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Heart Anatomy

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发表于 2017-5-13 09:22:32 | 显示全部楼层 |阅读模式
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Heart Anatomy.png
Heart Anatomy
Heart Chambers
    Your heart has 4 chambers. The upperchambers are called the left and right atria, and the lower chambers are calledthe left and right ventricles. The left ventricle is the largest and strongestchamber in your heart. The left ventricle’s chamber walls are only about a half-inch thick, but they haveenough force to push blood through the aortic valve and into your body.
The Heart Valves
Four types of valves regulate blood flowthrough your heart:
    •       The tricuspid valve regulatesblood flow between the right
        atrium and right ventricle.
    •       The pulmonary valvecontrols blood flow from the right
        ventricle into the pulmonary arteries, which carry blood to
        your lungs to pick up oxygen.
    •    The mitral valve letsoxygen-rich blood from your lungs
        pass from the left atrium into the left ventricle.
    •       The aortic valve opensthe way for oxygen-rich blood to
        pass from the left ventricle into the aorta, where it is
        delivered to the rest of yourbody.
The Conduction System
    Electrical impulses from your heart muscle(the myocardium) cause your heart to contract. This electrical signal begins inthe sinoatrial (SA) node, located at the top of the right atrium. The SA nodeis sometimes called the heart’s "naturalpacemaker." An electrical impulse from this natural pacemaker travelsthrough the muscle fibers of the atria and ventricles, causing them tocontract.
The Circulatory System
    Your heart works as a pump that pushesblood to the organs, tissues, and cells of your body. Blood delivers oxygen andnutrients to every cell and removes the carbon dioxide and waste products madeby those cells. Blood is carried from your heart to the rest of your bodythrough a complex network of arteries, arterioles, and capillaries. Blood isreturned to your heart through venules and veins.

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