metabolism

[ModerNietz]

I have a basic biology question:

We human absorb materials from the environment and the substance in our body constantly changes. Some even say the substance/cells in our body will be completely new after a certain period of time.

My question is, are there any cells in our body that won't be replaced? Neurons and some other brain cells for example. Because they are special.

[Big Cat]

"Special" is a word that perhaps should not be used in scientific contexts.

It would appear that most cells in the human body have some regenerative capabilities, including the famous non-replicating neurons. The only cells in humans that do not regenerate, under normal conditions, if lost, are the female's egg cells. Those are pretty much the only cells that are not/cannot be produced by an adult organism.

Then again, cell replication via mitosis/meiosis and cell regeneration/repairing are two different things. This is a complex subject.