Fascinating biological/philosophical question

[Alphathree33]

I'm sure that this has been studied and answered, but I personally just thought of it this morning: how much of the human body is 'recycled' from year to year, and how much of it is with us from beginning to end (say from age 18 to age 65?)

Obviously there are some things like bones which you'd expect don't gain or loose a great deal of mass, and there are things like blood which must obviously be reproduced again and again.

It's philosophical in my mind because it really blurs the line between "me" and "everything else". If I found out that 90% of me today won't be with me ten years from now, but I'll still be me, that would be weird.

 

[eLiu]

Originally posted by: Alphathree33
I'm sure that this has been studied and answered, but I personally just thought of it this morning: how much of the human body is 'recycled' from year to year, and how much of it is with us from beginning to end (say from age 18 to age 65?)

Obviously there are some things like bones which you'd expect don't gain or loose a great deal of mass, and there are things like blood which must obviously be reproduced again and again.

It's philosophical in my mind because it really blurs the line between "me" and "everything else". If I found out that 90% of me today won't be with me ten years from now, but I'll still be me, that would be weird.

i think your brain is one of the more well-known examples of stuff in your body that does not regenerate

 

[bleeb]

Actually your bones are constantly being reabsorbed and then redeposited. Since blood is the greatest faciliator of supplying and moving raw materials, and the bones have a very good blood supply, this is what happens.

 

[Maverick]

yeah humans can't regenerate brain cells. But sharks and birds can. Researchers are trying to figure out how to develop the same ability in humans without creating a race of superhuman Sharkmen.

 

[everman]

Originally posted by: Maverick
yeah humans can't regenerate brain cells. But sharks and birds can. Researchers are trying to figure out how to develop the same ability in humans without creating a race of superhuman Sharkmen.

With frickin' lasers on their heads!

 

[So]

Originally posted by: Maverick
yeah humans can't regenerate brain cells. But sharks and birds can. Researchers are trying to figure out how to develop the same ability in humans without creating a race of superhuman Sharkmen.

Actually, I believe recent science has disproven this. We can and do regenrate brain cells, constantly.

 

[Armitage]

IIRC, Ray Bradbury wrote a short story along this line.
One half of a married couple reads an article saying that such & such % of your body is "replaced" every year. So after so many years, their spouse really wasn't the person they had married - that person didn't exist anymore, so they were free to move on 😛

 

[Omegachi]

nerve cells can't regen?

 

[mordantmonkey]

you are greater than the some of the parts. you are a projection; a configuration. ooohh look at the trails...

 

[Heisenberg]

Originally posted by: Omegachi
nerve cells can't regen?

Not as far we know right now. That's why spinal cord and similar injuries are so bad.

Edit: I should say they don't regenerate under normal circumstances like skin does for example. However it may be possible to get them to under certain conditions, which is where a lot of research is directed.

 

[nakedfrog]

You are never the same person for very long. For example, when you have finished reading this post, your brain will have new information stored within, and yet you'll be the stupider for having read it 😀