What is the primary function of the epiglottis?

The primary function of the epiglottis is to stop food and liquid from entering the lungs during swallowing. It is a flap of cartilage situated at the root of the tongue that covers the entrance to the larynx. When a person swallows, the epiglottis folds down to cover the glottis, directing food and liquids into the esophagus instead of the airway. This action is crucial for protecting the respiratory system from aspiration and ensuring that the food is directed toward the digestive system, minimizing the risk of choking.

In the context of the other options, facilitating breathing is an important role of the respiratory structures, but the epiglottis specifically does not facilitate breathing. Instead, it temporarily obstructs the airway while swallowing. Producing digestive enzymes is a function of specific glands and organs in the digestive system, such as the pancreas and salivary glands, rather than the epiglottis itself. Supporting the trachea's structure is also a function performed by the cartilage rings surrounding the trachea, not the epiglottis. Thus, the role of the epiglottis is essential for proper swallowing and respiratory protection.