Psychology 12


It’s almost like running is this great friend we both
share…Anyways, that’s what I’d like to talk to you
about…running as a friend, a companion…in other
words, the relationship of running. “WHAT!?” many
of you will be saying, “I thought that I was going to
learn about how to improve my 10k time.” Go read
“Runner’s World” for that. You see, I don’t view
running as what I DO or what I AM, but as this thing,
this force, that changes me over time…
---from “Running and Me: A Love Story” by Joan
Nesbit, 1999

Why does the writer love running so much? One
of the reasons may be that people who do a lot of
running—especially long-distance running,
often talk of an effect called a “runner’s high.”
The longer they run, the more tired they get, of
course; but at some point, the runners will “push
through the wall” and “get their second wind.”
Why does this happen? Endorphins, which are
neurotransmitters, produce the euphoria of a
runner’s high. As the body deals with a very
physically stressful situation—running---the
runner’s body reacts to stress.
 What
other types of physically stressful
situations may the human body
encounter? How does the nervous
system react?
The nervous system
controls your emotions,
movements, thinking and
behaviour.
 Structurally, it is divided
into two parts—the
central nervous system
[CNS] ( the brain and the
spinal cord) and the
peripheral nervous
system [PNS] (the smaller
branches of nerves that
reach the other parts of the
body.

All parts of the nervous
system are protected: the
brain by the skull and
several layers of sheathing,
the spinal cord by the
vertebrae, and the
peripheral nerves by layers
of sheathing.
 The bony protection of the
spinal cord is vital. An injury
to the spinal cord could
prevent the transmittal of
messages between the brain
and the muscles, and could
result in paralysis.

Messages to and from the brain
travel along nerves, which are
strings of long, thin cells called
NEURONS.
 Chemical-electrical signals
travel down the neurons much
as a flame travels along a
firecracker fuse. The main
difference is that the neuron can
fire (burn) over and over again,
hundreds of times a minute.
 Transmission between the
neurons, or nerve cells, occur
whenever the cells are
stimulated—the neuron fires
according to the all-or-none
principle (when it fires, it fires at
full strength).

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The space between neurons is called the SYNAPSE. The
synapse is a junction or connection between the neurons.
A neuron transmits its impulse or message to another
neuron across the synapse by releasing chemicals called
NEUROTRANSMITTERS.
These neurotransmitters open chemical locks or excite
receptors
Neurons do not touch each other—a neuron sends a
message across a gap called a synapse by releasing a
neurotransmitter. These neurotransmitters are received
by the dendrite of another neuron.
FYI [the synapse is less than one millionth of an inch wide
and is filled with fluid that transmits the chemical from one
neuron to another]
There are many types of neurotransmitters; for
example,
Norepinephrine: involved in learning and memory
Endorphin: inhibits pain
Acetylcholine: movement and memory. An
undersupply is associated with paralysis and
Alzheimer’s disease
Dopamine: Learning, emotional arousal and
movement. An oversupply is linked to
schizophrenia—an undersupply is linked to
Parkinson’s disease
Serotonin: cognitive functions—memory and learning.
It also regulates intestinal movements and mood,
appetite, sleep, as well as muscle contraction.
An undersupply of serotonin and norepinephrine may
result in depression

Complete questions 1-5 on page 159.
 We
begin our exploration of
the brain at the lower end,
where the spinal cord joins the
base of the brain, and then
continue upward toward the
skull.
 Note that as we move from
bottom to top, “lower,” basic
processes like breathing
generally give way to
“higher,” more complex
mental processes.
 The
brain is the control center of the
body. Made up of dense "grey matter"
consisting of complicated networks of
interconnected neurons, the brain can be
superficially divided into three main
parts: the hindbrain, the midbrain and the
forebrain.

The brain can be divided
into THREE major sections:
the hindbrain,
midbrain, and
forebrain.

Also, the large section
labeled as the BRAINSTEM
includes parts of all three of
these3 sections and helps
regulate reflex activities
important to survival (ie,
heartbeat and respiration)

Throughout the tour,
note that certain brain
structures are
specialized to perform
certain tasks, a process
known as localization
of function, but also
note that most parts of
the brain are not so
specialized—they
perform overlapping
functions.

Have you ever wondered what allows you to
automatically breathe and your heart to keep
pumping—automatic behaviours and survival
responses like these are either controlled by or
influenced by parts of your hindbrain, which includes
the medulla, pons and cerebellum.

Medulla: Essentially is an extension of the spinal cord,
with many nerve fibers passing through it carrying
information to an from the brain. It also controls many
essential automatic brain functions like respiration
and heartbeat.

Cerebellum: (“little brain”) is evolutionarily, a very
old structure. It coordinates fine muscle movement
and balance. The cerebellum coordinates the
muscles so that movement is smooth and precise. It is
also crucial for our sense of balance and equilibrium

Pons: Located above the cerebellum and medulla, is
involved in respiration, movement, sleeping, waking,
and dreaming (among other things). It also contains
many axons that cross from one side to the other
(pons is Latin for “bridge”)

The midbrain is the small
part of the brain that helps
orient our eye and body
movements to visual and
auditory stimuli, and works
with the pons to help control
sleep and level of arousal. It
also contains a small
structure involved with the
neurotransmitter dopamine,
while deteriorates in
Parkinson’s disease.

Running through the core of
the hindbrain, midbrain, and
brainstem is the reticular
(netlike) formation (RF). This
finger-shaped network of
neurons filters incoming
sensory information and
alerts the higher brain
centers to important events.
Without your RF, you would
not be alert or perhaps even
conscious. In fact, some
general anesthics target the
RF so pain sensations never
register in the brain.


The Forebrain is the largest
and most prominent part of
the human brain. It includes
the thalamus,
hypothalamus, limbic
system, and cerebral
cortex.
The first three structures are
located near the top of the
brainstem. Wrapped around
them is the cerebral cortex
(cerebrum is Latin for “brain,”
and cortex is Latin for
“covering”)


Thalamus: Resembling two little
footballs jointed side by side, the
thalamus serves the major sensory
relay center for the brain. Like an
air traffic control centre that
receives information from all aircraft
and then directs them to the
appropriate landing or takeoff
areas, the thalamus receives input
from nearly all the sensory systems
and then directs this information to
the appropriate areas.
For example, while you are reading
this, your thalamus sends incoming
visual signals to the visual area of
your cortex. While listening to
music, the information is transferred
to the auditory area of the cortex.

Thalamus: Integrates input from
the senses
Thalamus: In addition to relaying
sensory information to the cortex
it also integrates information
from various senses and maybe
involved in learning and
memory. Injury to the thalamus
can cause deafness, blindness,
or loss of any other sense
(except smell). Damage may
cause the cortex to misinterpret
or not receive vital sensory info.
Interestingly, brain-imaging
research links thalamus
abnormalities to schizophrenia
(a serious psychological
disorder involving problems
with sensory filtering and
perception).


Hypothalamus: Controls
basic drives, such as
hunger
Hypothalamus: Beneath the
thalamus lies the hypothalamus
(“hypo” meaning “under”).
Although no larger than a kidney
bean, it has been called the master
control centre” for basic drives such
as hunger, thirst, sex, and
aggression. It also helps govern
hormonal processes by regulating
the endocrine system. Hanging
down from the hypothalamus, the
pituitary gland is considered the
key endocrine gland because it
releases hormones that activate the
other endocrine glands.
The endocrine system is a system of
glands, each of which secretes a type
of hormone into the bloodstream to
regulate the body.


Limbic System: Regulates
fear and other emotions
Limbic System: An
interconnected group of forebrain
structures, known as the limbic
system, is located roughly along
the border between the cerebral
cortex and the lower-level brain
structures (hence the term
“limbic,” which means “edge” or
“border”). Structures include
the hippocampus, amygdala,
thalamus, hypothalamus.
Responsible for emotions,
drives, and memory, and
involved in forming and
retrieving memories.


Limbic System: Regulates
fear and other emotions
Limbic System: The major focus of
interest in the limbic system, and
particularly the amygdala, has been
its production and regulation of
emotions (e.g.. aggression and fear)
Also known for its role in pleasure
or reward. A study done with rats—
stimulating certain areas of the
limbic system—cause a ”pleasure”
response. The feeling was so
rewarding that he rats would cross
electrified grids, swim through
water (which they normally avoid),
and press a lever thousands of times
until they collapsed from
exhaustion—just to have this area of
their brains stimulated.
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

Cerebral Cortex: Governs
higher mental processes, such
as thinking
Cerebral Cortex: The centre
for “higher” processing.
The gray, wrinkled cerebral
cortex is responsible for most
complex behaviours and
higher mental processes. It
plays such a vital role in
human life that may consider
it the essence of life. Without
a functioning cortex, we
would be almost completely
unaware of ourselves and our
surroundings.
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
Cerebral Cortex: Convolutions
Although it is only about
¼ inch thick, it is made up of
approximately 30 billion neurons and
nine times as many supporting cells.
When spread out, the cortex would
cover an area almost the size of a
standard newspaper page.
How does your cortex, along with all
your brain structures fit inside your
skull? Imagine crumpling and rolling
a newspaper sheet into a ball—you
would retain the same surface area,
but in a much smaller space. The
cortex contains “wrinkles” called
“convolutions” allowing it to hold
billions of neurons in the restricted
space of the skull.



Cerebral Cortex: Hemispheres
If you’ve ever watch brain surgery on
TV—once the skull has been opened,
you’ll first see a gray, wrinkled,
cerebral cortex that closely resembles
an oversized walnut. Like a walnut,
the cortex has a similar division
(fissure) down the centre, which marks
the left and right hemispheres of the
brain. They hemispheres are
connected by a band of fibers called
the corpus callosum. The two
hemispheres make up about 80% of
the brain’s weight and they are mostly
filled with axon connections between
the cortex and other brain structures.
Each hemisphere controls the
opposite side of the body



Cerebral Cortex: Hemispheres & Lobes of the Brain
The two cerebral hemispheres are divided into eight distinct
areas, or lobes—four in each hemisphere. Like the lowerlevel brain structures, each lobe specializes in somewhat
different tasks—another example of localization of function.
However, some functions overlap between lobes.

1.
2.
3.
4.
Cerebral Cortex: Lobes
Frontal Lobe: Receives and coordinates messages from other
lobes; motor control, speech production, and higher functions.
Includes the motor cortex which controls voluntary movements
and Broca’s area which controls speech production
Parietal Lobe: Receives information about pressure, pain, touch,
and temperature. Includes the Somatosensory cortex which
receives sensory messages.
Occipital Lobe: visual perception and vision—includes the Visual
cortex that receives and processes visual information
Temporal Lobe: Hearing, language, comprehension, memory, and
some emotional control—includes Wernicke’s area that controls
language comprehension
Cerebral Cortex: Frontal Lobes
The largest of the lobes, the two frontal lobes are located at the
top front portion of the brain hemispheres—right behind
your forehead. They receive and coordinate messages from
all other lobes, while also being responsible for at least 3
other functions:
1. Higher functions—functions that distinguish us from other
animals, such as thinking, personality, emotion, and memory.
Damage to the frontal lobes affect motivation, drives,
creativity, self-awareness, initiative, reasoning, and
emotional behaviour. Abnormalities in FL are often
observed in patients with schizophrenia

Cerebral Cortex: Frontal Lobes
2. Speech Production: In the left frontal lobe, on the surface
of the cortex near the bottom of the motor control area
lies Broca’s area, which is known to play a crucial role
in speech production.
3. Motor Control: At the very back of the frontal lobes lies
the motor cortex, which sends messages to the various
muscles that instigate voluntary movement. When you
call a friend on a cell phone, the motor control area of
your frontal lobes guides your fingers to press the
desired sequence of numbers.

Cerebral Cortex: Parietal Lobes
At the top of the brain, just behind the frontal lobes, are the
two parietal lobes. They contain the somatosensory
cortex, which interpret bodily sensations including
pressure, pain, touch, temperature, and location of body
parts.
When you step on a sharp nail, you quickly (and reflexively)
withdraw your foot because the messages travel directly
to and from your spinal cord. However, you do not
experience “pain” until the neural messages reach the
parietal lobes of the brain.

Cerebral Cortex: Temporal Lobes
The two temporal lobes (Latin for “pertaining to the
temples”)are responsible for auditory perception (hearing),
language comprehension, memory, and some emotional
control.
The auditory cortex (which processes sound) is located at the
top front of each temporal lobe. This area processes
incoming sensory information from the ears and sends it to
the parietal lobes, where it is combined with visual and
other sensory info.
In the LEFT temporal lobe, Wernicke’s area is involved in
language comprehension.

Cerebral Cortex: Occipital Lobes
(Latin “oh,” “in the back of,” and “caput,” “head”)—located
at the lower back of the brain. Occipital lobes are
responsible for vision and visual perception. Damage
to this area can produce blindness, even though the
eyes and their neural connection to the brain are
perfectly healthy. The occipital lobes are involved in
shape, colour, motion, and perception.

 Split-Brain
Surgery:
Cutting of the corpus
callosum to separate
the brain’s two
hemispheres. When
used medically to
treat severe epilepsy,
split-brain patients
provide data on the
functions of the two
hemispheres.
 This
information has
profoundly improved
our understanding of
how the two halves of
the brain function.
Hemispheric Specialization: although complex activities
occur in both hemispheres, specialization of function occurs in
some areas
Right Hemisphere
1.
Nonverbal Abilities: Music,
Left Hemisphere:
art, perceptual and
1.
Language Functions:
spatiomanipulative skills,
speaking, reading,
recognition of faces,
writing, and
patterns and melodies,
understanding
some language
language
comprehension
2.
Emotions: Associated
2.
Emotions: Associated with
with positive emotions
negative emotions, emotion
3.
Analytical: Figures
expression, and emotion
things out step by step
perception
3.
Synthetic: figures things out
4.
Controls and senses
by combining to form
the right side of the
wholes
body
4.
Controls and senses the left
side of the body.

 Imagine
yourself as a high school football
player (not too difficult for some!). If you
suffered a concussion while playing a
game, would you tell your coach?
There is mounting
evidence linking
multiple concussions
with permanent (and
possibly fatal) brain
damage…

According to a report,
“many of the 1.2
million teenagers who
play high school
football either don’t
know what a
concussion is or they
simply don’t care.
They continue to play
on and get hurt much
worse—sometimes
fatally.”
Millions of people suffer head injuries each year, and
most of these injuries are minor—thanks to the bony
skull’s protection for the brain. This is not the case
for traumatic brain injuries (TBI).
 TBI is defined as an injury to the brain caused by
significant trauma
 Symptoms: (range from mild to severe): headache,
loss of consciousness, convulsions, coma and death.
 Two most common brain injuries are concussions
(result from significant blow to the head) and
contusions (bruises to the brain). Either TBI can
result in prolonged or nonreversible brain damage
and serious problems, such as extreme changes in
personality, significant loss of motor skills, emotional
control, and mental abilities

A) Questions: Answer questions 3, 4 & 5 on
page 168.
B) Read the Case Study on page 169
Answer the following questions:
 How does split-brain surgery benefit both the
patient and humans in general? Should splitbrain surgery ever be performed on a person
with no brain disorders?
 Complete questions 1-3 from the case study.
 Let’s
work with our
right hemispheric
spatiomanipulative
skills—we are going
to build a 3-D
version of the brain.
Objective: To gain a better understanding
of the location and function of the parts of
the brain
Using your textbook, the slides and
the chart you created yesterday as
guides, create a 3-D cross section of
the left side of the brain, making
sure to include all the structures
listed in your charts (obviously,
none from the right hemisphere)
Use a numbering system on the
appropriate sections of the brain
(attached with sticky notes &
toothpicks) and write the
corresponding names of the
structures and their functions on
card stock (recipe cards)..
 Read
the Time article
on page 180-1.
 Answer
the Analyzing
the Article Questions
1-2