How a Human Heart Works
Heart is one of vital
organs of a human, which has the important role to pump blood throughout
the blood vessel to various parts of the body by repeated, rhythmic contractions.
The average human heart, beating at 72 beats per minute, will
beat approximately 2.5 billion times during an average 66 year lifespan, and
pumps approximately 4.7-5.7 liters of blood per minute. Therefore, this is why
the heart is very important. However, how does it work?
The human heart has four
chambers, two superior atria and two inferior ventricles.
The atria are the receiving chambers and the ventricles are the discharging
chambers. During each cardiac cycle, the atria contract first, forcing
blood that has entered them into their respective ventricles, then the
ventricles contract, forcing blood out of the heart. The pathway of the blood
consists of a pulmonary circuit and a systemic circuit, which function
simultaneously. Deoxygenated blood from the body flows via the vena cava into
the right atrium, which pumps it through the tricuspid valve into the right
ventricle, whose subsequent contraction forces it out through the pulmonary
valve into the pulmonary arteries leading to the lungs.
Meanwhile, oxygenated blood returns from the lungs through the pulmonary
veins into the left atrium, which pumps it through the mitral
valve into the left ventricle, whose subsequent strong contraction
forces it out through the aortic valve to the aorta leading
to the systemic circulation.
This is the entire
process how a human heart works.
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