How does the human circulatory system work?

Every day your heart beats about 1000 times, sending 2000 gallons of blood surging through your body. Although it’s no bigger than your fist, your heart has the mighty job of keeping the blood flowing through 60 0 miles of blood vessels that feed your organs and tissues.

to keep the blood flowing throughout our body. We have a pumping system and the heart is the pump which is composed of muscle that pumps blood throughout the body, beating approximately 72 times per minute of our lives.

Image by Clker-Free-Vector-Images from Pixabay


The human heart has four chambers the right atrium,
the right atrium,
the left atrium,
the right ventricle
and the left ventricle.

There are four valves in the heart. These valves are the tricuspid valve, mitral valve, aortic valve, and pulmonic valve. These valves are one-way valves. Now you have seen the structure of the heart. Let us find out how it works.

The blood becomes oxygen-rich by absorbing oxygen in the lungs. The function of the heart starts when oxygenated blood is carried from the lungs to the left atrium of the heart by means of the pulmonary veins.

The left atrium relaxes. This blood is pumped into the heart. When the left atrium contracts, the left ventricle relaxes simultaneously. The left atrium pushes the blood into the left ventricle through the one-way valve.

When the left ventricle contracts, the blood is pumped into the aorta which carries oxygenated blood to the different parts of the body, except the lungs. Oxygenated blood reaches the different parts of the body through the blood vessels called arteries.
The arteries get branched into capillaries which then reach the different organs of the body. The blood then becomes deoxygenated and the blood capillaries get mixed and form thicker blood vessels called veins. The veins carry deoxygenated blood to the heart. The blood vessels that carry deoxygenated blood to the heart are known as venue cavae

The deoxygenated blood from different parts of the body enters the upper right chamber of the heart, which is called the right atrium. The right atrium gets contracted, allowing the blood to flow into the right ventricle, which contracts with the expansion of the right atrium through the one-way valve. The right ventricle then contracts, pushing the blood into the pulmonary artery.

Image by burlesonmatthew from Pixabay

The pulmonary artery carries the deoxygenated blood to the lungs for oxygenation. The lungs oxygenate the blood by changing gases and flow back into the heart through the pulmonary vein and start the circulatory cycle all over again.

By Amarjeet

Mr. Govind is the Author & Co-Founder of He has also completed his graduation in zoology on this blog, we keep sharing updates related to Helth every day.

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