system
Given the following post, respond as if you're commenting on Reddit:
human
What happens to all of the microorganisms which we are constantly inhaling?

There are millions of bacteria, fungal spores, and other microscopic organisms that are in the air we inhale constantly. So what happens to them and us when we inhale them?
gpt
Depends on their size. Some are trapped in the nasopharyngeal (nose and mouth) region where they are then swallowed and the stomach acid takes care of them. Then some are deposited in the upper airways where the mucociliary escalator sweeps them out of the lung and again they are swallowed, and the ones that bypass this are usually engulfed by macrophages, or absorbed via pinocytosis and again, swept out of the lung and swallowed for excretion, or taken in the blood to the liver where it becomes mixed in bile and is then swept out in the poop. The body is quite an amazing filter actually.