What is the right atrium?
It can be found at the top right-hand side of the heart (on the left-hand side when somebody faces you), along the right border, slightly ahead of the left atrium.
In both men and women, it is usually slightly smaller than the left atrium and has thinner walls.
What is the right atrium’s function?
The right atrium, like the left atrium, maintains blood flowing to the heart.
It serves as a storage zone and booster pump within the heart, continuously passing deoxygenated blood (aka venous, impure, or blue blood) entering from the superior vena cava, inferior vena cava, coronary sinus veins, thebesian veins, and anterior cardiac veins to the right ventricle by way of the tricuspid valve.
Once the right ventricle contracts, venous blood high in carbon dioxide and low in oxygen is delivered to the pulmonary artery and the lungs, where it undergoes oxygenation, having passed via the pulmonary valve. This oxygenated blood then travels to the left atrium, settling there until it contracts.