system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why can’t the spinal cord repair itself like our other nerves can?

I hear about surgeons reattaching hands/fingers fairly often, with patients recovering at least some movement in those limbs, so why can’t the nerves on our spinal cord repair themselves when severed?
gpt
Because there are a LOT of nerves in the spinal cord... severe damage to it causes a loss of many, many functions (both control and feeling in the whole body below the injury). All of those nerves healing well enough that all of those functions in all those areas are totally restored is a much bigger task than nerves in a finger healing enough that you can move the finger again.

And the outcomes aren’t as different as you suggest. Some people with spinal cord damage eventually recover some or most of their function. Some people with reattached fingers do NOT recover use of them, or they might recover some feeling or movement but not fully recover both of them.