What happens to inhaled particles like dust in the respiratory system?

Inhaled particles such as dust have a well-defined process within the respiratory system. When air enters the respiratory tract, it carries these particles with it. The respiratory system is lined with mucous membranes that produce mucus, which plays a crucial role in trapping foreign particles, including dust, pollen, and other debris. This accumulation of mucus serves to protect the delicate tissues of the lungs by preventing these potentially harmful particles from reaching deeper lung regions.

Once trapped in mucus, the body's natural mechanisms can expel these particles. Ciliated cells in the respiratory tract beat in a coordinated manner to move the mucus, along with any trapped particles, upwards towards the throat, where it can be swallowed or expelled through coughing. Therefore, the correct answer highlights the initial and essential role of mucus in safeguarding the respiratory system by capturing inhaled particles.

While expelling particles through coughing is also a valid process, it is a subsequent action that occurs after particles have been trapped in mucus. The other options regarding absorption by blood and transformation into energy do not accurately describe the fate of inhaled particulate matter in the respiratory system.