sneeze
Sneezing, also known as sneezing reflex, is a kind of human and animal physiological reflection behavior. Reflected receptors in the nasal mucosa, transmitted by the trigeminal nerve to the brain. Before sneezing, the nose becomes sour and itchy. The process is generally inhalation, mouth opening, and then high-speed (up to 50 km per hour) through the nasal cavity and mouth at the same time exhaust, resulting in loud "A sneeze" sound (Cantonese "begging" shape sound). Sneezing, the saliva will form 1000-40000 pieces of droplets with high-speed air spray, the speed of 177 kilometers per hour (that is, about 49.2 meters per second), so it is a lot of infectious diseases of the vector. Usually sneezing at the same time will be closed eyes, may be to avoid droplets pollution. Foam diameter greater than 100 microns quickly landed, the small particles of water droplets evaporate, the formation of aerosols, can be suspended for several hours or longer. Sneezing is an instinctive reflex that is difficult to control. Out of courtesy and public health, should not splash the splash on others. It is best to use a handkerchief, facial mask cover, it is too late to use the back of the hand or sleeve elbow can also be. Tighten mouth nose and mouth sneezing, the middle ear and tympanic membrane pressure, is not conducive to health. In addition, sneeze when the upper body has a fierce movement, we should pay attention to avoid so sprained waist. ...