Figure 6.

Comparison of lung volume, alveoli number, and gas‐exchange surface area obtained using intact lungs vs. individual lung lobes. (A,B) Lung volume, (C,D) total alveoli number, and (E,F) gas‐exchange surface area were determined either directly, using whole, intact lungs, or mathematically, by the sum of the volumes of the five constituent lobes that had been determined separately for each lobe (summa loborum). Determinations were made for lungs of mice undergoing (A,C,E) normal (21% O₂‐exposed) or (B,D,F) aberrant (85% O₂‐exposed) late lung development. Male animals are indicated by blue symbols and female animals by red symbols. Data reflect mean ± SD (n = 6–7 animals per experimental group). Comparisons were made by unpaired Student's t‐test.