larynx

In mammals, a cavity at the upper end of the trachea (windpipe) containing the vocal cords. It is stiffened with cartilage and lined with mucous membrane. Amphibians and reptiles have much simpler larynxes, with no vocal cords. Birds have a similar cavity, called the syrinx, found lower down the trachea, where it branches to form the bronchi. It is very complex, with well-developed vocal cords.