Matthew Flood answered on 8 Nov 2017:
Wow. That’s a very tough question to answer.
It is a combination of so many different things but I’ll try to give you a very simple, brief answer.
Humans are like cars.
Some are big, some are small.
If you look after them, drive them properly, fix them as soon as they break, they will stay driving for years.
If you don’t look after them, then small undetected problems slowly get worse and start to spread.
Most people who live to 100, take very good care of themselves.
But like cars, sometimes it is not how we drive them that causes them to age.
It comes down to unavoidable external factors – poor roads, little scratches from other cars, bad weather.
As we get older, the smallest components of our body (cells, bacteria, neurons, muscle fibres, etc) get worn out by external factors and can’t be replaced. When they get too worn out, we die from old age.
Katie Benson answered on 9 Nov 2017:
The elderly are living longer and healthier than ever. I’ts important to remember that just as youth does not guarantee good health, old age does not guarantee poor health.As people get older, their cells simply don’t work as well, and they can’t fight off disease as easily or heal as well as they once could. As a result, older people may die from injuries or diseases that a younger person would easily survive. But nobody dies from simply being old.
Hugh J. Byrne answered on 11 Nov 2017:
It all starts with oxygen, which we need to live, but the reactions that generate the energy also already start to degrade our systems. We have repair mechanisms, but these are less effective when we grow older.
HOW long do dreams ussually last
How do you make elephant toothpaste
Have you ever been in hospital and knew what cure you needed but the doctor didn’t !?
whats yo favourite song
Are you currently working on a new invention?