How does your skin grow back when you get a cut or injury? How does your body know?
In: Biology
If you have Netflix, check out Cells Work. Its an anime, but it explains sooooo much about how your cells take care of you!
[Skin](https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/1223/2017/02/08005456/502_Layers_of_epidermis-1024×810.jpg) always grows, outwards, because it’s composed of cells and they divide / multiply (a lot), then eventually die, and the younger layers push the “older” layers outwards.
i don’t know how the body knows to do this but I do know how the skin repairs cuts. the skin actually does not “repair” anything, it replaces what was already there. A cut will not be closed directly. the lowest level of skin cells multiply and push up new layers just as they did without a cut, and the cut slowly disappears with new layers of skins filling up from the bottom. this is why even weeks after a cut is healed, your top layers of skin might still be damaged.
So when you have an injury that physically alters your body, such a bruise or cut, your body has two responses one of which is a chemical signal that calls white blood cells and platelets to move to the area of interests. The white blood cells attempt to quell any possible foreign entities from your body that may cause an infection and the platelets begin clotting the cut. The scab both helps to keep the cut closed and prevent future infection. Afterwards the cells around the cut attempt to bind back again to themselves from underneath the scab. Interruptions and different factors can lead to an over expression in younger skin cells which cause scarring.
I’m sorry this is a very, almost juvenile explanation, that may not answer your question