The Mammalian Heart
The position of valves ensures proper directional flow of blood through the cardiac interior. Note the difference in the thickness of the muscled walls of the atrium and the left and right ventricle.
This diagram of the heart indicates the superior vena cava, aorta, pulmonary artery, pulmonary vein, left and right atria, mitral valve, aortic valve, left and right ventricles, inferior vena cava, tricuspid valve, and pulmonary valve.
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"Diagram of the human heart (cropped)."
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