Physiological Basis of Cystic Fibrosis: A Historical Perspective. Physiol. Rev. 79, Suppl.: S3-S22, 1999. - Cystic fibrosis made a relatively late entry into medical physiology, although references to conditions probably reflecting the disease can be traced back well into the Middle Ages. This review begins with the origins of recognition of the symptoms of this genetic disease and proceeds to briefly review the early period of basic research into its cause. It then presents the two apparently distinct faces of cystic fibrosis: 1) as that of a mucus abnormality and 2) as that of defects in electrolyte transport. It considers principal findings of the organ and cell pathophysiology as well as some of the apparent conflicts and enigmas still current in understanding the disease process. It is written from the perspective of the author, whose career spans back to much of the initial endeavors to explain this fatal mutation.