Looking at the diagram of "Bags of stuff inside you" in "Thing Explainer" I was surprised to find that when annotating blood vessels, intestines etc he uses "ha

Looking at the diagram of "Bags of stuff inside you" in "Thing Explainer" I was surprised to find that when annotating blood vessels, intestines etc he uses "hallway" and not "pipe", which I thought would be in the 1000 most often used english words. How curious.