If All Your Body's Cells Are Replaced Every 7 Years. . .

[iLander]

. . . why do people still have their tattoos 10, 20, 30 years later?

You've probably heard it too, that your after 7 years, all the cells in your body have been replaced with new ones. Your cells use the DNA patterning to make sure you still have blue eyes, or brown hair, or freckles, or whatever. But a tattoo is an external event with no effect on your DNA, right?

So why are the tattoos still there?

No, I don't know the answer, I'm hoping someone else can explain it to me.

 

[perry]

Some cells last 20-30 years. If I recall correctly the mast cells are the longest living cells in the body (mast cells are where allergy response triggers are stored). Want to outlive an allergy - avoid the allergen for a minimum of 20 years (and it could go to 30).

Tattoos are in a base layer of skin/skin generation cells (nor a surface layer). I'm not sure of their cell life - and it may be that the dye stays and stains the new cell.

Have a great day,

Perry

 

[ksinger]

. . . why do people still have their tattoos 10, 20, 30 years later?

You've probably heard it too, that your after 7 years, all the cells in your body have been replaced with new ones. Your cells use the DNA patterning to make sure you still have blue eyes, or brown hair, or freckles, or whatever. But a tattoo is an external event with no effect on your DNA, right?

So why are the tattoos still there?

No, I don't know the answer, I'm hoping someone else can explain it to me.

Well, I can't tell you why tattoo ink is isn't absorbed and removed by the body, but , but every cell in the body is NOT replaced every 7 years. Some are faster, some slower, some even slower than slow, and some - like female egg cells, are never replaced at all...

 

[Kaleigh]

Another good reason not to get a Tat... Kidding guys, don't jump me....


Look, those cells have permanent dye in them... The only way to get rid of it is by laser... And from what I have seen on TV, it takes many visits, not just one and you're done.....

 

[HopeDream]

Interesting!

I googled and found this:

"Initially ink is taken up by keratinocytes, and phagocytic cells (including fibroblasts, macrophages and mast cells).

At one month the basement membrane of the epidermis (epidermal-dermal junction) is reforming and the basal cells contain ink. In the dermis, ink containing phagocytic cells are concentrated along the epidermal-dermal junction below a layer of granulation tissue that is surrounded by collagen. Ink is still being eliminated through the epidermis with ink present in keratinocytes, macrophages and fibroblasts.

At two to three months the basement membrane of the epidermis is fully reformed, preventing any further loss of ink through the epidermis. Ink is now present in dermal fibroblasts. Most of these ink containing fibroblasts are located beneath a layer of fibrous tissue which has replaced the granulation tissue. A network of connective tissue surrounds and effectively traps these fibroblasts. It is assumed that these fibroblasts are the cells that give tattoos their lifespan.

Then why does the tattoo fade over time?

It is debated whether all the ink particles are in fibroblasts, or if some remain as extracellular aggregations of ink. Also, the lifespan of the ink containing fibroblasts is not known. Presumably, ink particles are moved into the deeper dermis over time due to the action of mobile phagocytic cells (think immune cells), causing the tattoo to look bluish, faded and blurry. Examination of older tattoos (e.g. 40 years) show that the ink is in the deep dermis, and also found in local lymph nodes. Since some types of phagocytic immune cells migrate to lymph nodes to "present their goods", the discovery of ink in lymph nodes is consistent with the theory of phagocytic cells being the cause of ink movement."

sourced from http://academic.evergreen.edu/curricular/humanbio/tattooink.htm

I guess the ink is in realy long-lived cells...(and lymph nodes!)

 

[Autumnovember]

I'm currently taking Microbiology and this question makes me:

 

[Lady_Disdain]

The idea that tattoo ink ends up in lymph nodes is disturbing...

 

[iLander]

The idea that tattoo ink ends up in lymph nodes is disturbing...

It is, isn't it? People are so concerned about printer's ink, and a lot of those are soy-based now, to keep the environment safe. What's in tattoo ink?

But then again, the skin is the largest organ of the body (it's actually defined as an organ) and anything that you put on/in it has the potential to end up in lymph nodes. But that's pretty much their whole function, so maybe it's not totally bad?

Maybe all the smart posters, that answered my original query, will help with this new one?