How does the blood flow through the lungs during pulmonary circulation?

During pulmonary circulation, the primary function is to transport deoxygenated blood from the heart to the lungs for oxygenation. The correct answer emphasizes this crucial pathway: deoxygenated blood is pumped from the right ventricle of the heart through the pulmonary arteries to the lungs.

In the lungs, this blood passes through capillaries surrounding the alveoli, where carbon dioxide is exchanged for oxygen. Once oxygenated, the blood then returns to the heart via the pulmonary veins, flowing into the left atrium, and eventually to the left ventricle. This cycle is vital for maintaining proper oxygen levels in the body, ensuring that oxygen-rich blood can be distributed through systemic circulation.

The other options do not accurately describe the pulmonary circulation process. For instance, while it is true that deoxygenated blood flows into the right atrium, this occurs in systemic circulation as blood returns to the heart, not specifically relating to the pulmonary circulation itself. Similarly, oxygenated blood flowing from the heart to the lungs does not happen, as the lungs receive deoxygenated blood for oxygenation. The mention of blood circulating through the aorta is also irrelevant to pulmonary circulation, as the aorta primarily carries oxygenated blood from the left ventricle to the