 The same damage that stimulated vasoconstriction, the same damage, the same stimulus that caused vasoconstriction also causes the formation of a platelet plug. So let's make a little note that now we're talking about this platelet plug. And platelet plugs only happen when platelets are activated. And platelets get activated when exposed to damaged tissue. So think about this. In fact, one of the things, one of the molecules found in a blood vessel wall that's normally not exposed and is only exposed when damaged is collagen. Collagen fibers are found in connective tissues and there's connective tissues surrounding your blood vessels to make them stronger. And that connective tissue layering that you might be exposed to if there's damage to that vessel activates platelets. Now, here's the deal. Activated platelets, they grow, so they become bigger. They get irregularly sized. Okay, let's just say they have irregular shapes. So they like, not only do they get bigger, they like get wonky. Like they have little twangers twanging off into twangy land. They get super sticky. Dude, these guys, all of a sudden an activated platelet is going to stick to other activated platelets or stick to other platelets in general. And this is crazy. They get sticky and they produce chemicals that activate more platelets. One of those chemicals is thromboxane A2. Interesting, the platelets, when they become activated, they produce this thromboxane A2, which causes vasoconstriction and causes more platelets to activate. More platelets become activated and produce more thromboxane A2, which causes more vasoconstriction and causes more platelets to activate. Now, go back. Think about our sticky platelets. They're sticky, they're irregularly shaped. They're literally going to form a mass over the top of the damage. You can imagine that it's kind of a puffy, sticky, weird mass, but it's going to slow down the blood flow. That's not a clot. Clotting is the next thing that we're going to talk about. So the platelet plug is another whole process entirely. There, this is a little gift from Ashton, my favorite dog pound of a feather. She gave me this little cup of a bunch of platelets having a platelet party. You can see that they're all sticking together. And look, they're like, dude, this is awesome. Let's have a platelet party. And some of them are getting stuck on there. Like, look at that little guy. Oh, he got stuck on there. He's like, how did I get here? And they all are kind of differently shaped, but they, as they form this clot or plug of madness, they're stoked, they're having a party, but they're also doing a really important job slowing the bleeding. The little tiny damages to your vessel, the little tiny ones, awesome. The platelet plug is going to take care of business. In fact, the little tiny ones, like why even bother clotting? Like, our platelet plug will do the job. You can imagine that if our platelet plug got out of control, can you see how, I mean, it's a positive feedback cycle. And that, like they literally would clot all or platelet plug, activate all those platelets through your whole body. And then that's going to be a bad situation. Healthy, normal, intact endothelium in your blood vessels actually produce chemicals that say, you guys, seriously, you're out of control. You do not need to have any more parties. Quit sticking to each other, like, come on, be grown-ups for a change and then encourage those little platelets to not activate. So normal, healthy endothelium is saying, relax you guys, there's no need to activate. Damage endothelium produces that positive feedback that causes lots and lots of them to activate. Are you happy? Shall we find out what happens with clotting? Clotting is another whole ball of wax. Go find out how that works.