Pulmonary artery

Source: Wikipedia, the free encyclopedia.
Pulmonary artery
right ventricle
Identifiers
Latinarteria pulmonalis
MeSHD011651
TA98A12.2.01.101
A12.2.01.201
TA24077, 4091
FMA66326
Anatomical terminology]

A pulmonary artery is an artery in the pulmonary circulation that carries deoxygenated blood from the right side of the heart to the lungs. The largest pulmonary artery is the main pulmonary artery or pulmonary trunk from the heart, and the smallest ones are the arterioles, which lead to the capillaries that surround the pulmonary alveoli.

Structure

The pulmonary arteries are blood vessels that carry systemic venous blood from the right ventricle of the heart to the microcirculation of the lungs. Unlike in other organs where arteries supply oxygenated blood, the blood carried by the pulmonary arteries is deoxygenated, as it is venous blood returning to the heart. The main pulmonary arteries emerge from the right side of the heart and then split into smaller arteries that progressively divide and become arterioles, eventually narrowing into the capillary microcirculation of the lungs where gas exchange occurs.[citation needed]

Pulmonary trunk

high resolution CT scan of the thorax. The anterior thoracic wall, the airways and the pulmonary vessels anterior to the root of the lung
have been digitally removed to visualize the different levels of the pulmonary circulation.

In order of blood flow, the pulmonary arteries start as the pulmonary trunk that leaves the fibrous pericardium (

arch of aorta and in front of the left main bronchus.[1] Pulmonary trunk is short and wide – approximately 5 centimetres (2.0 in) in length[2] and 2 centimetres (0.79 in)-3 centimetres (1.2 in) in diameter.[3][4]

The pulmonary trunk splits into the right and the left main pulmonary artery.[5] The left main pulmonary artery is shorter than the right,[1] passes behind and downwards the descending aorta and above the left main bronchus to the root of the left lung. Above, the left main pulmonary artery is connected to the concavity of the proximal descending aorta by the ligamentum arteriosum.[2] The right pulmonary artery pass across the midline of the body, below the carina of trachea, and comes in front of the right main bronchus.[1]

Branches

At the far end, pulmonary arteries (labelled at the bottom) become capillaries at the pulmonary alveoli.

The left main pulmonary artery then divides into two lobar arteries, one for each lobe of the left lung.[6]

At the right root of the lung, it bifurcates into artery that supplies the right upper lobe of the lung, in front of the right upper lobe bronchus, and interlobar artery that supplies the right middle and inferior lobes of the lung, running together with bronchus intermedius.[1]

The right and left main pulmonary (lungs) arteries give off branches that supplies the corresponding

bronchial arteries, that has different origins, supply the bronchi of the lungs.[1]

Development

The pulmonary arteries originate from the

conus arteriosus.[9]
: 157 

By the third week of

development, the endocardial tubes have developed a swelling in the part closest to the heart. The swelling is known as the bulbus cordis and the upper part of this swelling develops into the truncus arteriosus.[9]: 159–160  The structure is ultimately mesodermal in origin.[9]: 157  During development of the heart, the heart tissues undergo folding, and the truncus arteriosus is exposed to what will eventually be both the left and right ventricles. As a septum develops between the two ventricles of the heart, two bulges form on either side of the truncus arteriosus. These progressively enlarge until the trunk splits into the aorta and pulmonary arteries.[9]
: 176–179 

During early development, the ductus arteriosus connects the pulmonary trunk and the aortic arch, allowing blood to bypass the lungs.[10]: 791 

Function

The pulmonary artery carries deoxygenated blood from the

oxygenated as part of the process of respiration.[12]

In contrast to the pulmonary arteries, the

bronchial arteries supply nutrition to the lungs themselves.[10]
: 790 

Pressure

The pulmonary artery pressure (PA pressure) is a measure of the

mitral valve stenosis, and other conditions, such as sickle cell disease.[15]

Clinical significance

The pulmonary artery is relevant in a number of clinical states.

COPD or scleroderma, or thromboembolic disease such as pulmonary embolism or emboli seen in sickle cell anaemia.[13]: 720–721  Most recently, computational fluid based tools (non-invasive) have been proposed to be at par with the current clinical tests (invasive) of pulmonary hypertension.[18]

Pulmonary embolism refers to an embolus that lodges in the pulmonary circulation. This may arise from a

deep venous thrombosis, especially after a period of immobility. A pulmonary embolus is a common cause of death in patients with cancer and stroke.[13]: 720–721  A large pulmonary embolus that becomes lodged in the bifurcation of the pulmonary trunk with extensions into both the left and right main pulmonary arteries is called a saddle embolus.[19]

Several animal models have been utilized for investigating pulmonary artery related pathologies. Porcine model of pulmonary artery is the most frequently used and it was recently found that their mechanical properties vary with every subsequent branching.[20]

Additional images

  • Image showing main pulmonary artery coursing ventrally to the aortic root and trachea, and the right pulmonary artery passes dorsally to the ascending aorta, while the left pulmonary artery passes ventrally to the descending aorta.
    Image showing main pulmonary artery coursing ventrally to the
    trachea, and the right pulmonary artery passes dorsally to the ascending aorta, while the left pulmonary artery passes ventrally to the descending aorta
    .
  • Pulmonary circuit
    Pulmonary circuit
  • Transverse section of thorax, showing relations of pulmonary artery.
    Transverse section of thorax, showing relations of pulmonary artery.
  • Original image from Anatomist 90
    Pulmonary artery
  • Pulmonary artery.Deep dissection.Anterior view.
    Pulmonary artery.Deep dissection.Anterior view.
  • CT scan of a normal lung, with different levels of pulmonary arteries.
    CT scan of a normal lung, with different levels of pulmonary arteries.
  • Bronchial anatomy
    Bronchial anatomy

See also

References

  1. ^
    ISBN 9780702029714
    .
  2. ^
    ISBN 9789350252758
    .
  3. PMID 10211060
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  4. PMID 22178898
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  5. ^ "Pulmonary Vasculature". University of Virginia School of Medicine. 2013. Retrieved 2017-06-24.
  6. PMID 30057869
    .
  7. ^ a b c "Pulmonary Artery Anatomy". University of Virginia School of Medicine. 2013. Retrieved 2017-06-24.
  8. PMID 18686729
    .
  9. ^
    ISBN 9780443068119
    .
  10. ^ a b Braunwald E (1992). Heart Disease: A Textbook of Cardiovascular Medicine (Fourth ed.). Philadelphia: W.B. Sanders.
  11. ^ "22.4 Gas Exchange – Anatomy and Physiology". opentextbc.ca. Archived from the original on 2020-10-19. Retrieved 2019-05-22.
  12. ^ "Exchanging Oxygen and Carbon Dioxide – Lung and Airway Disorders". MSD Manual Consumer Version. Retrieved 2019-05-22.
  13. ^
    ISBN 978-0-7020-3084-0
    .
  14. ^ "Normal Hemodynamic Parameters – Adult" (PDF). Edwards Lifesciences LLC. Archived from the original (PDF) on 2010-11-10.
  15. S2CID 26693444
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  16. PMID 30382495
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  17. PMID 5865788
    . Retrieved 15 January 2022.
  18. PMID 32007361
    .
  19. ^ Jones J, et al. "Saddle pulmonary embolism". Radiopaedia. Retrieved 2017-10-08.
  20. PMID 33814554
    .

External links
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