Nerves are bundles.
A neuron is not a nerve.
I like that, you get on my last good
bundle of axons not my last good nerve,
right, because a nerve is a bunch of axons bundled together
channeled in directions. Now neurons go all over the place. Interneurons have
connections
in multiple locations and dendrites can branch out or be pared down,
and axons can branch out or be pared down. You don't get
a new cell if you kill off a brain cell
but an adjacent cell can modify itself
to compensate for a lost cell by growing its axon into a region previously occupied
by the now dead brain cell,
and could do the same thing with the dendrites, right?
Use of your brain causes physical action
at the neuronal level, which means that you're firing neurotransmitters when
you're reading,
when you're talking, when you're sleeping, and breathing, right,
and the more you fire certain patterns as we'll see in the memory chapter
the more... the easier it is to fire them, therefore the
more easy it is to remember things that you've done. You're
actually physically altering your brain structure when you learn
and that is pretty profound if you think about it, right,
because if you lose brain structure you lose functionality.
So neurons then bundle together
into different pathways to create nervous system.
Afferent you now know is in. Efferent you now know is out,
and then we have networks of neurons, all kinds of intercommunication happening
between them all, with glial cells sales to support them. So you've got to break it down
into the CNS,
central nervous system, brain and spinal cord, know this for your test.
And we're going to talk about the CNS
and we're going to talk about the PNS. Now, PNS
can be a good way to remember that. Just think about your PNS.
Some people get it and some don't, right? The brains are firing in different ways.
I'm just saying. CNS is a lot easier to write than central nervous system
and PNS is something guys think about a lot,
girls sometimes think about that's easy mnemonic. When you're trying to think of
things and remember them
creative and sometimes outlandish thoughts
help you remember. That's what a mnemonic is. It helped you to remember
something P-
N-S is peripheral nervous system. Peripheral nervous system
is different from the central nervous system. You can look at a metaphorical
analog if you will of brain to computer,
right? Well your central nervous system is your motherboard,
right? That's the main
functioning unit of a computer and then you have other things that allow it to be seen
like a monitor
and actions that you can do like with the mouse
those those are called what? Peripheral devices.
So there's another nice way to remember it if you don't want to get nasty.
Just remember it in terms of computers, right?
You've got a central processing unit, a CPU, a central nervous system
and then you've got things that work around it which are
your peripheral devices. So we're going to look at that because
they operate in different ways. So the CNS
is the main processing unit but you've got to connect it to the rest of the body.
That's what the peripheral nervous system does; it connects your brain to the rest
of your body
and the rest of your body to your brain. So if I feel a touch
on my hand, it's because an afferent neuron picked up that perception of
pressure
and relayed it into my spinal cord and up into my brain to be read as touch.,
to be represented or modeled in my brain as a pressure point
on my skin. So that had to be taken in to the central processing unit
so to speak and it was done so by an afferent peripheral nerve.
Now we're going to break it down some more and this is where it gets a little tricky
but if you follow with me I'll give you some ways to remember these breakdowns
because they're important
to your survival they're important, to how people acquire phobias they're
important,
to how people acquire all kinds of issues
that they get conditioned to, this is important. It's the basic level.
Somatic nervous system are the nerves that communicate with voluntary muscles.
Now sometimes you have overlap. I blink
my eyes involuntarily all day long when I'm awake
but I can override that manually and do it
on purpose or prevent it from happening for a while
on purpose, but I can't keep them open forever before what?
They'll automatically override and do it anyway.
So, when I'm looking at somatic, I'm talking about something I can do
voluntarily,
something I can change like moving my muscles around.
So here we have these again, so it should be a
reiteration for you. It's not the first time you've seen these terms.
Afferent goes in. So I gave you the mnemonic before.
A comes first, going in as primary
just order it that way. It'll be easy to remember. Those are your sensory neurons. That's
what's bringing
energy from the outside to the inside.
The inside is only making models of the outside. It's not experiencing it directly,
right? I have to hear... sound waves have to vibrate
my eardrums which are then going to move the ossicles, the little bones
which is going to move the inner ear fluids which is going to wave
those little hairs, right, and those little hair cells are going to trigger
firing neurons
on the basilar membrane. The further up you go the higher the pitch, the lower you
go,
the lower the pitch. That firing of neurons is then going to go into my
temporal lobe and be quote read as sounds,
and then it's going to go through my inner neurons to be recognized as speech
or as musical tones or as noise from a jackhammer
or whatever I determine how I would label that noise.
But it's all being read here and if you cut that basilar membrane
then I don't hear anything even though the physical energy still exists; sounds waves
still exist.
My ability to read them now doesn't exist. So that's
what we're talking about. So efferent, if I want to move around and do things
I've go to send signals from the central processing unit back out to the
peripheral,
right? Now
autonomic nervous system!
Keep in mind I thank you all for coming today. I appreciate your attendance very
much.
All the stuff you want to know for your test
is indented. The reason the Central nervous system is sitting over there by itself is because we're going to cover it Saturday by itself as the wheel cover
separately,
right? We're going to reiterate it. Autonomic nervous system,
ANS, that could be remembered
colorfully too, if you thought about it or don't think about it, whatever you want to do.
I'm just trying to help you remember things. Nerves communicating with involuntary
muscles
and taking care of involuntary body functions. I don't have to think to blink.
Blinking happens, most of the time it's autonomic,
right? I don't have to think heartbeat heartbeat heartbeat heartbeat;
that happens automatically. I don't have to think about. It's autonomic. You could also
think of it as
automatic. That's another way of thinking about it.
It operates automatically so that you don't have to think about it. Can you
imagine
having to mentally make your heart beat every time it needed to beat?
You'd never do anything, right? So it happens automatically without your conscious
awareness;
turns out you could affect your own heart rate, right? You can learn deep
breathing techniques
and by controlling the rate of breathing which is normally autonomic
but I could take over with manual control, I can relax
and bring my heart rate down and my blood pressure down, and if anybody who knows
anybody with high blood pressure
or who is at stroke risk, that would be a good technique to teach them
and I'll teach you that technique on Wednesday night.
So we got this other thing to break it down again.
Gosh! Not another! Yes, one more.
One more break down. We've got a sympathetic division,
it's the fight or flight, the fight or flight is really an adrenaline rush.
You don't have to think to respond to a threat.
You respond almost automatically to a threat.
You ever been driving along and you saw the blue lights come on and all of a sudden you did
that and you got little butterflies in your stomach.
The butterflies in your stomach are the result of
adrenaline released and it happened instantaneously. You didn't go...
oh, blue light, get nervous, slow down.
The slow down part where you body moved
is going to be interesting because we're going to talk about that in operant conditioning.
The release of the adrenaline was classical conditioning,
because you didn't originally do that when you was a baby. When you saw blue lights you didn't
panic.
You learn to do that as an adult but once you learn to do it, the adrenaline
release is automatic so
you don't have to sit around and think about a threat. In fact, it could kill you
somebody just recently wrote - it wasn't recently but it came to my attention recently -
looking at just behavior in the wild. If you're a monkey walking down a path, you're
jogging along and all of a sudden you come around and there's another animal in front of you,
you've got a split second to make some very quick categorization.
Is it monkey or is it non-monkey?
If it's non-monkey, is it pro-monkey or anti monkey?
If it's monkey, is it female or male?
If its female and you're a male, is the female interested?
If it's male, is it higher or lower in the status in the
group, right? You've got like a half a second to make these decisions or you
might get attacked.
So it's the autonomic nervous system's sympathetic division that
is sympathetic to your situation.
It's trying to get you out of there. Fight or flight; what does that mean?
It means you either fight as hard as you can fight or you run as fast as you can
run
and which one is preferred in the wild? Flight!
You get in a fight, you get hurt, they don't have animal hospitals out in the wild, right?
You go, oh man, I was in a big old fight. I better go to the hospital. You might just
sulk off and be prey to some other animal that sees you as weak.
Flight is preferred. Fight is what you do when you have no choice
or when you are engaging in what? Mating rituals, and usually those aren't done
fatally.
They're done to establish hierarchies. Human beings experience the same thing.
If somebody puts a gun to your head you don't go - well gosh what do I do -
you immediately assess your options and if running is one of them, that's preferred,
right? If you can get away - if not you stand there with your deer in the headlight
look going oh God, what do I do, what do I do, what do I do?
But you are jacked. And when I say jacked I mean you are flooded with adrenalin. You hear about
these super people who do these super things
and they can pull a car off of a kid who is trapped underneath it and you go that's super human, you go no
it's super that we're human because that's adrenalin
and if you don't believe that, you ever watch cops?
You ever watch the guy on PCP which is on like every five or ten episodes, right?
He's naked and he's running around like a maniac and it takes like ten of them to pull
him down
cause he's jacked up with adrenalin and he's naked, he's hard to get a hold of, right,
so
he's sweaty and you're trying to get a hold of him but he is full on
juiced, right, because it brings you what?
Power, to fight as hard as you can, if you have to,
or to run as fast as you can, if you have to, but sometimes as human beings we
experience it when don't want it and
don't really need it. Anybody ever felt that kind of juiced
feeling when they got up to speak in front of a public audience
and your stomach starts quivering, the butterflies, maybe the hands start shaking
a little bit, they start getting clammy,
right? That's adrenaline. You ever get on a a roller coaster and you get off and your
stomach's got butterflies and you're like, wow! That's adrenaline!
It's the exact same process, physiologically being excited
and being panicked is adrenalin release
and if you know that and you have panic issues
that's helpful because most people don't know that. They think they're going crazy
or having a heart attack
and they go to the emergency room. The emergency room does the stress test and goes
yeah you don't have a heart attack going on here.
You've got a panic attack and they're like, I'm not crazy. Of course you're not, you're human.
What you've got is an errant shot of adrenaline
that's freaking you out because it doesn't seem to be tied to an obvious
threat. Well you can't stay jacked up constantly unless you're on PCP,
right, and that's going to wear off sooner or later. You're going to calm back down when
the threat is gone,
right? If somebody goes oh no it's just a squirt gun I was just kidding hahaha
and you go that ain't funny. You'll calm down really quickly right? If the threat is gone,
you can't operate at high levels of stress so the parasympathetic,
I say well the sympathetic is sympathetic to your problem and is going to give you what you
need to get out the problem. The parasympathetic - what's para mean?
Kind of - right? Kind of sympathetic say alright calm down calm down
you're alright. That's what a parachute is, right?
You kind of slow down before you hit the ground. It's para.
So you could think about that as a mnemonic. The sympathetic jacks you up
and gets you ready because it's sympathetic to your situation,
the parasympathetic calms you down and is in charge most of the time.
It's in charge most of the time because it's going to be the
automatic system that's usually operating, that keeps you breathing,
that keeps you metabolizing, that keep your heart beating, that keeps your eyes blinking;
it's doing what it does unless something overrides it with the sympathetic
division.
Make sense?
You all might have known this. Let me give you all a technical diagram.
I hate to be that complicated about it.
The PNS
peripheral nervous system basically breaks down into two
divisions. Somatic is your body, it's voluntary, it's what you choose to do with
your body.
By moving through the space that I am walking through
I'm using my somatic nervous system to walk through the space. I'm voluntarily
engaging in walking behavior and talking behavior and moving my head around and
looking around behavior.
That's all somatic system, it's voluntary. Over here,
I got my automatic system or my autonomic system, so my heart is still going to beat no
matter what I'm doing. I'm still going to breathe no matter what I'm doing. My eyes are still
going to blink,
my food is still going to get digested, peristalsis will occur,
that's where the intestine squeezes the poo,
right? You all know that anatomy and physiology.
OK, that's peristalsis. Talk about mastication later, you talk a bunch of masticators.
Everybody's a masticator. Autonomic division
is going to break that again. See people who took anatomy and physiology knows that ain't dirty.
It just means chewing. Parasympathetic is what's happening all the time.
It's kind of sympathetic. It wants to keep your body going so it just does.
It gets you going all day every day unless
you meet with a threat and a threat for monkey
is what? Whether or not you're going to be attacked but a threat for a human could be
being possibly in a car crash, well that's a physical threat
but being evaluated negatively by somebody if you were up in front of an audience,
right,
being rejected by somebody you care about. So you go into a job interview and you start
getting nervous. When you're getting nervous what is getting nervous?
Getting nervous is nothing more then your brain
is perceiving some type of threat and is trying to prepare you to fight or flight,
to stay or to go.
Go as fast as you can. A lot of times human beings are faced with situations
that are not overt
real physical threats but they respond to them as though they are
and that becomes problematic. About one in three people in their lifetime will have a
full-on panic attack.
Doesn't mean they go on to be diagnosed with anxiety disorder but that's a lot
of people
and there's nothing wrong with them. What's happening is that they have a
shot of adrenaline when they didn't expect it
so there doesn't seem to be a threat present but they're getting a threat
response
and then you look around to interpret it and without some kind of credible
threat external you interpret it internal. I'm having a heart attack. I'm dying. I'm
going crazy.
Why do I feel like I'm dying? Because that's exactly how you feel
when you're dying. You get jacked with adrenalin.