Hi. Welcome to our video series
on neurological disorders.
In this video, we'll take a look
at multiple sclerosis.
Now, MS is a disease
where the patient's own immune system
attacks the myelin sheath,
or the cells that produce
and maintain the myelin sheath.
So, one easy way for you
to remember that
is MS stands for multiple sclerosis
and myelin sheath.
Multiple Sclerosis leads to scarring.
So, the inflammation
that the patient experiences
in their immune system
is attacking them.
They end up with inflammation
and injury to that sheath
and the nerve fibers.
Well, when this sheath
and the nerve fibers are damaged,
you end up with multiple areas of scarring
and impaired nerve impulse transmission.
In order for those nerve impulses
to move smoothly,
you have to have intact areas.
So because of the inflammation
and the scarring
that comes from multiple sclerosis,
now we have problems with those nerves
being able to be transmitted.
Now looking at the myelin sheath,
what really is that?
Well, in the central nervous system,
the myelin sheath is this protein.
It's this protein and fatty substance
and insulates the nerve fibers.
Now, they're very important.
It's what help keeps the system
So, in your central nervous system,
that myelin sheath
is represented in our graphic
with that kind of blue-green color.
You see those little...
They almost look like pulled noodles
wrapped around that,
but think of that as the myelin sheath.
Now, the myelin is what helps
the transmission of the nerve impulses
along the axon.
We need that impulse
to move along the axon,
so the messages can be spread
from one to another.
So, you have myelin in the PNAS
or the CNS?
The answer is
myelin is present in both:
the central nervous system
and the peripheral nervous system.
Okay. Well, in the CNS,
myelin is produced by these cells.
Now, they're called oligodendrocytes.
That's a pretty big name.
But if you look in the drawing there,
you see those cells in the middle.
We've got them marked for you.
Those are the cells
in the central nervous system
that produce the myelin.
Now, over to the peripheral nervous system
or the PNS,
myelin is produced by the Schwann cells.
You can see it looks a little different,
but they both really help
Now, PNS and CNS myelin
are chemically different,
but they have the same function.
They promote the efficiency
of nerve impulse transmission
along the axon of the nerve cell.
So, multiple sclerosis
only affects the myelin
in the central nervous system.
So, it's present in both.
They do kind of the same thing,
but multiple sclerosis
definitely goes after the myelin
in the central nervous system.
Now, what happens
when you have these damages from MS?
Well, we know that it damages
and destroys the myelin
and the oligodendrocytes.
So, not only the sheath itself,
it also goes after the cells
that produce that sheath.
So, we have damage
to the underlying nerve fibers.
Now, when those fibers are damaged
with lesions and scars
along the nerve,
you can actually see those on an MRI.
So it's one of the exams
that a patient may have
to kind of look at where the status is
of their multiple sclerosis
or even in diagnosis.
So, because you have this damaged area
and these lesions along the line,
it's going to slow or really even stop
the nerve conduction in certain areas.
So now you have these neurological
signs and symptoms
that come from MS.
So, we're talking about multiple sclerosis.
We've got problems
with nerve transmission.
It's only in the central nervous system.
And because of this problem
with nerve transmission,
that's where the neurologic signs
that we see with MS come from.