So this is how the structures of the cardiovascular system are related to blood pressure. So here we have the vein and the artery and each made up of the three layers, the tunica adventisha, one over here, and the tunica media as well as the tunica intua and then you've got your lumen in the middle. And the difference here is that the tunica media on the artery is a lot thicker due to the fact that it has to handle a lot more blood pressure than the vein. The artery is dealing with blood that is being pumped directly from the heart. A considerable force whereas the vein is actually just draining blood to the heart. Here we have a diagram of the heart showing the atrium, the ventricle and the blood vessel. Here we have the valve open between the atrium and ventricle and of course the atrium ones are always open. And then this allows blood represented by these little lumen names here to flow right down into the atrium and through to the ventricle here. And then what happens is the atrium pressurizes itself so that you can fill the ventricle as with as much blood as possible as shown here. Now what happens here is that the blood pressure pushing up on this valve here closes the valve as shown here and then the ventricle begins to pressurize itself here. And of course with nowhere to go here and here as soon as that opens all of the blood is going to rush out into that blood vessel there like so. And that is how the cardiovascular system structures relate to pressure. This has been maxed by the way and this has been drawn fantastically by a malder and Bernadette.