CGI of Cilia Hairs. Cilia are usually present on a cell's surface in large numbers and beat in coordinated waves. Cilia are microscopic, hair-like structures that extend from the surface of certain cells. They are found in a variety of organisms, including animals, plants, and some bacteria. In animals, cilia are primarily involved in movement and sensory functions. They can be found in many parts of the body, including the respiratory tract, where they help to move mucus and debris out of the lungs. Also they are in the reproductive system where they help to move sperm and eggs. Cilia are also involved in sensory functions, such as detecting sound and movement in the inner ear, and in the olfactory system, where they help to detect odors. They also play a critical role in cell signaling and communication. They can act as antennae, receiving signals from other cells and transmitting signals back to the cell body. Cilia are essential for many physiological processes, and their dysfunction can lead to a range of diseases and disorders, including respiratory infections, infertility, and developmental abnormalities.