What favors the movement of Oxygen from alveolar into the blood?

The movement of oxygen from the alveoli into the blood is favored by the difference in partial pressure between the alveolar air and the blood in the pulmonary capillaries. Oxygen diffuses from areas of higher partial pressure in the alveoli to areas of lower partial pressure in the deoxygenated blood. Additionally, the large surface area and thin walls of the alveoli facilitate efficient gas exchange. The presence of a rich blood supply also helps maintain the concentration gradient necessary for oxygen diffusion.