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Course: Health and medicine > Unit 8
Lesson 11: Multiple sclerosisWhat is multiple sclerosis?
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Want to join the conversation?
- Why can't the brain just order the immune system to stop attacking the myelin?(8 votes)
- The immune system is not under conscious control.(17 votes)
- why is multiple sclerosis more common in women?(6 votes)
- Autoimmune diseases (cell or antibody mediated), including MS, occur more frequently in women. There are a lot of theories on why that could be, but so far studies can't provide a conclusive answer why that is. So far there is indication that the difference in autoimmmune respons might be involved. They found a relationship between vitamine D and MS (low levels, increased risk) and also smoking and MS (increased risk). As far as the gender plays a part, they found that lactation (breastfeeding) decreases the risk of an MS relaps. So in conclusion, they haven't found a reason on why MS is more common in women, but they have found relations between factors that might indicate why women are more succeptible. Reason enough for more studies to be done and get your question answered.(8 votes)
- Our immune system isn't that bright, isn't it...(0 votes)
- Well, without it, we would pretty much be dead, but yes, it isn't the smartest since it mistakes the body as foreign.(8 votes)
- how are the diseases gender specific ?(2 votes)
- Why does Multiple Sclerosis affect people of Northern European descent more than others?(2 votes)
- how does the immune system get into the brain? i thought the immune system only existed in the neck down area(1 vote)
- The immune system is everywhere, Connor. If it was just from the neck down, then what clots if you have a nose bleed? Or a cut on your face? It's everywhere.(3 votes)
- What if you killed the immune system and then built it back up again? Would the immune system still attack the myelin?(2 votes)
- The immune system protects against disease. If you killed a person's immune system, they would get sick from something else.
Some multiple sclerosis medications work as immunosuppressants; they make the immune system less strong but do not kill it.(1 vote)
- What´s the difference between plaque and sklerosis?(1 vote)
- Plaques are protein like substances formed in between neurons(just like plaques in teeth),sclerosis is more like hardening of tissues(1 vote)
- Best medicine for sugar b2 type(1 vote)
- Is it possible to have a single sclerosis? And if so what causes just a single sclerosis?(1 vote)
- The name of the condition is 'multiple sclerosis'. Sclerosis is a hardening of tissue. There are other types of tissue hardening disorders, such as atherosclerosis, hardening of arteries, but no ' single sclerosis'. This is an interesting hole in the naming process, which is haphazard at best. Here is a Wikipedia link to give further info, remember it is an open source, and not always reliable.
https://en.m.wikipedia.org/wiki/Sclerosis_(medicine)(1 vote)
Video transcript
- [Voiceover] Ok, so let's say
you have some kind of letter that you wanna, that you
wanna deliver, right? So you have a letter
that's in your mailbox, and let's say that this is the
sender of the letter, right? And so the sender of that letter
is gonna deliver that mail all the way over here
to the recipient, right? And the way that they're gonna
do that is you're gonna have this mailman in this truck
deliver it from the sender to the recipient, and they're
gonna drive along this road. But then let's say something happens. Let's say, for some reason,
an earthquake happens, right? And the earthquake actually
destroys the road over here. And so now, the mailman
can't really get to where they need to go anymore, right? Because the road has been damaged. So why am I giving this
extremely hypothetical scenario? Well I think that it serves
as a pretty good analogy towards understanding a disease
called Multiple Sclerosis. So Multiple Sclerosis is
a disease of the brain. And more specifically, it
affects the communication within the brain. So what do I mean by
communication in the brain? Well in the brain, you have
all these neurons, right? You have all these neurons
that are constantly talking to each other, kinda like
these two neurons over here. And so this neuron is going
to send an electrical signal down the length of a diaxon. And that electrical signal is in the form of an action potential. And so to improve the
efficiency of the communication, you have this stuff that
kind of insulates the axon, so, this stuff that I've drawn here in red is called myelin. And it really just makes
the action potential move down the axon much more quickly. So we can actually kind of compare this two-way communication system,
right, with our mailman. So, you know we have kind of
the sender of the message, that would be the first neuron, we have the message, that would be kind of like the action potential, we have the road, which
would be, you know, the myelin and the axon together, and we have the recipient. Now, in our analogy, we had an earthquake that actually destroyed the road somehow. So, in Multiple Sclerosis,
what happens is, well, you get destruction of the
road, and more specifically, you get a degradation of the myelin. And so because there's
degradation of the myelin, we can call Multiple Sclerosis
a Demyelinating Disease. So this is really where that disruption in the communication goes on, right? And when the myelin is
degraded, the action potential won't really travel down
the axon as quickly anymore, and sometimes it may not even
travel down to begin with. So what's causing that degradation? Well as it turns out,
in Multiple Sclerosis, the immune system actually
sneaks its way into the brain, and when the immune system
sneaks its way into the brain, for some reason it mistakenly
recognizes that myelin, right, this myelin over here, as foreign. And when it mistakenly
recognizes it as foreign, it starts to attack the
myelin, hence this degradation. And because the immune system
is attacking the body itself, we call Multiple Sclerosis an
Autoimmune Disease as well. So that's kind of a cellular perspective on Multiple Sclerosis, but
now I kind of want to give you a more macroscopic perspective on what the disease does
to the brain, right? So let me clear up some space over here. And let me actually show you
now two different brains. So this is just really a brain scan, or two different brain scans of, well, two different brains. So on the left, we have a
perfectly healthy brain. And on the right, we
have the brain of someone who's suffering from Multiple Sclerosis. Immediately on the
right brain you can tell that you have these bright
spots over here, right, called Plaques. So Plaque is also really
referred to as a Lesion. And a Lesion is really
just a piece of tissue that's been damaged. So let's say, for example, you know, you have a hand over here, you know, maybe you get a
cut on your hand somehow. Right, you can call that cut
kind of a Lesion of the skin. In Multiple Sclerosis you have
a Lesion in the brain, right? And those Lesions are really
coming from the damaged myelin from the immune system. So what happens is, you
have all these immune cells that kind of come together,
right, they kind of cluster around certain parts of the brain, and they attack it. And when you have a whole
bunch of immune cells coming together to attack
a certain part of the body, we call this Inflammation,
and because it's happening in the brain, we call
it Neuroinflammation. Now, the condition in which
you have these Lesions, in the brain, is called Sclerosis. In the case of Multiple Sclerosis,
you have multiple Lesions hence why we call it Multiple Sclerosis. Now notice how you're
getting these Lesions in different parts of the brain, ok. Different parts of the brain
are gonna be responsible for different functions. Some may be responsible for Vision, others may be responsible for Cognition, for moving around, for
Movement, for Touch, and so on and so forth. And depending on where these
Lesions form in the brain, you can get a variety
of different symptoms that can affect all of these functions. Now, why do these Lesions form? Why does the immune
system attack the brain? The problem is that we
don't actually know. We're not really sure with 100% certainty what causes Multiple Sclerosis. All we know is that some people may have a kind of Genetic Predisposition towards developing the disease, and that there are also probably some Environmental Factors that
may be involved as well. And the fact of the matter
is that your genetics can really interact with the environment, and that can kinda stimulate
the progression of the disease. Now the exact types of
genes that are involved, and the exact types of
Environmental Factors that may be involved will
be a talk that I'll cover in a later video, but
for now this is really all that we know about the
causes of Multiple Sclerosis. Now even though we don't
really know perfectly what causes Multiple Sclerosis, we do know who is more likely to develop the disease. So I'm gonna actually clear
up some more space here again. And so now I'm gonna show
you a picture of the earth. And the reason is because I wanna give you a global perspective on,
you know, the prevalence, and the incidence of Multiple Sclerosis. So the disease affects about
2.5 million people worldwide. Now, is everyone on the
planet equally likely to develop the disease? Well, no. As it turns out, if you move
north from the equator, right, so if you move north from here, you'll notice that the incidence
of MS actually increases. And the incidence is actually
pretty high, you know, in these northern areas,
right, so here in Canada, and in the northern
United States, and here in a lot of Europe and Russia as well. So it often affects Caucasians
more than other races. And more specifically
among the Caucasians, it affects people of Northern
European Descent more often. The disease is also more common
in women than it is in men. Right, and it's thought that
of the 2.5 million people worldwide about two
thirds of them are women. So 66% of them are women. So what age do people start to develop MS? It's usually in the age
range of 20 to 50 years old. And it's usually on the
earlier end of that spectrum. And lastly, one thing that
I really want to emphasize is that the disease itself is NOT FATAL. So the disease itself won't
actually kill you, right, but the Life expectancy is a bit lower. And it's thought to be
lowered by about, you know, a few months to a few years. Now even though it's not
fatal, the disease itself is quite debilitating,
and it can really affect the person's lifestyle
through a number of different signs and symptoms, and that'll be a topic that I'll cover in the next video.