Question

mucus occurs in both the nose and lungs of the respiratory system. what is its main immunological function?

increasing oxygen absorption

phagocytosis

physically trapping pathogens to expel them

to \gross out\ the pathogens so they exit on their own

Explanation:

• "Increasing oxygen absorption" is not the immunological function of mucus; oxygen absorption is related to gas exchange in alveoli.
• "Phagocytosis" is done by immune cells like phagocytes, not mucus.
• "To 'gross out' the pathogens..." is a non - scientific, incorrect description.
• Mucus in the respiratory system physically traps pathogens (like dust, bacteria) and helps expel them via mechanisms like coughing or sneezing, which is its main immunological - related protective function.

Answer:

C. physically trapping pathogens to expel them (assuming the options are labeled A, B, C, D with A: increasing oxygen absorption, B: phagocytosis, C: physically trapping pathogens to expel them, D: to "gross out" the pathogens so they exit on their own)