cell regeneration

[cracked]

i have a question. i have heard that every 7 or so years that all your celles from 7 years before have died and that new ones are in place basically meaning you have a different but roughly identical body than you did before. but i have also heard that braincells dont regenerate which would mean that the ones you have have always been there making the first statement false. so which is right?

drew

[osprey4]

The first figure might be right on average, but some organs do not have the turnover rate that others have.

No, brain cells do not regenerate, and you lose "grey matter" after your late teens. But this does not mean you're getting stupider (in most cases). Actually, the nerves in your brain are constantly building new connections and as you grow older, the connections allow your brain to function more efficiently. So old dogs can learn new tricks.

[ILC]

Almost all human cells can regenerate (divide is a more proper explanation) with the exception of skeletal muscle cells and neurons. Neurons are the cells that make the nervous system and are only dividing through development. Skeletal muscle cells also divide during development and then fuse together making very long multi-nuclear cells. This is just the general – not the law. Both neurons and skeletal muscle cells are known to divide throughout life under some circumstances.

Osprey, only the neurons can not regenerate in the brain. The vast majority of the brain is actually composed of glial cells which continue to divide all through life.

ILC