Which set correctly lists the structures of the upper and lower respiratory tracts?

• A. Upper: larynx, trachea, bronchi and bronchioles, lungs
• B. Upper: nose, nasal cavity, paranasal sinuses, pharynx; Lower: larynx, trachea, bronchi and bronchioles, lungs
• C. Upper: pharynx and nose; Lower: lungs
• D. Upper: nasal cavity; Lower: nose

Answer: (B)

The structures are divided by where air is conducted and where gas exchange occurs. The upper respiratory tract includes the nose, nasal cavity, paranasal sinuses, and pharynx, which are the passages that condition and move air toward the lungs. The lower respiratory tract includes the larynx, trachea, bronchi and bronchioles, and lungs, where air travels deeper and gas exchange happens. The boundary between these regions is commonly drawn at the larynx, which in many curricula is grouped with the lower tract. So, the set that places the nose, nasal cavity, paranasal sinuses, and pharynx in the upper and the larynx, trachea, bronchi and bronchioles, and lungs in the lower matches that convention, making it the correct choice. The other groupings mix structures (like placing lungs in the upper or placing the nose in the lower) and don’t reflect the usual anatomical separation.