View full lesson: http://ed.ted.com/lessons/how-do-scars-form-sarthak-sinha

It’s hard to escape childhood without racking up a few scars. Why do these leftover reminders of a painful cut or crash look different from the rest of our skin? And why do they stick around for so long after the incident that caused them? Sarthak Sinha explains how scars form.

Lesson by Sarthak Sinha, animation by Karrot Animation.