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How about the digestive system?
(feddit.org)
A place for majestic STEMLORD peacocking, as well as memes about the realities of working in a lab.

Rules
This is a science community. We use the Dawkins definition of meme.
is the ok symbol 👌 a hole?
what about membranes, pores?
The ok symbol is rather temporary but topologically that would count. I wouldn't count pores or membranes here (I mean by my arbitrary definition).