SciShow Tangents - Healing

Episode Date: May 26, 2020

Are you suffering from mild boredom, a grumpy frown, and a general lack of extremely niche scientific knowledge? Well, SciShow Tangents has the cure for what ails you!Follow us on Twitter @SciShowTang...ents, where we’ll tweet out topics for upcoming episodes and you can ask the science couch questions! While you're at it, check out the Tangents crew on Twitter: Stefan: @itsmestefanchin Ceri: @ceriley Sam: @slamschultz Hank: @hankgreenIf you want to learn more about any of our main topics, check out these links![Truth or Fail]Cleaner Shrimphttps://www.sciencedaily.com/releases/2018/08/180823092057.htmhttps://link.springer.com/article/10.1007%2Fs00227-018-3379-yDolphin letterhttps://web.archive.org/web/20111205105601/http://explore.georgetown.edu/news/?ID=57991&PageTemplateID=295Stressed Micehttps://www.sciencedaily.com/releases/2005/07/050729063608.htmhttps://www.fda.gov/consumers/consumer-updates/hyperbaric-oxygen-therapy-dont-be-misled[Fact Off]Ant Medicshttps://onlinelibrary.wiley.com/doi/abs/10.1002/ajp.1350160407https://www.nationalgeographic.com/news/2018/02/matabele-ants-rescue-heal-injured-soldiers/https://www.latimes.com/science/sciencenow/la-sci-sn-paramedic-ants-20180216-story.htmlhttps://royalsocietypublishing.org/doi/full/10.1098/rspb.2017.2457Two-Headed Flatwormshttps://www.cell.com/biophysj/fulltext/S0006-3495(17)30427-7https://journals.plos.org/ploscompbiol/article?id=10.1371/journal.pcbi.1002481https://www.sciencedirect.com/science/article/pii/S0005273612000855[Ask the Science Couch]Scar tissue vs. normal tissuehttps://www.nature.com/articles/d41586-018-07430-whttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC3840475/https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4352699/https://medicine.yale.edu/dermatology/dermsurg/Chapter%2018%20Time%20and%20Care%20Heals%20All%20Wounds_36907_284_5_v1.pdfReducing scarringhttps://medschool.cuanschutz.edu/surgery/specialties/endocrine/patient-care/adrenalectomy/scar-managementhttps://www.hopkinsmedicine.org/health/wellness-and-prevention/everyday-cuts-and-scrapes-how-to-prevent-scarringhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC3842869/Fetal wound healinghttps://hsci.harvard.edu/skin-regeneration-and-rejuvenationhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC4229131/[Butt One More Thing]Cow poop poulticehttps://books.google.com/books?id=0y6gAAAAMAAJ&pg=PA223&lpg=PA223&dq=In+dung#v=onepage&q=In%20dung&f=falsehttps://dictionary.cambridge.org/us/dictionary/english/poultice

Transcript
Discussion (0)
Starting point is 00:00:00 Hello and welcome to SciShow Tangents, the lightly competitive knowledge showcase starring some of the geniuses that make the YouTube series SciShow happen. This week, as always, I'm joined by Stefan Chen chen what's up what's your tagline juice sam schultz is with us as well sam hello who would you like to spend a nice quiet evening with oh nobody i like to either have like a rowdy night with people or a quiet night by myself i don't like to have a quiet night with people i don't know what to talk about sam what's your tagline french fried frog legs hello sari riley who is also here what's your tagline stone chicken and i'm in green and my tagline is buttermilk newspaper every week here at slash show tang, we get together to try to one-up a maze
Starting point is 00:01:05 and delight each other with science facts. We're playing for glory, but we're also keeping score and awarding sandbox from week to week. We do everything we can to stay on topic, but judging by previous conversations, we will suck at it. So if anybody deems a tangent super unworthy,
Starting point is 00:01:18 we'll force you to give up one of your sandbox. So tangent with care! Now, as always, we introduce this week's topic with a traditional science poem this week from Sari. Most poems about healing have heartbreak or sorrow, lost brothers or mothers or endless tomorrows, in grief or in tears or in painful distress. But now that I've got you, I'd like to address abscesses and compresses and other small messes, because healing is just goopy biological guesses. From blood
Starting point is 00:01:46 coagulation to inflammation, an influx of cytokines and cellular migration, broken skin, broken bone, broken muscle, a scratch, all token alarm bells for immune system dispatch. And I guess I can't leave out whole ecosystem repair, algae blooms that give way to new schools of fish fare, or crabs in an airport or drunk elephants keeling, humans are the virus, and nature is healing. That was great. That was so good. Thank you. Oh, we should put that one in a book with illustrations around it. I don't think that nature is healing is the thing that made the crabs in the airport. They don't belong there. that made the crabs in the airport.
Starting point is 00:02:24 No, I was going to say, they don't belong there. You haven't seen the video of the crabs in the airport. Oh, it's so good. Just search crabs in the airport. It's enjoyable if you don't hate crabs, which I do. Because they're terrible. Oh, come on. They're like giant armored spiders. I can kill a spider.
Starting point is 00:02:39 I don't know how to kill a crab. You don't need to kill a crab. It's got big claws! Friendly claws. Crabs can't surprise me in the way that spiders can. A crab's not going to fall on your head while you're sitting at your desk or something. Man, but what if it did, though? That would be really bad.
Starting point is 00:02:54 So the topic of today's episode is crab. No, it's healing. Healing, not crabs. Sari, what is healing? It seems like it has a pretty umbrella definition. Healing refers to anything that becomes healthy again. So whether it's... So was once healthy, stopped being healthy, got healthier again. Yes. And that is the healing process. So becoming, whether it's like a broken bone, mending itself, a lot of injuries,
Starting point is 00:03:27 a person who's sick, they can heal. Non-human things can heal as well. Yes. Or like non-animal things even. Like concepts can kind of heal and relationships can heal. Self-healing surfaces like the, you know, like the like clothes that are supposed
Starting point is 00:03:42 to knit themselves back together. They call those like self-healing. Did you look up the etymology of the word heal? I did. It comes from the Proto-Indo-European root kylo, which means whole. So it seems like from a pretty old point in our history, we realized that things could be broken and then things could be whole again. And that just adapted to things that started to sound more like heel, like hella, isla, hellen. And it's from the same root word as holy.
Starting point is 00:04:16 So like religious holy also came from health and happiness and wholeness. But whole, as discussed in a previous etymological discussion, H-O-L-E is not from that root, but W-H-O-L-E maybe is. Yes, yeah. The problem of an audio medium. Good catch. And now it's time for Triggered Fail. One of our panelists has prepared three science facts
Starting point is 00:04:44 for the education and enjoyment of the rest of us, but only one of those facts is actually real. The other panelists have to figure it out, either by deduction or wild guess, which is the true fact. If they do, they get a sandbuck. And if you are tricked, the presenter gets a sandbuck. And I'm instituting a new thing.
Starting point is 00:05:00 A new thing. Whoa. Right now. Oh, God. Which is I want to do a Twitter poll the day before this episode goes live. Okay. Where you people can play along with us. Alright, let me write this down.
Starting point is 00:05:12 If you listen to this, you can go to twitter.com slash scishowtangents and play along with us and choose which one you think is right. And don't cheat! Pick it before you hear the real answer. Yeah. Stefan, what are your three facts? I got three facts
Starting point is 00:05:27 related to non-human animal healing. So number one, reef fish are known to visit cleaning stations where cleaner fish attend to them, removing dead skin, parasites, and infected tissue. But there are also cleaner shrimp. And in 2018, a team investigated
Starting point is 00:05:44 the relationship between injured fish and the cleaner shrimp, and they found that the fish would visit the shrimp soon after the wound, get a little cleaning, and this led to less redness around the wound. And the team, their overall goal is to look for efficient, cleaner species that could be used to offset the use of chemical treatments in fish farming. Oh, dang it. I thought it was going to be for me. I want to get submerged in a shrimp tank. Number two. Dolphins are able to survive severe shark bites that would be fatal for a human.
Starting point is 00:06:16 And researchers looking into this in 2011 found that dolphins have a cocktail of five proteins that work together to accelerate wound healing that are similar to the proteins found in royal jelly, which is a substance that honeybees feed to developing queens and has been used in ancient medicine by humans on wound dressings. Number three, oxygen is an important part of the wound healing process and sort of for life in general. But in 2005, researchers found that mice who were psychologically stressed healed a skin wound more than 45% more slowly because stress limited the amount of oxygen in the tissues. And they put some of the mice in hyperbaric oxygen chambers.
Starting point is 00:06:57 So just like chambers where the pressure was above the normal atmospheric pressure. And they expected this to help because more oxygen should help the healing, but it actually further slowed down the healing process by suppressing a gene that lets the mice make the little tissue fibers that form around a wound and pull the tissues together. So our three facts are, one, you've got cleaner shrimp that help heal injured fish
Starting point is 00:07:22 and could be used at fish farms. Two, dolphins have proteins similar to the ones in royal jelly that allow them to heal quickly from shark bites. Or three, stressed out mice heal more slowly and they thought that putting them in a hyperbaric chamber with oxygen would help, but it did not. It made healing take longer because it interfered with the function of some Healy proteins. Healy is different. Healy's are those funny shoes.
Starting point is 00:07:51 Healy protein. The Healy protein, yeah. Gives you a wheel on your foot. Yeah. Man, if I was born with Healy's, I would be so cool. I'd never wear shoes. They'd be hard to clean.
Starting point is 00:08:03 They'd get really stinky, I think. The little wheel that would pop out. You'd have to really get in there. Oh, why did you ruin it? Ugh. All right. I think that cleaner shrimp sounds entirely possible and even likely. Are there freshwater shrimp?
Starting point is 00:08:21 Yes. Okay. Can you farm a saltwater fish? Yes. Okay. So that doesn a saltwater fish? Yes. Okay. So that doesn't help at all. Good try though, Sam. It sort of reminds me of like medicinal maggots
Starting point is 00:08:35 and how those are used in wounds just to like clean up the rough edges. I can see a shrimp just like nibbling away at a fish wound. At the dead parts. Yeah. That seems like something that Stefan could make up, though. I feel like the other two do not seem like something that Stefan could make up.
Starting point is 00:08:51 So dolphins and royal jelly, bees and dolphins. Not closely related. It seems really, really unlikely that royal jelly and dolphin proteins would be similar to me okay yeah but that also makes it a good fact too because i'm sure stefan found an article that was like b protein founded dolphins whoa whoa whoa and that is how he found it i don't know all i can think of have you seen the picture of the mola mola that got a bite taken out of it by a seal. Yes. Yeah, that's all I'm imagining. Oh, no!
Starting point is 00:09:29 Blankenfort just collapsed. We're like eight weeks into recording at home and then Blankenfort finally collapsed. A tragedy. Yeah, a skeleton fell on me. A skeleton fell on you. Yeah, so I have this, like, I bought it for Halloween for $3.
Starting point is 00:09:47 This skeleton with a tray. And that was my entire upper support of the... Well, I'm just going to podcast like this. I'm sorry if the audio is worse. I can't believe that is your support. Yeah, I don't have many things. Sarah just doesn't... She's not an owner, you know?
Starting point is 00:10:06 Not a person who owns stuff. She's got two blankets and a plastic skeleton. That's all she needs. And then finally, we've got stressed out mice that heal more slowly in the hyperbaric chamber.
Starting point is 00:10:19 So first you stress out a mouse and then you're like, also we're going to put you in a hyperbaric chamber. I'm sure that will help. And they gave him wounds wounds now we don't like to talk about that but yes these aren't these aren't mice that just like fell down skateboarding i just don't know enough about the biochemistry of the immune system and healing and things like that to know like what no oxygen would really do it sounds like something that's vaguely involved in like what you
Starting point is 00:10:46 would do to put someone in a coma. Like, oh, you can like deprive them of oxygen and then it'll stop their body for a little while. Is stress something that reduces the amount of oxygen that you get? I think it would increase because like stress increases your heart rate.
Starting point is 00:11:02 Blood flow, yeah. And then blood flow which increases the amount of oxygen to your cells. Hmm. I was leaning that way until you said that. All right, everybody. We're about to cast our votes, so go cast yours at twitter.com slash scishowtangents and see how everybody did.
Starting point is 00:11:20 Sari, you go first. I'm going with shrimp because it seems straightforward, logical, and cute. I'm still going with mice, even though you've made me second-guess myself. I'm sticking to my guns. I think I'm going to go with mice also. Now I feel like it's shrimp. Oh, come on.
Starting point is 00:11:36 Because Sam can't possibly be right about it. What the... Oh, man. Well, it was shrimp. Ah! Oh, man. Well, it was shrimp. Ah!
Starting point is 00:11:46 So according to this paper, 30 to 50% of fish and fish farms in Southeast Asia are lost to parasites. Whoa! But this project is led by someone who is at the Center for Sustainable Tropical Fisheries and Aquaculture, and they're basically trying to find ways to farm fish a little more sustainably and address the fish loss for this they injured some fish they all had the same like cut injury and they set up
Starting point is 00:12:13 some cameras and watch the fish stop by these little cleaning stations they said that the fish were in control of how much cleaning the shrimps were doing. And so right after the injury, the fish would be like, okay, don't do so much on this side of my body where I have a large incision. Maybe just stick to this side of the body for now. But that was only like right after the wound. Then later, it was sort of even split. And so overall, that seems to have reduced the redness on the wounds, which they associate with the inflammatory response in the fish. So they think that that probably leads to a reduction in how many opportunistic infections are happening in the wounds. It didn't seem like from this that
Starting point is 00:12:57 they had identified this as like, this will be a great species to use in fish farms. But I don't know. They're looking into it. So the dolphin thing, that's from 2011. And I didn't see any... It's not a paper. It's a letter from this researcher who went around and talked to a bunch of people, like dolphin experts and marine biologists and stuff. So he just talked to them, got all this info, and then put out this letter saying, dolphins have amazing healing ability. And they did have a series of pictures documenting two specific cases where dolphins healed really quickly from shark bites. Dolphins heal quickly with apparent indifference to pain,
Starting point is 00:13:40 resistance to infection, hemorrhage protection, and near restoration of normal body contour, which is super weird because if you chop up a starfish, it restores its body shape, but larger creatures often do not. I really wanted to find some follow-up research, but I couldn't find anything. So I don't know that we've figured out anything about these dolphins and how they heal
Starting point is 00:14:05 he had some ideas about like i guess when they dive they move their blood more towards the inside of their body and so that maybe that would curb blood loss and just from sampling toxins in the blubber of different animals they knew that there are my antimicrobial compounds in dolphin blubber. And I just, I had seen a different article about the royal jelly thing and was just like, eh, sure. Proteins, royal jelly, why not? And so then the mice one, they gave all these mice wounds and then some of them, they put in like confinement for, create the psychological stress and that did slow the healing process quite a bit and i don't know if this is how stress works in other animals but they mentioned that it constricted the blood vessels and limited the oxygen and so all the
Starting point is 00:14:57 like normal cellular processes that you need to be happening for like healing to take place are happening less so i I was, I, we were right about the fact that Sari was wrong. And that's all that matters. And so the stress also suppressed the gene that, that lets the mice make the little fibers that pull the wound together. But putting the mice in a hyperbaric oxygen environment completely reversed this slowdown of healing. It was mostly just by providing more oxygen.
Starting point is 00:15:29 And so the mice were still super stressed out, but they at least were able to heal at a normal rate, I guess. So you're saying I should go into an oxygen chamber. So this I have to mention because hyperbaric oxygen therapy is a thing that people make all kinds of claims about and there's not a lot of things that have like we have clinical evidence for but there are certain medical conditions and things that we do use hyperbaric oxygen therapy for the main one is just like decompression sickness i think from diving next we're going to take a short break then the fact off. Welcome back, everybody.
Starting point is 00:16:21 Sam Buck total. Sari has two for getting one right. And the poem, I got nothing. Sam's got nothing and stefan fooled us both for a total of two points now it's time for me and sam to get a crack at some sam bucks because it's time for the fact off two panelists have brought facts to present to the others in an attempt to blow their minds the present easy to have a sam buck to award the fact that they like the most however if both facts are a giant snooze, the presentees can award their Sandbuck to the trash can instead. And to decide who goes first,
Starting point is 00:16:50 we have a trivia question, but I don't have it because I'm doing this. Who's at the trivia question? I have it. The trivia question is, the adhesive bandage, Band-Aid, was invented 100 years ago this June. What year were decorative Band-aids introduced?
Starting point is 00:17:05 Yeah, I feel like it wouldn't take long for someone to just slap like a jewel on it and call it. Here's the thing. Nobody cared about anything. People didn't have time or money to do stuff until like the 70s. Yeah, people hated fun until the late 60s, I think. I'm going to say 1979.
Starting point is 00:17:26 Yeah, I think it's got to be sometime in the 70s, and it was probably like flower power flowers. I'm going to go with 75. Sam wins, but way earlier than both of you. 1951. 51? Yeah. Well, I guess we know what day fun started,
Starting point is 00:17:43 or at least what year. Before that, fun was not allowed. Certainly not commercialized product-based fun. So, Sam guess we know what day fun started, or at least what year. Before that, fun was not allowed. Certainly not commercialized product-based fun. So, Sam, you got it right. You want to go first? Yeah, sure. I'll go first. If a human gets badly hurt, in an ideal scenario, they're taken to a hospital where trained experts tend to them and help them recover.
Starting point is 00:17:59 But if an animal gets badly hurt, barring it being rescued by a human, it's pretty much a shit creek. Many animals live solitary lives and even groups of animals don't have the resources, technology, or the knowledge to care for hurt members of like their tribe or whatever. And even empathetic animals like elephants can pretty much only go as far as comforting
Starting point is 00:18:19 the hurt and dying family members around them. So you'd probably think that that would go double for something like an ant, which is just a small part of a colony of thousands.. So you'd probably think that that would go double for something like an ant, which is just a small part of a colony of thousands. And mostly you'd be right, except in one case, you would be wrong. Metabele ants are a sub-Saharan species of ant that eat termites. And to get termites, they pretty much have to invade the termite hills like knights invading a castle pretty much
Starting point is 00:18:42 and just like fight to the death to eat termites. But termites. But termites are also very mean and they fight back. So a lot of the ants get messed up pretty bad, having their limbs torn off or getting chomped by termites that refuse to let go. Like even after death, their heads can still be chomped onto these ants. So in 2018, researchers studying metabele ants noticed that instead of leaving the messed up ants to die they would gather up their wounded and they would be very discerning about it so ants with just a leg or two chomped off would like make a big show of stumbling around and acting like they were hurt until a healthy
Starting point is 00:19:15 ant would come over and check them out and then they would lay down in the fetal position and let the friend who was checking them out pick them up. But if they had all their legs ripped off, they would just flail around and freak out and they wouldn't let anybody pick them up. Then the wounded ants would get taken back to the colony where they would have the chompers of the termites removed from them and their wounds would be licked clean. And then they would learn to walk with their less number of legs,
Starting point is 00:19:43 which they could do like in about a day. So in lab tests, they took a bunch of these ants and they made them fight termites. And then they watched them bring them back. And in lab tests, 90% of the ants that were treated in this manner would live when otherwise like 80% of the ants would die if there wasn't any treatment given to them. And like I said, it's a very rare behavior in animals. And I found quotes saying that there were a handful of observed cases of an animal providing
Starting point is 00:20:11 medical care to another animal, but I couldn't find any write-ups of them except for one where a capuchin monkey was observed cleaning the head wound of its baby in 1988. And that's the only one I could find. And it was using plants, it said, too, but it was only like a blurb and I couldn't get past the paywall. And it was from 1988, so I couldn't really figure that one out.
Starting point is 00:20:34 So now researchers are trying to figure out why these ants even bothered to do this in the first place because they live in colonies just as big as any other ant. So it doesn't seem like there's really any reason for them to go to the extra trouble. but they're also at the same time trying to find out if like every social ant species does this and we just have never noticed before it's very strange to me that this is so strange like that's the weirdest part that like animals never take care of each other unless they're this species of ant or a shrimp taking care of a fish
Starting point is 00:21:05 that's it it seems like in an animal that has like millions of individuals in the colony like if a couple we lose a couple invading the termites like whatever it's a resource thing so it's like you're playing starcraft right like you might throw your zurg army out there and just like have them all explode but it's better if they don't, right? And if the ones that survive, you're going to heal them up. The thing to remember about ant colonies is that they don't really behave like a bunch of individual animals. They kind of behave like one animal. And so it's almost like the colony is healing rather than the individual ants.
Starting point is 00:21:45 Yeah, but then it's cool that some of them sort of self-triage and they're like, nah, don't worry about me. I'm gonna wiggle out of your grip. That might be the weirdest part. All right, Sam, it's time for me to take you on. So planaria are flatworms and they are notable and you've probably heard of them because they can regenerate really well. Like if you cut one of them in half,
Starting point is 00:22:03 you end up with two that resemble the original worm, basically clones of the original. And in fact, you can cut a flatworm, or this kind of flatworm, you can cut a planaria into a hundred pieces and in the right circumstances end up with a hundred worms. There is a limit to this. Eventually you can't keep chopping smaller and smaller and keep getting forever worms, but But 100 is definitely doable. 200 seems like also possibly doable. More than that gets a little bit fuzzier. But who cares? It's 100 worms. want to understand like development in general embryonic development how bodies plan themselves because this isn't just like healing it's like regrowing it's like ultimate healing so a few years ago researchers amputated the head and tail off of a planaria and then they dunked them in they dunked the fragments in octanol and then uh even though the entire population was clones,
Starting point is 00:23:07 25% of them ended up, instead of growing back a head and a tail, they grew back two heads. Why? Our cells use bioelectric signals to communicate. So different concentrations of ions inside and outside your cells and that creates an electric potential and that can be sensed by cells
Starting point is 00:23:24 that are close to each other. And we know that these electric signals come into play in neural and cardiac muscle systems, but now researchers are exploring how they control processes like embryo development and regeneration. So the researchers had previously seen that in planaria regeneration, cells in the body undergo changes in their electrical charge distribution while the regeneration is happening so the changes helped probably they think that the changes help the cells communicate and coordinate where they are in the body what they need to do when they need to set the right set of genes into making the right kinds of proteins, basically.
Starting point is 00:24:06 But octanol, the stuff that they dunked it into, disrupts that communication by closing off the channels used to send and receive these ionic signals. So when the researchers treated the trunk fragments with octanol, they basically prevented the cells from being able to coordinate with those signals. So the population all has the same DNA, but this isn't a genetic thing. This is a bioelectric signal thing. And when those signals get crossed, some of them will have cells that are working with the wrong set of instructions during regeneration, and you just get a worm with two heads. So weirdly, it seemed to mess things up like permanently.
Starting point is 00:24:43 So 75% of the worms regenerated correctly, but if they were then again later cut and then grown in normal water instead of octanol, some of them would grow up with two heads instead of a head and a tail. This sort of all gives us like a little bit of a sense that there's a kind of, at least for planaria, a kind of nervous system that controls, like,
Starting point is 00:25:07 regeneration and probably also their embryonic development that is a little bit completely unknown. And this is sort of our first hints into its existence. Do they die if they have two heads? I actually don't know. I did not read the eventual outcome of having two heads. I feel like, yeah. I guess you have to poop outcome of having two heads. I feel like, yeah. I guess you have to poop out of something.
Starting point is 00:25:26 Yeah, I'd be curious if the head would adapt into a butt. Would one mouth just get the short end of the stick and have to be the butt? It's a living. Is this the first evidence of a sort of nervous system guiding development in an animal? a sort of nervous system guiding development in an animal? Or now do we think that other animals use electrical signals in a similar way to like help guide where cells go? We do think that. This is an indication that that is a thing.
Starting point is 00:25:55 And like calling it a nervous system is probably the wrong way to talk about it. But like an electrical ion potential based way for cells to know where they are and to know what to do based on where they are and that thing has always been such a cool weird mystery to me like that we're all different shapes and sizes like humans and animals but like we can like our body plans still work like you could have somebody uh who dwarfism, but like the body plan still works because like all the cells know where they're supposed to be. All the organs know where they're
Starting point is 00:26:28 supposed to be. And you can have somebody who's like eight feet tall and somebody who's four feet tall and it works in all the cases. All right. So it's time to choose Sam's fact about ants being triaged and taken care of by their fellow ants, or mine about messing with bioelectric signals and amputated planaria flatworms to cause them to grow back two heads. Three, two, one. Sam. Oh, God.
Starting point is 00:26:54 I need those points. It reminded me of the ants movie. Oh, do they do that in the ants movie? Well, they fight termites. Oh, okay. Right, right, right, right. Do they flail around and let their brothers die, Stefan? Well, it didn't get to that part.
Starting point is 00:27:10 I don't think that part was cinematically interesting. All right, now it's time to ask the science couch. We've got a listener question for our couch of finely honed scientific minds. At Demelo True says, what determines if a wound heals over with normal tissue versus scar tissue? I don't know. I mean, I have a vague set. Like, when it's worse, there's a scar.
Starting point is 00:27:36 There, I did it. There's not always a scar, even if it's, like, almost imperceptible when you heal. After digging into it more, I think that's true. I think it's always like slightly different skin than the skin that existed there before. So whether or not we call that a scar, but basically the way that wound healing works is, so let's say you got a scrape on your knee or something like that. The first step is sending platelets and stuff to clot it and form a scab. Then it's inflammation. And that's when white blood cells arrive and it
Starting point is 00:28:12 sort of like cleans up the area. A bunch of other chemicals go in there. That is when I believe a lot of the new proteins get deposited. So like in skin, collagen is a major structural protein in the extracellular matrix to give it the properties that make it skin. Elastin's there too that makes it stretchy, but collagen's like what makes it taut and strong and like you can pull on it without it snapping and breaking. And that's where the big difference is. So it seems like during development, So it seems like during development, your collagen is deposited in a more mesh-like structure. But whenever you heal a wound as an adult, the collagen is more rigidly laid out or more orderly. And that gives that scar tissue its characteristic look where it's like a little bit stiffer.
Starting point is 00:29:03 It's a little bit less pliable. And depending on the extent of the wound injury and a lot of other factors that we don't quite know. So people seem to think more inflammation around the injury leads to more scarring and it's different from person to person. So some people might have a discolored scar. Some people might have a keloid scar, which is one that bulges out and keeps growing, like the collagen and skin cells just keep getting built up on top of it. And over time, it seems like scars tend to heal, like they become less discolored. And I've seen this on my own body. And it just seems like, I don't know, as cells turn over, maybe the collagen
Starting point is 00:29:41 gets a little bit more randomized. Whatever extra deposits of melanin or color get a little bit more normalized. There are age-related changes to how we heal, which is kind of cool. Babies don't scar, which is weird, and we don't know why. Yeah. I just, yeah. Yes. I don't know. I was like, I was looking for the joke and every thought I had was not for out loud. You don't want to make a joke about hurting babies? That's sort of how I, yeah, that's sort of what I came to, yes. I mean, is it just because like babies are still getting made? That is, seems to be the consensus.
Starting point is 00:30:25 I don't know. It has something to do with babies are still getting made and they have weird biological mechanisms going on because of that, including less inflammation. But then they have differences
Starting point is 00:30:38 in their extracellular matrices and their inflammatory response and their gene expression. And so I think that combination of like a freshly baked baby, it's probably easier for their body to just repair a wound. If you want to ask the Science Couch
Starting point is 00:30:53 your questions, follow us on Twitter at SciShowTangents where we'll tweet out topics for upcoming episodes every week. Thank you to at Artemis Myths, at OmniPlatypus, and everybody else
Starting point is 00:31:02 who tweeted us your questions for this episode. Sandbuck, final score! Sari and Stefan come in in the lead with two points each. Hank and Sam in the behind with one point each. That leaves us with a widening gap between our leaders, Sari and Stefan, and our losers, Hank and Sam. Stefan and I are the flatheads with two heads because we got so many brains. and I are the flatheads with two heads
Starting point is 00:31:25 because we got so many brains. You guys are the flatheads with two butts. If you like this show and you want to help us out, it's easy to do that. First, you can leave us a review wherever you listen. That helps us know what you like about the show. Second, you can tweet out your favorite moment from the episode.
Starting point is 00:31:40 And finally, if you want to show your love for SciShow Tangents, just tell people about us. If you want to listen to SciShow Tangents ad-free, you can do that on Luminary. Thank you for joining us. I've been Hank Green. I've been Sari Reilly. I've been Stefan Chin. And I've been Sam Schultz. SciShow Tangents is a co-production of Complexly and the wonderful team at WNYC Studios. It's
Starting point is 00:31:59 created by all of us and produced by Kaylin Hoffmeister and Sam Schultz, who also edits a lot of these episodes along with Hiroko Matsushima. Our editorial assistant is Deboki Chakravarti. Our sound design is by Joseph Tuna-Medish. And we couldn't make any of this without our patrons on Patreon. Thank you. And remember, the mind is not a vessel to be filled, but a fire to be lighted. But one more thing. In 1894, in a journal called The Medical Age,
Starting point is 00:32:39 one article recommended to treat foot bruises on children by gathering a lot of cow poop and wrapping it around their feet with a cloth to, quote, ripen the swelling in a few hours, immediately soothe the pain, and so soften the skin that it is easily removed. Which is a very vague use of it, in my opinion, because it sounds like they want the skin to come off, but I think they mean the poop. And in reality, it's probably just like warm and wet, but nothing too special. I don't know. It's like putting a damp cloth, but cow poop instead. Yeah, I guess it seems good to cover it up.
Starting point is 00:33:11 But I feel like there are better things to cover it up with. But we've never tried, have we? Let's put the bacteria-laden leavings of a giant animal on our feet.

There aren't comments yet for this episode. Click on any sentence in the transcript to leave a comment.