Middle
(Tracheobronchial)
– Trachea (windpipe), bronchi
– Rings of cartilage and muscle
Cartilage provides structural support
Muscles contract to help force air
– Coughing, sneezing
– Lined with mucous membrane and hairs (cilia)
Cilia move like waves to push mucus and particles upward
Cigarette smoking can paralyze the cilia
Particle-laden mucus is removed by coughing, expectorating, or swallowing