Drugs seem to have little effect on esophageal function. Many patients with hypertension and other disorders receive drugs affecting autonomic function, yet dysphagia and pyrosis are not commonly produced. There are at least two explanations. Esophageal motor dysfunction could occur but remain asymptomatic or trivially symptomatic. Second, the nerves that govern esophageal motor function could be of a kind not affected by such agents. Both explanations are probably true. It is now recognized that manometrically detectable esophageal motor dysfunction occurs (in diabetes and alcoholism, for example) without much symptomatic evidence. Also, at least some of the nerves that govern the operation of the esophagus appear neither to be adrenergic nor cholinergic.
The esophagus contains three physiologically-distinct regions, the striated muscle segment, the smoothmuscled esophageal body, and the lower esophageal sphincter. These three regions will be discussed separately.
EFFECT OF DRUGS ON STRIATED MUSCLE OF THE ESOPHAGUS
Motor nerves to striated