when we suffer from cold we breath in air from the side buccal cavity but still the air that goes in dont go to stomach instead it goes to lungs . how?

Dear student,
 When we suffer from cold we breathe air through our mouth (mouth is connected to the trachea as our nose is connected through it), the air goes to the lungs and also stomach but air from the stomach is expelled back to the mouth. 
But in long run if we keep breathing through our mouth then problem can arise like crooked teeth, gum disease, bad breath etc. which can give rise to different diseases.

Regards