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I'm actually gonna take a step back, clear out some of these stuff,

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You've understood the first half of how this process of atherosclerosis happens,

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and we're gonna finish off the second half.

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So all of the action is still gonna happen in the tunica intima.

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So they're much --is gonna stay the same.

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And so far we've talked about macrophages,

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and we talked about how they form foam cells,

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and they --they eat up all the fats,

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then form this kind of lake of fat.

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And so, let me --let me leave it there,

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so that's where the picture's out so far.

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And now, let's talk about what happens after that.

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So, the next step, step five, is

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basically what happen with smooth muscle cells.

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smooth muscle cells.

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We haven't talked about them so far.

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smooth muscle cells.

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they (..) or they dance over --let's write dance~ over to tunica intima.

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So really, again, everything is happening in the tunica intima.

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Right, you can see that.

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That's all the action is.

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So when I say they dance over them,

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I'm being a little bit silly,

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but basically what happen is that these red smooth muscle cells,

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these are the smooth muscle cells,

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smooth muscle.

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They are gonna start migrating.

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They're gonna start migrating or moving.

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And they're gonna start migrating into the space,

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maybe that one will go over there,

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maybe this one go over here, perhaps this one.

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And why these start kind of migrating is that,

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you know, there's a lot of actions going on,

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the macrophages are there, you got the LDL in that lake of fat.

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And a lot of chemicals are being released by these cells.

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And so they sense that something's happening.

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So they can move over there.

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What they begin to do is make a fibrous cap.

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That's step six.

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So they make a fibrous cap --actually let me

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--let me write who makes it.

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So it's very clear: smooth muscle cells, S-N-C.

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Smooth muscle cells make a fibrous cap.

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And what a fibrous cap is? It's--

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Think about when you're really young and you're playing,

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and you know, you never really pay attention in fellow a lot,

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you might've come home with skinned knees.

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And I (..) my mom always remarks on that.

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And those skinned knees turned into scab, right?

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And so these smooth muscle cells made fibrous caps.

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Basiclally, think of it as a scab.

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A scab that formed over this lake of fat.

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So I've been drawing for you this yellow lake of fat,

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and now, these smooth muscle cells, they coming and say,

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"well, you know, we've gotta make a cap over this thing".

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Let me erase again, and draw for you what that might look like.

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So, let's say that this lake is getting bigger

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This lake over time is ...