How does the body's immune response contribute to upper respiratory symptoms?

• A. By producing antibodies only
• B. By generating inflammation
• C. By reducing swelling
• D. By preventing infection completely

Answer: (B)

The immune response contributes to upper respiratory symptoms mainly through inflammation in the mucosal linings. When a pathogen is detected, immune cells release signaling molecules that widen blood vessels and increase their permeability in the nasal and throat tissues. This creates swelling (edema) and excess mucus production. The swollen, mucus-filled passages irritate nerves and clog airways, leading to congestion, runny nose, sneezing, sore throat, and coughing. Antibodies are important for fighting the invader, but they aren’t the primary cause of these mucosal symptoms; the inflammatory response is what actually drives them. It’s also not realistic to expect infection to be completely prevented, so the presence of symptoms reflects the normal inflammatory defense trying to clear the pathogen rather than an absence of infection.