• CrazyLikeGollum@lemmy.world
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        9 hours ago

        The nostrils are connected to the throat through the sinuses as are the ear canals. Topologically making them all part of the same mouth-anus throughole.

        • itslilith@lemmy.blahaj.zone
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          9 hours ago

          Not true, topolgically the route

          left nostril -> sinus -> right nostril

          is another hole. So is

          any nostril -> sinus -> mouth.

          ears have the eardrum, so they don’t count.

          For the more formal definitions of topological holes, look up Betti numbers, I think there’s a VSauce video about it? For humans, the number of holes is at least 3 (but I’m sure I’m missing many more holes). Unless you’re missing the entire septum.