Video - Zones of pulmonary blood flow

The zones of pulmonary blood flow refer to the three anatomical regions of the lung that differ in their perfusion and ventilation. Zone 1 is the region closest to the apex of the lung where alveolar pressure is highest, and pulmonary blood flow is limited. Zone 2 is the intermediate region where the pulmonary blood flow is determined by the balance between the alveolar pressure and the pulmonary artery pressure. Zone 3 is the region closest to the base of the lung where pulmonary blood flow is the highest due to the high pulmonary artery pressure.