[Lilymoon (OP)]

I read some where when you are young the skin cells are nice and smooth and elastic but when you get older the reason your face and skin get wrinkled is because it becomes hard and less elastic. Not sure why it get hard and less elastic?

Some thing to do with the human body that replace extracellular protein elastin with less pliable collagen? The build up of collagen and less elastic or less pliable collagen?

Also some thing to do with cells not dividing or dividing very slow because of telomere caps? That the telomeres have a cap and cells stop dividing or are dividing very slow because of the telomeres cap.

Not sure why people when they get older get thin hair or very little hair may be it is some thing to do with person DNA?

[evan_au]

You could start here: https://en.wikipedia.org/wiki/Ageing#Biological_basis

[Eternal Student]

Hi.

Can some one here explain the biology of aging?

    No, I couldn't offer a good explanation.  The wiki reference given by evan_au is usefull.

   The very simple theory of aging  (which is only partially true) is that there is an accumulation of errors in the DNA as time progresses.   Some of those errors are caused by environmental factors like exposure to background radiation and some are just a natural result of cells continuing to divide and needing to duplicate the DNA material in that process.   That simple theory is good enough for school study upto about 16 years of age.   You might add to it that the telomeres (which are just repetitive strands of DNA code that form the "ends" of chromosomes) do tend to get shortened on each cell division, so the DNA replication doesn't seem to produce a perfect copy of what you started with.
   

...(Skin becoming less elastic is .... )   Some thing to do with the human body that replace extracellular protein elastin with less pliable collagen?

   All these sorts of things can be explained by damage to the DNA.  Your DNA carries the code required to manufacture every protein that you make anywhere in your body.  This includes the protein "elastin".  If the DNA coding for elastin is damaged or there is just some damage to the DNA around that region which slows down or hinders the expression of those genes, then the body makes less elastin.
    Damage to DNA can be used to explain every change we would describe as "aging".   However, just because it could work as an explanation doesn't mean that it is actually the right explanation.   There just isn't enough evidence for the right sort of damage being done to the DNA in a consistent way   yet  the effects and appearance of aging are quite consistent across most people in the world.

    There is a lot of research being done on aging and someone else might be able to tell you what the very latest ideas are.

Best Wishes.

[evan_au]

when you get older the reason your face and skin get wrinkled is because it becomes hard and less elastic.

Skin ageing is caused in part by TGF-β, which reduces the subcutaneous fat that gives skin a pleasant appearance and texture.

[Lilymoon (OP)]

when you get older the reason your face and skin get wrinkled is because it becomes hard and less elastic.

Skin ageing is caused in part by TGF-β, which reduces the subcutaneous fat that gives skin a pleasant appearance and texture.

It still does not explain why the skin build up lots of collagen and how to counter it.

When a person is young the skin is nice and smooth and texture is nice and smooth and elastic. When the person gets older the skin is hard and not elastic because of the build up of collagen.

I also read things like free radicals and problems with the mitochondria can cause aging.

So it may not be one or two things but number of things causing aging.

And nice and smooth skin cells is just one of them.

I also hear the cells not dividing or dividing very slow because of the short telomere caps problem.

[Eternal Student]

Hi.

So it may not be one or two things but number of things causing aging.

   Yes, exactly.  It is most probably the consequence of many different things acting together.

I also hear the cells not dividing or dividing very slow because of the short telomere caps problem.

     Yes  - that is one thing that may be a factor in aging.   Exactly as you said there are almost certainly other contributing factors as well.

Best Wishes.

[Lilymoon (OP)]

What causes collagen build up? Does scientist know what causes collagen build up? I would think if scientist knew what causes collagen build up there would be drug or gene therapy to counter it.

From what I understand when people get older the skin starts to build up lots of collagen and this is what makes the skin very hard and less elastic.

When person is young the skin is very mice and soft and smooth. It is very elastic.

[wolfekeeper]

There's almost certainly not any one thing. Ageing is caused by the build up of damage of one kind or another; and is in turn related to how well protected the organism is. Animals that are very well protected age much more slowly.

For example a tortoise has a hard shell, so can live for centuries, so has evolved genes for ageing very slowly. Humans are very good at looking after themselves so have evolved to live quite a long time. Birds can fly away, so live decades. Mice and bats are both mammals, but mice have short lives usually ending in crunchy squeaks when they get predated, whereas bats are a similar size but fly extremely well, and thus can largely avoid danger; again they can live for decades.

Ageing slowly is thought to require extra genes. If an organism is going to die anyway before those genes make much difference, those genes will not be selected for, and they will disappear from the organisms genome.