Pulmonary trunk

Course

After birth, the only arterial trunk carrying deoxygenated blood: arises from the right ventricle's conus at the pulmonary valve, runs up and back, and divides under the aortic arch into left and right pulmonary arteries at the T5–6 disc level.

Branches

Left and right pulmonary arteries; the ligamentum arteriosum anchors it to the aorta — the foetal ductus arteriosus's remnant.

Clinical relevance

Pulmonary embolism occludes it or its branches — the third commonest cardiovascular death. The ductus's failure to close after birth (patent ductus arteriosus) leaves a continuous machinery murmur and a shunt.

Related conditions

• Pulmonary embolism
• Pulmonary hypertension