Like a radiator hose under pressure, the wall can rupture. Blood can then spill out of the circulatory system into the body cavity. If an aneurysm ruptures in the aorta, death is almost certain. Excellence The systemic veins also can have problems. When the valves in the veins break down, blood can pool in the lower legs, causing varicose veins.
Clots can also form in veins of the legs.
These clots can break loose and flow to the lungs, causing a pulmonary embolism and possible death. The capillary beds are not without their problems. True capillaries do not have any smooth muscle in their walls. They have no way to control excess pressure other than a small muscle, the precapillary sphincter. A precapillary sphincter encircles each capillary branch at the point where it branches from the arteriole.