Which structure prevents foreign matter from entering the trachea?

• A. Epiglottis
• B. Larynx
• C. Bronchi
• D. Diaphragm

Answer: (A)

Protecting the airway during swallowing relies on a flap that closes off the entrance to the trachea. The epiglottis is a leaf-shaped piece of cartilage at the base of the tongue that moves to cover the opening of the larynx (the glottis) when you swallow. By sealing this passage, it prevents food and liquid from entering the trachea and directs material toward the esophagus. The larynx itself helps regulate airflow and houses the vocal cords, but it’s not the mechanism that blocks entry during swallowing. The bronchi are deeper airways into the lungs, and the diaphragm is a breathing muscle, neither of which prevent foreign matter from entering the trachea.