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How does pulmonary circulation move blood between the heart and lungs?
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Circulatory system
Human circulatory system.
Pulmonary circulation is the specific circuit of the circulatory system responsible for transporting blood between the heart and the lungs to facilitate gas exchange.1
The process follows this sequence:
- Departure from the Heart: The cycle begins when the right ventricle pumps oxygen-poor blood through the pulmonary valve into the pulmonary artery.12
- Transport to the Lungs: The pulmonary artery divides into right and left branches, which subdivide into smaller vessels until they reach the dense capillary networks surrounding the alveoli.12
- Gas Exchange: Within these capillaries, carbon dioxide diffuses out of the blood to be exhaled, while oxygen from inhaled air moves into the bloodstream.12
- Return to the Heart: The now oxygen-rich blood flows into progressively larger vessels that form the pulmonary veins, which return the blood to the left atrium of the heart for distribution to the rest of the body via systemic circulation.312
Because this circuit operates at lower pressures than systemic circulation, it protects the delicate lung tissues while ensuring efficient oxygen replenishment.1