Cardiovascular physiology: Pulmonary circulation
The pulmonary circulation has a special arteriolar response to hypoxia. The primary control of local blood flow is via the arterioles constricting in response to hypoxia.
Unlike other areas of the body the pulmonary circulation does not respond to signals from the autonomic nervous system or the build up of metabolic byproducts.
As can be seen from the images above hypoxic pulmonary vasoconstriction serves to maintain ventilation-perfusion matching.
Unlike other areas of the body the pulmonary circulation does not respond to signals from the autonomic nervous system or the build up of metabolic byproducts.
Hypoxic pulmonary vasoconstriction is the main regulator of pulmonary blood flow
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Normal oxygenation of blood in pulmonary circulation
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Effect of hypoxic segment without hypoxic vasoconstriction response
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Hypoxic vasoconstriction results in diversion of blood away from hypoxic areas so that it may become oxygenated prior to being returned to the pulmonary veins and left atrium
As can be seen from the images above hypoxic pulmonary vasoconstriction serves to maintain ventilation-perfusion matching.
In conditions where there is global hypoxia (e.g. lung disease or high altitude) widespread pulmonary vasoconstriction will result in increased pulmonary artery pressure and pulmonary hypertension. This may lead to right heart strain and cor pulmonale