Final answer:
The epiglottis is a piece of cartilage that prevents food from entering the trachea during swallowing. Epiglottitis is the inflammation of the epiglottis, which can obstruct the airway.
Step-by-step explanation:
The epiglottis is a leaf-shaped piece of elastic cartilage located in the larynx which plays a critical role in the respiratory and digestive systems. During the act of swallowing, the epiglottis folds downward to cover the opening of the trachea, known as the glottis. This action prevents ingested food and drink from entering the respiratory tract, ensuring that they pass into the esophagus instead. Epiglottitis is an acute inflammation of the epiglottis, which can cause swelling and potentially obstruct the airway, making it a serious medical condition that requires prompt attention.