What is the reason that the pressure drops in the central circulation?especially if you go from arteries to arterioles you get a huge pressure drop. If you look what is changing if you go from arteries to arterioles then it is that you get many many branches this leads to an increase of total radius.(the individual radii of the arterioles are smaller but the sum of them all is larger than aorta/arteries). So because of this increase in total radius you could say that the resistance should drop. So if the resistance is dropping(in stead of increasing) how is it that you get this huge pressure drop?