Question

How wind pipe blocks during cough?

Answer 1

Wind pipe/trachea has a flap called "epiglottis" that covers windpipe to prevent the entering of food particles through the windpipe (where in it has a chance to reach the lungs) while it must actually go to the food pipe/oesophagus.
So, if epiglottis does not do its job, ie., to cover the trachea , it has a wide chance for u to cough. There by, it prevents cough!!

I hope it helped u out ...!!