Neuromuscular control of the oropharynx and esophagus in health and disease.

The oropharynx and esophagus convey swallowed materials from the mouth to the stomach and protect the airways from aspiration. These functions are subserved by complex neuromuscular interactions that coordinate the timing of the peristaltic contractions of the swallowing organs. The oropharynx and upper esophagus are composed of striated muscle, whereas the distal esophagus is composed of smooth muscle. The central nervous system completely controls peristalsis in the striated muscle organs. In the distal esophagus, neuromuscular mechanisms intrinsic to the esophagus control peristalsis. Diseases of the striated muscle, of the smooth muscle, or of the nervous system can lead to a derangement of peristalsis and disrupt the propulsion of swallowed materials to the stomach.