[Music]
hi it's mr. Andersen and in this video
I'm going to talk about the brain
structure and function remember
structure is what it's made up of and
function is what does it do we sometimes
refer to this as the anatomy or
structure and the physiology or the
function and so the cool thing is that
we're going to go through 17 different
structures in the brain kind of lay out
the basic plan of the brain but you're
using your brain to process it and if
you do a good job when we get to the end
and I review all the parts you should be
able to tell me what their structure is
and what their function is and so what
type of organisms have brains it's the
animals animals use nerves they have
muscles to move around and so they have
to organize that movement and so they
use a brain and so if we look at the two
basic body plans of animals some are
radially symmetrical in other words
they're built around almost a tire and
then some are bilaterally symmetrical in
other words a tiger you could draw a
line right down the middle there's going
to be a clear right side and a left side
there's going to be a clear front and
end and as we became bilaterally
symmetrical we had to organize that
movement so this is a simple animal body
plan and so this animal is going to move
towards the right and as it does so it
has to take in information we call that
sensory information using neurons and so
right now you're taking in sensory
information from your eyes from your
ears and then inside your brain you're
going to integrate that information
you're going to make sense of it and
then you're going to figure out what you
want to do how you're gonna act
dependent upon that and so then we have
this loop of motor neurons out or motor
nerves and so this loop in simple
animals is also important in
understanding how our brain works but if
we look at these real primitive brain
they find that they have a real common
structure they have these four humps and
we call those the well the first one is
not a hump but the spinal cord we then
have the hind brain the midbrain and
then we finally have the forebrain and
we find this consistent throughout all
animals and if we look at something like
a shark it pretty much looks just like
that primitive brain you can see down
here we've got the spinal cord that's
bringing information in we then have the
hind brain the midbrain and the
forebrain and so one thing you should
remember is
the closer we are to that spinal cord
the more basic the functions are and so
we're right down in this hindbrain
it's going to be basically keeping the
heart beating keep the circulation going
digestion in the shark but when a shark
decides to attack you or it has some
kind of an emotional response that's
going to be way up here in the forebrain
now if we look at you when you were
really little when you were an embryo
you had a brain that looked very similar
you had a spinal cord you then had a
hind brain you had a midbrain and then
you had a forebrain but during
development that that brain changes
radically and so this is what an adult
brain looks like so we still Steve see
that spinal cord we then have the hind
brain we have the midbrain
but look how large that forebrain is
going to be and so that's where all of
those emotions and memories and all of
that thinking we generally attribute to
the brain is going to be in the
forebrain and so let's get to the actual
anatomy and so they're going to be 17
parts that we're gonna go through so you
should always be thinking what's the
name of the structure where is it and
then what's the function what does it do
so if we look at a basic brain plan we
find these four things jump out right
away we're gonna see the brainstem
we then see a cerebellum on the back of
the brain so again to get yourself
oriented right the eyes are gonna be
right up here and so this would be
towards the back of the head so that's
going to be the cerebellum we then have
the area of the thalamus hypothalamus
and then finally we have the cerebrum
which is going to be that dominant upper
portion of the brain and so let's begin
with the brainstem the brainstem is
broken down into three individual
structures so if we start at the bottom
we've got the medulla oblongata the pons
and then we finally have the midbrain
and so those three things medulla
oblongata pons and midbrain make up what
we call the brainstem so that's the
structure what's the function well it
really does two things the first thing
it's going to do are these more basic
needs it's going to keep your self
breathing keeps circulation going
digestion swallowing all of that is
going to be controlled by the brainstem
if there's any damage to the brainstem
it's going to be catastrophic
what else does it do then we have
information coming in so we have sensory
information just like that worm did
coming up to the brain and then we have
motor nerves
going out and so the brain stem is
important in routing that information
and filtering that information sending
it where it needs to go what's behind
that we have the cerebellum the
cerebellum and the function of that is
motor control so as you do sports for
example it's the cerebellum that's
giving you that coordination and it also
gives you motor memory so as you learn
to ride a bicycle and you remember how
to ride a bicycle that's going to be
thanks to your cerebellum if we keep
moving up we now have the thalamus the
thalamus again sits right on top of the
brainstem and so the best analogy I
could come up with is a router
it's basically sorting data and sending
it where it needs to go if we were to
look below that there's a little
structure here that's incredibly
important it's called the hypothalamus
that's going to be really right above
the roof of your mouth
what is that accountable for its
homeostasis oh it's maintaining body
temperature it's maintaining osmolarity
all of that stuff is contained right up
in the hypothalamus also important in
circadian rhythms and then if we look
right below that you can see a little
gland hanging out and one half of that
pituitary gland the posterior pituitary
is technically part of the brain and
it's important in basically sending off
hormones and so there are nerves that
flow into that pituitary and it's
sending out things like antidiuretic
hormone that keeps your water balance
the same oxytocin it be another
important hormone that comes out of
there if we keep moving up then we get
to the level of the cerebrum what's the
function of the cerebrum that's
integration so what we're doing is
making sense of all that data that comes
in now what makes up that cerebrum are
going to be all these neurons there's
tons of neurons that are connected
together billions of neurons and
billions and billions of synapses or
connections between these neurons and
that's where we're making sense of
information as it comes in now if you
were to look at this image right here so
of that brick wall so take a moment to
look at that and I'm going to show you
some other images now focus on this and
then that and then that and what we find
is as you look at those images your
brain is integrating it's making sense
of all that information and it used to
be a black box we didn't know really
what was going on but
now we can use technology like a
functional MRI functional magnetic
resonance imaging and what we're looking
at here is a brain in action so the same
study was done on females and what they
would show them is something neutral
like a brick wall and then a kitten and
then something like dirt and then
something like puppies and so what we're
seeing is as those images are switching
back and forth we can start to see where
blood is flowing around in the brain and
we can start to figure out what the
different parts of the brain actually do
we're able to figure out their function
so when we're looking at the cerebrum
every picture that I've showed you is
from the side so the eyes up here but if
we were to rotate that 90 degrees now
we're looking at it head-on
we'll find that there are two
hemispheres there's going to be a right
and a left hemisphere now they're
connected in the middle using something
called the corpus callosum so that's a
connection of nerves in between the two
hemispheres and we do tend to show
lateralization there are going to be
certain things that we put kind of on
the left side of our brain like
mathematical reasoning and logic and
things that we put on the right side
like facial recognition now this is
plastic in other words we can move these
functions back and forth and you can
even have a radical hemispherectomy were
you cutting one of these out and you
still have a functioning brain now if we
were to go right below the corpus
callosum we get into this area called
the basal ganglia and it's made up of a
bunch of nuclei what are nuclei or what
is a nucleus in a brain it's basically a
bunch of neurons that are right next to
each other that have the same function
and so all of these nuclei together make
up what's called the basal ganglia you
can see this would be the corpus
callosum connecting it together as well
so this is below the cerebral cortex
what's the function of that well
scientists have been able to figure out
this is this complex interaction of
inhibition and excitatory response
between these neurons and basically it
controls a lot of our motor control and
if you have somebody who's Parkinson's
disease then we're having problems in
this big basal ganglia area as we move
farther up the brain we eventually get
to the cerebral cortex and that's going
to make up about 80% of the brain so
it's most of the brain itself and it's
broken apart into these four lobes and
so if we start in the front of the brain
we have what
called the frontal lobe what's the
function of that it's mostly executive
function so it's kind of like the boss
of your brain
it's emotional control up there and if
we have people who have damage to that
frontal lobe they have really huge
emotional swings as we move back towards
the back of the brain we get to the
parietal lobe what's the function of
that it basically is sensation it's you
dealing with and reacting to your
environment so we have a lot of neurons
coming in here from a sensory input as
we move to the back we have the
occipital lobe the function of that is
vision primarily vision and then we
moved on to the side we have what are
called the temporal lobe temporal lobe
is going to be important in language
it's important in hearing it's also
important in memory we have a lot of
memories in there and so each of these
lobes have different functions that are
associated with it and hopefully those
little icons help you remember those
functions now if we to go inside the
parietal zone we'd find a really
important part here it's called the
somatosensory cortex and that's where
sensory information is coming into the
brain and then on the other side of the
lobe we have what's called the motor
cortex and so going way back to that
worm we have information coming in
sensory information and then we have
motor output coming out and so that's
going to be a point of integration where
we get information in decide what we
want to do with it and then send that
message back out now for you to look at
that somatosensory cortex and map it
along the cerebral cortex we would find
that we dedicate huge amounts of that
brain surface area to things like your
fingers your tongue your lips in other
words we have way more neurons and way
more sensory information and coming in
from your fingers as opposed to for
example your back we don't have as much
of it dedicated to that on the back side
we could also use functional MRIs and
then even an operation to figure out
where a lot of these things are located
like speech and smell and hearing but
over the future we're gonna get really
really good at figuring out specifically
what are all the different parts of the
brain what are the nuclei what do they
do
and even mapping it down to the level of
the neuron so how did you do do you
remember those 17 different structures
and their functions well it's time to
review so let's go through it what's
this one at the bottom over
we call that the brainstem hopefully you
got that um what are the three parts of
the brainstem though do you remember
that could you pause the video and then
say what they are while starting from
the bottom remember we have the medulla
oblongata we then have the pons and then
we have the midbrain so that's going to
be the structure and where it's found
can you remember the two functions of
the brainstem two big things were number
one is to maintain breathing heart rate
digestion swallowing so these
fundamental properties of life but
what's the second one remember it's to
sort information going up and down
what's behind that what's that structure
called that is the cerebellum and so
what's the cerebellum do remember that's
coordination motor control and also
motor memory do you remember what sits
right up above the brainstem that is the
thalamus
what's the thalamus do remember it's
sorts information as it moves up to the
upper parts of the cerebrum what's below
that that is the hypothalamus underneath
that what's that do remember that's
homeostasis it's maintaining that
internal body state
do you remember what hangs off the
bottom of that that is the posterior
pituitary hopefully you're doing well so
far if we keep going then what is this
upper portion of the brain called we
call that the cerebrum okay let's keep
going into the cerebrum then so do you
remember what's that connection between
the two hemispheres of the brain we call
that the corpus callosum and do you
remember what we call those little
nuclei that are found below that
cerebrum those are called the basal
ganglia and they're really important in
motor control and remember the corpus
callosum allows our hemispheres to
connect if we were to go up to the upper
portion what do we call this you know
highly folded upper portion of the
cerebrum that's called the cerebral
cortex do you remember what the front
lobe is called that was pretty easy
that's called the frontal lobe what
about the yellow lobe right here that's
called the parietal lobe do you remember
what they do frontal lobe remember is
executive or boss like functions and
then parietal is going to be sensation
of the environment what about at the end
do you remember that that's called the
occipital and then what about at the
bottom that's the temporal occipital
remember is the location where
we have vision and then temper roll is
going to be more language hearing
memories are there now there are two
other parts in our lobe so what do we
call this area right here and then this
area right here those are called the
somatosensory cortex remember that takes
in information make sense of it and then
we have the motor cortex which is
sending information out so those are
those 17 structures if you don't
remember them you may want to watch the
video again maybe make some flashcards
but that's the brain and I hope that was
helpful
[Music]