Question: If the body replaces all of it cells every 7 years, shouldn't we release all inmates after 7 years as they're not the same person anymore?

Cheryl Andisi answered on 27 Jan 2017:

@ Amanda,
Interesting! And the thought of it worrying too! It would mean that if you are married, your hubby is not the same person, if you have kids, you have a new one every 7 years, or your parents are different people every seven years!
I think your cells are just part of what you are-maybe they make up most of your physical being but you are much more than just that!
Apart from that, even though different cell types have different rates of renewal, not all cells in your body are replaced. Red blood cells for instance live for about four months, while white blood cells live on average more than a year. Skin cells live about two or three weeks. Colon cells die off after about four days. Sperm cells have a life span of only about three days, while brain cells (neurons) typically last an entire lifetime. However, several recent studies in mice have found that neurogenesis ie formation of new neuron takes place even in adults but at a much slower rate. Some of these studies suggest that the integration of these neurons with your “old” neurons while helping you adapt to new environments, tastes etc, may also be responsible for memory loss. And the fact that most of your neurons don’t die so often means that you can keep some of your childhood memories forever-or for much much longer!
Imagine if your brain cells died every 4 days like your colon cells! By now, I wouldn’t even know what i am a scientist is ;P !!