Final answer:
In the pulmonary arteries, the partial pressure of oxygen is about 40 mm Hg, and hemoglobin is approximately 75% saturated with oxygen. This saturation occurs as the blood transports to the lungs for oxygenation, with hemoglobin saturation increasing to about 95-96% in the alveoli.
Step-by-step explanation:
In the pulmonary arteries, the partial pressure of oxygen is approximately 40 mm Hg, and hemoglobin is approximately 75% saturated with oxygen. This lower saturation level is due to the fact that in the pulmonary arteries, the blood is coming from the body and heading towards the lungs to be oxygenated. The alveolar oxygen partial pressure (PALVO 2) is approximately 104 mm Hg, and it is this oxygen-rich environment inside the alveoli that facilitates the diffusion of oxygen into the blood of the pulmonary capillaries, raising hemoglobin saturation to about 95-96% as it leaves the lungs through the pulmonary veins.