Re: tears

Phil Nicholls (pnich@globalone.net)
Sat, 21 Oct 1995 03:40:03 GMT

jamesb@hgu.mrc.ac.uk graced us with the following words:

>hubey@pegasus.montclair.edu (H. M. Hubey) wrote:

>>
>>>One problem with this: the salinity of human tears matches the salinity
>>>of the body. They are not used as a salt excretion mechanism.
>>
>>First sentence doesn't justify the second. If you can get rid
>>of salt from your body, it's a salt excretion mechanism.

>Quite right, even though the tears are only as salty as body fluids, the
>weeper still loses salt.

>James Borrett.

The purpose of excreting something is to reduce the concentration of
the substance in the body. Hence secretions must have a higher
concentration of this substance than plasma or intercellular fluid.
Therefore tears cannot excrete salt unless they have a higher
concentration of salt than blood plasma. They don't.

Phil Nicholls pnich@globalone.net
"To ask a question you must first know most of the answer"
-Robert Sheckley