Providing considerable resistance to blood flow because of their small diameter, arterioles help steady the pulsating flow from the heart before emptying into capillaries. The small vessels are also of great consequence in the determination of which tissues and regions of the body receive the greatest supply of blood. The muscular wall of the arterioles is strong enough to completely close off the vessel, as well as to expand itself to a significantly larger size. Such capabilities enable the arterioles to adjust blood flow based on bodily needs.