Those plaques are plaques we've been installing around North America.

Some plaques are actually unstable. These plaques just grow and grow and grow.

These plaques are unstable. It can actually rupture.

So this formation of these plaques we call atherosclerosis.

Already had a look at all your plaques and your citations.

You can have these plaques build up along the walls of the artery.

Plaques, or I should say, clotting factors can clot these released pieces from the plaque.

And the formation of these plaques that obstruct the actual blood vessel, that actually obstruct the artery.

You can imagine all these blood flows, as plaque grows, the blood flows become a little turbulent around these plaques.

So in the last video we talked about these plaques forming, and if this plaque is unstable at some point it could rupture.

And in fact just to highlight the fact that this person has very stiff vessels let me show you these atherosclerotic plaques sitting inside their arteries making them stiff.

And the plaques, the material inside of them are lipids, so things like fat, cholesterol and also dead white blood cells, which is this kind of messy substance right over here.

So over time if a person doesn't have the right diet, or maybe they just have a predisposition to it, you can have these things called plaques form on the walls of the arteries.

Now we saw on the video on myocardial infarctions or heart attacks that sometimes, one of these plaques might become unstable and they break off and then you have a complete blocking of a vessel, and we called this if it's an embolus... and remember that an embolus is something that is just floating around and eventually blocks a vessel, and if it was a due to a ruptured plaque that also had clotting factors around it when it was released, then we would call this a thromboembolism.