Topography
- Pulmonary trunk (truncus pulmonalis): leaves the conus arteriosus of the right ventricle on the left side of the heart base. It curves dorsocaudally to the left of the aorta and divides into the right and left pulmonary arteries.
- Ligamentum arteriosum: the fibrous remnant of the fetal ductus arteriosus, between the bifurcation of the pulmonary trunk and the aortic arch.
- Pulmonary arteries: enter each lung at the hilus beside the principal bronchus and branch with the bronchial tree. On a lateral radiograph the cranial lobar artery is dorsal to its vein; on a dorsoventral view the caudal lobar arteries are lateral to their veins.
Clinical relevance
- Dirofilariosis: adult worms live in the pulmonary arteries and cause endarteritis and pulmonary hypertension; the lobar arteries look enlarged and tortuous.
- Pulmonic stenosis: a common congenital defect; it causes post-stenotic dilation of the pulmonary trunk.
- Patent ductus arteriosus: on a dorsoventral radiograph the pulmonary trunk bulges at the left cranial border of the heart.
3D model
Segmented from the heart CT. Arteries were told apart from veins by position, as on a radiograph: the arteries lie lateral and dorsal, and the veins lie medial and converge on the left atrium. The branches continue inside the lungs.