I've been trying to find a copy of the episode (Goes Cellular) where the kids of the Magic School Bus dive inside Arnold's body when he turns orange, but youtube seems to be short on it.
Instead, return to your elementary days with these
YouTube - Arnold probably should have stayed home today
YouTube - Inside the Human Body
YouTube - Magic Tool Bus
YouTube - Magic School Bus Verdampen PMK
I have so many decade old memories surfacing. It's wonderful, things I had nearly forgotten.