00:01
So let's look at disorders
of water balance.
00:05
There are three principal
abnormalities of water balance.
00:09
The first is dehydration.
00:12
Extracellular fluid water loss
can be due to things like
hemorrhage,
severe burns,
prolonged vomiting
or diarrhea,
profuse sweating,
water deprivation,
diuretic abuse,
or endocrine disturbances.
00:30
Signs and symptoms
of dehydration include
a cottony oral mucosa
or cottonmouth,
thirst,
dry flushed skin,
or oliguria.
00:44
This may also lead to weight loss,
fever,
mental confusion,
hypovolemic shock,
and loss of electrolytes
from the body.
00:55
The consequences of dehydration
are that as solutes are loss
the cells in our body will shrink.
01:02
This happens because
the excessive loss of water
from our extracellular fluid
means that the
extracellular osmotic pressure
is going to rise.
01:13
In response to this rise
in osmotic pressure,
the cells will lose water to the
extracellular fluid by osmosis.
01:22
As the water leaves the cells and
goes into the extracellular fluid,
our cells will shrink.
01:31
The second disorder of
water balance is going to be
hypotonic hydration.
01:37
This is also sometimes referred to
as water intoxication
or cellular over hydration.
01:45
This can occur when
there's a renal insufficiency,
but more likely this occurs
when there is rapid
excess water ingestion,
such as if you were having
in a contest,
a water drinking contest
and that contestants were
trying to drink as much water
as fast as possible.
02:06
The extracellular fluid osmolality
is going to drop
and this is going to cause a
condition known as hyponatremia,
or low sodium levels.
02:18
This results in a
net osmosis of water
into our tissue cells,
causing our cells to swell.
02:26
Symptoms of hypotonic hydration
includes:
severe metabolic disturbances,
nausea,
vomiting,
muscular cramping,
cerebral edema,
and also possibly death.
02:41
This is treated by administering a
hypertonic saline solution,
which will then pull the fluid
back out of the cells
toward the extracellular fluid
compartment.
02:54
The consequences of
hypotonic hydration include
when the water and solutes
are going into the cells,
the cells will begin to swell.
03:05
This is due to excessive water
entering the
extracellular fluid compartment,
which causes the osmotic pressure
of the extracellular fluid to fall.
03:16
Because of this pressure change,
water will now move into the cells
by osmosis,
leading to the swelling
of the cells.
03:25
The third disorder of water balance
is edema.
03:29
This is an atypical accumulation of
our interstitial fluid,
resulting in the swelling
of our tissues.
03:37
Please note that this is not
the swelling of cells
that we saw
with water intoxication,
and only the volume of the
interstitial fluid is increased
and not the
other compartments.
03:51
This can impair tissue function
by increasing the distance
for diffusion of
oxygen and nutrients
from the blood into the cells
as it increases the distance
between these cells
and the blood capillaries.
04:06
This could be caused by an increased
fluid flow out of the blood
or a decreased return to
of the fluid back into the blood.