Presentation Plus! Understanding Psychology
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CHAPTER FOCUS
SECTION 1 The Nervous System:
The Basic Structure
SECTION 2 Studying the Brain
SECTION 3 The Endocrine System
SECTION 4 Heredity and
Environment
CHAPTER SUMMARY
CHAPTER ASSESSMENT
3
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Press the ESC key at any time to exit the presentation.
Chapter Objectives
Section 1: The Nervous System: The
Basic Structure
• Understand that the nervous system
helps us know how messages that are
sent to the brain cause behavior. 
Section 2: Studying the Brain
• Discuss the many parts of the brain that
work together to coordinate movement
and stimulate thinking and emotions.
4
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the information.
Chapter Objectives (cont.)
Section 3: The Endocrine System
• Explain how the endocrine system
controls and excites growth and affects
emotions and behavior. 
Section 4: Heredity and Environment
• Identify heredity and environment and
how they affect your body and behavior.
5
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the information.
Click the mouse button to return to the Contents slide.
Reader’s Guide
Main Idea
– Learning about the nervous system helps us
know how messages that are sent to the brain
cause behavior. 
Objectives
– Identify the parts of the nervous system. 
– Describe the functions of the nervous system.
7
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information. Section 1 begins on page 155 of your textbook.
Reader’s Guide (cont.)
Vocabulary
– central nervous system (CNS) 
– spinal cord 
– peripheral nervous system (PNS) 
– neurons 
– synapse 
– neurotransmitters 
– somatic nervous system (SNS) 
– autonomic nervous system (ANS)
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to listen to Exploring
Psychology.
8
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information. Section 1 begins on page 155 of your textbook.
Introduction
• People who do a lot of running for
exercise, 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.”
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Introduction (cont.)
• 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. 
• So, in effect, running really does
change you. 
• In this section, you will learn how
your nervous system can produce a
runner’s high.
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How the Nervous System Works
• The nervous system is never at rest;
there is always a job for it to do. 
• Structurally, the nervous system is divided
into two parts. 
• One of the two parts of the nervous
system is the central nervous system
[CNS] (the brain and the spinal cord).
central nervous system
(CNS)
the brain and spinal cord
11
spinal cord
nerves that run down the
length of the back and
transmit most messages
between the body and brain
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How the Nervous System Works (cont.)
• The other part of the nervous system is
the peripheral nervous system [PNS]
(the smaller branches of nerves that
reach the other parts of the body). 
• The nerves of the peripheral system
conduct information from the bodily
organs to the central nervous system and
take information back to the organs.
peripheral nervous system (PNS)
nerves branching out from the
spinal cord
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The Nervous System
13
Neurons
• Messages to and from the brain travel
along the nerves, which are strings of
long, thin cells called neurons. 
• Transmission between neurons or nerve
cells occurs whenever the cells are
stimulated past a minimum point and emit
a signal.
neurons
the long, thin cells of nerve
tissue along which messages
travel to and from the brain
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Anatomy of Two Neurons
15
Neurons (cont.)
Basic Parts of a Neuron
• Neurons have three basic parts: the cell
body, dendrites, and the axon. 
• The cell body contains the nucleus and
produces the energy needed to fuel
neuron activity. 
• The dendrites–short, thin fibers that stick
out from the cell body–receive impulses,
or messages, from other neurons and
send them to the cell body.
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Neurons (cont.)
Basic Parts of a Neuron
• The axon is a long fiber that carries the
impulses away from the cell body toward
the dendrites of another neuron. 
• A white, fatty substance called the myelin
sheath insulates and protects the axon for
some neurons. 
• Small fibers, called axon terminals,
branch out at the end of the axon. 
• Axon terminals are positioned opposite
the dendrite of another neuron.
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Neurons (cont.)
The Neuron Connection
• The space between the axon terminals of
one neuron and the dendrites of another
neuron is called the synapse. 
• A neuron transmits its impulses or
message to another neuron across the
synapse by releasing chemicals called
neurotransmitters.
synapse
the gap that occurs between
individual nerve cells
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neurotransmitters
the chemicals released by
neurons, which determine
the rate at which other
neurons fire
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Neurons (cont.)
The Neuron Connection
• These neurotransmitters open chemical
locks or excite the receptors. 
• The neurotransmitters can excite the next
neuron or stop it from transmitting
(inhibition). 
• The neurotransmitters are like the valves
in a water system that allow flow in only
one direction. 
• There are many different neurotransmitters.
19
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The Synapse
20
Neurons (cont.)
Neuron Activity
• The intensity of activity in each neuron
depends on how many other neurons are
acting on it. 
• Each individual neuron is either ON or
OFF, depending on whether most of the
neurons acting on it are exciting it or
inhibiting it. 
• There are different types of neurons:
afferent neurons, efferent neurons,
and interneurons.
21
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Voluntary and Involuntary Activities
• Some of the actions that your body
makes in response to impulses from
the nerves are voluntary acts, such as
lifting your hand to turn a page (which
actually involves many impulses to
many muscles). 
• Others are involuntary acts, such as
changes in the heartbeat, in the blood
pressure, or in the size of the pupils.
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Voluntary and Involuntary
Activities (cont.)
• Somatic nervous system (SNS) refers to
the part of the peripheral nervous system
that controls voluntary activities. 
• Autonomic nervous system (ANS) refers
to the part of the nervous system that
controls involuntary activities, or those that
ordinarily occur “automatically.”
somatic nervous system
(SNS)
autonomic nervous
system (ANS)
the part of the peripheral nervous the part of the peripheral
system that controls voluntary
nervous system that controls
movement of skeletal muscles
internal biological functions
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Voluntary and Involuntary
Activities (cont.)
• The autonomic nervous system itself has
two parts: sympathetic and
parasympathetic nervous systems. 
• The sympathetic nervous system prepares
the body for dealing with emergencies or
strenuous activity. 
• In contrast, the parasympathetic nervous
system works to conserve energy and to
enhance the body’s ability to recover from
strenuous activity.
24
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Voluntary and Involuntary
Activities (cont.)
• All of this takes place automatically. 
• Receptors are constantly receiving
messages (hunger messages, the need
to swallow or cough) that alert the
autonomic nervous system to carry out
routine activities. 
• Imagine how difficult it would be if you had
no autonomic nervous system and had to
think about it every time your body needed
to digest a sandwich or perspire.
25
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Section Assessment
Review the Vocabulary List and
describe the parts of the neuron.
The parts of the neuron include the
cell body, which produces the energy
needed to fuel neuron activity. The
dendrites receive messages from
other neurons and send them to the
cell body. The axons carry impulses
from the cell body toward the
dendrites of another neuron.
26
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Section Assessment (cont.)
Visualize the Main Idea In a diagram
similar to the one shown on page
159 of your textbook, list the
divisions of the nervous system.
Structurally, the two parts of the
nervous system are the central
nervous system and the peripheral
nervous system.
27
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Section Assessment (cont.)
Recall Information What is the
difference between afferent and
efferent neurons? What are
interneurons?
Afferent neurons relay messages from
the sense organs to the brain. Efferent
neurons send signals from the brain to
the glands and muscles. Interneurons
carry impulses between neurons.
28
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Section Assessment (cont.)
Think Critically Marty runs in
marathons. Explain the functions
of Marty’s sympathetic nervous
system and the parasympathetic
nervous system during and after
the race.
Answers should demonstrate an
understanding of the sympathetic and
parasympathetic nervous systems
and their reactions to emergencies or
strenuous activities.
29
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Section Assessment (cont.)
Revisit the Exploring Psychology
feature at the beginning of this
section. Use the information in this
section to explain the “runner’s high.”
30
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Reader’s Guide
Main Idea
– There are many parts in the human brain
that work together to coordinate movement
and stimulate thinking and emotions, resulting
in behavior. 
Objectives
– Identify the structure and functions of the
human brain. 
– Discuss the different ways psychologists
study the brain.
32
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information. Section 2 begins on page 160 of your textbook.
Reader’s Guide (cont.)
Vocabulary
– hindbrain 
– midbrain 
– forebrain 
– lobes 
– electroencephalograph (EEG) 
– computerized axial tomography (CAT) 
– positron emission topography (PET) 
– magnetic resonance imaging (MRI)
Click the Speaker button
to listen to Exploring
Psychology.
33
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information. Section 2 begins on page 160 of your textbook.
Introduction
• In the 24 centuries since Hippocrates'
observations, many attempts have been
made to explain the mass of soggy gray
tissue known as the human brain. 
• How could the brain create the theory of
relativity, the Sistine Chapel ceiling, and
the energy crisis? 
• The mind, however, remains a mystery
to itself.
34
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The Three Brains
• The brain is composed of three parts: the
hindbrain, midbrain, and forebrain. 
• The hindbrain, located at the rear base of
the skull, is involved in the most basic
processes of life. 
• The midbrain is a small part of the brain
above the pons that integrates sensory
information and relays it upward.
hindbrain
a part of the brain located at
the rear base of the skull that
is involved in the basic
processes of life
35
midbrain
a part of the brain above the
pons that integrates sensory
information and relays it
upward
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The Three Brains (cont.)
• The forebrain, covering the brain’s
central core, includes the thalamus,
which integrates sensory input. 
• Just below the thalamus is the
hypothalamus. 
• It controls functions such as hunger, thirst,
and sexual behavior.
forebrain
a part of the brain that covers
the brain’s central core
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The Three Brains (cont.)
• The “higher” thinking processes–those
that make us unique–are housed in
the forebrain. 
• The outer layer of the forebrain consists
of the cerebral cortex; the inner layer is
the cerebrum. 
• The limbic system, found in the core of
the forebrain, is composed of a number of
different structures in the brain that
regulate our emotions and motivations.
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The Parts of the Brain
38
The Lobes of the Brain
• The cerebrum is really two hemispheres,
or two sides. 
• The cerebral hemisphere is connected
by a band of fibers called the
corpus callosum. 
• Each cerebral hemisphere has deep
grooves that form regions, or lobes.
lobes
the different regions into
which the cerebral cortex
is divided
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The Lobes of the Brain (cont.)
• Some areas of the cortex receive
information from the skin senses and
from muscles. 
• The amount of brain tissue connected to
any given body part determines the
sensitivity of that area, not its size. 
• The part of the cortex that receives
information is called the somatosensory
cortex. 
• The association areas mediate between
the other areas and do most of the
synthesizing of information.
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The Cerebral Cortex
41
The Lobes of the Brain (cont.)
Left and Right Hemispheres
• There is much concern that information
about properties of the left and right
hemispheres is misinterpreted. 
• The left hemisphere controls the
movements of the right side of the body;
for most people, speech is located here. 
• The right hemisphere controls the left side
of the body; the right hemisphere is more
adept at visual and spatial relations.
42
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Functions of the Brain’s Hemisperes
43
The Lobes of the Brain (cont.)
Split-Brain Operations
• In a normal brain, the two hemispheres
communicate using the corpus callosum.

• Whatever occurs on one side is
communicated to the other side. 
• Many psychologists became interested in
differences between the cerebral
hemispheres when “split brain” operations
were tried on epileptics like Harriet Lees. 
• Not only did the operation reduce the
severity of seizures, but it also resulted
in fewer seizures (Kalat, 1992).
44
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The Lobes of the Brain (cont.)
Split-Brain Operations
• Another experiment with split-brain
patients involves studying tactile
stimulation, or touch. 
• To explore emotional reactions in splitbrained individuals, researchers designed
a test to incorporate emotional stimuli with
objects in view. 
• Research on split-brain patients has
presented evidence that each hemisphere
of the brain is unique with specialized
functions and skills.
45
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How Psychologists Study the Brain
• Mapping the brain’s fissures and inner
recesses has supplied scientists with
fascinating information about the role of
the brain in behavior. 
• Psychologists who do this kind of
research are called physiological
psychologists, or psychobiologists. 
• Among the methods they use to explore
the brain are recording, stimulating,
lesioning, and imaging.
46
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Recording
• Electrodes are wires that can be inserted
into the brain to record electrical activity
in the brain. 
• The electrical activity of whole areas of
the brain can be recorded with an
electroencephalograph (EEG).
electroencephalograph (EEG)
a machine used to record the
electrical activity of large portions
of the brain
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Stimulation
• Electrodes may be used to set off the
firing of neurons as well as to record it. 
• Brain surgeon Wilder Penfield stimulated
the brains of his patients during surgery to
determine what functions the various
parts of the brain perform. 
• Stimulation techniques have aroused
great medical interest. 
• Furthermore, some psychiatrists have
experimented with methods to control
violent emotional behavior in otherwise
uncontrollable patients.
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Lesions
• Scientists sometimes create lesions
by cutting or destroying part of an
animal’s brain. 
• If the animal behaves differently after
the operation, they assume that the
destroyed brain area is involved with
that type of behavior. 
• The relations revealed by this type of
research are far more subtle and complex
than people first believed.
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Accidents
• Psychologists can learn from the tragedies
when some people suffer accidents. 
• These accidents may involve the brain. 
• Psychologists try to draw a connection
between the damaged parts of the brain
and a person’s behavior.
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Phineas Gage’s Skull
51
Images
• Dr. Paul Broca uncovered the connection
between brain and speech. 
• Researchers proved Dr. Broca’s theory
using PET scans. 
• Today psychologists and medical
researchers are using this and other
sophisticated techniques, including CAT
scans and MRI scans.
52
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Images (cont.)
• In the 1970s, computerized axial
tomography (CAT) scans were used to
pinpoint injuries and other problems in
brain deterioration. 
• The positron emission topography
(PET) scan can capture a picture of the
brain as different parts are being used.
compurterized axial
tomography (CAT)
positron emission
topography (PET)
an imaging technique used to study an imaging technique used to
the brain to pinpoint injuries and
see which brain areas are being
brain deterioration
activated while performing tasks
53
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Images
• Another device, magnetic resonance
imaging, or MRI, enables researchers to
study both activity and brain structures. 
• Researchers use a new technique of
imaging, functional magnetic resonance
imaging (fMRI), to observe directly both
the functions of different structures of the
brain and which structures participate in
specific functions.
magnetic resonance
imaging (MRI)
an imaging technique used
to study brain structure
and activity
54
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Brain Activity on a PET Scan
55
Section Assessment
Review the Vocabulary List and
describe the main functions of the
lobes of the human brain.
The occipital lobe is where visual
signals are processed. The temporal
lobes house hearing, memory,
emotion, and speaking. The frontal
lobes are concerned with organization,
planning, and creative thinking. The
parietal lobes are concerned with
sensory information.
56
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Section Assessment (cont.)
Visualize the Main Idea In a
diagram similar to the one shown
on page 168 of your textbook, list
the parts of the brain.
The hindbrain includes the cerebellum,
medulla, and the pons. The midbrain
integrates sensory information. The
forebrain includes the thalamus,
hypothalamus, cerebral cortex, corpus
callosum, and pituitary gland.
57
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Section Assessment (cont.)
Recall Information What are the
functions of the thalamus and
hypothalamus?
The thalamus integrates all sensory
information except smell. The
hypothalamus controls basic
biological needs.
58
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Section Assessment (cont.)
Think Critically If a person suffers
a traumatic head injury and then
begins behaving differently, can we
assume that brain damage is the
reason for the personality change?
Why or why not?
Psychologists try to draw a connection
between the damaged part of the
brain and the person’s behavior.
The experience of trauma may also
affect behavior.
59
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Section Assessment (cont.)
Discuss which of the methods
for exploring the brain promises
to yield the most practical
benefits for treating human
behavioral problems.
60
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Reader’s Guide
Main Idea
– The endocrine system controls and excites
growth and affects emotions and behavior
in people. 
Objectives
– Describe the endocrine system. 
– Identify hormones and their function in the
endocrine system.
62
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Reader’s Guide (cont.)
Vocabulary
– endocrine system 
– hormones 
– pituitary gland
Click the Speaker button
to listen to Exploring
Psychology.
63
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information. Section 3 begins on page 170 of your textbook.
Introduction
• Every year in Pamplona, Spain, many
people experience what some consider
the ultimate “adrenaline rush.” 
• Fighting bulls and steers run through the
town every morning of a nine-day fiesta. 
• Hundreds of revelers literally run with
the bulls. 
• The bull-racing ritual is inhumane (more
than 50 bulls are killed each day), and
participants risk death if they should get
gored by a bull.
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Introduction (cont.)
• Why do people do it? 
• Many do it for the “rush.” 
• The rush comes from a hormone secreted
by the endocrine system called adrenaline
or epinephrine. 
• The adrenal hormone declares an
emergency situation to the body, requiring
the body to become very active.
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The Endocrine Glands
• The nervous system is one of two
communication systems for sending
information to and from the brain; the
second is the endocrine system. 
• The endocrine system sends chemical
messages, called hormones, which
are produced in the endocrine glands
and are distributed by the blood and
other body fluids.
endocrine system
a chemical communication
system, using hormones, by
which messages are sent
through the bloodstream
66
hormones
chemical substances that
carry messages through the
body in blood
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The Endocrine Glands (cont.)
• Hormones have various effects on
your behavior. 
• They affect the growth of bodily structures
such as muscles and bones–so they affect
what you can do physically. 
• Hormones affect your metabolic processes;
that is, they can affect how much energy
you have to perform actions. 
• Essentially all the physical differences
between boys and girls are caused by a
hormone called testosterone.
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Pituitary Gland
• Under the direction of the hypothalamus
in the brain, the pituitary gland acts as
the “master gland.” 
• The pituitary gland, located near the
midbrain, secretes a large number
of hormones, many of which control
the output of hormones by other
endocrine glands.
pituitary gland
the center of control of the
endocrine system that secretes
a large number of hormones
68
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Pituitary Gland (cont.)
• What do these hormone messages tell
the body to do? 
• They carry messages to organs involved
in regulating and storing nutrients so that
despite changes in conditions outside the
body, cell metabolism can continue on an
even course. 
• They also control growth and
reproduction, including ovulation and
lactation (milk production) in females.
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Thyroid Gland
• The thyroid gland produces the hormone
thyroxine. 
• Thyroxine stimulates certain chemical
reactions that are important for all tissues
of the body. 
• Too little thyroxine makes people feel lazy
and lethargic–a condition known as
hypothyroidism. 
• Too much thyroxine may cause people to
lose weight and sleep and to be
overactive–a condition known as
hyperthyroidism.
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Adrenal Glands
• The adrenal glands become active when
a person is angry or frightened. 
• They release epinephrine and
norepinephrine (also called adrenaline
and noradrenaline) into the bloodstream.
• The adrenal glands also secrete cortical
steroids. 
• Cortical steroids help muscles develop
and cause the liver to release stored
sugar when the body requires extra
energy for emergencies.
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
Sex Glands
• There are two types of sex glands–testes
in males and ovaries in females. 
• Testes produce sperm and the male sex
hormone testosterone. 
• Low levels of testosterone are also found
in females. 
• Ovaries produce eggs and the female
hormones estrogen and progesterone,
although low levels of these hormones are
also found in males.
72
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Sex Glands (cont.)
• Testosterone is important in the physical
development of males, especially in the
prenatal period and in adolescence. 
• Estrogen and progesterone are
important in the development of female
sex characteristics.
73
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The Endocrine System
74
Hormones vs. Neurotransmitters
• Both hormones and neurotransmitters
work to affect the nervous system. 
• When a chemical is used as a
neurotransmitter, it is released right
beside the cell that it is to excite or inhibit. 
• When a chemical is used as a hormone, it
is released into the blood, which diffuses it
throughout the body.
75
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Hormones vs. Neurotransmitters (cont.)
• Hormones and neurotransmitters
appear to have had a common origin
(Snyder, 1985). 
• As early multicellular organisms evolved,
the system of communication among cells
coordinated their actions so that all the
cells of the organism could act as a unit. 
• As organisms grew more complex, this
communication system began to split into
two communication systems.
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Section Assessment
Review the Vocabulary What are
three ways that the endocrine
system affects behavior?
The endocrine system can heighten
emotions, create symptoms of
PMS, and make people feel lazy
or be overactive.
77
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Section Assessment (cont.)
Visualize the Main Idea In a chart
similar to the one shown on page
173 of your textbook, identify the
hormones produced by the glands
and the functions of the hormones.
Charts should reflect understanding
of the endocrine system and its
functions.
78
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Section Assessment (cont.)
Recall Information How does the
endocrine system differ from the
nervous system?
The nervous system sends chemicalelectrical messages directly to the
brain to create rapid responses. The
endocrine system secretes hormones
(chemical messages) into the
bloodstream to create slower but
more widespread communication
within the body.
79
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Section Assessment (cont.)
Think Critically Explain what
psychologists might learn about
behavior by studying sex hormones.
Psychologists can learn differences
between males and females and
understand more about the way
circadian rhythms affect the body
and behavior.
80
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to display the answer.
Section Assessment (cont.)
Revisit the Exploring Psychology
feature at the beginning of this
section. What happens to the
endocrine system when the bulls
are released?
81
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to display the answer.
Click the mouse button to return to the Contents slide.
Reader’s Guide
Main Idea
– Heredity is the transmission of characteristics
from parents to children. Environment is the
world around you. Heredity and environment
affect your body and behavior. 
Objectives
– Give examples of the effects of heredity and
environment on behavior. 
– Summarize research on the effects of heredity
and environment on behavior.
83
Click the mouse button or press the Space Bar to display the
information. Section 4 begins on page 174 of your textbook.
Reader’s Guide (cont.)
Vocabulary
– heredity 
– identical twins 
– genes 
– fraternal twins
Click the Speaker button
to listen to Exploring
Psychology.
84
Click the mouse button or press the Space Bar to display the
information. Section 4 begins on page 174 of your textbook.
Introduction
• How much do genetic factors contribute
to our behavior? How much do
environmental factors? 
• These questions have haunted
psychologists for years. 
• Some psychologists believe that genetics
is like a flower, and the environment is like
rain, soil, or fertilizer. 
• Genes establish what you could be, and
the environment defines the final product.
85
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to display the information.
Heredity and Environment
• People often argue about whether human
behavior is instinctive (due to heredity) or
learned (due to environment). 
• Heredity is the genetic transmission
of characteristics from parents to
their offspring.
heredity
the genetic transmission of
characteristics from parents to
their offspring
86
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to display the information.
Heredity and Environment (cont.)
• Do people learn to be good athletes, or
are they born that way? 
• Do people learn to do well in school, or
are they born good at it? 
• The reason for the intensity of the
argument may be that many people
assume that something learned can
probably be changed, whereas
something inborn will be difficult or
impossible to change. 
• The issue is not that simple, however.
87
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to display the information.
Heredity and Environment (cont.)
• Inherited factors and environmental
conditions always act together in
complicated ways. 
• Asking whether heredity or environment is
responsible for something turns out to be
like asking, “What makes a cake rise,
baking powder or heat?” 
• Obviously, an interaction of the two
is responsible.
88
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A Question of Nature vs. Nurture
• The argument over the nature-nurture
question has been going on for centuries. 
• Nature refers to the characteristics
that a person inherits–his or her
biological makeup. 
• Nurture refers to environmental factors,
such as family, culture, education, and
individual experiences. 
• Many psychologists have emphasized the
importance of the environment.
89
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to display the information.
A Question of Nature vs. Nurture (cont.)
Genes and Behavior
• Genes are the basic units of heredity. 
• They are reproduced and passed along
from parent to child. 
• All the effects that genes have on
behavior occur through their role in
building and modifying the physical
structures of the body. 
• Those structures must interact with their
environment to produce behavior.
90
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to display the information.
DNA and Genes
91
Twin Studies
• One way to find out whether a trait is
inherited is to study twins. 
• Identical twins develop from a single
fertilized egg (thus, they are called
monozygotic) and share the same genes. 
• Genes are the basic building blocks
of heredity.
identical twins
twins who come from one
fertilized egg; twins having
the same heredity
92
genes
the basic building blocks
of heredity
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to display the information.
Twin Studies (cont.)
• Fraternal twins develop from two
fertilized eggs (thus, dizygotic), and their
genes are not more similar than those of
brothers or sisters. 
• Twins growing up in the same house
share the same general environment,
but identical twins also share the
same genes.
fraternal twins
twins who come from two
different eggs fertilized by two
different sperm
93
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to display the information.
Twin Studies (cont.)
• Psychologists at the University of
Minnesota have been studying identical
twins who were separated at birth
and reared in different environments
(Holden, 1980). 
• One of the researchers, Thomas
Bouchard, reports that despite very
different social, cultural, and economic
backgrounds, the twins shared many
common behaviors.
94
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Twin Studies (cont.)
• Many researchers now believe that many
of the differences among people can be
explained by considering heredity as well
as experience. 
• Contrary to popular belief, the influence
of genes on behavior does not mean
that nothing can be done to change
the behavior.
95
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to display the information.
Section Assessment
Review the Vocabulary Explain the
difference between fraternal twins
and identical twins.
Identical twins have identical genetic
makeup; fraternal twins come from
two eggs and share no more genetic
similarities than other siblings.
96
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to display the answer.
Section Assessment (cont.)
Visualize the Main Idea In a diagram
similar to the one shown on page
176 of your textbook, explain how
proponents of each view argue the
nature-nurture debate.
Nature supporters argue that a
person’s genetic makeup determines
a person’s behavior, whereas nurture
supporters argue that a person’s
surroundings (environment)
determine a person’s character.
97
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to display the answer.
Section Assessment (cont.)
Recall Information What role do
the genes play in influencing
someone’s behavior?
Their role in behavior occurs through
the gene’s role in building and
modifying structures of the body.
98
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to display the answer.
Section Assessment (cont.)
Think Critically Sue and Tracy are
identical twins. Sue is good at
drawing. Tracy is a starter on the
basketball team. Explain what may
cause differences in these twins.
The difference is likely due to
environmental factors that affected
how the girls developed.
99
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to display the answer.
Section Assessment (cont.)
With advances in genetic
engineering, scientists may soon
isolate the genes that are linked to
certain behaviors. Would you
favor being able to select the
behavioral characteristics of your
children? Explain.
100
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Section 1: The Nervous System: The
Basic Structure
• The nervous system is divided into two
parts: the central nervous system and the
peripheral nervous system. 
• Messages to and from the brain travel
along the nerves. 
• Nerve cells called neurons have three basic
parts: the cell body, dendrites, and the
axon.
102
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to display the information.
Section 1: The Nervous System:
The Basic Structure (cont.)
• The somatic nervous system controls the
body’s voluntary activities, and the
autonomic nervous system controls the
body’s involuntary activities.
103
Section 2: Studying the Brain
• The brain is made of three parts: the
hindbrain, the midbrain, and the
forebrain. 
• The cortex of the brain is divided into the
left and the right hemispheres; the left
hemisphere controls the movements of the
right side of the body, and the right
hemisphere controls the movements of the
left side of the body. 
• Psychologists use recording, stimulation,
lesions, and imaging to study the brain.
104
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to display the information.
Section 3: The Endocrine System
• The endocrine system, in addition to the
nervous system, is a communication
system for sending information to and from
the brain. 
• The endocrine system sends chemical
messages, called hormones.
105
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to display the information.
Section 4: Heredity and Environment
• Heredity is the genetic transmission of
characteristics from parents to their
offspring. 
• Genes are the basic units of heredity; they
are reproduced and passed along from
parents to child. 
• All the effects that genes have on behavior
occur through their role in building and
modifying the physical structures of the
body.
106
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to display the information.
Click the mouse button to return to the Contents slide.
Reviewing Vocabulary
Use the correct term or concept to complete the following
sentences.
1. The part of the nervous system that controls
nervous system
voluntary activities is the somatic
___________________.
Fraternal twins develop from two fertilized
2. ______________
eggs, and their genes are not more similar than
those of brothers or sisters.
3. The space between neurons is called the
synapse
__________.
4. The __________
forebrain is the part of the brain that
integrates sensory information.
5. As a neuron transmits its message to another
neuron across the synapse, it releases chemicals
called ________________.
neurotransmitters
108
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to display the answers.
Reviewing Vocabulary (cont.)
Use the correct term or concept to complete the following
sentences.
6. ____________
Identical twins develop from a single fertilized
egg and share the same genes.
7. Located at the rear base of the skull, the
__________
hindbrain is involved in the basic processes of
life.
8. The _____________
pituitary gland acts as the “master gland” of
the body, controlling the output of hormones by
other endocrine glands.
109
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to display the answers.
Reviewing Vocabulary (cont.)
Use the correct term or concept to complete the following
sentences.
9. __________
Hormones are produced by endocrine glands
and are distributed by the blood and other body
fluids.
10. The part of the nervous system that controls
activities such as heartbeat is the
______________________.
autonomic nervous system
110
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to display the answers.
Recalling Facts
Explain how messages travel to and
from the brain through the nervous
system.
Messages travel along the nerves,
which are strings of cells called
neurons. Neurotransmitters are
chemicals that carry the signal across
the synapses between neurons or
inhibit the neurons from transmitting.
111
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to display the answer.
Recalling Facts
Using a chart similar to the one on
page 178 of your textbook, describe
the main function of each of the four
lobes of the cerebral cortex.
occipital: processes visual signals;
parietal: processes information from
senses all over the body; temporal:
regulates hearing, memory, emotion,
and speech; frontal: concerned with
organization, planning, and creative
thinking
112
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to display the answer.
Recalling Facts
Describe four methods used to study
the brain.
Four methods used to study the brain
are recording, stimulation, lesioning,
and imaging.
113
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to display the answer.
Recalling Facts
How are the messages of the
endocrine system transmitted
throughout the body?
The messages are transmitted by
hormones that circulate though the
bloodstream to specific glands.
114
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to display the answer.
Recalling Facts
One way to find out whether a trait is
inherited is to compare the behavior of
identical and fraternal twins. Explain
how this works.
Identical twins share the same genes,
while fraternal twins do not. Twins growing
up in the same house share the same
environment. Identical twins who grow up
together share both environment and
genes. If identical twins prove to be more
alike on a specific trait than fraternal twins
do, it probably means that genes are more
important than environment for that trait.
115
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to display the answer.
Building Skills
Interpreting a Graph
Researchers have found
that the brains of
patients with Alzheimer’s
disease have a large
number of destroyed
neurons in the part of the
brain that is crucial for
making memories
permanent. These
patients have also
exhibited a loss of the
neurotransmitter
acetylcholine, resulting
in memory difficulties.
Review the graph below
and then answer the
questions that follow.
116
Building Skills
Interpreting a Graph
According to the
graph, how many
people in the United
States suffer from
Alzheimer’s disease?
about 4 million
117
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to display the answer.
Building Skills
Interpreting a Graph
How would you
describe the
projected number of
cases of Alzheimer’s
by the year 2050?
a steady increase that more than doubled in
60 years
118
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to display the answer.
Building Skills
Interpreting a Graph
What impact might
the researchers’
findings and the
information in the
graph have on the
direction researchers
might take to find a
cure for the disease?
As the incidence of Alzheimer’s disease grows
and is expected to continue a rapid growth,
researchers may attempt to find a cure involving
acetylcholine as quickly as possible to help the
millions afflicted with this disease.
119
Click the mouse button or press the Space Bar
to display the answer.
I am a device that records both
brain activity and brain structures.
What am I?
MRI (magnetic resonance imaging)
120
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to display the answer.
Click the mouse button to return to the Contents slide.
Explore online information about the
topics introduced in this chapter.
Click on the Connect button to launch your browser and go to the
Understanding Psychology Web site. At this site, you will find
interactive activities, current events information, and Web sites
correlated with the chapters and units in the textbook. When you
finish exploring, exit the browser program to return to this
presentation. If you experience difficulty connecting to the Web
site, manually launch your Web browser and go to
http://psychology.glencoe.com
Ask yourself why it is important for
psychologists to study the brain and
nervous system. Write your answer to this
question in your journal and justify your
response.
Explain how neurons work using the
metaphor of a relay race.
Imagine that you had a severe disorder that
doctors said could be relieved only through
surgery to split the brain. Write a list of
questions that you would want to have
answered before you decided to have the
surgery.
One Person…
Two Brains?
Read the case study presented on
page 169 of your textbook. Be
prepared to answer the questions that
appear on the following slides. A
discussion prompt and additional
information follow the questions.
Continued on next slide.
This feature is found on page 169 of your textbook.
One Person…
Two Brains?
Why did Victoria choose to have a splitbrain operation? What did the operation
involve?
She wanted to relieve the seizures and be able to
live a more normal life. The operation involved
opening her skull and separating the hemispheres
of her brain by cutting the corpus callosum. Victoria
and her doctors realized that by cutting the major
pathway between the two hemispheres, each
hemisphere would function almost completely
independently after the operation.
Continued on next slide.
Click the mouse button or press the Space Bar to display the
answer. This feature is found on page 169 of your textbook.
One Person…
Two Brains?
What questions did researchers set
out to answer after Victoria’s
operation?
What functions can each hemisphere
perform? What communication capability
does each hemisphere have?
Continued on next slide.
Click the mouse button or press the Space Bar to display the
answer. This feature is found on page 169 of your textbook.
One Person…
Two Brains?
Critical Thinking What problems do you think
Victoria might encounter in everyday life?
Answers will vary. Examples should focus on the
problem of each hemisphere having its own
separate set of memories that are inaccessible to
the recall processes of the other. Examples could
include conflicts in communication such as deciding
to select something to eat and trying to pick up that
item with one hand or holding a conversation using
only one hemisphere of the brain.
Continued on next slide.
Click the mouse button or press the Space Bar to display the
answer. This feature is found on page 169 of your textbook.
One Person…
Two Brains?
Discuss the following:
How does split-brain surgery benefit both
the patient and humans in general?
Should split-brain surgery ever be
performed on a person with no brain
disorders?
Continued on next slide.
This feature is found on page 169 of your textbook.
One Person…
Two Brains?
Split-brain patients have provided
psychologists with an excellent
opportunity to explore how the brain’s
hemispheres operate. Each instance
adds a little more to our knowledge of the
brain.
Continued on next slide.
This feature is found on page 169 of your textbook.
One Person…
Two Brains?
– In one experiment, a split-brain patient was blindfolded
and given a familiar object, such as a toothbrush. 
– When asked to name the item, the patient could not
give it a name. 
– When asked what the item was used for, the patient
immediately began to brush his teeth. 
– Researchers concluded that the patient knew what the
item was, but his right brain had no language capability
and therefore could not name it.
Continued on next slide.
Click the mouse button or press the Space Bar to display the
information. This feature is found on page 169 of your textbook.
One Person…
Two Brains?
– When the patient was told to transfer the item to his
right hand, he was immediately able to identify the
item as a toothbrush.
Continued on next slide.
Continued on next slide.
Answers:
1. synapse 
2. neurotransmitters 
3. myelin sheath 
4. dendrites
Click the mouse button or press the Space Bar to
display the answers.
Continued on next slide.
Answers:
1. the reticular
activation system 
2. forebrain, midbrain,
hindbrain 
3. regulates posture,
balance, breathing,
and various
reflexes 
4. It regulates hunger
and thirst. The
forebrain also
controls learning,
abstract thinking,
and emotions.
Click the mouse button or press the Space Bar to
display the answers.
Continued on next slide.
Answers:
1. thyroxine
deficiency 
2. adrenaline 
3. heartbeat and
breathing rate
increase, extra
energy results 
4. sleeplessness,
hyperactivity,
weight loss
Click the mouse button or press the Space Bar to
display the answers.
Continued on next slide.
Answers:
1. Environmental factors
such as soil
conditions, sunlight,
and rainfall affected
the tree’s growth and
development. 
2. Most will see it
as placing more
emphasis on
environment. 
3. Your answers
may include that
similarities of
identical twins
raised apart
support the
strength of
heredity.
Click the mouse button or press the Space Bar to
display the answers.
Glimpses of the Mind
Introduction
Use the Reader’s Dictionary that appears
on the next slide to help explain unfamiliar
terms as you read the article on pages
180–181 of your textbook. Be prepared to
answer the questions that follow.
Continued on next slide.
This feature is found on pages 180–181 of your textbook.
Glimpses of the Mind
Reader’s Dictionary
flashbacks: reliving a past
occurrence vividly in one’s
mind
conundrums: questions or
problems that have no clear
solutions
ethereal: having no material
substance, intangible
percolates: seeps into,
penetrates
magnetic resonance imaging
(MRI): a technique that
produces computerized images
of internal body tissues
positron-emission
tomography (PET): a
procedure in which a crosssectional image of internal body
tissues is produced by tracking
the interaction of body tissues
with a radioactive substance
injected into the patient
province: belonging to, proper
Continued on next slide.
function of
This feature is found on pages 180–181 of your textbook.
Glimpses of the Mind
Analyzing the Article
How do we know we exist, according to
Descartes?
He said, “I think, therefore I am.” According to
Descartes, we are only aware of our existence
because we are conscious of it.
Continued on next slide.
Click the mouse button or press the Space Bar to display the
answer. This feature is found on pages 180–181 of your textbook.
Glimpses of the Mind
Analyzing the Article
CRITICAL THINKING How does
physical trauma affect us? How can
you explain Bill Noonan’s flashbacks
from the Vietnam War?
Physical trauma destroys or damages various parts
of the brain. For example, memories may be
distorted by physical trauma. Bill Noonan’s
flashbacks are due to abnormal activity in the
amygdala, even though the intellectual memory of
emotions are routed through the hippocampus.
Continued on next slide.
Click the mouse button or press the Space Bar to display the
answer. This feature is found on pages 180–181 of your textbook.
Glimpses of the Mind
Discussion
How is current research disproving
René Descartes’s philosophy that the
mind is a nonphysical structure entirely
separate from the physical tissues of the
human body?
MRI’s and PET scans show the changes in
brain activity (physcial tissue) as a result of
stimuli and emotional responses.
Continued on next slide.
Click the mouse button or press the Space Bar to display the
answer. This feature is found on pages 180–181 of your textbook.
Glimpses of the Mind
Discussion
According to the article, how does
stress affect the brain?
Severe stress can change the biological
functioning of the brain.
Continued on next slide.
Click the mouse button or press the Space Bar to display the
answer. This feature is found on pages 180–181 of your textbook.
Glimpses of the Mind
Discussion
What world events have occurred in
your lifetime that you will never forget?
This feature is found on pages 180–181 of your textbook.
The Brain and Nervous System
From the Classroom of Susan Morton Hernandez
Morris Knolls High School, Rockaway, NJ
Objective: To gain a better understanding
of the location and function of the parts of
the brain.
Materials: Teacher-designed chart;
clay/dough that dries on exposure to the
air; plastic bags or plastic containers for
storage between classes; masking tape to
label containers
Continued on next slide.
The Brain and Nervous System
From the Classroom of Susan Morton Hernandez
Morris Knolls High School, Rockaway, NJ
Procedure: 
1. After discussing the structures and functions of
the brain in class, design a 3-column chart, the far
left column listing the structure, and the remaining
columns titled “Location” and “Function.” 
2. Using a container of clay or dough and your chart,
build a 3-dimensional cross section of the left side
of the brain, making sure to include all the
structures listed in your charts.
Continued on next slide.
The Brain and Nervous System
From the Classroom of Susan Morton Hernandez
Morris Knolls High School, Rockaway, NJ
Procedure: (cont.):
4. When you have completed your models, place
them somewhere safe to dry overnight. 
5. Conduct an assessment by writing each structure
on a separate 3" x 5" index card. Select 5 different
index cards and use the models to identify not
only where the structure is, but what function it
performs.
Recent studies have shown that men
convicted of violent crimes are more likely to
have abnormalities of their frontal lobe and
their right hemisphere.
Archaeology has found fossil evidence that
most primitive tools were designed for righthanders. Research has shown that over time
and across cultures, 9 out of 10 people are
right- handed. No similar preference for
handedness is found in monkeys or
chimpanzees.
Computer Models
The increasing power of the computer allows
psychologists and other researchers to create
neural network models, which are computer
programs that seek to represent what a neuron
does. The computer program is actually a series of
computations that assumes that each neuron
receives inputs from many others. By adding the
inputs, any sum that exceeds a predetermined
threshold results in an output. Researchers are
beginning to use these models to explore such
topics as attention, memory, and perception.
Dyslexia
• Dyslexia is a common reading disorder that is strongly
linked to differences in brain function. 
• For years, poor readers were labeled as lazy or slow. 
• Today we recognize that dyslexics’ brains function
differently. 
• Several recent studies indicate that dyslexics use more of
their brain area to complete simple language tasks. 
• Imaging techniques like PET scans and MRIs assist
researchers in explaining how dyslexics’ brains function. 
• Researchers are also exploring a genetic link that may
indicate that dyslexia is largely an inherited trait.
Click the mouse button or press the Space Bar to display the
information.
• Read the Psychology and You feature on
page 171 of your textbook. 
• Discuss the following:
Why may a tongue display indicate
that a person is concentrating and
does not want to be disturbed?
Click the mouse button or press the Space Bar to display the
information.
Roger Wolcott Sperry
1913–1994
Click the picture to listen to
a biography on Roger
Wolcott Sperry. Be
prepared to answer
questions that appear on
the next two slides.
This feature is found on page 164 of your textbook.
Roger Wolcott Sperry
1913–1994
What did Sperry’s
experiments
demonstrate?
how nerve cells connect to
the central nervous system
and how each hemisphere of
the brain functions
Click the mouse button or press the Space Bar to display the
answer. This feature is found on page 164 of your textbook.
Roger Wolcott Sperry
1913–1994
What are the behavioral
implications for “splitbrain” research?
The research begins to help
us understand the parts of
the brain responsible for
various human behaviors.
Click the mouse button or press the Space Bar to display the
answer. This feature is found on page 164 of your textbook.
End of Custom Shows
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shows and return to the main presentation.
Click the mouse button to return to the Contents slide.