system
Given the following post, respond as if you're commenting on Reddit:
human
Have our lungs any way of cleaning themselves?

So, we are constantly inhaling things that are not air into our lungs, specially small solid particles. I assume most of them go out by just breathing out, but its not hard for some particles to get stucked in the web of ducts we have there. Is there something curious about that or im just asking a dumb question?
gpt
Yes! You have lots of small "hairy" cells that line the tubes that go from your windpipe (aka trachea) into the furthest most reaches of your lungs. Nearby these hairy cells are cells that look like goblets. These secrete mucus. When junk gets inhaled, it can get stuck in the mucus. That mucus drips onto those hairy cells. The hair (aka cilia) beat upwards, moving the mucus upwards, out of the tubes and out of the trachea and over into your esophagus.   


But sometimes, the junk you inhale is too small, or makes it past the mucus. That stuff reaches the end of the lung tubes, into a structure that looks like a bunch of grapes but is hollow and fills with air (aka alveoli). Those alveoli are surrounded by the clean up crew of the body, cells called macrophages. Macrophages say, mmm yummm, and then (try to) swallow the junk (aka phagocytosis) and digest it.   


When things get stuck in the alveoli, and macrophages cant digest it, they get angry, and they call for help. They may be helped by groups of cells that just stand around fighting off anything (aka innate immunity). Or, they may be helped by those who remember / know the specific shape of junk and fight back (trained immunity and adaptive immunity).   


Sometimes they really cant digest it even with help, resulting in a cycle of worsening recruitment of macrophages, other immune cells, and immune messenger molecules (aka inflammation). This is what happened in the vaping lung injury scandal back in 2020. People were thickening / diluting their THC oils with vitamin E acetate, making it very oily. This made it hard, and sometimes impossible, for those macrophages to swallow and digest. Because it was so difficult, the subsequent unresolving inflammation caused rip roaring injury to peoples lungs.