Which of the following structures is NOT found in the upper airway?

Which of the following structures is NOT found in the upper airway?

• A. Trachea
• B. Larynx
• C. Alveolus
• D. Bronchus

Answer: (D)

The main idea is knowing which structures belong to the upper airway versus the lower airway. The upper airway includes the nose, mouth, pharynx, and larynx — the pathway through which air enters before it reaches the lungs. Below that, the trachea and beyond are considered the lower airway, continuing into the bronchi and then the alveoli where gas exchange occurs. Among the listed structures, the bronchus is located inside the lungs as a subdivision of the lower airway, so it is not part of the upper airway. The larynx sits in the upper airway, while the trachea and alveoli are lower airway components as well, even though they’re not the immediate terminal structures of the upper airway.

The main idea is knowing which structures belong to the upper airway versus the lower airway. The upper airway includes the nose, mouth, pharynx, and larynx — the pathway through which air enters before it reaches the lungs. Below that, the trachea and beyond are considered the lower airway, continuing into the bronchi and then the alveoli where gas exchange occurs. Among the listed structures, the bronchus is located inside the lungs as a subdivision of the lower airway, so it is not part of the upper airway. The larynx sits in the upper airway, while the trachea and alveoli are lower airway components as well, even though they’re not the immediate terminal structures of the upper airway.