The pulmonary artery springs from the right ventricle at the conus arteriosus. It curves upward, backwards and medially and divides behind the aortic arch into right and left pulmonary arteries.
It is related in front to the right atrium and behind to the left atrium and medially to the aorta.
It is enclosed along with the latter in a common sheath of the visceral part of the serous pericardium.
Near its termination divides into two branches, it is connected to the aorta by the ligamentum arteriosus, the remnant of the fetal ductus arteriosus.
The right pulmonary artery is a little longer than left.
It passes under the bifurcation of the trachea to the hilus of the lung and inside the latter accompanies the bronchial tree on its ventrolateral surface.
The left pulmonary artery passes backwards under the left bronchial lymph gland and enters the root of the left lung below the left bronchus.
