The Geometry of the Pulmonary Microcirculation

Abstract

The geometric patterns of the pulmonary microcirculation are similar in the cat, rabbit, and dog and consist essentially of right angle branching out to the precapillary alveolar vessels. The latter supply the alveolar wall as they course through the intersecting planes of adjacent alveoli. The small pulmonary veins drain the midportion of each plane surface to the rear of the alveolus in a configuration suggesting a flattened funnel and merge in vascular patterns similar to the pulmonary artery branches. The implications of this branching microvascular system are discussed with reference to a possible pressure-stabilizing mechanism in the pulmonary circulation. The silicone rubber injection method was used.