And that's exactly why our body prefers to use hemoglobin as the carrier and the transport of oxygen inside our body. Now, that discussion was a more qualitative approach. Now let's take a look at a more quantitative approach as to why our body actually uses hemoglobin instead of myoglobin as the transporter and carrier of oxygen from the lungs to the tissues of our body. So let's begin by recalling some basic biological facts. Inside our lungs, the partial pressure of oxygen is about 100 mercury inside our resting tissue. When we're not exercising, the partial pressure drops to 40 mercury.