FLEISCHNER LECTURE - LOOKING INTO THE LUNG - WHAT CAN IT TELL US

Looking into the lung: what has it told us? The most remarkable insight from looking into the lung with an electron microscope is the recognition that an ingenious structural design of tissue and cells allows an exceedingly thin tissue barrier to be maintained over an extraordinarily large surface in order to ensure efficient gas exchange between air and blood. Three conclusions are of importance: (1) The structure of this pulmonary gas exchange apparatus is likely to be a rate limiting factor for O2 uptake in the lung. (2) The size of the gas exchange apparatus can be matched to the O2 needs of the organism by regulating the growth of lung tissue. (3) The very delicate tissue of the alveolar septa is also very vulnerable. It is limited in its capacity to repair any damage and follows a most specific reaction pattern that essentially determines the course of the adult respiratory distress syndrome. Clearly, looking into the lung is a rewarding and informative enterprise.