Question

how does regular exercise help maintain a healthy respiratory system?
it helps lungs from becoming too large
it helps cilia in the lungs eliminate mucus
it helps lungs exchange gases at a slower rate
it helps lungs become more efficient at gas exchange

Answer 1

Correct answers:
- it helps cilia in the lungs eliminate mucus
- it helps lungs become more efficient at gas exchange

Why:
- Regular aerobic activity increases airway airflow and stimulates mucociliary clearance and coughing, helping cilia remove mucus and debris.
- Exercise improves overall gas‑exchange efficiency by increasing ventilation, strengthening respiratory muscles, improving pulmonary blood flow and ventilation–perfusion matching, and increasing the body’s ability to take up and deliver O2.

Why the others are wrong:
- Exercise does not “keep lungs from becoming too large” — lung size is not controlled that way by exercise.
- Exercise does not make gas exchange slower; it increases the rate and capacity for gas exchange when needed, while improving overall efficiency.