The Wonders of Coagulation

"I praise you because I am fearfully and wonderfully made..." ~Psalm 139:14

Yes, in case you could not tell from the title, I am a nursing student. I'm not going to shy away from it. God has shown me some of the wonders of the human body through Anatomy and Physiology, and all I can say is that He truly is amazing for having created us.

So I am offering a slight warning. I'm going to talk about the amazing-ness of blood clotting. I will not post any pictures (mainly because I hate using pictures from the internet and I don't particularly feel like bleeding for a camera), so those with squeamish stomachs are safe. I will, however, talk in-depth about blood clotting and do my utmost best to point out the beauty in this single body system. And it's not even a single body system. It's a very small portion of the circulatory system, but every part of blood clotting is so intricate and amazing.

So it starts with an injury. I bashed my knee when I slipped on Saturday at work. I broke a couple small blood vessels (the bruise on my knee is evidence enough) near my patella (knee). Immediately, to prevent major blood loss into the tissue around my knee, the blood vessels constricted. Little fragments of cells called platelets noticed that there was a gap in the blood vessel when they could see the collagen that is right outside the vessel walls, and they started sticking to the collagen and to each other. They quickly formed a platelet plug. While they are sticking, they do something called degranulate - which basically means they release their contents, including factors that call white blood cells and platelets (to keep up the sticking cycle) to the site, as well as triggering coagulation and more constriction of the blood vessel.

Thus begins coagulation. There is an extrinsic mechanism and an intrinsic mechanism that MUST happen in order for a clot to form. Both include a cascade. One factor activates another factor which activates another factor, which activates two more factors, which one activates another factor, and the other goes back in the cycle and keeps activating other factors. I think I just confused myself with that sentence. But you get the picture. If ONE of these factors does not work properly, the entire cascade is thrown off. That's how intricate this system is. Isn't it cool? Scientists call it "irreducible complexity" which is fancy language for saying that this system is so complex that it cannot have steps taken out without disrupting the whole system. Bleeding disorders like hemophilia or von Willebrand disease occur when one of the factors isn't working properly or there isn't enough to trigger the rest of the reaction.

I guess you could look at it as a chain reaction where one of the chains explodes in a different direction. Or with dominoes, if you set them up in a line where one will tip down one and then another, and so on and so forth, and one of the dominoes is set a little farther than the others, either the tipping will stop sooner than you wanted, or it will stop altogether. This is where I wish I had a set of dominoes and a camera...

It's so cool! The human body is made in a beautiful way so that each system works. The heart itself has backup mechanisms that will kick in if something doesn't work right. We don't bleed to death. What's more, our body automatically fixes stuff. When I stub my toe (or bruise my thigh...) I don't have to tell my platelets and clotting factors, "Hey, guys I could use a little help here..." I don't have to tell my heart to beat at the intensity it does. I don't have to tell my body to do a lot of the things it does. It's really quite amazing. Anyone who cannot see the wonder and beauty in the body is a fool, indeed.

Our God certainly is creative. *love*