  When the sensitive tissues inside your nose are irritated, your nose tries to get rid of the irritation. A signal is sent to the muscles that help you breathe, and they suddenly contract. Air bursts from your lungs. Some of it exits through your nose, the rest through your mouth. It carries away the irritating substance. But a lot of other stuff gets expelled too, like water vapour, water droplets, and mucus from your nose. This moisture may be full of microorganisms, and some of those may be unhealthy ones. This cloud of air and moisture can move as fast as 160 kilomtres per hour ... as fast as hurricane winds! So cover that sneeze! |