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How do cilia move mucus and trapped germs out of the airways?

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Immune stimulation by activated helper T cells — immune system Stimulation of immune response by activated helper T cells. Activated by complex interaction with molecules on the surface of a macrophage or some other antigen-presenting cell, a helper T cell proliferates into two general subtypes, T_H1 and T_H2. These in turn stimulate the complex pathways of the cell-mediated immune response and the humoral immune response, respectively.

In the respiratory tract, cilia—small, hairlike projections on the surface of epithelial cells—function as part of a protective mechanism known as the mucociliary escalator.12

The process works as follows:
* Trapping: Cells in the respiratory lining secrete mucus, which acts as a sticky trap for inhaled particles, debris, and germs.13
* Synchronized Movement: The cilia are submerged in a layer of low-viscosity fluid and beat in a synchronized, rhythmic, and sweeping motion.2
* Conveyor Belt Action: This ciliary action drags the overlying, more viscous blanket of mucus toward the pharynx.2

By acting like a conveyor belt, the cilia steadily propel the mucus and trapped contaminants up and out of the airways, where they are typically swallowed and removed from the respiratory system.12