Lining the mucosa of the trachea beat continuously to propel contaminated mucus to the throat.

Long hair-like cilia lining the mucosa of the trachea beat continuously to propel contaminated mucus to the throat. This part of the trachea is responsible for preventing any form of debris or solid particle to enter the lungs allowing the passage of clean air through the trachea. Without the cilia functioning, it would be easy for particles to enter the lungs which may cause respiratory complications or failure.

✧･ﾟ: *✧･ﾟ:*  your muscle vs. fat ratio ✧･ﾟ: *✧･ﾟ:*

Your BMI doesn't reveal anything about the makeup of your body, such as how much muscle vs. fat you have. That's why conclusions based only on this number can be misleading.