Complete the following paragraphs about the circulatory system: In the lungs the blood becomes oxygenated. It returns to the heart in the pulmonary (7) . These enter the left (8) . When this contrac

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In the lungs the blood becomes oxygenated. It returns to the heart in the pulmonary (7) veins. These enter the left (8) atrium. When this contracts it pushes blood into the left (9) ventricle. This has a thick wall because when it contracts it generates high pressure to force the blood through the (10) aorta to the head and body.