Which of the following structures is NOT part of the upper airway?

The trachea is not considered part of the upper airway. The upper airway is defined as the anatomical structures that facilitate breathing and air passage leading into the lungs, including the nose, pharynx, and oropharynx. These structures are responsible for filtering, warming, and humidifying the air before it reaches the lower airway, which includes the trachea and lungs.

The trachea, in contrast, is a component of the lower airway and serves as the main passage for air to travel to and from the lungs. Understanding the distinction between the upper and lower airways is crucial for first responders, particularly in medical emergencies, as it informs techniques for airway management and interventions such as intubation and ventilation.