Difference Between Atria and Ventricles

Atria vs Ventricles

Human circulatory system has a four- chambered heart with two separate atria two separate ventricles. The main function of heart is to pump blood to all the body parts through the blood veins. The human heart maintains two types of circulation cycles called pulmonary circulation and systemic circulation. According to these circulations, the left atrium receives oxygen rich blood from lungs and left ventricle pumps it to the rest of the body while right atrium receives deoxygenated blood from the body and right ventricle pumps the blood to the lungs. During these circulations, both atria simultaneously contract, pumping their blood into ventricles. Then ventricles also contract simultaneously, pushing blood into the pulmonary and systemic circulation. Because of these simultaneous contractions, the human heart is known as a two-cycled pump.

Image of heart anatomy


The human heart consists of two atria, which make the upper portion of the heart. In general, atria receive blood and pass it to two ventricles by simultaneous contractions. The left atrium receives oxygenated blood from lungs through pulmonary veins and pumps into the left ventricle via bicuspid valve. The right atrium receives deoxygenated blood from the body through superior and interior vena cava, and pumps into the left ventricle via tricuspid valve. In the human heart, the left ventricle is quite smaller than the right atrium.


There are two ventricles found in the human heart; left ventricle and right ventricle. Both ventricles are situated below the atria, and they make the lower portion of the heart. The left ventricle is quite smaller than the right ventricle. The left ventricle receives oxygenated blood from the left atrium and pumps the blood to the body via the aorta. The right ventricle receives deoxygenated blood from right atria and pumps the blood to lungs through pulmonary artery via pulmonary semilunar valve. Unlike the right atrium, the left atrium is lined by a thick wall, which helps to get a large force in order to distribute the blood to all the body parts. (Read more: Difference Between Left and Right Ventricle)

What is the difference between Atria and Ventricles?

• Atria are situated at the top of the heart, whereas ventricles are at the bottom.

• Atria are quite smaller than ventricles.

• Atria receive blood from body parts and lungs and pass the blood to ventricles. Ventricles then pumps the blood received from atria to the body parts including lungs.

• Ventricles are lined up with thick walls than atria.

• Atria and ventricles are separated by tricuspid and bicuspid valves in the heart.

• Unlike in the atrial walls, Purkinje fibers (bundle of His) are found in the ventricle walls.

• Superior and inferior vena cava and pulmonary vein open into atria, while aorta and pulmonary artery open into ventricles.


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