition. About a year ago I reported to this society that experiments which I had made on rabbits demonstrated that the esophagus is capable of peristaltic movements not initiated by deglutitions. Injections of indifferent solutions or of air directly into the esophagus cause there a regular peristaltic movement. This latter form of peristaltic movement, which for the sake of brevity I shall henceforth term secondary peristalsis, differs from the primary peristalsis, the one which follows deglutition, essentially through the nervous mechanism by which it is controlled. All the movements of the complicated act of deglutition are managed by a reflex mechanism, with only one sensory stimulus for its initiation and a series of consecutive motor impulses going to every part of the long path of deglutition; it is practically a single reflex. The reflex mechanism of the secondary peristalsis, on the other hand, consists of a chain of reflexes; each part of the esophagus sends up to the center a sensory impulse started by the presence of the bolus in that part and receives in turn a motor impulse.

The secondary peristalsis therefore requires the presence of some sort of a bolus within the esophagus and presupposes the integrity of the latter; whereas the primary peristalsis requires neither a bolus nor the integrity of the esophagus; even if a large section of the latter is removed, the peristalsis appears in the lower segment in due time after each deglutition as long as the vagus nerves remain intact.

Recently secondary peristalsis was studied in the esophagus of dogs, in which animals it appeared promptly and was easily demonstrable.