The larynx, also known as the voice box, is a part of the respiratory system that is located in the anterior aspect of the neck. It is a cartilaginous segment of the respiratory tract that connects the pharynx to the trachea. The primary function of the larynx is to protect the lower respiratory tract from aspirating food into the trachea while breathing. It does this by closing the epiglottis, a flap-like projection into the throat, to prevent food from entering the windpipe and lower airways. The larynx also contains the vocal cords and functions as a voice box for producing sounds, i.e., phonation. The vocal cords close together and vibrate as air expelled from the lungs passes between them, producing sound. The larynx also helps provide smooth passage of air from the nasal cavity to the lungs. When a person is breathing normally, the vocal cords are relaxed and partly open. If the body needs more oxygen, the vocal cords open more widely during inhalation. Additionally, the larynx helps prevent choking when eating and drinking. When food is swallowed, a small flap called the epiglottis covers the opening of the larynx to keep food and drink out of the windpipe.