00:00:00
good morning afternoon evening night
00:00:01
whenever you're watching this welcome
00:00:03
back to the mr sim channel today we're
00:00:04
going to be talking about unit 2 topic 6
00:00:06
of ap psychology the brain by the end of
00:00:09
this video you'll be able to identify
00:00:10
different key locations of brain
00:00:12
structures you'll understand their
00:00:14
functions and you'll have an
00:00:15
understanding of different contributions
00:00:17
made to our understanding of the brain
00:00:18
and if all of that sounds good to you
00:00:20
well smash that subscribe button hit
00:00:22
that like button and let's get learning
00:00:23
so it is no secret that the brain is one
00:00:25
of the most important organs in your
00:00:28
body it has over 86 billion neurons over
00:00:30
100 000 miles of axons and over 10
00:00:33
trillion synapses and consumes 20 of
00:00:35
your body's oxygen those are some pretty
00:00:37
impressive statistics if i do say so
00:00:39
myself now brain research dates all the
00:00:41
way back to the first century bc where
00:00:43
hippocrates started speculating that a
00:00:45
person's brain was split into two halves
00:00:48
and each half was capable of independent
00:00:50
processing now over time there have been
00:00:51
many people have made significant
00:00:52
contributions to our understanding of
00:00:54
the brain but for time's sake i'm only
00:00:56
going to talk about two of them carl
00:00:57
wernicke and paul broca both looked at
00:01:00
our brains and language paul broca first
00:01:02
identified a region in the left cerebral
00:01:05
hemisphere of the frontal lobe which
00:01:06
became known as broca's area this area
00:01:09
of the brain is in charge of facial
00:01:10
muscles that are needed for us to
00:01:12
physically speak broke a base's
00:01:13
hypothesis off of case studies of
00:01:15
patients who had damaged an area in
00:01:17
their brain which resulted in the
00:01:19
individual losing the ability to speak
00:01:21
this became known as broca's aphasia
00:01:22
which is the loss and ability to produce
00:01:24
language while the individual may lose
00:01:26
their speech they still are able to
00:01:28
comprehend the language carl wernicke
00:01:30
discovered the area in the cerebrum
00:01:32
which is responsible for language
00:01:34
vernicki created a model that looked at
00:01:36
language he believed that the part of
00:01:38
the brain known as wernicke's area
00:01:40
located in the left temporal lobe
00:01:42
creates meaningful speech while broca's
00:01:45
area located in the left frontal lobe
00:01:47
determines movement needed for
00:01:48
vocalization and sends that information
00:01:50
to the motor quartet if wernicke's area
00:01:52
was ever damaged it would result in the
00:01:55
person losing meaningful speech a person
00:01:57
would still be able to say words and
00:01:59
sounds but they would have no real
00:02:01
meaning and they also would no longer be
00:02:03
able to comprehend sounds or speech this
00:02:05
disorder became known as wernicke's
00:02:07
aphasia so the brain is part of the
00:02:08
central nervous system and as we can see
00:02:11
from research done by broca and wernicke
00:02:13
each part of our brain is in charge of
00:02:15
specific tasks the brain can be broken
00:02:17
up into three major regions the first
00:02:19
region is the hindbrain located at the
00:02:21
bottom of the brain moving up from the
00:02:23
base of our brain we have the smaller
00:02:25
midbrain this part of the brain is
00:02:27
difficult to see because it's surrounded
00:02:29
by the last region of our brain which is
00:02:31
the forebrain the forebrain is what most
00:02:33
people typically visualize when thinking
00:02:35
about the brain starting out the heim
00:02:37
brain is made up of the pons the medulla
00:02:39
oblongata and the cerebellum these parts
00:02:41
of the brain allow us to survive by
00:02:43
controlling our basic biological
00:02:45
structure the medulla takes care of
00:02:46
important autonomic functions these
00:02:48
happen without us consciously thinking
00:02:50
about them it's located right above the
00:02:53
spinal cord and below the pond this part
00:02:55
of the brain is going to regulate your
00:02:57
cardiovascular and respiratory system on
00:02:59
top of the medulla is the pons the pons
00:03:01
is primarily a bridge between the
00:03:03
different areas of the nervous system it
00:03:05
connects the medulla with the cerebellum
00:03:07
and it works with the cerebellum to
00:03:09
coordinate movement the main functions
00:03:11
of the pons that we're going to focus on
00:03:12
this video is with sleep and dreams a
00:03:14
tip for remembering the pons is to think
00:03:16
of the pons as a pillow p for pillow and
00:03:18
it's located on top of the bed b for
00:03:20
brain stem next we have the cerebellum
00:03:22
which is located at the base of the
00:03:24
brain in the back the main function of
00:03:25
the cerebellum is that it allows you to
00:03:27
maintain balance and manage your
00:03:29
coordination so you're able to walk
00:03:31
straight in a line without tripping over
00:03:33
your feet and you're able to scoop
00:03:35
cereal into your mouth with a spoon
00:03:36
instead of tossing it on your head it
00:03:38
also plays a role with things that
00:03:39
require practicing to improve such as
00:03:42
playing an instrument or learning to
00:03:43
ride a bike it helps your body remember
00:03:45
how to perform those actions the
00:03:47
cerebellum in latin is called the little
00:03:49
brain since it's two wrinkled halves
00:03:51
that look like a brain attached to the
00:03:53
brainstem if this area becomes damaged
00:03:55
the cerebellum would make a person's
00:03:57
movements very unbalanced and clumsy
00:03:59
very much like a drunk person who can't
00:04:01
walk a straight line and since i've
00:04:02
mentioned the term brain sim let's quick
00:04:04
go into a couple specifics about the
00:04:05
brain stem it's located at the base of
00:04:07
the brain on top of the spinal cord it
00:04:09
includes the medulla the pons and the
00:04:11
midbrain if the brain stem is ever
00:04:13
severely damaged the result is death
00:04:15
because the functions of the brain stem
00:04:17
is the autonomic function we also need
00:04:19
to quickly talk about the spinal cord
00:04:21
remember that the spinal cord is what
00:04:22
connects your brain to the rest of your
00:04:24
body it starts at the base of your brain
00:04:27
and runs down the spine think about it
00:04:28
like the information highway the spinal
00:04:30
cord allows your nerves to send
00:04:32
information from your brain to the rest
00:04:34
of your body and vice versa all right so
00:04:36
we talked about the hindbrain now it's
00:04:37
on to the next region which is the
00:04:38
midbrain this is on top of the brainstem
00:04:40
and just right above the hindbrain this
00:04:42
part of the brain is very difficult to
00:04:44
observe since it's buried under the
00:04:46
other parts of the brain and is very
00:04:47
small in humans it's actually the start
00:04:49
of your brainstem when thinking about
00:04:51
the midbrain think about a relay station
00:04:53
visual and auditory information is sent
00:04:55
here and then sent to the appropriate
00:04:56
structures of the brain the two
00:04:57
important structures of the midbrain are
00:04:59
the reticular formation and the
00:05:01
reticular activating system the
00:05:03
reticular formation is a structure that
00:05:05
tunnels down the brainstem its main
00:05:07
function is arousal in the awake and
00:05:09
sleep cycle and if you damage this area
00:05:11
you'll go into a coma so don't damage it
00:05:13
this structure contains lots of neurons
00:05:14
from different parts of the brain stem
00:05:16
and coordinates reflexive and autonomic
00:05:18
vital functions such as respiratory
00:05:20
control as well as pain modulation the
00:05:22
reticular activating system encompasses
00:05:24
the reticular formation but it's also a
00:05:27
network of nerves that run through the
00:05:28
brain stem and out to the thalamus its
00:05:31
function is to stimulate higher centers
00:05:33
when something important happens that
00:05:35
needs immediate attention for example
00:05:37
when someone says your name it is
00:05:38
screening and filtering the incoming
00:05:40
stimuli and sending that information to
00:05:42
the thalamus now so far we've spent some
00:05:44
time talking about the midbrain and also
00:05:46
the hindbrain which are responsible for
00:05:49
our involuntary function now we're going
00:05:51
to go into the forebrain which is in
00:05:52
charge of our voluntary function the
00:05:54
forebrain is the largest part of the
00:05:56
brain it allows us to have complex
00:05:58
thoughts and also behaviors the
00:06:00
forebrain it consists of all parts of
00:06:02
the brain except for the brainstem and
00:06:04
cerebellum the term forebrain is a way
00:06:06
to describe the region cerebrum is the
00:06:08
name of the brain parts that are not the
00:06:10
brain stem and the cerebellum which
00:06:12
equal roughly about 85 percent of the
00:06:14
brain the function of the cerebrum is
00:06:15
all brain processes that aren't just for
00:06:17
survival like complex sauce moving
00:06:19
deeper into the cerebrum we have the
00:06:22
cerebral cortex which is a thin outer
00:06:24
layer of billions of nerve cells that
00:06:26
cover the whole brain these neurons are
00:06:28
called gray matter all higher cognitive
00:06:30
functioning happens here inside of the
00:06:32
cerebral cortex is the corpus callosum
00:06:34
this structure is shaped like an arch
00:06:36
that stretches from the front to the
00:06:38
back of the brain it's made up of
00:06:39
different nerve fibers that connect the
00:06:41
two cerebral hemispheres this allows
00:06:43
your hemispheres to talk and communicate
00:06:45
with one another one trick to
00:06:46
remembering this is to think about the
00:06:48
corpus call oh some as calling the other
00:06:50
hemisphere to communicate the cerebral
00:06:53
cortex can be broken down into two
00:06:54
different hemispheres a right and a left
00:06:57
and this is where we get into our four
00:06:58
different lobes the first level we'll
00:06:59
talk about is the frontal lobe as the
00:07:01
name suggests this lobe is located in
00:07:03
the front of your brain it's actually
00:07:04
right behind your forehead its function
00:07:06
is higher level thinking and we can see
00:07:09
there's two important areas of this low
00:07:11
the first is the prefrontal cortex which
00:07:13
allows you to have foresight judgment
00:07:15
speech and complex thought this lobe
00:07:17
will continue to grow and develop into
00:07:19
your 20s this is also where your broca's
00:07:22
area is located remember we talked about
00:07:24
this area at the start of the video the
00:07:25
second is the motor cortex which allows
00:07:27
you to have voluntary movement and is
00:07:29
located in the back of the frontal lobe
00:07:31
and runs from ear to ear it's kind of
00:07:33
like an arch the left motor cortex
00:07:35
controls movement on the right side of
00:07:36
your body and the right motor cortex
00:07:38
controls movement on the left side of
00:07:39
your body the motor cortex is
00:07:41
represented by a figure called the motor
00:07:42
homunculus this shows us a visual
00:07:44
representation of the amount of brain
00:07:46
area that's dedicated towards a specific
00:07:49
body part what we understand from this
00:07:50
visual representation is that more brain
00:07:53
tissue is devoted to the body parts that
00:07:55
are the most controlled by us like our
00:07:57
hands and our mouth the next lobe is the
00:07:58
parietal lobe which sits on the top of
00:08:00
your head right behind the frontal lobe
00:08:02
it's separated by the central sulcus the
00:08:04
main function of this lobe is to receive
00:08:07
sensory information it lets you
00:08:08
understand different senses such as
00:08:10
touch pain temperature and spatial
00:08:13
orientation all right so remember how we
00:08:14
talked about the motor cortex and how it
00:08:16
sits like a headband from ear to ear as
00:08:18
part of that frontal lobe well the
00:08:20
somatosensory cortex is parallel and
00:08:22
touching the motor cortex it's located
00:08:24
in the front area of the parietal lobe
00:08:25
and is in the front of the parietal
00:08:26
lobes in between the parietal lobe and
00:08:29
also the motor cortex the somatosensory
00:08:31
cortex is part of the parietal lobe
00:08:33
which allows you to register touch and
00:08:35
movement sensation this is what is in
00:08:37
charge of your skin the left sensory
00:08:39
cortex control sensations for the right
00:08:41
side of your body and the right sensory
00:08:43
cortex control sensations for the left
00:08:45
side of your body and of course just
00:08:46
like we talked about with the motor
00:08:48
homunculus there is also a sensory
00:08:50
homunculus this is a visual
00:08:51
representation of the amount of brain
00:08:53
area that's dedicated towards a specific
00:08:55
body part in relation to how sensitive
00:08:58
it is to stimulate what we understand
00:08:59
from this visual representation is that
00:09:01
there's more brain tissue devoted to the
00:09:03
body parts that are the most sensitive
00:09:05
like our hands and tongue you'll notice
00:09:07
there is a difference between the motor
00:09:09
and sensory homunculus behind the
00:09:10
parietal lobe is the occipital lobe this
00:09:12
is the lobe that makes it possible for
00:09:14
you to see this is located in the back
00:09:16
of your head here you also have your
00:09:18
visual cortex now if you're struggling
00:09:20
to remember where this is located just
00:09:22
try to remember the saying they've got
00:09:23
eyes in the back of their head now the
00:09:25
visual cortex is located in the bottom
00:09:27
of the occipital lobe and your eyes do
00:09:29
kind of an interesting thing when they
00:09:30
process information the left side of
00:09:32
your visual cortex is actually
00:09:33
interpreting the information that comes
00:09:35
in from the left side of each eye which
00:09:37
is reading the right field of vision
00:09:39
while the right side of your visual
00:09:40
cortex is interpreting the information
00:09:42
that comes in from the right side of
00:09:44
each eye which is interpreting the left
00:09:46
field of vision now up next is the
00:09:48
temporal lobe which is located right
00:09:49
above your ears on both sides this lobe
00:09:52
helps you recognize faces smell hear
00:09:54
noises balance and assist with memory
00:09:56
this lobe consists of a few different
00:09:57
parts first remember wernicke's area
00:09:59
it's responsible for language and also
00:10:01
comprehension it's located in the
00:10:03
temporal lobe we talked about it at the
00:10:05
start of this video located near
00:10:07
wernicke's area is the angular gyrus
00:10:09
which allows you to read words on paper
00:10:11
and also transfer that information as an
00:10:14
auditory form this is what allows you to
00:10:16
process what you read also located in
00:10:17
the temporal lobe is the auditory cortex
00:10:20
which is located in the upper areas of
00:10:22
the temporal lobe this cortex is what
00:10:24
processes your hearing and is actually
00:10:26
hearing what is happening from the
00:10:28
opposite ear one last thing i wanted to
00:10:30
highlight about the lobes is that they
00:10:31
all have association areas these are
00:10:33
regions of the cortex which connect the
00:10:35
sensory and also motor area it allows us
00:10:37
to have higher level thinking process
00:10:39
our external information and lets the
00:10:41
cerebral cortex communicate with
00:10:43
different parts of the cortex
00:10:44
association areas make up about 75 of
00:10:47
the cerebral cortex all right the next
00:10:48
structure we're going to talk about is
00:10:50
the thalamus it takes all the different
00:10:52
sensory information that you get every
00:10:53
single second and sends that information
00:10:55
to the forebrain to be interpreted so
00:10:57
right now when you're watching this
00:10:58
video the sound and the visuals are
00:11:01
being picked up by your eyes and your
00:11:02
ears and the thalamus is sending the
00:11:05
sound information to the temporal lobes
00:11:06
and the visual information to your
00:11:08
occipital lobes allowing you to
00:11:10
understand the information in this video
00:11:12
the thalamus is a two-symmetrical
00:11:14
egg-like structure at the top of the
00:11:16
brainstem next up is the limbic system
00:11:18
which is a ring-shaped group of
00:11:19
structures between the brain stem and
00:11:21
the cerebral cortex the function of the
00:11:23
limbic system is emotions learning
00:11:25
memory and some basic drive first up is
00:11:28
the hippocampus this structure is
00:11:29
surrounding the thalamus and it's inside
00:11:32
the temporal lobe this area allows you
00:11:33
to create memories this is how you learn
00:11:35
new information and form memory remember
00:11:38
this is where memories are created but
00:11:40
not stored that's going to be important
00:11:42
to distinguish next is your amygdala
00:11:44
this structure is located at the end of
00:11:46
each arm of the hippocampus two round
00:11:48
clusters on the end of each arms to be
00:11:50
exact this is where you get your
00:11:51
emotional reactions from specifically
00:11:53
fear anxiety and aggression under the
00:11:56
thalamus is the hypothalamus which keeps
00:11:58
your body balanced this allows us to
00:12:00
have homeostasis this is what controls
00:12:02
your drives thirst hunger temperature
00:12:04
and of course sex the hypothalamus also
00:12:06
works with the pituitary gland to
00:12:08
regulate and control your hormones
00:12:09
remember we talked about hormones and
00:12:11
also the endocrine system back in our
00:12:13
unit two topic two videos so that's the
00:12:15
limbic system now don't worry we are
00:12:17
almost done with the video we're down to
00:12:19
our last two brain structures but before
00:12:21
we get there if you're finding value in
00:12:22
this video don't forget to hit the
00:12:23
subscribe button and drop a like on the
00:12:25
video it's free and it lets me know that
00:12:27
you want more content okay so first we
00:12:28
have the nucleus accumbens this is
00:12:30
located in the forebrain near the limbic
00:12:33
system it's associated with drug
00:12:35
dependency as its function is in the
00:12:37
pleasure and reward circuit and
00:12:38
motivation and last but certainly not
00:12:40
least we have the basal ganglia these
00:12:42
neuron cell bodies are involved in
00:12:44
intentional body movement they link the
00:12:46
thalamus with the motor cortex so the
00:12:48
information that is sent from the motor
00:12:50
cortex gets modified by the basal
00:12:52
ganglia damage to this area leads to
00:12:54
parkinson's cerebral palsy and
00:12:56
huntington's disease the basal ganglia
00:12:58
are located in the midbrain and also the
00:13:00
forebrain now believe it or not this was
00:13:01
actually just a quick overview of the
00:13:03
brain there's a lot more complexities to
00:13:05
the brain and more structures that we
00:13:06
could get into but for now we need to
00:13:08
practice what we just learned answer the
00:13:10
questions on the screen and check your
00:13:11
answers in the comments section below
00:13:13
and when you're down there checking your
00:13:14
answers don't forget to go to the
00:13:15
description of this video and check out
00:13:16
my ultimate review packet the packet has
00:13:19
information on every single unit of ap
00:13:21
psychology i also have more practice
00:13:22
sheets for the brain the neuron the
00:13:24
endocrine system the nervous system and
00:13:26
also all the other units there's topic
00:13:27
review videos practice quizzes answer
00:13:29
keys and much more it's a great resource
00:13:31
that'll help you get an a in your class
00:13:33
and also a five on the national exam
00:13:35
plus there's also the discord server
00:13:36
there where you can study with thousands
00:13:37
of students around the world and of
00:13:39
course don't forget that subscribe
00:13:41
button so you don't miss out on any
00:13:42
future mr sin content thank you guys so
00:13:44
much for watching i'm mr sin and until
00:13:46
next time i'll see you online
00:14:02
[Music]
00:14:08
you
