Pulmonary venous compartment of the airways circulation.

Bronchial circulation has three components: a systemic arterial component represented by the bronchial arteries; a pulmonary venous component represented by the pulmonary veins; and a systemic venous component represented by the bronchial veins. We have used vascular casting, microscope dissection coupled with tracers and light microscopy to define the detailed anatomy of the pulmonary venous compartment of the bronchial circulation. We have found that the extrapulmonary drainage territory of the pulmonary veins correlate with the forming pattern of the right superior pulmonary vein. In the case of a large apical venous trunk, pulmonary veins drain the venous blood of the main bronchia, terminal portion of the trachea and of the tracheobronchial lymph nodes. In the case of the systemic venous drainage of the extrapulmonary airways, we constantly found a pulmonary component which drains the venous blood from the subcarinal lymph nodes and the medial side of the main bronchia.

Venous circulation of the bronchial wall.

Bronchial supply plays an important role in both the protecting mechanisms and the pathogenic ones of many chronic inflammatory, infections or ischemic diseases of the lung. However, little is known regarding the bronchial supply development; the appearance of the connections to the functional pulmonary supply; the territory supplied by the bronchial veins. In this study, we follow the distribution of the pulmonary veins branches at the level of the subcarinal airways and their relationship to the bronchial veins in the human lungs. For studying the venous supply of the airways, we used the corrosion and colored gelatin injection methods followed by microdissection by means of an operator microscope. Venous circulation of the intrapulmonary airways is mainly tributary to the pulmonary vein branches. Venous circulation of the extrapulmonary airways is tributary to both the pulmonary and the bronchial veins. Taking into account the difference of sizes, we consider that, under physiologic conditions, the main venous collector is represented by the pulmonary veins.