National Physical Therapy Examination (NPTE) Practice Exam

Esophageal achalasia is primarily characterized by the inability of the lower esophageal sphincter (LES) to adequately relax during swallowing. This dysfunction prevents food from passing from the esophagus into the stomach, leading to a range of symptoms such as dysphagia (difficulty swallowing), regurgitation, and chest pain.

In achalasia, the normal neurological control that facilitates the relaxation of the LES during swallowing is impaired. This condition can result from an autoimmune response that affects the ganglion cells in the esophagus, especially in the myenteric plexus. Because the LES fails to open properly, food accumulates in the esophagus, leading to expansion and increased pressure, which can worsen symptoms and potentially lead to further complications.

The other choices refer to different conditions or mechanisms that do not specifically explain the pathophysiology of achalasia. Abnormal distention of the esophageal tract and inflammation of the esophageal walls might be consequences or symptoms arising from various esophageal disorders, but they are not the underlying cause of achalasia. Similarly, the development of sacs in the lining of the esophagus is more indicative of conditions like esophageal diverticula and does not relate to the mechanism by which achalasia occurs.