your nerves are literally everywhere
around here
we'll start from the most important ones
which are going through your spine and
your brain
this thick cluster of nerves is called
the central nervous system
or cns it's responsible for everything
you do
from breathing to tapping your finger on
the side of your smartphone while
waiting until i get to the topic already
when a signal gets to the cns in the
brain from any part of the body
it sends back a command to react
according to the situation
pinch yourself now yeah please do it
the place you've just pinched has a lot
of neurons just like anywhere else
when you press the skin they flared up
and sent the information about pain to
the brain
which reacted by sending back a message
that it hurt
it all happened in less than a
millisecond but the signal traveled
several feet there and back
let's go to the spinal cord now and
carry out a little experiment
on the count of one i'll sever the
connections between the neurons here
and you'll see what happens ready one
see you've just become limp from your
waist down and can't feel anything in
your legs
it's because your cns can't figure out
where they are
okay restoring the connections now don't
worry
this is why both your brain and spinal
cord are naturally protected by
bones the skull and the vertebrae inside
the spinal column
there's also cerebrospinal fluid a
liquid substance that protects the
nerves
helps better conduct signals and gets
rid of weights
okay now let's take a closer look at all
the rest of the nerves
starting with the ones at the tips of
your fingers
everything that's not the cns is called
peripheral nervous system
or pns will you kindly wave your hand
now
thanks you've been able to do that
because your brain
consciously sent several million signals
to the peripheral nerves in your
shoulder
forearm wrist and hand together they
made a common
effort to lift your arm fix it in a
certain position
and wave the hand from side to side and
responsible for this effort
is your voluntary or somatic nervous
system
your eyebrows going up at this fact are
also controlled by the same nerves
did you count how many breaths you took
while listening to my ramblings
a beat your heart had made you shouldn't
have these things are regulated by your
vegetative or
involuntary nervous system your cns
sends signals to the periphery
and tells your heart to beat your
respiratory system to let the air in and
out
and even your bowels to digest the food
you eat
now blow all the air out of your lungs
and hold your breath for as long as you
can
okay this will take some time so fast
forward to the point where you start
wanting to breathe in
letting the air out and holding your
breath are your conscious actions
so it's you who tells your brain to send
signals to the breathing organs
but when you start lacking oxygen it's
already your brain that tells you to
stop fooling around
oh i see you're becoming blue in the
face please inhale already
and now i'll do something you'll have to
forgive me for ow
sorry you dropped the phone because i
sent a little shock through it
the point is you subconsciously let your
phone go
as soon as you felt the pain when i
asked you to pinch yourself
you activated your voluntary nervous
system so
you expected the pain and could continue
pinching if you wanted to
this shock came unexpectedly though so
your involuntary nervous system jolted
in
and made you move away from the threat
asap
that said your self-preservation
instinct is something that's regulated
by your nerves as well
your body will try to save itself from
harm even without your consent
hey what's that itch ah you need to
scratch it now
thanks itching appears when there's
something on or
under your skin that doesn't belong
there like an insect
or a bite at left nerves at the site
flare up like beacons
and your brain sends signals to that
spot but when you scratch the itch
you feel two opposite things at once
consciously you experience relief
because it's not itching anymore
on the subconscious level though your
brain perceives scratching as
pain and shifts your attention from the
itch to the scratch instead
basically by scratching you trick your
brain into believing
there are more important things to do
than paying attention to the itch
hey is it me or is it a bit too hot here
yeah i see droplets of sweat on your
forehead
when the outside temperature rises your
cnn reacts to the change
billions of signals flashed through your
entire body
sweat glands receive them in the blink
of an eye and start working
furiously sweat appears on your skin
cooling it down
i recommend going to the ac and turning
it higher a bit thank you
hey i said a bit not all the way up ah
great now you're shivering your brain is
confused but is still working fast
reacting to the change of circumstances
once again
it sends billions of signals to all the
neurons in your muscles
telling them to start contracting as
quickly as they can
by doing so they create friction and
friction generates heat
your heart starts beating faster too by
the way pumping blood to your limbs to
keep them from freezing
all this also makes you think sliding
that counter up a notch is a good idea
on the topic of thinking neurons are
responsible for that too
for example this is your first time
watching this video you can't possibly
know what i'm going to do or say next
maybe i'll do a barrel roll or just
end the whole video abruptly your brain
is only now creating the neural
connections necessary for you to
remember
what's coming up next this is why you're
still bearing with me
you want to know but as soon as you've
watched it until the end
the interest is gone no matter how
fascinating i
am your cns has created enough
connections between the neurons
and if you start over they will tell you
what to expect
still the pathways are very basic a
simple example
what did i say exactly three minutes and
five seconds into the video
you can't remember because your neural
connections aren't strong enough yet to
give such details
but the more times you watch the
stronger and more numerous they become
and after a number of attempts you'll be
able to repeat the whole text word for
word the same happens when you learn
some new skill
like roller skating at first you can't
move
even a single foot your brain encounters
an unusual task
and is all ablaze with signals it's
sending every which way
you fall but then you stand up and try
once more
this time several million neurons are
already connected
and your cns doesn't waste time creating
new links
you fall again and again and again
but every time you rise and repeat your
brain gets more and more adapted
until finally on your 5th 10th or 50th
attempt
you skate forward the brain captures the
moment you stop falling
and create strong neural connections to
prevent you from
repeating your previous mistakes and
soon enough
with more practice and links in your cns
you'll be skating like a pro
wondering how you could be so clumsy
before
yet the best thing about these
connections is that they never
completely go away even if you learned
skating as a kid
and then didn't put on the skates for 10
years it'll take you just a couple of
minutes to
recall how it's done so hey if you're
afraid to take that dusty guitar hanging
on the wall for years
don't be go strum the strings it'll all
come back to you in a jiffy
yeah maybe not the calluses