salt content of cells

cotegl at cotegl at
Mon Oct 2 09:15:26 EST 1995

In article <44juh8$khb at>, chimo at 
>I am a high school biology teacher interested in finding out the salt
>content of human cells, preferably lung cells.  Is it true that the
>salt content of these cells is isotonic with 'typical' seawater?  I am
>in a debate with another biology teacher about the subject.  I've heard
>that you are more likely to survive a near drowning in seawater other
>than fresh water.
>Lori Karn

"Typical" seawater contains approximately. 2.5% to 3.5% NaCl by weight, 
depending on location.  On the other hand, human blood serum contains 
approx. 0.9% NaCl by weight.  Different body tissues may vary slightly, 
but in general, their salt concentration should be nearly isotonic with 
blood serum, i.e., 0.9% NaCl (w/v).  Other solutes in serum may bring the 
total osmotic pressure up, especially glucose, proteins, etc. 
 As far a drowning is concerned, lungs full of water cannot breathe, 
regardless of the salt concentration.  Water temperature does play a 
role, though, with colder water slowing down metabolism and initiating 
what is known as the "diving response".  Some victims, especially young 
children, have survived immersion in ice-cold water for extended periods 
(over 20 minutes in one case, if newspaper accounts can be believed). 

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