How Your Heart Works

1102 Words Oct 25th, 2010 5 Pages
How Your Heart Works

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Your heart is a pump. It keeps blood moving around your body. The blood delivers oxygen and nutrients to all parts of your body, and carries away unwanted carbon dioxide and other waste products.

The heart has four chambers - two on the left side and two on the right. The two upper chambers are called the atria, and the two lower chambers are called the ventricles. The two sides of the heart are divided by a muscular wall called the septum. Each side of the heart has a ‘one-way valve system’, which means that the blood travels only in one direction through the heart.

The heart and circulatory system

With each contraction, or heartbeat, the heart pumps blood forward from the left side of the heart
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The Right Atrium, as it is called, receives blood from the upper and lower body through the superior vena cava and the inferior vena cava, respectively, and from the heart muscle itself through the coronary sinus. The right atrium is the larger of the two atria, having very thin walls. The right atrium opens into the right ventricle through the right atrioventicular valve(tricuspid), which only allows the blood to flow from the atria into the ventricle, but not in the reverse direction. The right ventricle pumps the blood to the lungs to be reoxygenated. The left atrium receives blood from the lungs via the four pulmonary veins. It is smaller than the right atrium, but has thicker walls. The valve between the left atrium and the left ventricle, the left atrioventicular valve(bicuspid), is smaller than the tricuspid. It opens into the left ventricle and again is a one way valve. The left ventricle pumps the blood throughout the body. It is the Aorta, the largest artery in the body, which originates from the left ventricle.
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The Heart works as a pump moving blood around in our bodies to nourish every cell. Used blood, that is blood that has already been to the cells and has given up its nutrients to them, is drawn from the body by the right half of the heart, and then sent to the lungs to be reoxygenated. Blood that has been reoxygenated by the lungs is drawn into the left side of the heart and then pumped into the blood stream. It is the atria that draw