Which is the main structure of the respiratory system?

Which is the main structure of the respiratory system?

• A. Lungs
• B. Larynx
• C. Trachea
• D. Diaphragm

Answer: (A)

Gas exchange occurs in the lungs, making them the main structure of the respiratory system. The lungs house the alveoli, tiny air sacs with very thin walls surrounded by capillaries, where oxygen from inhaled air diffuses into the blood and carbon dioxide diffuses out to be exhaled. Other parts like the larynx and trachea are airways that move air to the lungs, and the diaphragm is a breathing muscle that helps expand and contract the chest to draw in and push out air. While these structures are essential for getting air in and out, the lungs are the primary site where gases are exchanged.

Gas exchange occurs in the lungs, making them the main structure of the respiratory system. The lungs house the alveoli, tiny air sacs with very thin walls surrounded by capillaries, where oxygen from inhaled air diffuses into the blood and carbon dioxide diffuses out to be exhaled. Other parts like the larynx and trachea are airways that move air to the lungs, and the diaphragm is a breathing muscle that helps expand and contract the chest to draw in and push out air. While these structures are essential for getting air in and out, the lungs are the primary site where gases are exchanged.