Difference Between Right and Left Atrium

The key difference between right and left atrium is that right atrium receives deoxygenated blood from the body while left atrium receives oxygenated blood from the lung.

The human heart has four muscular chambers: two atria and two ventricles. Atria are the two upper chambers of the heart that receive blood. The atrium situated at the right side of the heart is right atrium while the atrium situated at the left side of the heart is left atrium. The left atrium receives oxygenated blood from the lung while the right atrium receives deoxygenated blood mainly from superior vena cava. Then the blood flows from left atrium to left ventricle. Similarly, blood flows from the right atrium to the right ventricle. Both atria are equally important.

1. Overview and Key Difference
2. What is Right Atrium
3. What is Left Atrium
4. Similarities Between Right and Left Atrium
5. Side by Side Comparison – Right vs Left Atrium in Tabular Form
6. Summary

What is Right Atrium?

Right atrium is one of the two atria of the mammalian heart. It is the upper chamber located at the right side of the heart. It receives deoxygenated blood from the body through superior and inferior vena cava. Through the tricuspid valve, blood flows from the right atrium to right ventricle. Right atrium has comparatively thin wall than the left atrium. Moreover, the pressure of the blood is low compared to the pressure of the blood in the left atrium.

What is Left Atrium?

Left atrium is the left upper chamber of the mammalian heart. It receives oxygenated blood from the lungs through pulmonary veins. Then, the blood flows from the left atrium to left ventricle through the mitral valve.

Difference Between Right and Left Atrium

Figure 01: Heart

Moreover, the left atrium wall is thicker than the wall of the right atrium. Furthermore, the left atrium plays an important role in pulmonary circulation.

What are the Similarities Between Right and Left Atrium?

Right and left atria are the upper chambers of the heart.
Both atria receive blood to the heart.
Also, they do not have valves at their inlets.
Blood flows from both atria to ventricles.

What is the Difference Between Right and Left Atrium?

Atria are the upper chambers of the heart. Right atrium is the right upper chamber that receives deoxygenated blood from the body while left atrium is the left upper chamber that receives oxygenated blood from the lung. Therefore, this is the key difference between right and left atrium.

Moreover, a further difference between right and left atrium is that the right atrium receives blood through superior and inferior vena cava while left atrium receives blood through pulmonary veins. In addition, right atrium has a thinner wall while left atrium has a thicker wall.

Below info-graphic presents more comparisons related to the difference between right and left atrium.

Summary – Right vs Left Atrium

Right atrium is the right upper chamber of the heart while left atrium is the left upper chamber of the heart. Both right and left atria are the chambers that receive blood to the heart from the body and the lungs, respectively. Right atrium connects with the right ventricle while left atrium connects with the left ventricle. Right atrium receives blood through superior and inferior vena cava while left atrium receives blood through the pulmonary vein. Thus, this summarizes the difference between right and left atrium.

Reference:

1. “Right Atrium.” Right Atrium – an Overview | ScienceDirect Topics, Available here.
2. “Atrium (Heart).” Wikipedia, Wikimedia Foundation, 29 May 2019, Available here.