Progress in radiology: historical review of the changing concepts of lower esophageal anatomy: 430 B.C.--1977.

Some of the classic studies on the anatomy of the lower esophagus are reviewed. In every case, the original sources have been consulted. The basis for a proposed anatomic description of the lower esophagus is established on the basis of the most modern research. The genesis of ideas on the anatomic nature of the cardia, phrenoesophageal membrane, esophageal pouches, esophageal sphincters, esophageal rings, gastroesophageal angle, flap valve, and cardiac notch is traced.