Short Stuff: Blaschko's Lines

see you in February. Hey, I'm welcome to the Shorts to Find Josh and there's Chuck tally Ho. It's short Stuff time and we're talking about something that admittedly I kind of understand and kind of hope you really understand. I do good. I do. Also, before we started, wanting to give a hat tip to my wife, you me who came up with this one said have you ever heard of this? It's crazy? And I looked into it and I was like, this is crazy because what you we found and what we're about to explain to all

of you is that humans are a species. Don't forget we're animals with stripes. We actually are a striped species of animal. Did you know that before? I've never heard of this. I did not know we were all brindle coated animals like my dog Nico. Yeah, that's exactly right, that's exactly what we are. We have beautiful patterns of swirls and whorls and drips and drops and all sorts of cool stuff all over us, but we can't see them normally under normal circumstances because we don't see on

the UV side of the spectrum. But if we did, we'd be like, hey, I like your stripes. Oh, I like your stripes. And with some people, depending on the condition they have, they actually their stripes actually show. It's pretty interesting stuff. But the whole thing we're talking about, if you noticed, um the title of this episode, or what are called blash cos lines, those are the stripes that all humans have. Now did this happen? Because you mean had a black light and went, oh my god,

I don't know where she turned this one up. I didn't ask her. I'll have to ask her and then we'll record a pick up. All right, So hold on insert answer here. Uh So, blash cos lines that is in fact a name. Uh. It was named after a dermatologist, Alfred Blaschko and the nineteen hundreds. He was the first person to uh notice this basically and write about it. Um. He thought he was a little bit off though, because he thought that they followed predefined patterns on humans. Um.

But they don't. And the weird thing is is you might think is like, all right, so maybe these are um lines that sort of indicate where your blood vessels are or your nerve endings are, or your nerves or whatever. Um, that is not the case. Uh, these stripes are not blood vessels that you could see under a black light at all. But we kind of know what it is now, right right, Yeah, there's no system in the body that

these things follow. Instead, they're their own thing. They seem to be their own thing, um, and they are distinct on all people. But there are kind of some general patterns that we'll talk about. But what what we've come up with finally today is still today we're not certain that this is correct, but the general consensus is that what blash cos lines are evidence of the migratory route that our skin cells took and then settled into while

we were developing in the womb. Right. Um, I'm just gonna read this little bit from mental Flass because I think it kind of sums it up nicely. Yeah. I thought so too, And we always love to shout out our our old pals at Mental Flass, the m f fs, the ms uh. Basically, they said, these are cellular relics of our development, basically from single cell uh things you quoting this, No, I'm paraphrasing the beginning. Um, as the cells of I did, they differentiated, some became muscles, others bones,

still others organs, and some became skin. As those skin cells continued dividing, they expanded and stretched to cover a quickly growing body. One cell line pushed and swirled through another like steamed milk poured into an espresso to make a latte, and Blash goes. Lines are the molecular evidence of those swirls. It was very pretty writing. It was. So the reason that we can see these lines, Chuck,

I think we should talk about after a break. So the reasons we can see these lines, Chuck, I think we're you talk about now? Very nice. So, Um, they believe that the reason that there's differences even though you can only see them under the UV spectrum. Under normal, normal circumstances, you cannot see the difference between skin cells on your arm, or on your shoulder, or on your torso wherever, and you have blash cost lines all over your body, as we'll see, because the cells that make

up our skin are almost entirely identical. They all come from generally the same genetic information, so they all start out from the same cell or gloves of cells. Like mental falls pointed out, UM, But because of like the different minute experiences that each cell has, those instructions get produced and just slightly different ways, so that um, we think of ourselves as like genetically monolithic beings. Right, It

turns out the term for humans UM are mosaics. All of those cells are so slightly different that it's almost like slightly different colored tiles being put up against one another. And they're so similar that again, under normal light, you can't see the difference. But when you put the put yourself under a black light in a dark room, those differences show up. That's why they think we're able to see blash cost lines. That's why they think we have them.

It's the same reason when you look at identical twins. They're they're actually a little bit different. Is again these environmental factors that happen when you're a twin and and in fact, uh, we just did an episode recently, what was that on just this week on Doppelgangers. Doppelgangers when they've seen a lot of evidence like when twins are split up at birth, Um, they end up being quite a bit different. And it's because of epigenetics. Isn't these

environmental factors. But even if they they aren't broken up, even if they're together, these twins are these you know, these minute little jenette differences that end up meaning these twins are a little bit different. And that's the same basic concept here. Yeah, but rather than whole people, we're talking about the difference between genetically identical cells within one person. There is something else called chimerism. So instead of mosaicism,

this is chimerism. And some people can have different genetic material within them. So like um, very famously people with two different eyes, they're chimeras, or they they're chimeric, I should say, because different genetic information went into constructing each eye and that's why they have two different colored eyes. That's extraordinarily rare mosaicism apparently is universal that we're all.

We're just not if you took one cell in another cell and you could get as granular as possible and investigating them, you'd see that they're just slightly not the same, even though they came from the same blueprint. Yeah, there's a New York Mets picture that has one blue eye and one dark eye? Is that David Bowie number seventy two. It's Max Scherzer, And uh boy, it's just I didn't even notice it until last year. And this is a guy who's sort of at the latter stages of his career.

But then once you see a picture of this guy, you're like, oh my god, it's really a striking difference because it's a very very blue eye and a very very brown eye. Uh and I just think it's so cool looking. Yeah, like what a I don't know. I would just always just go right up to people's faces and and go, hi, how are you just like freak him out a little bit? I think it's really cool. Give him the left side, and then the right side,

and left side and the right side. Yeah. So, like we said, they're like there, there's kind of some general rules that like these lines will follow depending on where you are on your body. Right, Yeah, there's like patterns, which makes sense because you know all of us sort of grow generally in the same way as far as arms and legs and finghies and toes and torsos and necks and armpits and all that stuff. So depending on what can we keep naming parts about the dirty parts,

let's start, Um, they're only two. Uh So when you're looking at a body, like there will be maybe a V shape down your back, uh and inverted you from the breast to the upper arm. Your lateral trunk will have a wave like shape. There might be an S

shape on your abdomen, stuff like that. Yeah, your scalp. Actually, if you look at your whole head, it looks like as far as your blash co lines are are concerned, that you're wearing a ball of clava like around around your eye areas open, but there's different like lines surrounding it elsewise, and apparently on your scalp at spirals, whereas on the side of your face it comes there like

kind of vertical lines. It's pretty cool. There's um, I think blash Coo himself, did you know, some initial um descriptions of it through sketches, but since then science has really kind of gotten pretty good at drawing it. So there's a lot of neat drawings of blash cos lines on on the Internet of all places. But was he early? He was like nineteen o one from what I saw, Okay,

the earliest. But Chuck, I think you should take the fact of the short stuff, um, that the blash cos lines don't just exist on the skin, right, Yeah, this was pretty freaky. Um. Apparently your teeth and eyes and tongue all have blash cose lines as well. Yeah, which I mean anything that that forms from cells, you know,

expressing themselves, writing poetry and songs. You mentioned earlier though about there are certain conditions that someone might have where these lines are revealed in in regular light with regular vision, right yeah, yeah, so vital eye where your skin loses

its pigmentation. Um, it often follows blash COEs lines. Um. Also there's other types of congenital conditions, I believe, and some inquired ones where um, so vidaigo would be like a negative of your your blash COEs lines, whereas the some of the other ones, they're like it's like a tiger stripes. Like you can see the person's blash COEs lines because it's hyper pigmented, so you can see them without UV light. You can just see him under normal

visible light. And it's pretty cool looking, actually, I have to say yeah, although usually if you look up on the internet see what this looks like, it's just like close ups of armpits and stuff. Sure, sure, and I say it's pretty cool looking. I don't know how you know, somebody who has a condition where their blash goes lines are showing all the time feel about it. But as

an observer, I think it's pretty interesting and neat. And then also when you stop and think about if you're like that person's skin is striped, your skin is striped to pal you just don't see it because you have to see it under normal UV lights. Yeah, pretty cool. Yeah. So that's it for blash Coast Lines a A thanks you me and thank you friend for listening to this episode. Stuff You Should Know is a production of I Heart Radio.

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