The air carries oxygen to your body when it is inhaled into your lungs.The blood carries oxygen through you body to the vcells that use it as part of their metabolism.
so that the blood which carries oxygen can reach every part of our body.
Blood supplies oxygen and nutrients to all parts of the body.
viens...
blood
It carries out respiration. Oxygen is needed for that
The red blood cells carry the oxygen in blood.
hemoglobin
Capillaries
The red blood cells contain a globular protein called Haemoglobin, which carries oxygen by combining the oxygen molecules to its haem groups.
The circulatory system does all this but the blood and plasma are the "part" that you are talking about. The hemoglobin carries the oxygen and some of the waste gas called carbon dioxide but the plasma carries the rest. The plasma is the liquid part of the blood.
the heart supplies blood to the brain and every other part of the body, and the blood carries oxygen which is consumed to power your body