Why Your Hair Grows the Way It Does

You've probably noticed that the hair on your head grows a lot longer than the hair on, let's say, other parts of your body. Hair follicles each have their own terminal length, meaning how much time they spend on growing a hair, and how fast, before they give up and let the hair fall out. And then that follicle will start over again, or maybe not. The hair follicles on your body come in different types with different programming, and those on your head are the most productive, up to a point. Believe it or not, these follicles can be transplanted to a different body part! 

But everyone's follicles are different. Some women never cut their hair, and they still have different lengths because their hair follicles are programmed differently. This TED-Ed lesson from Maksim Plikus explains what's going on inside those follicles to give you the hair you have. -via Damn Interesting