16 November 2009

Swimming and an Autonomic Reflex

Once upon a time I watched part of a BBC documentary on the human body, in which they revealed that babies, under a certain age, will automatically hold their breath when dunked under water. As the babies get older, however, they lose this reflex. The video of babies "swimming" by themselves was kind of neat. Cute, too.

Being too cheap to purchase prescription swim goggles, I haven't as much as dipped a toe in a swimming pool for decades. Nevertheless, I still remember that I never required a nose clip to prevent water from flowing up my nasal passages. I just held my breath, and that was it.

As a young child I vaguely remember wondering, upon first viewing some competitive swimmers wearing nose clips, why they bothered. After the split second I considered this weighty conundrum, I concluded that as they obviously swim much faster so water must as a consequence threaten to go up their nose with greater force... thus nose clips as a preventive measure. Kids, eh?

Anywhoo, I never thought about it again, until recently (hence, this post). Apparently the use of nose clips is all dependent on how people were trained. In the beginning, everyone's nasal passage will close off and prevent water from going up their nose -- assuming they hold their breath underwater, obviously. However, those who first learn to swim with nose clips lose this autonomic reflex.

So this is an ability acquired in the womb... still possessed in young babies... then lost... then regained... and then, perhaps, lost again.

Interesting, eh? Well... I think it's interesting.

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