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?

Question

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?

In: Biology

Answer 1

Basically your body generates skin by generating cells at a base layer pushing them up. As they are pushed up they die, and eventually slough off (get brushed off). When you remove a chunk of skin in an injury, you expose a lower layer of your skin. Your body heals the wound, but your body continues as per usual with the base layer creating cells underneath and pushing them up until the wound bed sloughs off. This reveals a new layer of skin that will also sometime in the future die and get sloughed off. The only reason the skin at your wound doesn’t overgrow is because your regular skin doesn’t overgrow everyday!