Cilia are ciliated cells with microscopically small hairs that line the upper respiratory tract and are able to transport even the smallest foreign bodies out of the body.
Cilia can also * mediate movements of fluids (for example, in the kidney tubule) or help with * hearing in the cochlea (cochlea) or * mediating the balance.
https://de.wikipedia.org/wiki/Zilie (Wikipedia CC-by-sa-3.0)
https://de.wikipedia.org/wiki/Flimmerepithel (Wikipedia CC-by-sa-3.0)