Final answer:
The respiratory system features ciliated epithelium, which forms a mucociliary escalator moving mucus and trapped particles upward toward the throat, playing a critical role in keeping airways clear.
Step-by-step explanation:
An example of a tract with fluid and particulate material that is moved by motile cilia can be found within the respiratory system. Here, ciliated epithelium forms a mucociliary escalator that sweeps dust, germs, and other foreign particles away from the lungs. Cilia beat in a pattern that moves mucus mixed with trapped particles upward toward the throat. This action helps prevent respiratory infections by keeping the airways clear of debris and pathogens.
The nasal cilia perform a similar function but sweep the mucus downward toward the throat. This mucus, along with the trapped particles, is typically swallowed and sent to the acidic environment of the stomach. In the reproductive system, ciliated cells in the lining of the oviduct help move the ovum from the ovary towards the uterus. Thus, cilia serve crucial roles in maintaining health by aiding in the transportation of various substances and cells within the body.