system
Given the following post, respond as if you're commenting on Reddit:
human
What changes in our cells as we grow older that makes it more difficult to recover from an injury?
gpt
A part of it is that we have fewer stem-cells ready to take the place of any damaged cells. As we grow our initial stem cells take find their homes and begin specializing. We always have a certain number of stem-cells in our bodies, but fewer as we age. Also, each time a cell divides it loses a link in a chain of "telomeres". After it loses all its telomeres it will stop dividing. Obviously as we age, fewer cells are replicating themselves to replace damaged ones. Under normal circumstances you don't need your cells to keep diving except for maintenance, so this is expected behavior, but can lead to longer recovery times from injury.