In addition to their placement, the primary difference between the left and right atria is that the left atrium receives oxygenated blood while the right atrium receives deoxygenated blood. Each atria is fed by different parts of the circulatory system.
The normal human heart in particular is made of four chambers:
- Left atrium
- Right attrium
- Left ventricle
- Right ventricle
The heart is connected to the rest of the circulatory and pulmonary system by the aorta, superior and inferior vena cava, pulmonary artery, pulmonary veins and coronary arteries. The heart is divided into left and right sides by the septum as well as the top (atria) and bottom (ventricle) chambers.
The heart returns blood from the body and lungs to the atria, which then contract to send blood into the vetricles. The atria are connected by the interatrial septum.
The left atrium receives oxygenated blood through a smooth-walled portion of its construction from the pulmonary veins. It releases the blood into the left vetricle, which connects via the left AV or mitral valve. The right atrium receives blood from other parts of the body through the sinus venarium, which connects to the vena cava. It releases blood into the right ventricle through the right AV or tricuspid valve.