00:01
Welcome.
00:02
In this lecture,
we will be learning about
the fluid, electrolyte, and
acid base balance of the body.
00:10
So first let's look at the
two main fluid compartments
found in our body.
00:15
This is going to be
where the most of our bodies
water content is located.
00:21
We have the intracellular fluid
compartment,
which is the fluid found
inside of all of our body cells,
and accounts for two-thirds
of the total body fluid.
00:32
The second compartment is the
extracellular fluid compartment.
00:37
This fluid compartment
can be further broken down
into two main types of fluid.
00:42
And this fluid compartment
consists of all of the fluid
outside of our cells.
00:48
This accounts for one-third
of our total body fluid.
00:53
The two body fluids found in our
extracellular fluid compartment
include our plasma,
which is a component
of our blood,
and the interstitial fluid.
01:04
This makes up about 12 liters
of our total body fluid
and it's found in the spaces
in between our cells.
01:13
Fluids such as the lymph,
cerebral spinal fluid,
the humors of the eye,
synovial fluid,
serious fluids,
and gastrointestinal secretions
are all considered a part
of the interstitial fluid.
01:30
So if we were to break down
our total body water count,
we would find that our body contains
about 40 liters of water or fluid
and makes up about 60%
of our total body weight.
01:46
If we divide this up into the
different compartments,
we find that our
intracellular fluids
are going to make up about 25 liters
of our fluid content.
01:57
Whereas,
the extracellular fluid is going
to make up the remaining 15.
02:03
If we divide that remaining 15 up
into the different types
of extracellular fluid,
we find that the
interstitial fluid
is going to have a volume
of about 12 liters
while the plasma has the remaining
3 liters of volume.
02:19
So, what is our bodies fluids
mostly made of?
The main component
of our body fluids is water.
02:27
The reason why is because
water is a universal solvent
and many different other
constituents can dissolve in water.
02:37
Substances that are dissolved
in water are referred to as solutes.
02:41
And water is the solvent.
02:44
We can classify solutes based on
how they react in water.
02:50
We classify them as either
nonelectrolytes or electrolytes.
02:56
Nonelectrolytes are going to mostly
be organic molecules
and these are not going to
dissociate or break apart
when they are placed in water.
03:08
Examples of nonelectrolytes
include things like
glucose, creatinine, and urea.
03:15
Lipids is also an example
of a nonelectrolyte.
03:18
But unlike these other examples,
it does not
dissolve in water at all.
03:24
We also have electrolytes.
03:27
Electrolytes are going to dissociate
into separate ions
when they are placed in water.
03:33
Examples of electrolytes include
inorganic salts,
all of our acids and bases,
and also some of our proteins.
03:44
The electrolytes
that break down into ions
are then able to conduct
electrical currents.
03:50
This is especially important
for our electrically excitable cells
in our body,
such as our neurons
and our muscle cells.
04:01
Each of our fluids compartment
have distinctive patterns
of electrolytes.
04:07
If we start with the
extracellular fluid compartment,
we find that the electrolyte content
is pretty much similar
all over the body,
except for in the plasma,
where we have a higher protein and
lower chloride ion content.
04:22
Outside of this, however,
the major cation
in our extracellular fluid
is going to be sodium ion.
04:30
The major anion,
in our extracellular fluid
is going to be chloride ion.
04:36
In our
intracellular fluid compartment.
04:39
This is going to actually contain
mostly soluble proteins.
04:45
This is going to have a
low sodium and chloride content.
04:50
And the major cation
found inside of ourselves
is going to be potassium.
04:56
The major anion in ourselves
is going to be phosphate ion.
05:02
When it comes to numbers,
electrolytes are going to be
our most abundant solutes
in our body fluids
and are going to determine
most of our
chemical and physical reactions.
05:14
When it comes to how much
space they take up however,
the bulk of our dissolved solutes
are going to be
proteins, phospholipids,
cholesterol, and triglycerides.
05:27
These are going to take up about
90% of our plasma,
60% of our interstitial fluid,
and 97% of our
intracellular fluid.