3 ms·

Your cells are new every 10 years. [Citation Needed]

• arram 17y ago
  The exact number is a little controversial, but there's pretty universal agreement that most of your cells wear out, die, and are replaced within your life time. I didn't elaborate, because though it's useful for illustration, my point doesn't really depend on it - even if we had the same cells throughout our lives, we could swap them out one by one and still be us.
• pygy_ 17y ago
  ... with the notable exception of (most) of your neurons. The only exception happens in the hippocampus which is involved in long term memory. (As a side note, a reduced turnover of these neurons is associated with depression, but I don't know what's the cause and what's the consequence.) Some cells have a much higher turnover(almost daily). I think of the immune system and of some epithelial cells (especially in the digestive tract). Your ten years figure seems to be a reasonable median, but I don't have any data to back it up either.