The purpose of a sneeze is to keep air passages free of mucus that has picked up dust and other impurities from the air in the process of breathing. A sneeze is an excellent way to spread a virus to a new host. Parts affected The irritation initially triggers activity at nerve endings in the upper respiratory tract.
Signals travel to the sneeze reflex center in the brain .
The reaction from this center is to instruct the diaphragm and rib muscles to inhale a large amount of air. Once the volume of air taken into the lungs reaches its capacity, the larynx closes above the air and the diaphragm pushes the other way. The air pressure in the lungs rises and the larynx reopens. Air, in the form of a sneeze, explodes through the nose and mouth. Added pressure if the mouth is closed may drive mucus into the sinuses and ears, where it may form a breeding ground for bacterial infections.