So for relatively large arteries such as our femoral artery, the femoral artery it only expands by about 10%. So in diagram A we have the relaxed state of our artery and no blood actually flows across. But when blood actually fills the arteries the fluid, the blood pushes against the walls but the walls push right back and so it expands only by a tiny amount and that means that arteries have a low compliance. A very, very high force is actually needed. A very high pressure is needed to actually expand our arteries. So arteries can withstand high pressures without increasing in volume by too much, meaning they have a low compliance.