Kind of a weird question, but yeah. Take a look.

Switch Kicker · Post by **Switch Kicker** » 04 Jul 2008 23:05

Right, the question is, "How much of your body is renewed/replaced frequently."

So, what I mean is, like, obviously, your hair grows, and your nails grow, and you skin flakes off in very very small peices, and grows back. And new skin is grown in it's place.

But I wanna know just how much of your body is replaced through this. I would GUESS that 99% if not all of the Heart is not replaced at all... and I would also GUESS that most of the brain, if not all of it, isn't replaced either... But yeah.

Anyone wanna shed some thoughts on this?

My guess, would be that it goes likes this, blood and other bodily fluids, finger nails, hair, skin, muscles (maybe?) and then a lot of the organs.

What I DON'T think renews itself, is veins, arteries, bones, heart, brain... and eyes. Oh, and nerves. (I think teeth would be thrown in with bones.)

Anyone know any articles about this, or have any ideas? I was just thinking about this the other day, thinking.. how much of my body right now.. came from some plant or meat... (meat coming from an animal that ate plants, plants comeing from soil which is made of fertalizer... and such... And now it's this... skin, and hair and such...

But yeah.. discuss! =D

shredzilla · Post by **shredzilla** » 04 Jul 2008 23:12

99% of every atom in your body is replaced every 7 years. 100% of your cells (including the heart)

sniikeri · Post by **sniikeri** » 05 Jul 2008 01:43

Yeah shredzilla's right, only the speed varies (some cells last longer than others).

Bringerofpie · Post by **Bringerofpie** » 05 Jul 2008 09:29

I was under the impression that everything besides your brain cells were replaced.

sniikeri · Post by **sniikeri** » 05 Jul 2008 11:33

Apparently they do renew, but very slowly.

dan the man · Post by **dan the man** » 05 Jul 2008 14:37

i thought that nerves could not be replaced, and thats why when you cut a nerve tissue, your screwed....

Jack Stutler · Post by **Jack Stutler** » 05 Jul 2008 14:46

well i assume the body can maintain tissues like that as long as they are normal. it might be hecka slow, but it makes sense to me that the body can do this, otherwise your nerves would start breaking down as soon as you were born. however i think your right, once somehting like the brain or a nerve gets damaged beyond functioning, its gone, can't be remade.

dyalander · Post by **dyalander** » 06 Jul 2008 19:33

I'm sure I read somewhere that the 7 year thing was a myth - I think I know where so I'll check and get back to you.

crazylegs32 · Post by **crazylegs32** » 06 Jul 2008 22:21

certain organs dont heal well if at all after damage. Most of your cells may be replaced? But still if some cells are damaged they are just replaced with increasingly damaged cells.

Jeremy · Post by **Jeremy** » 07 Jul 2008 15:22

Switch Kicker wrote: I was just thinking about this the other day, thinking.. how much of my body right now.. came from some plant or meat... (meat coming from an animal that ate plants, plants comeing from soil which is made of fertalizer... and such... And now it's this... skin, and hair and such...

All of your body is made up out of your food. Your body can't create matter, it gets it from food.

Plants aren't made out of soil or fertiliser. Plants are mainly made out of carbon and water. They take a small (relative) amount of nutrients from the soil which are needed for various processes. Primary growth in a plant occurs at the top of the plant and it's through photosynthesis that plants get the material to grow.

I don't know about time frames, but I would assume all living cells are replaced. Plants have a lot of dead cells in them, so these obviously aren't replaced.

Switch Kicker · Post by **Switch Kicker** » 07 Jul 2008 17:56

Jeremy wrote:
Switch Kicker wrote: I was just thinking about this the other day, thinking.. how much of my body right now.. came from some plant or meat... (meat coming from an animal that ate plants, plants comeing from soil which is made of fertalizer... and such... And now it's this... skin, and hair and such...

All of your body is made up out of your food. Your body can't create matter, it gets it from food.

I know that. I kinda meant the food I ate last week... not the food my mother ate while I was in the womb. I'm not stupid.

Jeremy wrote:Plants aren't made out of soil or fertiliser. Plants are mainly made out of carbon and water. They take a small (relative) amount of nutrients from the soil which are needed for various processes. Primary growth in a plant occurs at the top of the plant and it's through photosynthesis that plants get the material to grow.

Fertalizer is a major contributer to a plant's health. I'll be sure to include diagrams and every detail of how a plant draws in it's nutrition next time, instead of just listing one.

Jeremy wrote:I don't know about time frames, but I would assume all living cells are replaced. Plants have a lot of dead cells in them, so these obviously aren't replaced.

Plants and mammals have little in common...

Jeremy · Post by **Jeremy** » 09 Jul 2008 15:03

Sure, well I'm studying biology at University and my text book says that plants grow through photosynthesis which converts water and carbon dioxide into sugars and oxygen using light. Nutrients (the most common fertiliser being nitrogen, which is a macro nutrient) are very important for a number of processes occurring in a plant and make up 6% of a typical plant. Carbon and water make up 90% of a plant. Yes fertilisers can be important (although obviously the vast majority of plants grow fine without fertiliser, and nutrients certainly are crucial to the survival of all plants, but they certainly don't make up a large part of a plant.

Reference;

Biology of Plants Raven, P., Evert, R., Eichhorn S., 2005. Chapter 29; Plant nutrition and Soils pg 646.

edit; Nice of you to point out the differences between plants and mammals. Given that I've studied plant, animal and cell physiology, I'm pretty aware of the differences, and I stand by my comment that all living cells are replaced, while dead ones are not.

dyalander · Post by **dyalander** » 09 Jul 2008 18:20

99% of every atom in your body is replaced every 7 years. 100% of your cells (including the heart)

Unfortunately the article I had about this myth isn't in the book I thought it was in and can't be bothered searching - it shouldn't be too hard to find stuff about this though.

If I remember correctly - and it was a while ago so I might not - the initial study about atom replacement was a seperate issue to cellular turnover. There are a range of atoms that pass in and out of the body and I think the study calculated that the longest an atom could come into the body and remain there was 7 years. This is a very different thing to cellular turnover in general beacuse not all cells are involved in taking up atoms that come into the body in the same way. The myth came about by projecting the findings of the study far beyond their actual scope.

I know there are a number of brain cells that last way longer than 7 years, I'm pretty sure there are neurons that are never 'replaced' (even at an atomic level). The spinal chord is another area where I'm sure there are cells and atoms that remain in the body for way longer than 7 years. It usually highly specialised cells that are difficult or impossible to replace and that do not rejuvinate or regenerate themselves over time.

I think the study of the micro-biology of cells is called "Histology"? I think there was also a book by that name which would answer these sorts of questions. You could probably also find answers in "Cellular Biology" textbooks.

Switch Kicker · Post by **Switch Kicker** » 09 Jul 2008 23:09

dyalander wrote:
99% of every atom in your body is replaced every 7 years. 100% of your cells (including the heart)
Unfortunately the article I had about this myth isn't in the book I thought it was in and can't be bothered searching - it shouldn't be too hard to find stuff about this though.

If I remember correctly - and it was a while ago so I might not - the initial study about atom replacement was a seperate issue to cellular turnover. There are a range of atoms that pass in and out of the body and I think the study calculated that the longest an atom could come into the body and remain there was 7 years. This is a very different thing to cellular turnover in general beacuse not all cells are involved in taking up atoms that come into the body in the same way. The myth came about by projecting the findings of the study far beyond their actual scope.

I know there are a number of brain cells that last way longer than 7 years, I'm pretty sure there are neurons that are never 'replaced' (even at an atomic level). The spinal chord is another area where I'm sure there are cells and atoms that remain in the body for way longer than 7 years. It usually highly specialised cells that are difficult or impossible to replace and that do not rejuvinate or regenerate themselves over time.

I think the study of the micro-biology of cells is called "Histology"? I think there was also a book by that name which would answer these sorts of questions. You could probably also find answers in "Cellular Biology" textbooks.

Hair and fingernails (If left to grow) would never replace themselves would they? And they would still be considered part of your "body"... at least I would assume that.

Jeremy wrote:Sure, well I'm studying biology at University and my text book says that plants grow through photosynthesis which converts water and carbon dioxide into sugars and oxygen using light. Nutrients (the most common fertiliser being nitrogen, which is a macro nutrient) are very important for a number of processes occurring in a plant and make up 6% of a typical plant. Carbon and water make up 90% of a plant. Yes fertilisers can be important (although obviously the vast majority of plants grow fine without fertiliser, and nutrients certainly are crucial to the survival of all plants, but they certainly don't make up a large part of a plant.

Reference;

Biology of Plants Raven, P., Evert, R., Eichhorn S., 2005. Chapter 29; Plant nutrition and Soils pg 646.

edit; Nice of you to point out the differences between plants and mammals. Given that I've studied plant, animal and cell physiology, I'm pretty aware of the differences, and I stand by my comment that all living cells are replaced, while dead ones are not.

You really know how to dull down a conversation.

james_dean · Post by **james_dean** » 10 Jul 2008 04:59

fuck I musta got lost, I thought i was in the discussion forum...

wait what now? I'm so fucked...................... peanuts.

Jeremy · Post by **Jeremy** » 10 Jul 2008 20:04

Switch Kicker wrote:
You really know how to dull down a conversation.

Sure, but I don't think plants are made out of soil either.

Switch Kicker · Post by **Switch Kicker** » 10 Jul 2008 23:54

Jeremy wrote:
Switch Kicker wrote:
You really know how to dull down a conversation.
Sure, but I don't think plants are made out of soil either.

This would be what I'm referring to when I made taht post in the "rape" topic. The technicality shit... Soil contributes to a plants health.

Jeremy · Post by **Jeremy** » 11 Jul 2008 00:33

Sure, but your first post isn't about the health of plants, it's about the fact that humans are made out of meat and plants. You go on to say that meat comes from plants, and plants come from the soil.

Interestingly this idea was proven wrong in the early 1600s.

Tsiangkun · Post by **Tsiangkun** » 11 Jul 2008 07:29

Some of the best plant in california is grown sans soil.

modified

Kind of a weird question, but yeah. Take a look.

Kind of a weird question, but yeah. Take a look.

Re: Kind of a weird question, but yeah. Take a look.

Re: Kind of a weird question, but yeah. Take a look.