The alveoli, which are the smallest functional units of the lungs and responsible for gas exchange, are intimately in contact with the cardiovascular system. The walls of the alveoli are surrounded by capillaries, which are tiny blood vessels that allow for the exchange of oxygen and carbon dioxide between the lungs and the bloodstream. This close association between the alveoli and the cardiovascular system is essential for the efficient exchange of gases that allows us to breathe and maintain cellular function.
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~~~Harsha~~~