Did you know about one out of every three people have a tattoo? That number can go over 40 percent if you just take into consideration the younger generations! I think it's important that we use real human skin to go over the anatomy of tattoos, or in other words how tattoos work, what layer does the ink specifically go into, and why doesn't our body try to get rid of the ink? It's technically a foreign substance... Also what (do) we mean [that] tattoos are permanent, because certain things can cause tattoos to fade with time. Obviously we have some questions to answer. So, let's do this! If we're going to talk about how tattoos work we definitely need to have a basic understanding of the skin. The skin belongs to a system called the Integumentary System, or just the Integument. It's comprised of three main layers. From top to botto — or superficial to deep — starting with the Epidermis, then the Dermis, and then the Hypodermis, also known as the Subcutaneous Layer. We are definitely going to take a look at all three of these layers on real human skin but, I have to mention something important about these layers as it pertains to tattooing and ink deposition. Each one of these layers, the Epidermis, Dermis, and Hypodermis is made out of a completely different tissue when you compare it to the other. In other words the Epidermis is made out of a totally different tissue than the Dermis, and the Dermis is made out of a totally different tissue than the Hypodermis. Why is that important? Because, the nature of the tissue will definitely influence how ink is deposited in that layer, how permanent the ink is in that layer, and even just how the tattoo works. In other words, it influences how the ink is going to behave in each individual layer. Let's start with that Epidermis. Here we've got two skin grafts. Let's start with this one. This outer layer here is the actual Epidermis. I always find it interesting when we bring the Esthetic students in here — they always notice the freckles and the sun damage here. But, this Epidermis, if I show you the cut edge is just that top paper-thin layer there. The majority of the tissue you see here is actually the dermal tissue. Just that top paper thin edge is the Epidermis, which is pretty remarkable because it can be up to 50 cell layers thick. The Epidermis is your protective layer, and it's made out of a tissue called Epithelial tissue. Epithelial tissue is a highly cellular tissue. What I mean by that is that the cells are just packed together and stacked on top of each other. Like I mentioned earlier, it can be up to 50 cell layers thick and sometimes more, but to the naked eye that's only about .1 millimeters, so, relatively thin from our perspective. But these cells that are at the bottom of the Epidermis or this Epithelial tissue that makes up the Epidermis, copy themselves. So, when one cell copies itself, one of the copies goes on top. Guess what happens next? It makes another copy, and the cell that was right here gets pushed up and the new copy comes underneath it. That continues to happen, and cells move upward. As the cells move upward closer to the surface they start to flatten out and die because they get pushed further from the blood supply. We don't care about that because those dead flat cells give us a nice protective barrier from friction and abrasion. That's what I'm doing here — not itching my skin here, but, it protects us from that friction and abrasion. That process just continues on every single day. Now as the cells move up, eventually they're going to get to the very top and flake off you can shed over a million cells per day. You can think that's disgusting, but it's anatomy, so it technically is under the classification of being "awesome." Now think about how that influences tattoo and ink deposition. This wouldn't be a great layer to tattoo or put ink into, but the reality is some of the ink as it is being injected into the skin does get deposited into this layer, and therefore some of the cells. Because those cells are moving upward, eventually any ink that's in there is going to flake off. It takes around four weeks or so from a cell for a cell to get from the bottom to the top. So, any of the ink that does get deposited in there you can see it pretty much scattered throughout your house to have to dust. So the next layer down is extremely important to tattooing and ink deposition. As we mentioned earlier this was called the Dermis. Let's take a look again at the cadaver dissection. Remember the majority of this cut edge here was the Dermis, or the Dermal tissue where that paper thin top was the Epidermis. The Epidermis is again made of Epithelial tissue, but the Dermis or this Dermal tissue is made out of a totally different tissue called Dense Irregular Connective Tissue. It's the nature of this Dense Irregular Connective Tissue that allows ink to be deposited and, for it to last many, many years or what we would think of as permanent. For us to more fully appreciate how the ink can be permanent or relatively permanent in this layer, we're going to zoom in to this cut edge of the Dermis here like on a little "Magic School Bus" ride by zooming in to the model. So this would be that same cut edge here and to orient you. This would be the Epidermal layer here, or the Epidermis. From my thumb to my pointer down here would be the Dermis. Now (these are) very different tissues — the Epidermis and the Dermis. Remember this had tons of cells packed together. (In) the Dermis we wouldn't see that. We see only a few cells scattered throughout the spaces between all these other structures and those cells are important because they are called Fibrocytes and they produce a protein fiber called Collagen, one of the most abundant proteins in the human body. Now the model is actually trying to show you, if we zoom into it the fiber orientation of the Collagen you can see some lines going this way, some other lines in between the other spaces going in other directions. That is why the tissue or the Dermis is referred to as a Dense Irregular Connective Tissue because the Collagen fibers are going in all directions which we'll talk about the interaction with ink here soon. But, because the Collagen is going in all directions it gives skin its strength to be tugged on in every which way, or in other words — all directions. Now the skin is not just made up of — or I should say specifically the Dermis — is not just made up of Fibrocytes and Collagen. As you can see from the skin model, there are a whole bunch of other structures in here. We've got sweat glands, blood vessels coming through here, nerve endings, and even hair follicles that have pushed down from the Epidermis. So again, how does this anatomical knowledge help us understand how tattoos work in this layer? Ink is being deposited into the Dermal layer, and a lot of that ink is going to get suspended in that collagen matrix, and some of it will be even taken up by those Fibrocytes or those cells I mentioned earlier. That's not the only thing that's going on here. You see during tattooing, a needle is puncturing the skin at anywhere from fifty to three thousand times per minute that's creating trauma as well as injecting a foreign substance into the skin. Now usually when our body deals with trauma, or a foreign substance gets introduced, our immune system has something to say about that and the inflammatory process gets activated. Now we could do a whole video just on the process of inflammation. One of the main take-home points for us is that inflammation is getting white blood cells to the site of injury, infection, or to deal with foreign substances. That's what happens during the tattoo process. White blood cells get called to the area, they'll leave these blood vessels, and then go roam through the tissue which is a really interesting thing because, these cells — specifically these white blood cells called Macrophages — are these little engulfers. In other words they engulf or take up foreign substances that could be viruses, that could be bacteria, dead tissue, and debris. But in this case, they start trying to engulf the ink. Now that engulfment process is a technical term called Phagocytosis. Typically once a white blood cell Phagocytozes, or, engulfs something it starts to break it down and digest it. However, it's used to breaking down and digesting biological substances. Ink can include dye, plastics, and even solids that our immune system or our white blood cells are not really equipped to break down very well or digest. So what's the solution? We think with some of the research that's leading to this, is instead of being able to break it down because they can't, it's more like, "let's isolate it and contain it and not let this ink go to other areas of the body." That's pretty crazy to think about! Those white blood cells getting some of that ink from the collagen. They'll even engulf some of the dead Fibrocytes, and that ink stays in them. You can see that through the surface of the skin. The idea is that those white blood cells just kind of stay put there. If you're like me you're kind of thinking, "you know, white blood cells don't last a person's lifetime... so how is that staying there for the majority of this tattoo, or for the length of a person's life?" Tattoos are relatively permanent. What they have started to find, is that when the Macrophages that engulf the ink, when they die they release the ink, and then guess what happens? A new macrophage comes in and engulfs that ink. It's almost like this engulf, release, engulf, release... is a kind of cyclic process, that happens to maintain the tattoo in that area. But remember I mentioned the whole idea — at least the going theory — is we're going to just contain the ink here and it does obviously a pretty good job because those of you who have tattoos or have seen people with tattoos, you notice the tattoo doesn't move. But you do notice that it sometimes fades with time. So there's a couple of going theories with this one. It’s that as a Macrophage dies and releases that ink the new incoming macrophage engulfs most of the ink and some of the smaller broken down ink particles will get taken away into the lymphatic vessels. We know that some of the ink gets into the lymphatic system, because they've done biopsies on distant lymph nodes and found tattoo ink in there. That is likely contributing to the fading of tattooing over time. Granted other things like UV light can fade tattoos and break the ink down, but, that's one of the ideas of how these are relatively permanent with some changes over time. Now one other thing I need to address — some of you may be thinking "Jonathan sure has used the phrase foreign substance multiple times throughout the video... Should I be worried about getting a tattoo or even worried about the tattoo that I already have?" No, not so much. We've used foreign objects or substances in things like surgeries, knee replacements or metal rods, for preparation of major fractures, or for support of those bones, even mesh for things like hernia repairs. Now that doesn't mean people haven't had reactions to those substances or even reactions to tattoo ink but the majority of people do just fine. The most important parts of getting a tattoo are one, going to a reputable tattoo artist that uses precautions to help mitigate risk of infection and reactions. As well as this other important concept when it comes to getting a tattoo and that is aftercare. That's why I really love the sponsor of this video called Saniderm Medical. They truly understand the importance of aftercare and even skin care prior to and during the tattooing process. Like I said, I want to say thank you to the sponsor of this video Saniderm for supporting this project. Saniderm brings you the best of the best of skin and wound care products from sterile clear breathable wound bandages, to dermal supplements, to replenishing lotions and balms and even invigorating soaps — which I'm pretty excited about. Now while Saniderm is world renowned as a dermal authority in the tattoo industry, they're bringing that expertise well beyond the world of ink. They are now bringing the medical grade, uncompromised ingredients to the masses for everyday skin care. Saniderm focuses on healing and protecting the skin from the inside out and through all stages of life, and why not? We have to carry around this Integument, or the skin, through the entirety of our life and frankly we're kind of mean to it. Sometimes we get sunburns, dirt, and grime, abrasions, so we might as well protect it and help it heal with amazing skin care products that Saniderm provides. If you go to saniderm.com and type in the code "iohaskin" they're going to give you a 20% discount code on your first initial purchase there. We'll put that link in the description, and while you're down there you might as well comment, subscribe, and smash that like button. That takes care of the most important layer when it comes to tattooing, the Dermis. However, we mentioned Epidermis, Dermis, and the Hypodermis or Subcutaneous Layer. That Hypodermis or Subcutaneous Layer is still important to some topics with tattooing, specifically a topic known as blowout or when the tattoo lines start to blur. Let's dive into that. So again let's go back to our skin dissection here and here was the Dermal edge here. I'm going to rotate it over and if you look closely you can see some yellowy tissue especially down here on the bottom edge. That is the Hypodermis. The Hypodermis, again made out of a different tissue than the two above, is made of Adipose Tissue or fatty tissue. If I go to the other dissection you can see it even better. You can see all of that yellowy tissue is the Hypodermis, and again fatty tissue. Now the nature of this tissue is kind of more of an oily type of a tissue, and if ink gets down into that layer because of the nature of the oily tissue it can kind of blur the lines — or it almost looks like it kind of dissipates into the skin, a little bit more. Think of the interactions between oils — which would be fats and other liquid substances — and you can kind of get that idea of why it might start to blur the lines. Now there's another really important concept to think about as far as why some areas are more at risk for blurring than others, and that is a discussion of skin thickness. When we're talking about skin thickness, I love to show these two cadaver dissections because this skin dissection, and this one right here that I'll bring a little closer in a second, are from the same cadaver. Look at the thickness of the Dermis here. This is from the mid back of a cadaver, and then I come to this, and you can see it's just so much more flimsy and that edge is mostly the Dermal tissue from the same person or same cadaver. This came from the lower leg. Now I'm not a tattoo artist but when I've talked to tattoo artists they talk about the idea of what causes a blurred line or blowout. That tends to deal with (how much pressure) they push on the skin. If you push harder, the idea is some of that ink might get more likely pushed down into the Hypodermis, but it's also influenced just on the region. You almost have more "give" — or more room for error in the Dermis on the mid-back as opposed to say something on the lower leg where the Dermal tissue is thinner. So it wouldn't take as much pressure to get the ink down into the Hypodermis and potentially cause some of that blurring or blow out. So now we've made it through all three layers of the skin and gave us this idea about how important the nature of the tissue is in influencing what happens with the tattoo ink. We know with the Epidermis, if anything gets in those cells, it flakes off after about four weeks. The Dermis is where we want all the majority of that ink. It's the most stable for permanence and nice crisp artwork. We now know the Hypodermis is more at risk for bleeding out or blurring or that blowout because of the nature of the adipose and that oily tissue underneath. Thanks for watching the video everyone! Thank you again to Saniderm for sponsoring this video. Remember, go to saniderm.com and use the coupon code iohaskin to get 20% off some amazing skin care products. We'll put the link in the description below as well as the associated information and while you're down there go ahead like, leave a comment, and if you're feeling up to it go ahead and subscribe to our channel. We'll see you in the next video.