During which circulation does blood become oxygenated in the lungs?

In pulmonary circulation, blood becomes oxygenated in the lungs. This process begins when deoxygenated blood, rich in carbon dioxide, is pumped from the right side of the heart through the pulmonary arteries to the lungs. In the lungs, carbon dioxide is exchanged for oxygen as blood passes through the capillaries surrounding the alveoli. Oxygen enters the blood, binding to hemoglobin molecules in red blood cells, while carbon dioxide is expelled through exhalation. After this exchange, the now oxygen-rich blood returns to the left side of the heart via the pulmonary veins, ready to be distributed to the rest of the body for use in cellular metabolism. This makes pulmonary circulation the key phase where oxygenation of blood occurs, contrasting with other types of circulation that serve different functions.