Describe the anatomical and physiological features of the respiratory system that limit the establishment of pathogenic organisms

Question

What will be an ideal response?

Answer 1

When air enters the upper respiratory tract, it passes through the paranasal sinus cavities. These cavities are lined with mucous membranes which secrete mucous to trap microbes and debris. The mucous is swept toward the nose and mouth for expulsion by cilia, hair-like projections lining the airway. In the pharynx, the epiglottis is a cartilage structure that seals the entry to the lower respiratory tract while swallowing, preventing the entry of food, beverages, and associated microorganisms to the lungs. The lower respiratory tract airways which include the trachea, bronchi, and bronchioles are lined with ciliate mucous membranes which trap microbes and debris and sweep them upward away from the lungs. This is called the mucociliary escalator. Respiratory infection symptoms such as a runny nose, cough, and sneezing help to expel pathogens but also provide a means for the pathogen to move to the next host. The respiratory tract has an abundant microbiome, even in the lungs. Microbiome members may prevent the establishment of pathogens by competing with pathogens for space and producing antimicrobial peptides.