Nervous System [7]: Brain and Neurone Pathways (A Level Biology)


Uploaded by freeeschool on 02.09.2012

Transcript:
A Level Biology_Nervous System 7 – Brain and Neurone
Hi, and welcome to my seventh video in this series to do with the nervous system and this
one is looking at the brain. This diagram shows an image of some neurons within the
brain. The green ones show the ones that are firing and the red one show the ones which
are not. What happens whenever you learned a new task
where you do something new? For instance, it’s the first time that you begin writing,
what happens is the neurones that control that movement fire and connect with one another,
and that can be shown in this diagram here. The ones in green show the neurones, let’s
say, for instance, you’re writing, are firing. Now, the first time that you do something,
what essentially happens is those neurones connect for the first time. Then, slowly but
surely as as you practice more and as you get better at writing, that neurone pathway
gets stronger and stronger and stronger, and hence, why you get better at things like writing.
Now, this is true for any new skill that you learn. So, it could be juggling, it could
be kicking a bowl, it could be learning to do mental arithmetic, the neurones in the
brain that control those different actions will connect up, and the more that you practice
something, the stronger those connections will be. So, for instance, if you were a novice
to golf, the first time that you swing a golf club, the neurones that control the muscles
in your arm that can swing the golf club, they will make a connection. But if we were
to compare that to someone who’s a professional, then the neuron pathway that controls their
muscles is very, very strong. Essentially, the more you practice, the stronger the neuron
pathway gets. The converse is true; the less that you practice,
the more that this neuron pathway actually breaks down and becomes less strong and, hence,
where you can’t form the action is whereas you could have done if you did practice more
often. This works in two respects. The more that you practice, the stronger it gets; the
less you practice, the weaker it gets. Within the different parts of the brain, you
have several different sections and they control several different things. Essentially, you
can look at the brain or if you look to our brain compared with other organisms, then
our brain, if you compare it to our body size, is very, very large and it has a really big
surface area. Generally speaking, you can think of all of
the essential things, controlling things like heart rate, controlling things like breathing
being near at center of the brain are more complex things. So, dealing with things like
logic or thinking or learning new skills is towards the outside of the brain. That’s
why the brain actually has these pits and folds in it. What those increases the surface
area. If you look to other brains in comparison, we have a huge surface area on the surface
of our brain and, hence, we have loads of areas of these neurones to connect up.
One of things about the human brain is it has billions and billions of these neurones
and they can connect up in a variety of ways. Because we’ve got so many neurons, it means
that there are so many different connections that you can make and it would appear that
the volume of things that we can actually learn is almost limitless because these neurons
can connect up in different ways which means we’re hugely adaptable on what we can learn
a huge amount. There are some interesting areas of study
looking at brain development, particularly in adolescence and young children, these beliefs
that if certain neuron pathways are not developed by a certain age, then those neuron pathways
can’t then be developed in adulthood or adolescence. A good example of this is the
feral children, children that have grown up in the wild without human contact. It’s
been shown that these children are being found that they cannot develop language or certain
speech patterns. This is down to the fact that these pathways haven’t developed in
early life and hence, they can’t develop them in later life.
Any time that you learn anything new, you’ll have a new pathway being laid down. So, a
new skill that you’ve never done before, this is a sporting like a new sport you’ve
tried, tennis or snooker or billiards or something to that effect, then what will happen is the
muscles or the neurones that control those muscles will fire and form new pathways.
In summary, whenever you learn a new skill, then a new neurone pathway will be formed.
For instance, if it’s the first time you play golf or swung a golf club, the neurone
pathway or the neurones that control that muscular movement will connect up. Like any
skill, the more that you practice, the stronger this neurone pathway will get and also the
less you practice, the weaker it will get. Because the brain has so many neurones in
it, it means that you can make a near infinite number of different types of connections and
so you can learn a multitude of different skills. It has been established over that
if you haven’t learned certain or haven’t made certain neurone pathways by a certain
age, then it won’t be developed in later life. An example of this is with speech in
feral children.