HA9: Trachea and esophagus, monkey
HA9 illustrates the trachealis muscle (M), which is smooth muscle in the lamina propria between the two ends of the tracheal C ring. The ends of the C-shaped hyaline cartilage are connected by dense irregular CT. If the trachealis muscle contracts during coughing, how would that help expel the material that initiated the cough reflex?