Right pulmonary artery

At a glance

English

Right pulmonary artery

Latin (TA2)

Arteria pulmonalis dextra

System

Artery

Region

Trunk

Side

Single, on the midline

About the right pulmonary artery

The right pulmonary artery begins where the pulmonary trunk divides, under the arch of the aorta at about the level of the fifth thoracic vertebra. It is longer and slightly wider than the left pulmonary artery, because the trunk lies to the left and the right lung is the larger. Like the trunk, it carries blood low in oxygen from the right ventricle to the lung.

Its course is longer and nearly horizontal across the middle of the chest. It runs to the right below the aortic arch, passing behind the ascending aorta and the superior vena cava. Behind it lie the oesophagus and the right main bronchus, and the descending aorta is behind and to the left near its start. The azygos vein arches over the right lung root above it.

Even before it reaches the right lung's hilum, it gives its first large branch, the anterior trunk (truncus anterior), which supplies the upper lobe. The rest of the vessel carries on as the interlobar artery, the lower and larger branch, which runs down in the oblique fissure and gives the arteries to the middle and lower lobes. Each lobar branch then divides into segmental arteries that follow the bronchi into each bronchopulmonary segment. At the hilum the right upper lobe bronchus lies above the artery, so the right pulmonary artery sits lower relative to its bronchus than the left one does.

Like its partner, the right pulmonary artery can be blocked by a clot travelling from the deep veins of the leg, and a large clot may sit across the bifurcation into both arteries. It widens in pulmonary hypertension. Its path behind the superior vena cava and ascending aorta matters in cardiac and lung surgery, and in some heart defects surgeons join the superior vena cava straight to it to send venous blood to the lungs without passing through the heart.

Course and supply

Arises from

One of the two terminal branches of the pulmonary trunk, arising under the aortic arch.

Ends in

Gives the anterior trunk to the upper lobe and continues as the interlobar artery to the middle and lower lobes, which then divide into segmental arteries.

Supplies

Carries deoxygenated blood from the right ventricle to the right lung for gas exchange.