<Li> In humans, for example, motile cilia are found in the lining of the trachea (windpipe), where they sweep mucus and dirt out of the lungs . </Li> <Li> In female mammals, the beating of cilia in the Fallopian tubes moves the ovum from the ovary to the uterus . </Li> <P> The functioning of motile cilia is strongly dependent on the maintenance of optimal levels of fluid bathing the cilia . Epithelial sodium channels ENaC that are specifically expressed along the entire length of cilia apparently serve as sensors that regulate fluid level surrounding the cilia . </P> <P> Ciliates are microscopic organisms that possess motile cilia exclusively and use them for either locomotion or to simply move liquid over their surface . </P>

What cellular structure is associated with movement of cilia