I took part in a quiz in which the following question was asked: 鈥淵our bodily functions stop when you sneeze. True or false?鈥� I answered 鈥渇alse鈥�, but the quizmaster said it was true. Does he have a case, and if so, what happens physiologically when you sneeze?
鈥� Sneezing is a reflex, used to clear debris and excess mucous from nasal passages and internal nose hairs. This is necessary because the nose is designed as an air-filtering station: the hairs and mucous catch dust and smoke particles, pollen, viruses, bacteria and anything else that should not get into our lungs.
鈥淪neezing鈥檚 main purpose is to clear debris and excess mucous from nasal passages and nose hairs鈥�
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Sneezing has two phases: nasal and respiratory. The first phase is triggered by physical or chemical irritants (such as dust, pollen, a cold virus, and for some people sudden exposure to bright light, or a particularly full stomach) and the impulse is transmitted via the trigeminal nerve to the 鈥渟neeze centre鈥� in the brain stem.
In response, the brain activates a number of muscles. Our eyes close (the mechanism is unclear and apparently protective), we take a deep breath, the palate and glottis close, the pressure in our lungs increases and then we are into the second phase鈥� atchoo! An explosive exit of air through the opened glottis, mouth and nose clears out mucosal debris. The sneeze reflex involves not only the muscles in our throat, larynx and windpipe but also the diaphragm, chest, abdomen, thighs, back and even our sphincters (some people have continence issues when sneezing).
Do bodily functions stop? It depends what you mean. The statement doesn鈥檛 stand if we take only the vital bodily functions of breathing and heartbeat: sneezing consists of inhaling and forcefully exhaling air, so breathing doesn鈥檛 really stop, and heartbeat doesn鈥檛 stop either. It may slow for a brief moment, due to stimulation of the resulting from the change of pressure in the chest, before resuming its rhythm. In a nutshell: the quizmaster does not have a case 鈥� you should demand a recount.
Joanna Jastrzebska, Auckland, New Zealand