What is meant by oxygenated blood?
Oxygenated blood refers to a high saturation of oxygen in the haemoglobin of red blood cells at high PO2 (partial pressure of oxygen) to form oxyhaemoglobin, this is usually at the capillaries that run adjacent to the alveoli. As this blood is pumped by the heart to the rest of the body, the oxygen carried in the red blood cells can be utilized by respiring tissue that are at lower PO2 as the rbc gives up the oxygen more readily.