Where is the thirst center located
How the Body Corrects Concentration Changes - Thirst and ADH
so this is how the brain senses changes
in concentration and now how does the
body correct those changes well it does
so in two ways so the first way that the
body corrects changes in concentration
is by changing the amount of water that
you drink
so it'll affect thirst and how does this
happen
well we already have an osmolar scepter
here in the brain that's been activated
by the change in concentration so it
just sends a signal to another nearby
part of the brain that causes you to
become more thirsty and the second way
that you correct your change in
concentration is to change the amount of
water that your kidneys are excreting
and the way that this works is that you
have some ozma receptor here in the
hypothalamus that's been activated and
it actually secretes a hormone into
circulation so it secretes a hormone
which is called anti diuretic hormone
often abbreviated ADH but it actually
has many names sometimes instead of ADH
it's called vaso pressin sometimes it's
even called a third name which is
arginine vaso pressin or even arginine
vasopressin peptide which can be
abbreviated a V P so it's kind of
irritating there are so many names but
just try to remember that these are all
the same thing and you should know that
these Osmo receptors project it down
into this little part of the brain which
has a name as well this is called the
posterior pituitary and it's a gland we
call it a gland because it secretes
stuff what does it secrete well one of
the things is this ADH so the posterior
pituitary and gland so at the posterior
pituitary gland ADH is secreted into
circulation so let's put it in a little
blood vessel there and then it goes all
the way through systemic circulation and
eventually makes its way to the kidney
and that's where it has its effect to
change water excretion so these are all
the details that you need to know the
overall picture here is the brain is
sensing changes in concentration and
then it's going to correct them by
changing your thirst and changing your
water excretion and to be a little more
specific let's say you had an increase
in concentration what's that going to do
that's going to cause a increase in
thirst because you want to take in more
water to offset that concentration rise
and a decrease in water excretion and on
the other hand a decrease in
concentration is going to cause a
decrease in thirst so that you don't
dilute your fluids even more and an
increase in water excretion so that you
can raise your concentration back to
normal levels now the last thing I want
to mention this video is getting long
and intense
but ADH causes decreased water excretion
so when you have a rise in your
concentration you're gonna want to
reduce your water excretion and you do
that by increasing your ADH whereas here
when you have a drop in concentration
you want to excrete more water and you
do that by secreting less ADH
