Trachea and Bronchi

From the larynx, the air goes down through a long hollow tube called the trachea. The trachea, also known as the windpipe, is made up of columns of tissues called cartilage.

Air passes through the trachea, which branches into two smaller tubes called bronchi. The bronchi further branch into tubes called bronchioles. From the bronchioles, air reaches tiny balloon-like air sacs called alveoli.