Right pulmonary artery

The right pulmonary artery (RPA) originates form the pulmonary trunk after the bifurcation of pulmonary trunk. Then the RPA follows a longer and more horizontal course than the left pulmonary artery (LPA), as it crosses the mediastinum. It is within the pericardium for more than three-fourths of its length It passes underneath the aortic arch, behind the ascending aorta, and in front of the descending aorta. It courses posterior to the superior vena cava and in front of the right bronchus.

After the origin of its first branch, the truncus anterior, the interlobar pulmonary artery runs inferiorly between the bronchus intermedius posteriorly and the superior pulmonary vein anteriorly. It turns posteriorly behind the origin of the middle lobe bronchus, continues as the common basal trunk and terminates in branches to the basal segments. The truncus anterior supplies the right upper lobe; and the interlobar artery, which runs in the interlobar fissure, supplies the right middle and right lower lobes. 

Branches of right pulmonary artery (RPA) :

• Superior lobar artery of right lung (Upper lobar artery; High anterior trunk; Truncus anterior) that supplies blood to the right upper lobe

• Interlobar artery, the inferior and larger branch of the RPA, that divides into the middle lobar artery or right lung and inferior lobar artery of right lung