Good news: a large number of our organs in our bodies can regenerate themselves. Bad news: some of the organs cannot change for our entire lifetime.
We are used to think that our bodies, except that are prone to aging, consist of the same cells and organs since we were born. But, it seems that this is not true.
According to this video, it turns out that every part of our body has its own life. For example, the internal membrane of the stomach is constantly attacked by acids and it can restore for several days. Bones can renew once in a ten years period. New red blood cells are created for four months.
Then, is there something that remains the same?
As a start, half of our heart. For the changes of the other half you must be more careful. A bad news is that our brain remains, at least a great percentage, the same as it was when we were born.