[Significance of anastomoses in the lung in microembolism]

The importance is demonstrated of anastomoses between the pulmonary artery and the bronchial artery as well as of the arteriovenous anastomoses that arise from these in microembolism. In cases of air embolism, microembolism in the lungs is seldom. Therefore, there must be particular circumstances that make it possible for little air bubbles to pass the anastomoses from the pulmonary artery via the bronchial artery and the arteriovenous anastomoses into the bronchial vein. The pressure in the bronchial artery must decrease. Under these conditions, blood is shunted from the pulmonary artery to the bronchial artery and little air bubbles can pass via the above-mentioned anastomoses into the pulmonary vein.