What are some of your body's defense mechanisms against foreign matter?

The body's defense mechanisms against foreign matter include various physical and biological barriers that work together to protect against pathogens and contaminants. The nose and mouth, for example, serve as the first lines of defense, filtering out larger particles and pathogens from the air before they can enter the lungs. The mucous membranes produce mucus, which traps dust, bacteria, and other foreign particles, preventing them from infiltrating deeper into the respiratory system. Cilia, tiny hair-like structures lining the airways, work in conjunction with mucus; they beat in a coordinated manner to move trapped particles upwards towards the throat, where they can be swallowed or expelled.

This option emphasizes the respiratory defense mechanism, highlighting the specific structures involved in filtering and trapping harmful substances inhaled through the nose and mouth. Each of these components plays a crucial role in preventing respiratory infections and maintaining overall health.