Subpleural vascular anastomoses in lungs of human fetuses

Studies were performed on 35 left lungs, originating from human fetuses, who died at the age of 20 to 29 weeks of fetal life, using corrosion casts, microangiographic technique or methyl salicylate induced translucency. A typical network of subpleural vessels was observed, which joined pulmonary arteries and veins and formed direct anastomoses between pulmonary arteries and veins within pulmonary acini of the subpleural layer.