Re: Brains size and sweat

jparm@warren.med.harvard.edu
Wed, 8 Jan 1997 14:28:09 -0500

In response to some of the stuff on sweat, we seem to be
ingoring the importance of the circulation in aiding
evaporative heat loss. I am a little rusty on some of the
physiology here, but when we are hot we not only sweat, but
vasodilate in order to aid in the conduction of heat from
its source to the site of heat loss - i.e. the skin. It may
not make a whole lot of difference where the heat is
generated as long as the circulation is efficient.

As for dessert animals, they need to conserve water, and
have superbly efficient kidneys with extra long and
efficient loops of Henle to concentrate the urine. They
would not be expected loose too much water through sweating
but would have to find other methods of cooling - can anyone
tell us what?

Jonathan Arm