FRONTIERS IN BIOSCIENCE; CILIA
	Cilia (green arrowheads) are motile structures. Their contastant movements contribute to the flow of fluid over the cell surfaces. For example, in the respiratory tract, a constant flow of fluid over the mucosal layer leads to gradual movement of foreign bodies that are deposited on the surface of the respiratory epithelium. Within the fallopian tube, the cilia contribute to the movement of the ovum or the blastocyst towards the endometrial cavity. The movement of cilia is controlled by the basal bodies (blue) that reside within the cellular end of the cilia. Basal bodies are similar to the centrioles that play a role in cell division.