system
Given the following post, respond as if you're commenting on Reddit:
human
What happens to the food/drinks that "go down the wrong pipe" and aren't coughed back up?

As many of us know, humans are bad at eating and drinking. Our epiglottises (?) occasionally fail at their ONE job and let small bits of food or drinks into our windpipe. Often, when this happens, we cough up whatever "went down the wrong way" and it's fine. If it doesn't happen, there are potentially really serious effects, including pneumonia. I get all of that.

What I don't know (and am having surprising trouble Googling) is what happens if something *doesn't* get coughed up and *doesn't* create a significant-enough problem that it requires medical intervention. Lungs (obviously) don't have stomach acid or muscles designed to break down the thing, so does it just stay there, like the thin layer of crumbs under the couch cushions? Does liquid eventually get absorbed into Gatorade-fueled pleural fluid? What actually happens?
gpt
The upper branches of bronchi to your trachea are lined with ciliated epithelium, little brush-like projections, that beat rhythmically to help get smaller dust and liquid particles mixing with mucous back up to your pharynx, where you hack a bit and swallow them or spit them out. 

Anything too big or too far down gets slowly diluted by mucous producing cells and absorbed (liquids), or potentially walled off and slowly degraded by immune cells like macrophages (solids).