And now the deoxygenated blood that contains the waste products travels along the Venuel, then to the veins and finally into the heart of our body. Now, it turns out that osmotic pressure on the Venuel side is not that much higher than the hydrostatic pressure. And what that means is not all of that blood plasma that left the capillary actually returns back into that capillary on the Venuel side. In fact, about 10% of that fluid that left the capillary and entered our tissue will remain in that interstitial space, in the space surrounding our capillary. The question is, what happens to this 10% fluid if this 10% fluid is not removed in any way, there will be a build up of pressure as a result of the build up of fluid inside that tissue. And that will lead to swelling, the process of edema.