Re: Sodium homeostasis... was Re: tears
pete (VINCENT@REG.TRIUMF.CA)
30 Oct 1995 22:10:57 GMT
J. Moore (j#d#.moore@canrem.com) sez:
`The problem for the body, in terms of excreting of sodium (or
`potassium, etc.), is maintaining a balance (homeostasis) of water
`and sodium (or potassium, etc.). If an excreted solution has the
`same ratio of sodium to water as is in plasma, it doesn't change
`this balance, and the organ excreting this solution is not going
`to be able to rid the body of excess sodium. The solution itself
`is said to be isotonic. This is the situation with human tears.
`Human sweating excretes a substance which is hypotonic, having a
`lower ratio of sodium to water than is in plasma. Here too, the
`solution is not useful at ridding the body of excess sodium --
`quite the opposite -- since the body is eliminating proportionately
`more water than sodium from its plasma as it sweats.
Nevertheless, electrolyte loss through sweating is a problem,
because people drink fresh water to replenish their fluid loss,
so the net result is a constant fluid content, with fewer salts.
Thus the advent of electrolytically balanced drinks for athletes.
--
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vincent@triumf.ca <== faster % Pete Vincent
vincent@freenet.vancouver.bc.ca % Disclaimer: all I know I
% learned from reading Usenet.
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