How do scarring and tattooing work?

Every seven years we are totally different on a cellular level, neh? - so how come we don't replace scar tissue, say, with not scar tissue when we slough off our outer sheath? How does our body remember to replace the scar tissue with more scar tissue that looks identical to the tissue we have just sloughed off? Why don't we replace it with healthy and not scarred tissue?

I WANNA KNOW

Why is Evans still here after seven years?

YOU'RE NOT TODD NOR ARE YOU A GENIUS BIOLOGIST....Why are you HERE?

I don't think scar tissue cells regenerate.

Cue Rob with the wikipedia pastes.

scarring is not tissue, as much as it is the extracellular matrix (ECM) that surrounds tissue. When you are injured, and you heal, ECM, which is made up of collagen, fibronectin and other fibrillar proteins form a scaffold for the growing cells and blood vessels to reattach and fill the would.

Once the wound is healed this 'tissue' which is largely acellular remains.

So they repair but don't clean up the mess afterwards. Do I have that right?

Thanks Todd, that has been bothering me in the periphery of my mind for a while ...so how does the inking in tattoos stay there? Is this a similar thing?

The smaller the wound, the better the repairing. If there is a big wound less so. There are a lot of factors that play into it, the amount of inflammation in the wound, and the propensity to scar.

Tattoos are dyed below the level of the growing cells, and the ink is seen thru these cells. the thickness of these cells is very small.

Or that is how I understand it. Also, the dyes are water insoluble, so that they never diffuse into the blood as waste.

I have heard that the layer of skin where the tattoo is placed is critical to a tattoo lasting. Too shallow and it blurs.

So that lower layer of skin is not made of cells that are replaced every seven years? Or is the "all your cells are completely replaced ever seven years" just BS?

your freckles never move right? They dont go away, or change. Same idea.

not a tattoo expert, tho.

Freckles do fade, or merge. But, I think that has more to do with the melanin pigments and age. I am getting anti-freckles now. Spots with no pigment that almost look like a scar.

That is really neat about the scar tissue. I know that scars can get too much of the fibrous stuff and essentially become cartilage. But, I didn't know the mechanics involved.

This tissue isn't as durable either. It's documented that "old wounds long healed" open up on the malnourished. It used to happen to old time sailors on long voyages.