empty your lungs

recent videos of the earthquake and tsunami that hit japan have been horrifying.  i can't imagine having that much destruction in my home.  besides the physical damage to the marinas, farmland and buildings caused by the quaking ground and then the forceful waters, there were many lives lost.

i have to think that some people were killed by explosions, some by blunt force and many probably drowned.  drowning has long been one of my greatest fears and yet i don't understand the a&p behind it.

here it is:  upon submersion, the victim holds his breath until forced to inhale.  he gulps water.  the water induces spasms of the larynx, which closes off the trachea to protect the lungs.  little water enters the lungs. with the trachea blocked by laryngospasms, no fresh air enters the lungs and the supply of oxygen begins to fail.  lack of oxygen, anoxia, affects the brain and within 30 seconds the laryngospasms begin to weaken with imminent brain failure.  the victim then inhales again, this time aspirating water into the lungs before a fresh spasm closes the trachea again but for a shorter duration.  with each successive inhalation, more water is aspirated; anoxia increases and the laryngospasms duration decreases until they are finally abolished and the lungs are filled with water.

unfortunately, i am no less afraid now than i was before.