And this outside portion is basically the area where we have cells of some particular tissue. Now, these are the red blood cells. And inside these red blood cells, we have a bunch of these hemoglobin. And these hemoglobin carry the oxygen. Now, as the red blood cells travel, let's say, from this side to this side, inside the blood plasma, we have a relatively high concentration of oxygen. And so the partial pressure of oxygen inside our capillary will be relatively high compared to the partial pressure of oxygen inside the cells of our tissue.