• CrazyLikeGollum@lemmy.world
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            7 days 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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              7 days 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.