What type of blood do the atria contain?

The atria of the heart serve as receiving chambers for blood coming from various parts of the body. The right atrium receives deoxygenated blood from the systemic circulation via the superior and inferior vena cavae. In contrast, the left atrium receives oxygenated blood from the lungs through the pulmonary veins. Therefore, it is accurate to state that the atria contain both oxygenated and deoxygenated blood. The right atrium, while it solely holds deoxygenated blood, enters into a chamber that is part of a network that also includes oxygenated blood from the lungs, thus leading to the conclusion that the atria as a whole contain both types of blood. This dual function of the atria reflects their role in managing the flow of blood as it circulates through the heart and body.