ELI5 When you have a small chunk of skin removed, say you cut your fingertip off, how does the body know how much skin to replace to get it looking like it did before the injury?

It regrows to the exact size it was, no extra skin no less skin. Unless of course it?s a serious injury but I?m talking minor skin removal. Obviously gunshot wounds, flesh eating bacteria and animal bites don?t do this because of scar tissue I assume but even with them it?s remarkable how close it comes to filling in the area. How does the body know when to stop growing the new tissue to fill it in and how come with these deeper wounds the body has a harder time figuring it out?


Source.