What structure connects the pharynx to the trachea?

The structure that connects the pharynx to the trachea is the larynx. The larynx, often referred to as the voice box, serves several important functions. It acts as a passageway for air, enabling airflow from the pharynx to the trachea and subsequently to the lungs. It is also responsible for producing sound and protecting the airway against food aspiration during swallowing.

In contrast, the bronchi are the air passages that branch off from the trachea and lead into the lungs, while the nasal cavity is primarily involved in filtering, warming, and humidifying the air we breathe, not in connecting the pharynx and trachea. The alveoli are tiny air sacs in the lungs where gas exchange occurs, and they do not have a direct role in the connection between the pharynx and the trachea. Thus, the larynx is the correct answer as it specifically serves as the connector between these two structures within the respiratory system.