How does blood progress through the heart?

Understanding how blood circulates through the heart involves recognizing the roles of its various chambers. The correct sequence begins with de-oxygenated blood entering the right atrium, which receives blood returning from the body via the superior and inferior vena cavae. From the right atrium, blood flows into the right ventricle.

Once in the right ventricle, the heart pumps this de-oxygenated blood through the pulmonary arteries to the lungs. In the lungs, the blood receives oxygen and releases carbon dioxide, becoming oxygenated. After this gas exchange, the oxygen-rich blood returns to the heart via the pulmonary veins and enters the left atrium. Eventually, it moves into the left ventricle and is pumped out to the rest of the body through the aorta.

This sequence highlights the critical pathways of blood flow and the functional anatomy of the heart, making it clear why this answer accurately captures the full circuit of de-oxygenated blood to oxygenation and back to systemic circulation.