Well, that's because we have to apply a very high pressure to actually increase the volume of our artery. But in the case of our vein, we can apply a time pressure to actually increase the volume because they can't actually push back on that blood very well. So for arteries, the slope is small, as shown here. And so that means compliance is small as well. And that means that they can resist high pressures without actually really increasing in volume by that much. On the other hand, a very tiny change in pressure, if we even apply the slightest pressure to our veins, they will easily expand by a great percentage.