The epiglottis is a small, leaf-shaped sheet of elastic cartilage that is located behind the tongue, at the top of the larynx or voice box. Its main function is to protect the respiratory system by preventing food and liquid from entering the windpipe and lungs while swallowing. When a person swallows, the free end of the epiglottis flips backward to cover the opening of the larynx, and when food or fluid gets close, the free end of the epiglottis flips up and pushes food or liquid away from the larynx towards the esophagus. The epiglottis also helps with some aspects of sound production in certain languages. Swelling of the epiglottis is called epiglottitis, which can block airflow to the lungs and is potentially life-threatening.