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

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This is a science community. We use the Dawkins definition of meme.
Technically, the digestive system (i.e., the full gastro intestinal tract) is considered as part of the "outside" of the body, acting as an external surface similar to the skin. The space that an object can travel through without crossing a cell membrane or entering blood or tissue is called "lumen". So the same intuition as in the meme actually holds true here, too.