What does the upper respiratory tract consist of?

• A. Nasal cavity, Pharynx, Larynx
• B. Trachea, Bronchi tree, Lungs
• C. Larynx, Trachea, Esophagus
• D. Pharynx, Larynx, Esophagus

Answer: (A)

The main idea is which structures form the upper airway of the respiratory system. The upper respiratory tract includes the nasal cavity, where air is filtered, warmed, and humidified; the pharynx, which channels air from the nose and mouth toward the larynx; and the larynx, which serves as a gateway to the lower airway and houses the vocal cords. The other structures listed belong to the lower respiratory tract or to a different system: the trachea, bronchi, and lungs are part of the lower airway where gas exchange occurs, while the esophagus is part of the digestive system and lies behind the airway. So, nasal cavity, pharynx, and larynx together comprise the upper respiratory tract.