A comparison of static volume-pressure relations of excised pulmonary lobes of dogs

Comparison was made of essentially static volume-pressure relations of the lobes of excised dogs' lungs during stepwise deflation from a maximal distending pressure of 30 cm H 2 O. No systematic differences were found among the right apical, middle, and left apical lobes nor between the right and left lungs when gas volume was expressed per unit of tissue weight. However, the right mediastinal-lower and left lower lobes held smaller volumes for any pressure than did the others. The differences were small and appear to play a subordinate role in causing the uneven ventilation typical of healthy lungs. These observations relate only to elastic variations among lobes and are not intended to characterize variations that may exist within lobes.