How the Heart Pumps Blood

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Passage of Blood through the heart The human heart is a great mystery on its efficiency and function. The heart beats average about 70 times per minute, every second of every day. It never needs a rest and never pauses for a break, the only reason it would pause for a break or “rest” is if you were not alive anymore. Now, let’s follow how a blood cell travels toward your heart and how it flows through your four chambers. Blood returns to the heart in many vessels known as veins. As the veins approach the heart, they begin to come together, becoming larger and larger. Eventually, only two of the major veins remain, they are called the inferior and superior vena cava. As a basic rule, blood from the upper parts of your body drain into the superior vena cava, and blood from the lower parts return to the heart through the inferior vena cava. So our assumed little blood cell is passing through one of the vena cavas, it doesn't matter which one it passes through. This is because both of the vena cavas spill into one of the top chambers of the heart, known as the right atrium. The right atrium is a thin walled chamber, just a little smaller than a golf ball, and slightly larger than a ping pong ball. Interestingly, it is in the cells of the right atrium that the electrical signals are generated which control the heartbeat. When the right atrium contracts, it pushes the blood cells through a valve which leads to another chamber in the heart. This valve is called the tricuspid valve. It is named this because it has three leaflets. It is a one way valve, which normally only allowing blood to travel from the right atrium to the right ventricle. There are certain conditions where the flow can reverse. This being called tricuspid regurgitation (rejection), but this is not normal. This can cause a distinctive murmur if you were to listen to it flowing backwards. Once the blood
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