Why are the bronchi and trachea prone to infection?

The bronchi and trachea are prone to infection due to their role as conduits for air, making them directly exposed to pathogens inhaled from the environment. Additionally, their mucosal lining produces mucus, which can trap bacteria and viruses, but also provides a medium for infections to thrive if the immune response is compromised. Factors like smoking, pollutants, and respiratory illnesses can further weaken the respiratory defense mechanisms, increasing susceptibility to infections.