is a kind of cough
seen especially in smokers. Any irritant present in the respiratory system
may trigger cough, however, smoker's cough develops as a consequence of phlegm
buildup in the trachea
. Many long-term smokers end up beginning their day with bouts of severe coughing.
In the trachea, the walls are lined with cilia
, small hairs that protrude from the tracheal epithelium
. They move in a synchronous wavelike motion, thereby moving foreign bodies trapped in phlegm upwards towards the oropharynx
, so they may be swallowed. Cigarette smoke destroys or paralyzes these cilia, so the only way that phlegm can be removed is via coughing.