Left pulmonary artery
Arteria pulmonalis sinistra
The shorter of the two terminal branches of the pulmonary trunk, carrying deoxygenated blood from the heart into the left lung.
At a glance
- English
- Left pulmonary artery
- Latin (TA2)
- Arteria pulmonalis sinistra
- System
- Artery
- Region
- Trunk
- Side
- Single, on the midline
About the left pulmonary artery
The left pulmonary artery is one of the two vessels into which the pulmonary trunk divides, in the concavity of the aortic arch at about the level of the fifth thoracic vertebra. Like the rest of the pulmonary circulation it carries blood that is low in oxygen, pumped by the right ventricle, to the lungs. It is shorter and a little narrower than the right pulmonary artery, because the trunk lies to the left of the midline and the left lung is the smaller one.
From the division it runs backwards and to the left, almost horizontally, passing anterior to the left main bronchus and the descending aorta. It arches over the left main bronchus, so at the hilum of the left lung the artery lies above the bronchus, unlike on the right, where the upper lobe bronchus sits higher. It enters the root of the lung together with the bronchus and the pulmonary veins.
Near its beginning it is joined to the underside of the aortic arch by the ligamentum arteriosum, the fibrous remnant of the ductus arteriosus. The left recurrent laryngeal nerve hooks round the arch just beside this ligament. Within the lung the artery divides into lobar branches, one to the upper lobe and one to the lower, and these divide further into segmental arteries that follow the bronchi. The upper lobe branches are numerous and variable.
A clot that travels from the leg veins can lodge in the left pulmonary artery or its branches as a pulmonary embolism. The vessel can also become enlarged in pulmonary hypertension, and in a ductus arteriosus that stays open after birth blood passes from the aorta into the pulmonary arteries. Its position under the arch is important in surgery on the left lung root.
Course and supply
- Arises from
- One of the two terminal branches of the pulmonary trunk, arising in the concavity of the aortic arch.
- Ends in
- Enters the hilum of the left lung above the left main bronchus and divides into upper and lower lobar arteries, then segmental branches.
- Supplies
- Carries deoxygenated blood from the right ventricle to the left lung for gas exchange.
Anthromica
See the left pulmonary artery where it really sits, with every layer of the body around it.
- Every layer, one body. Peel from muscle to bone, nerve, vessel and organ, and turn it any way.
- English and Latin. Every structure named the way your exam names it.
- Quiz until it sticks. Short drills on the structures you keep missing.
Free to start. No card.
