The larynx, also known as the voicebox, houses the vocal cords. By opening and closing, our vocal cords help us breathe, talk and swallow safely.
When we breathe, the vocal cords are wide open to allow unobstructed air passage.
When we talk, the vocal cords are closed loosely. Air is forced from the trachea up through the vocal cords, making them vibrate. This produces our voice with the help of the tongue and the lips.
When we swallow, the vocal cords are closed tightly. Also, a group of muscles elevate the larynx so that the epiglottis can shield the laryngeal opening better. The epiglottis diverts food from the tongue to either side of the larynx, towards the esophagus. (The epiglottis usually does not cover the larynx!)
When we cough, the vocal cords open suddenly, and a blast of air from the trachea clears the airway.