 So if we're going to talk about the process of blood clotting or hemostasis, stop the bleeding, then we have to talk about our platelets. Platelets, I'm back to histoland. I'm back to feel good happy land because I wanted to remind you of what platelets actually look like. These things, they look like dirt on your slides. Remember back in the day when you were hunting for it, you were doing the Easter egg hunt for blood cell types. The platelets look like dirt, and it's because they're tiny little fragments of cells, they're not actual cells. They come from the giant megakaryocytes that are so huge that they can't actually squeeze out into the bloodstream, but they want to. And so they try, and as they squeeze themselves out through the blood vessel, the blood coming by like smashes into the megakaryocyte and the pieces of megakaryocyte break off. So the megakaryocyte gets like all torn to all heck and gone, and the little torn up pieces are platelets. So they're not really cells. Because they came off of the guy who wanted to come out and play with everybody else, they are containing some cell parts. Like they have little pieces of endoplasmic reticulum, and they've got little pieces of mitochondria and a few ribosomes. So they can do some stuff. They don't live very long, probably because they don't have any cell parts to take care of all their needs. Platelets are something that when you go donate blood, they'll often ask you, pretty please with sugar on top, will you just donate platelets? And that involves sitting down at the aphoresis machine for a whopping like two hours while they filter your blood. They leave most of it in there, they just take out the platelets. And you get kind of cold in that process, and you get to sit there for half an hour, or for two hours and like watch movies and stuff. Yeah, I'm in. I would totally do it. Apparently, I and lots of women, which is really interesting, have a antibody in our systems that is associated with increased respiratory issues, with blood transfusions. And so we're not actually, there's a whole herd of us that are not allowed to donate platelets in that manner. We can donate whole blood though, which I think is really interesting. Okay, so little fragments that play a role in clotting, and in this next section, this is going to be a long one, we're going to look at the whole process of clotting and clarify the role that the platelets are actually playing. Let's see if I can find the off button.