What causes rigor mortis?

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Josh Clark: Hello, and welcome to our podcast. We call it Stuff You Should Know, with your host Josh Clark and Charles W. Bryant. I'm Josh Clark.

Chuck Bryant: We were told to call it Stuff You Should Know.

Josh Clark: Yeah, what did you think about that opening?

Chuck Bryant: It was good.

Josh Clark: I still have to keep trying.

Chuck Bryant: Yeah.

Josh Clark: Okay, well, we'll try it next time.

Chuck Bryant: One hundred plus episodes in. We're still working out the first 20 seconds.

Josh Clark: Still working out the kinks. Yeah. Isn't it? It's not just the first 20 seconds, Chuck. You're right. I mean from beginning to end, its herky and jerky. The whole shebang!

Chuck Bryant: It's evolving, Josh.

Josh Clark: So Chuck, I'll tell you who wasn't evolving for about 17 hours back in May of 2008. You want to hear about a woman named Val Thomas?

Chuck Bryant: Yes, and that was awesome, by the way, that setup.

Josh Clark: Thank you.

Chuck Bryant: Very good.

Josh Clark: Val was a 59-year-old West Virginia woman, and in May of 2008, she died. Died! Seventeen hours. No brain activity. Her heart was stopped. They had her on a ventilator even during this time. She was dead. And worst of all, rigor mortis set in.

Chuck Bryant: Right, which his sure fire sign, I would think, that you're dead.

Josh Clark: Yeah because it's not even part of the process of death. It's you've been dead for several hours now, and here is this new process that happens to a corpse. The weird thing is - this is not - wouldn't necessarily be significant under any other circumstances but this because we all go through rigor mortis. But Val Thomas woke up. She came back.

Chuck Bryant: You're kidding.

Josh Clark: I am not kidding. After rigor mortis set in and everything. She's dead for 17 hours. She woke up, started talking.

Chuck Bryant: Then she popped a breath mint and cracked her knuckles, I suppose.

Josh Clark: Yeah, and I was wondering what would it feel like - what would your muscles feel like after rigor mortis set in? I can't imagine it would feel very good. You'd probably feel really sore. Right?

Chuck Bryant: Yeah, I would imagine so.

Josh Clark: Because I mean what is rigor mortis except a contraction of the muscles. Right?

Chuck Bryant: Well, is it?

Josh Clark: It is, Chuck. Let's talk about rigor mortis today. You want to?

Chuck Bryant: And that's the rigor mortis setup.

Josh Clark: There you have it.

Chuck Bryant: Very nice.

Josh Clark: Chuck and I have had fun all afternoon sending each other gross pictures of corpses in rigor mortis.

Chuck Bryant: Of stiffs.

Josh Clark: Stiffs, exactly. That's where the term comes from.

Chuck Bryant: Absolutely.

Josh Clark: Have you ever heard of that book, Stiff, by Mary Roach?

Chuck Bryant: I think so. Is that the pictures of dead people?

Josh Clark: No. It's a book about what happens to the body afterwards, and basically, what it's like to be a cadaver, all the uses for cadavers. I haven't read it. I was reading the introduction today, and I was also listening to the thrash metal band, Rigor Mortis.

Chuck Bryant: I saw them, too.

Josh Clark: Yeah? Were you listening to them?

Chuck Bryant: I wasn't, but I was surprised they were able to get the domain name. It seems like some sort of mortuary would have gotten that.

Josh Clark: They've been around for a while. They released their debut album in 1988.

Chuck Bryant: Really?

Josh Clark: Yeah. So they were probably on top of it back in the '90s.

Chuck Bryant: Sounds like it.

Josh Clark: But I was listening to them on LastFM, and I was like, "Rigor Mortis isn't as good as I remembered," so I went over to the Children of Bodom Channel, and they were all right. You ever heard of them?

Chuck Bryant: No.

Josh Clark: They're pretty serious. You should check them out.

Chuck Bryant: I will.

Josh Clark: But anyway, so yeah, I was prepping for this podcast, reading Stiff, and Ms. Roach mentions that - she was talking about all the ways cadavers have been used to help further humanity. And one of them was there was this French scientist back in the late 19th Century who was trying to find out whether or not the Shroud of Turin was real or not. And he actually got his hands on cadavers, and he was the first one to establish that Christ could not have been crucified through his palms because this guy determined that that would only hold about a 90-pound man or body to a crucifix. You know how he found out? By nailing cadavers to a crucifix!

Chuck Bryant: So it was through the wrist? Is that what he did?

Josh Clark: Through the wrist. Yeah. Apparently, there's some joint. I can't remember what' it's called, but I think the place where your - what, tibia and fibula? Oh, I hope that's right. I don't want viewer or listener mail. Is it tibia and fibula?

Chuck Bryant: I doubt it.

Josh Clark: Humerus? Humerus and - ah [beep]. We can't put [beep] in there? Anyway, I am, I assume, going to get some listener mail for that one. But the two bones where they come together at your wrist to connect to your metatarsal or metacarpal - metacarpal because it's carpel tunnel syndrome. Anyway, there is a hole there that you could drive a stake through, and it will hold up a substantial adult sized male. But this guy, this French physician figured it out by nailing cadavers to a cross.

Chuck Bryant: And I guess the other option is that Jesus was a 90-pound weakling, which doesn't seem likely to me.

Josh Clark: I don't know. I can't imagine they were all that well nourished back then.

Chuck Bryant: Yeah, but 90 pounds? Come on.

Josh Clark: Yeah, that is kind of tiny.

Chuck Bryant: It's slight.

Josh Clark: Sure. So cadavers, rigor mortis!

Chuck Bryant: Yes, rigor mortis, Josh.

Josh Clark: What does it mean in Latin?

Chuck Bryant: Well, Josh, it's not so important what it stands for in Latin because we know Latin is a dead language. Latin is suffering from rigor mortis. What is important is how it works because that's what we're here to educate folks on.

Josh Clark: You want to talk about that, or you want me to?

Chuck Bryant: Well, we'll both get into it. I thought one thing that was interesting is that three hours or so after a human or animal dies, it starts to happen, and it happens from head to toe, which I thought was pretty interesting.

Josh Clark: Whose law is that? Nysten's Law!

Chuck Bryant: Yeah, Nysten. He discovered this way back in 1812.

Josh Clark: The reason why it starts from head to toe, basically, they think is because you have smaller, more delicate muscle tissue around the face. So usually, it's the eyes and the mouth that require very delicate, precise movements that rigor up first.

Chuck Bryant: Right, which is why every movie in history, every death scene with the guys' eyes wide open, a friend will come by and gently shut them.

Josh Clark: Maybe put a couple of half dollars over them.

Chuck Bryant: Oh, yeah. If it was a western!

Josh Clark: Sure. So rigor mortis, Chuck, is nothing but the stiffening of the muscles. Right?

Chuck Bryant: Yeah.

Josh Clark: Okay, let's talk physiology here for a second, buddy. So we have two different kinds of muscle fibers. We've got skeletal muscles, and we have smooth muscle tissue. Smooth muscle tissue is like your heart. It's what your heart is made out of.

Chuck Bryant: Right. This is microscopic.

Josh Clark: Sure, it is. Then when you bundle them together, you have a muscle. What we see as a muscle. But yeah, they're all made up of individual fibers. And all of these are connected or commanded by neurons. Right?

Chuck Bryant: Yes.

Josh Clark: So you have motor neurons that command skeletal muscles, and you have fast twitch muscles, which are the ones that require precise movement. So your fast twitch neurons are the ones controlling like your eye movement, your tongue. That kind of thing! Then you have kind of the big, oafish neurons of the physiology world. Those are slow twitch neurons.

Chuck Bryant: That was a good oaf imitation, by the way.

Josh Clark: Thank you very much.

Chuck Bryant: You looked very lumbering.

Josh Clark: We need to go video, Chuck.

Chuck Bryant: We will.

Josh Clark: Okay. So anyway, when the brain says, "Hey, raise your left arm," it transmits an electrical impulse to the neuron, which says, "Okay, we've got to get this going." What happens is when this transmission takes place, there's a biochemical process that happens. We've got these calcium ions. Right?

Chuck Bryant: Right.

Josh Clark: And they exist outside of the cell, but they like to go into the cell whenever they get a chance. Right? So they'll go into the cells that make up our muscle tissue, and they kind of throw everything off balance. What they allow to happen - so these two proteins to connect. And we have two different kinds of skeletal muscle fibers.

Chuck Bryant: I know what they're called.

Josh Clark: Let's hear it.

Chuck Bryant: Myosin and actin.

Josh Clark: Okay, myosin makes up thick filament fibers. Right?

Chuck Bryant: Right.

Josh Clark: And then actin makes up thin filament fibers. And when you connect the two, when myosin and actin connect to one another, they're molecules. Right?

Chuck Bryant: Yep.

Josh Clark: Then you have a contraction. So calcium ions allow myosin and actin to connect, which makes your muscle contract. So to get a muscle to relax, you have to uncouple myosin and actin. And through oxygen, through aerobic - an aerobic process! When we breathe in oxygen, some of it goes to produce the stuff called adenosine triphosphate.

Chuck Bryant: ATP.

Josh Clark: ATP. Sure. And that stuff actually decouples myosin and actin, causing the muscles to relax.

Chuck Bryant: Yep.

Josh Clark: When we're dead, though, we have two problems. No. 1, we're not breathing anymore, so there's no oxygen, which means we're not producing ATP any longer. But secondly, the - apparently, those calcium ions, their natural state is trying to get into the cell. So there's a buildup of calcium ions, which means your muscles all start to contract. Hence rigor mortis!

Chuck Bryant: There you have it.

Josh Clark: That's it.

Chuck Bryant: Dr. Clark.

Josh Clark: Thank you.

Chuck Bryant: That is not it, though, Josh.

Josh Clark: Oh, it's not? Okay, I stand corrected.

Chuck Bryant: What's important about rigor mortis is what we should talk about next. And we know how it happens, and you can become stiff, and it's funny to play with a stiff, dead body. We all know that.

Josh Clark: Sure. Put them in like silly positions.

Chuck Bryant: Yeah, it's a good time. But it can actually be used at things like crime scenes.

Josh Clark: Oh, it can. Yes.

Chuck Bryant: Yes. Do we need to talk about that?

Josh Clark: Well, yeah. Well, how about this. You said that it sets in after three hours.

Chuck Bryant: Yes. Well, not always.

Josh Clark: Well, okay, but about how long does it last?

Chuck Bryant: It lasts up to 18 hours. Twelve to 18 hours, and then it fades away again.

Josh Clark: I've heard up to 36, 72. Just doing side research on this, it sounds like nobody can say definitively how long it lasts.

Chuck Bryant: Well, and it depends on a lot of things.

Josh Clark: What are they dependent on?

Chuck Bryant: Well, temperature is one obvious thing. Temperature, Josh, is one thing. That's pretty obvious. If it's warmer, it'll speed up rigor mortis, and it'll also go at a slower pace. Or I'm sorry, faster pace.

Josh Clark: Right, so it sets in faster, but it lasts a shorter amount of time. Right?

Chuck Bryant: Right because basically, it creates a good environment for bacteria for the decay process, which starts after rigor mortis.

Josh Clark: Right, and ultimately, that's what gets rid of rigor mortis. This process called autolysis, and that is basically where the cells kill themselves.

Chuck Bryant: Yeah, they kind of give up.

Josh Clark: The enzymes and cells basically break down the cellular structure, and this is the case for the cells that make up muscle tissue. Right?

Chuck Bryant: Right.

Josh Clark: So as the cells decompose, the muscles can no longer hold an erection, and you're no longer in a state of rigor mortis.

Chuck Bryant: Very nice, Josh. I'm proud of you.

Josh Clark: Thank you. Thanks.

Chuck Bryant: When it's cold, on the other flip side of the coin, it'll slow the process down. So if you die outside in the freezing cold, like Jack Nicholson in the shining, he was a stiff. He probably wasn't just frozen in that scene. He probably had rigor mortis.

Josh Clark: Probably, yeah.

Chuck Bryant: And was frozen at the same time.

Josh Clark: And it would have lasted a long time. I heard it can last up to 28 days under the right conditions.

Chuck Bryant: Yeah, if you're freezing out there, for sure. So physical exertion just prior to death! That's another thing that can affect it.

Josh Clark: Yeah because your muscles are already contracted.

Chuck Bryant: Exactly, so -

Josh Clark: Or if you're drowning or something, you're already starved of oxygen, so you're not producing ATP anyway. So it can set in immediately. Right? Which is called a cadaveric spasm? Right?

Chuck Bryant: Uh huh.

Josh Clark: I actually saw a beaver undergo a cadaveric spasm once.

Chuck Bryant: Really?

Josh Clark: Yeah, when I was in Tennessee, I saw a beaver get hit by a car, and it went - and just immediately died because the next day, I was driving down the same stretch of road, and the beaver was in the same position, making the same face that it was the moment it died. It was crazy. I saw something undergo a cadaveric spasm.

Chuck Bryant: Wow. So if police are investigating a crime scene, and someone has still got their fist clenched around their purse or something, that means they might have died while in a struggle against an attacker. So that can help out the cops. And then fat distribution is another one. Fat is an insulator, as we both know because we're very warm guys.

Josh Clark: So what would that mean? Would you and I undergo rigor mortis more quickly or less quickly?

Chuck Bryant: More slowly if you had more fat. And then age is another thing. If you have low muscle mass, like if you're a little kid, if you're really old, or I guess I should say elderly is a little more sensitive way to say it.

Josh Clark: Either way, they're going to undergo rigor mortis.

Chuck Bryant: That'll happen a lot faster, too. So those are some things that can affect the speed of the onset and the pace.

Josh Clark: But because of that, all those different circumstances surrounding rigor mortis and prol onging it or shortening it, it's not quite that precise. Right? So there's a bunch of other stuff that forensic crime scene investigators use or prefer to use over rigor mortis to establish time of death. Correct?

Chuck Bryant: Yeah, and that's not just time of death, too. You can also tell if a body has been moved post mortem, which is usually a big clue toward finding out if there was foul play, probably.

Josh Clark: Or if there were teenagers around afterward.

Chuck Bryant: Yeah, I guess so, playing with the body. Were you talking about liver mortis?

Josh Clark: That's one thing, yeah.

Chuck Bryant: That's a good one.

Josh Clark: I like that one.

Chuck Bryant: Yeah, liver mortis is when all the blood cells basically in all the blood go to the place where it's lowest.

Josh Clark: So if you're lying on your back, the blood is going to pool in your back. Or if you're on your side and your face is face down on the concrete, your face is going to be flush with blood.

Chuck Bryant: Exactly.

Josh Clark: It's pretty gross. Also know as lividity.

Chuck Bryant: Exactly.

Josh Clark: And there was another one, too. Right!

Chuck Bryant: There is. You talking about algor mortis!

Josh Clark: Yeah. Right. It has to do with power point presentations.

Chuck Bryant: Actually, that's just the cooling off of the body until it matches the room temperature.

Josh Clark: Right. And that happens at a predictable rate, too. Right? It's like one and a half to two degrees Fahrenheit per hour, I think. So that's a pretty good way of calculating time of death, too, actually. Unless the person had a fever!

Chuck Bryant: True.

Josh Clark: Because you're generally assuming that the person is starting out at 98.6. If they were sick and had a fever, that's going to set it off by a couple of hours.

Chuck Bryant: Right. I think the official body temperature changed, though. Didn't it?

Josh Clark: Did it?

Chuck Bryant: I'm pretty sure I read that a few years ago. It changed by .01 degree or something. I'll have to look into that.

Josh Clark: I haven't heard that.

Chuck Bryant: And we will determine this and follow up on that.

Josh Clark: Sounds good, Chuck.

Chuck Bryant: Another thing the cops can do is look at the contents of your stomach, just like they did in jaws when they cut the shark open.

Josh Clark: Or in Seven.

Chuck Bryant: Oh, did they do that in Seven!

Josh Clark: The gluttony guy. Yeah.

Chuck Bryant: Oh, right. Gnarly. And that can obviously - you can see how much your food is digested, the last thing you ate, and that can gauge how long you've been dead.

Josh Clark: And then my favorite. Insects!

Chuck Bryant: Yeah, I think as we all know, dead things tend to attract flies and other insects. And that is because they are feeding on your fluids. They're not just there because of the smell. And boy, this is interesting. They're feeding on your fluids, Josh.

Josh Clark: Well, what's fascinating is somebody was clever enough to figure out, "Hey, we know so much about, in the US, the blue bottle fly and every stage of its development. And it develops so quickly. And its lifespan happens over such a short period of time. We can walk up and say, "Oh, there's maggots! And they're blue bottle fly maggots, so we know that this body is only X number of hours dead." Or if they hit the pupa stage or the adult stage! You know? We can use the stages of these flies and maggots burrowing around in somebody's dead corpse to determine how long ago they died. That fascinates me.

Chuck Bryant: Pretty cool stuff.

Josh Clark: Yeah, I think we should talk about body farms sometime soon. I think we should do a podcast on body farms.

Chuck Bryant: We should. And then forensic pathology, period. I know John Fuller wrote a good article on that.

Josh Clark: Let's do it. We'll do a whole suite of just corpse stuff.

Chuck Bryant: Sure.

Josh Clark: Sweet.

Chuck Bryant: Sounds good.

Josh Clark: So Chuck, I think with that promise, we've pretty much reached the end of rigor mortis. Right?

Chuck Bryant: Let's hope not.

Josh Clark: Autolysis is starting to set in. We're starting to decompose. I'm a little gamey, I can tell you that.

Chuck Bryant: I can agree with that.

Josh Clark: So does that mean that it's listener mail time?

Chuck Bryant: I believe so.

Josh Clark: Let's do listener mail then. And I think all of you, friends out there listening, should make note we plugged nothing today. Yeah, that's right. Our producer Jerry just gave us the thumbs up, baby.

Chuck Bryant: In fact, we refuse to plug anything because we don't want you to read our blog or to buy our spoken word album.

Josh Clark: Reverse psychology, Chuck.

Chuck Bryant: We refuse to plug. The anti plug!

Josh Clark: So it's listener mail time.

Chuck Bryant: It is. So Josh, this comes to us from David in Atlanta right here.

Josh Clark: Hey. I know Atlanta.

Chuck Bryant: And David is commenting on our Ponzi podcast.

Josh Clark: Wait, Chuck, you can't just say it like that.

Chuck Bryant: I don't know what you're talking about.

Josh Clark: You know what I'm talking about. Wait, Chuck, we're not proceeding until you say it correctly.

Chuck Bryant: Just let me read.

Josh Clark: Okay.

Chuck Bryant: This is from David. I was listening to your podcast about the Ponzi scheme. Happy?

Josh Clark: Yes.

Chuck Bryant: And it reminded me of a company, quote unquote, that I did some work for a few years back in Atlanta. He names the company, but I won't name it. They were running a real estate based Ponzi scheme, and they hired his company to come in and work on their computers, like an IT deal. And he said he knew something fishy was going on. He saw a few red flags in just the couple of days he was there. There was a high level of security for a small company. The owner of the company had a personal bodyguard, and there were several security guards in the little, tiny office. Second the pitch that the sales staffs were giving promise typical Ponzi scheme results, high return, that kind of thing. And this is, to me, the big red flag is he said that they would not let anyone from Georgia invest in their company.

Josh Clark: Really?

Chuck Bryant: They're based out of Atlanta, and they wouldn't let anyone in Georgia invest in their company. So he suspected this was a big cover up and a big scheme and it turns out that it was. It only lasted about a month, and he heard that they had been operating before that, though, clearly because they bilked people out of about $70 million.

Josh Clark: Holy cow.

Chuck Bryant: And his company did not even get paid, and that's the end of David's story.

Josh Clark: Wow. Well, thanks a lot, David.

Chuck Bryant: A first hand account.

Josh Clark: I hope things have come around again since then for your company. If you have any fascinating stories about Ponzi schemes or pyramid schemes or any kind of scheme whatsoever, or you just want to say, "What up," to Chuck and I, Chuck and me, you can send an e-mail to StuffPodcast@HowStuffWorks.com.

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