The Aged Lung

Dissection of corrosion models of the left lungs of two aged men, who had no respiratory symptoms, revealed a variety of emphysematous lesions in the acini. The underlying pathology of the various lesions is believed to be a degenerative process of the individual alveolar septal membranes. These may rupture, and result in fusion or coalescence of alveolar spaces. The abnormalities thus produced are discussed in relation to the structure of the acinus. The effect on the vasculature, with particular emphasis on the capillary network, is also described.