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What route does blood take through the human heart and lungs?

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Illustration of a human heart cross-section showing four chambers-left and right atria and ventricles-with labeled major blood vessels. An inset highlights cardiac muscle tissue, showing myocytes and intercalated disks. — human cardiovascular system The human heart is both a pump and a muscle. Its four chambers move blood efficiently, while cardiac muscle cells joined by intercalated disks synchronize each contraction.

In the adult human cardiovascular system, blood follows a specific path through the heart and lungs to facilitate gas exchange, a process known as pulmonary circulation.

The route is as follows:

Right Ventricle: Oxygen-poor blood is pumped from the right ventricle into the pulmonary artery.12
Lungs: The pulmonary artery branches to carry this deoxygenated blood into the lungs, where it reaches capillary networks surrounding the alveoli.1
Gas Exchange: Within these capillaries, carbon dioxide diffuses out of the blood to be exhaled, while oxygen moves from the lungs into the bloodstream.31
Pulmonary Veins: The now oxygen-rich blood is collected into pulmonary veins.31
Left Atrium: These veins return the oxygenated blood to the left atrium of the heart, where it is then prepared to enter systemic circulation for distribution to the rest of the body.312