Eli5 : How does your body push out unnatural stuff, like gravel in a wound or a splinter in your thumb?

Question

Eli5 : How does your body push out unnatural stuff, like gravel in a wound or a splinter in your thumb?

In: Biology

Answer 1

Depends on how deep and how big the foreign object is (lol that’s what she said). If it’s shallow, during the wound healing it’s pushed out as skin heals from the deep layers to the shallow layers. If it’s deep, immune cells like macrophages are recruited to destroy it and eat its pieces for further breakdown. If it cannot be broken down it either evokes a big inflammatory response that requires medical attention to remove or just stays there biologically inert and gets surrounded by fibrotic scar tissue (extracellular proteins get deposited around it).