Segmental lung vessels !
The segmental lung vessels are the small arteries and veins of each lung segment; the arteries follow the airways, the veins run between segments.
Official name: Pulmonary trunk
Opens in the Durgical app, no sign-up needed.
What it is
The branches of the pulmonary arteries and veins to each lobe and segment.
What it does
Follow the bronchial tree into every segment.
Key facts
- Where
- Segmental arteries run with segmental bronchi in center of segments; pulmonary veins run in intersegmental planes
- Function
- Arteries bring deoxygenated blood to each segment; intersegmental veins drain adjacent segments (surgical landmark)
- Into
- Veins join lobar veins, then pulmonary veins to left atrium
Relations
- Course
- Each segmental artery enters its segment at the apex beside the segmental bronchus and branches with it down to the respiratory bronchioles; segmental veins start at the periphery and pass in the intersegmental septa back to the hilum
How to find it
Seen only in surgery or on imaging. At segmentectomy the segmental artery and bronchus are identified at the root of the segment, and the intersegmental vein guides the cut; inflating or deflating the lung, or an injected dye, shows the plane on the surface.
On imaging
On CT each segmental artery runs beside its bronchus with a similar diameter, while the veins lie apart from the bronchi. CT pulmonary angiography shows segmental and subsegmental emboli as filling defects; 3D CT reconstructions map the branching before segmentectomy.
Common problems
- Pulmonary embolism: a clot, usually from a leg vein, lodges here; causes sudden breathlessness and chest pain and can be fatal.
- Pulmonary hypertension: high pressure that strains the right ventricle.
How it is diagnosed
CT pulmonary angiography; D-dimer blood test; echocardiogram.
Treatment
- Blood thinners; clot-dissolving drugs or catheter removal for large clots.
Clinical notes
- Small peripheral emboli in segmental branches tend to cause pleuritic chest pain and haemoptysis more than large central clots
- Pulmonary arteriovenous malformations join an artery directly to a vein, often in hereditary haemorrhagic telangiectasia, giving a right-to-left shunt and risk of paradoxical emboli
- Segmentectomy depends on dividing the correct segmental artery and bronchus; their branching is checked on CT beforehand
Anatomical variants
- Segmental artery branching varies widely, especially in the left upper lobe, which receives a variable number of separate branches from the left pulmonary artery
Related conditions
Test yourself
Think of the answer, then tap the question to see it.
Where do segmental arteries and segmental veins of the lung run in relation to the segment?
Arteries run with the bronchus at the centre of each segment; veins run between segments in the intersegmental planes.
Which segmental lung vessel guides the cut in a segmentectomy?
The intersegmental vein, which marks the plane between neighbouring segments.
Why is lung infarction after small segmental emboli less common than the blockage itself?
The bronchial arteries usually keep the lung tissue alive.
Educational information, not medical advice. For any symptom, see a health professional.
Its names
- Official Latin (TA2)
- truncus pulmonalis TA2 4075
- Official Spanish (DeCS)
- Ramas lobares y segmentarias de las arterias y venas pulmonares DeCS D011651
- English (TA2)
- Pulmonary trunk
- Also called
- arteria pulmonalis
Sources: Terminologia Anatomica (TA2); DeCS; Anatomy, Thorax, Lung Veins; Anatomy, Thorax, Lungs.
Spotted a mistake?We are always improving for the community. Tell us what is wrong and our team will review it.Report a mistake
Representative model, for educational purposes only.
