Esophageal motor physiology

Abstract

The esophagus is a muscular tube that serves to propel the ingested food to the stomach by sequential, aborally progressive contraction of the esophageal circular muscle in concert with shortening of the esophagus effected by longitudinal muscle contraction. Whereas esophageal muscle contraction in the proximal striated muscle segment is activated directly via vagal efferent neurons, control of peristalsis in the distal smooth muscle segment is more complex. Although vagal efferent pathways are necessary for initiating swallow-induced peristalsis, peripheral neuromuscular mechanisms play a key role in generating the sequential contraction of circular muscle in the smooth muscle esophagus, via a complex interplay between cholinergic and nitrergic nerves, as well as the myogenic properties of the muscle.