So in diagram A we have an axon that is thick and that is short. In diagram two, in diagram B we have a long axon that is very thin. Now, from our discussion above we see that diagram B describes the axon that would ultimately propagate that action potential at a much greater rate than diagram B because in A we have a large area and a small length and that would decrease the resistance inside that axon. Now of course, because the size of our body is limited, that means the length and the thickness of that axon is also limited. That is, we cannot actually make our axon too thick or too short or too long. Now, instead of actually increasing the area or increasing the area or decreasing the length of the axon, the way that our body increases the speed at which our action potential moves along the axon is by using a special type of insulating material.