Esophagus in rumination

Abstract

Esophageal motility studies of deglutition and rumination were performed in two sheep, two goats, and one calf. The esophageal motor response to balloon distention was investigated in the two sheep. Deglutition and rumination were studied cinefluorographically in the two sheep and one goat. All animals had a ruminoesophageal pressure difference of from 3 to 8 mm Hg, but none exhibited an inferior esophageal sphincter. Primary peristalsis progressed at a rate of 23.5–27.5 cm/sec. Secondary peristalsis was present only in the distal 10 cm of the esophagus, and only distal to the distending balloon. Rumination, unrelated to respiration, produced an initial pressure plateau interpreted as ruminoesophageal reflux, terminating in a contraction wave which was frequently of retrograde peristaltic character in the sheep and calf, traveling at rates averaging 42.5 and 53.8 cm/ sec in the sheep, 112.5 cm/sec in the calf. Rumination begins with ruminoesophageal reflux, facilitated by the ruminoesophageal pressure difference and absence of the inferior esophageal sphincter. The bolus is frequently carried toward the mouth by retrograde peristalsis.