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Do older adults have decreased cilia in their airways? The impact of aging on respiratory defense

Healthy aging leads to a decrease in the efficiency of the mucociliary clearance system, a critical defense mechanism of the lungs. In response to the question, **do older adults have decreased cilia in their airways**, the answer is complex: while a significant decline in the *number* of ciliated cells is not well-established in humans, their *function* and *structure* do deteriorate with age.