Cilia

The cilium is a short hair-like membrane protrusion from many types of eukaryotic cell. The cilium has the shape of a slender threadlike projection that extends from the surface of the much larger cell body. Eukaryotic flagella found on sperm cells and many protozoans have a similar structure to motile cilia that enables swimming through liquids, but they are longer than cilia and have a different undulating motion.