What part of the respiratory system helps protect the airway during swallowing?

The epiglottis plays a crucial role in protecting the airway during swallowing. It is a flap of cartilage located at the base of the tongue that opens and closes over the larynx (the voice box) to prevent food and liquid from entering the trachea (the windpipe) and the lungs. When swallowing, the epiglottis folds down to cover the larynx, directing the swallowed materials into the esophagus, which is responsible for carrying food to the stomach.

This function is vital because it helps prevent choking and aspiration, which can lead to serious respiratory complications. While the trachea, larynx, and nasal cavity all play important roles in respiration and the overall function of the respiratory system, it is the epiglottis specifically that acts as the protective mechanism during swallowing, making it the correct answer to the question.