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Does The Human Body Really Replace Itself Every 7 Years?

Key Facts In This Video

  1. Your body mostly replaces itself every 7–15 years. Some parts are never replaced, and some parts are replaced much more quickly. 00:19

  2. The organs that work the hardest have the fastest changeover. You get a whole new skin every 2-4 weeks, red blood cells last only half the year, and your liver renews itself at least once every couple years. 00:37

  3. Some parts of your body stay with you for life. The cells on the inner lens of your eye were formed when you were an embryo. Tooth enamel never regrows, and evidence indicates that you can't regrow the neurons of the cerebral cortex. 01:14