Podiatry and Medical - Set 1

Answer − D - When a person breathes, the exchange of gases takes place in the alveoli. Thin and moist, the surface of the alveoli is covered with thin capillaries. Oxygen passes from the alveoli into the bloodstream where it is being distributed to the cells. The waste product, carbon dioxide, is carried by the blood where it returns to the alveoli and is breathed out.