Science Fact - Cilia Cilia and flagella are projections from the cell. They look like tiny hairs.  They are made up of microtubules. They are designed either to move the cell itself or to move substances over or around the cell.   In this regard, they are a lot like the legs and arms of humans. The primary purpose of cilia in mammalian cells is to move fluid, mucous, or cells over their surface. Cilia and flagella have the same internal structure. The major difference is in their length. To learn more about Cilia, visit this page.