Esophageal physiology.

Esophageal peristalsis and sphincter function involve coordinated neuromuscular processes the nature of which differs according to regional muscular anatomy and, to a degree, according to whether motility is initiated by swallowing or esophageal distension. The physical characteristics of the bolus and the conditions of testing may alter the speed and force of the propulsive contraction. Neural control of these processes and their modulation involves parasympathetic, sympathetic and enteric innervation of the organ. In smooth muscle regions, myogenic mechanisms may also play a role.