Trachea
Step-by-step explanation:
The trachea, commonly called the windpipe, is the main airway to the lungs. It divides into the right and left bronchi at the level of the fifth thoracic vertebra, channeling air to the right or left lung. The cartilage in the tracheal wall provides support and keeps the trachea from collapsing. The mucous membrane that lines the trachea is similar to that in the nasal cavity. Mucus traps airborne particles and microorganisms, and the cilia propel the mucus upward, where it is either swallowed or expelled.