Download Unit Two

Unit 2: The Body and
Behavior
The importance of the brain and biological influence!
The influence of the Body on Behavior
The Phinneus P. Gage Story
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Back in the 1800’s, there was a man named Phinneus P.
Gage who was working on a railroad. His job was to
use explosives to blow away ground so that they could
lay track. He was generally considered a kind and
gentle man. One day an accident happened and the
tamping rod was blown clean through his head.
Surprisingly he did not die, but he did show a complete
personality change. He became a drunk, was violent,
and completely irresponsible. This led to an interest in
how the brain controls behavior and personality.
Physiological Psychology
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This field of study has
been called physiological
psychology but is now
more frequently called
Psychobiology,
biopsychology, or
neuroscience. The focus
of study is generally how
the brain controls all
aspects of our behavior.
How the Nervous System Works
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The Nervous System is never at rest…It is always
regulating your body functions.
There are 2 primary parts to the structure of the
Nervous System:
1.) Central Nervous System (CNS): The Brain and
Spinal Cord. Note: The spinal cord is comprised of
nerves that run up and down the length of the back
and transmit most messages between the body and the
brain.
2.) Peripheral Nervous System (PNS): Nerves
branching out from the spinal cord.
Why is it important to protect the Spinal Cord?
The Central and Peripheral Nervous
System
How the Nervous System Works
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Messages to and from the brain travel along the
nerves, which are long, thin cells called neurons.
Neurons: The long, thin cells of nerve tissue
along which messages travel to and from the
brain.
The Neurons consist of 3 basic parts:
- 1.) The Cell Body: is the main, or center
part of the neuron. It contains the nucleus and
produces the energy needed to fuel neuron
activity.
How the Nervous System Works
- 2.) The Axon: a tail like structure that carries
information away from the cell body.
- 3.) The Dendrites: are usually small, short
thin fibers that stick out from the cell body.
They receive impulses, or messages, from other
neurons and send them to the cell body.
How do We Protect the Neurons?
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Myelin Sheath: Many axons, especially the longer ones are
covered by a white fatty substance called myelin.
This “cover” not only helps to protect portions of the
neuron, but it also helps to speed the transmission of
impulses.
In order for the nervous system to properly function, there
must be a space between each neuron. This space is called a
synapse.
Synapse: The gap that exists between individual nerve
cells.
What can happen if the Myelin Sheath is destroyed?
Multiple Sclerosis (erratic and uncontrolled behavior.)
Diagram of a Neuron
How do the Neurons Transmit
Information?
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Action Potential:
Neurons transmit
messages in the
form of
electrochemical
impulses called an
action potential.
Information is transmitted in the form of electrical impulses.
Continued…
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These messages are transmitted by the releasing
of chemicals called “neurotransmitters.”
Neurotransmitters: The chemicals released by
neurons, which determine the rate at which
other neurons fire.
And Now for a quick break…
What just happened here?
An in depth look at the Nervous System
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Definition: The Nervous System connects our
entire body and allows communication that
controls our behavior and bodily functions.
There are 2 major parts:
1.) The Central Nervous System (CNS)
 2.) The Peripheral Nervous System (PNS)
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- We have already discussed much of the CNS, so
lets break down the Peripheral Nervous System…
Peripheral Nervous System (PNS)
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The Peripheral Nervous System is divided into 2 major
parts:
- 1.) The Somatic Nervous System (SNS): This is
the part of the Peripheral Nervous System that controls
voluntary movement of the skeletal muscles…In other
words, how you move.
- 2.) The Autonomic Nervous System (ANS): This
is the part of the Peripheral Nervous System that
controls internal biological functions…In other words,
your heartbeat, stomach activity, bowels, etc…
Diagram of the Nervous System
The Structure of the Brain
The Structure of the Brain
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The Human Brain is VERY Complex. It is still
widely considered to be the most complex
structure ever discovered or created by man.
There are approximately 10 billion nerve cells in
the brain and each one has the potential to contact
every other one.
There is however, NO relationship between brain
size and intelligence.
What does relate to intelligence are the fissures,
wrinkles, and folds of the brain. No animal has as
many of these folds (convolutions) as a human
except the porpoise.
The Structure of the Brain
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Oxygen Consumption: The brain needs oxygen
to survive. The brain contributes about 1/50th
of your body weight yet consumes 25% of your
oxygen.
Deprivation of oxygen to the brain will lead to
you passing out in 15 seconds and brain damage
within 4 minutes.
The Structure of the Brain
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Important: There are NO pain receptors in the
brain. If you have a headache it is usually due to
dilation of the blood vessels that surround the
brain.
In other words, your brain cannot feel pain, but
the blood vessels and nerve system that
surround it can.
The Structure of the Brain
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The Brain Stem: Our
basic body processes
are mediated in the
brain stem, the
portion of the brain
just above the spinal
cord.
The “3” Brains
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The brain is comprised of three major parts; the
hindbrain, midbrain, and forebrain.
Hindbrain: A part of the brain located at the
rear base of the skull that is involved in the basic
processes of life.
 The
Hindbrain includes the Cerebellum, Medulla,
and Pons.
The “3” Brains
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The Cerebellum, which is located behind the spinal
cord, helps control posture, balance and voluntary
movements.
The Medulla regulates vital body functions such as
breathing , heartbeat, and a variety of reflexes. This is
why people that are called “brain dead” can still survive
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Medulla? Where have I heard this word before? Oh Yeah!
The Pons, deals with the sensory and motor
information and regulates sleep and arousal. It also
functions as a bridge between the Spinal Cord and the
brain.
The “3” Brains
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Midbrain: is a small part
of the brain above the
Pons. The midbrain
contains primitive
centers for vision and
hearing and plays a role
in the regulation of
visual effects.
The “3” Brains
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Forebrain: A part of the brain that covers the
brains central core.
Hypothalamus: Controls functions such as hunger,
thirst and sexual behavior.
 Cerebral Cortex: This is the center for higher
mental process. It is what sets humans apart from
other animals.
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The Cerebral Cortex gives you the ability to learn and
store complex and abstract information, and to
project your thinking into the future.
 Your Cerebral Cortex allows you to see, read, and
understand this sentence.
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What Parts of the brain are being
used here?
The Lobes of the Brain
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The brain is divided into 2 hemispheres (right
and left). The 2 hemispheres are divided by a
band of fibers called the “corpus callosum.”
The brain also has 4 areas, or lobes. Lobes are
the different regions that the brain is divided
into.
1.) The Occipital Lobe: This is where the visual
signals are processed. It is located in the back
of your brain.
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2.) The Parietal Lobe: This is where
information from sensors all over the body is
processed. (Supposedly located on the left side
of the brain.)
3.) The Temporal Lobe: This is where your
hearing, memory, emotion, and speaking
functions are processed. (Supposedly located on
the right side of the brain.)
4.) The Frontal Lobe: Is concerned with
organization, planning, and creative thinking. (I
wonder where it is located.)
Left and Right Hemispheres
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There are many myths about the differences
between the left and right hemispheres of the
brain. You may have heard of people being
“right or left brained” before…This is simply
not true.
In reality, the left and right side merely
compliment one another.
Right = Left….Left = Right…whaaaaaaaa?
The Electroencephalograph…
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Wow that’s a long word…How about EEG
machine.
What is it?
It is a machine used to record the electrical
activity of large portions of the brain.
Wires are connected to various areas of your
scalp, allowing the rhythms, or brain waves
caused by the neurons to be read.
The Endocrine System
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Why do people run with bulls
in Spain? Why skydive?
Heck, why do we ride roller
coasters?
Many do it for the “rush.”
This “rush” comes from a
hormone secreted by the
endocrine system called
adrenaline or epinephrine.
It’s basically sending your
body into a state of
emergency!
3 Cheers for Adrenaline!
The Endocrine System
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Our body and behavior
are controlled not only
through neural impulses
from the brain but also
through a slower
chemical system called
the endocrine system!
Isn’t that sweet 
The Endocrine System
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Endocrine System: A chemical communication
system, using hormones, by which messages are
sent through the bloodstream.
Hormones: Chemical substances that carry messages
through the body in blood.
 Hormones can have various effects on your bodies
behavior. They effect the growth of bodily structures
such as muscles and bones, so they can effect what you
can do physically. They also effect how much energy you
have to perform certain actions, attractions you may have,
and the different “moods” you may be in.
 In fact, all of the physical differences between boys and
girls are caused by hormones! (testosterone) Jamie Lee
Curtis example.
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The Endocrine System
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The Importance of “glands.”
The Pituitary gland: is the center of control of
the endocrine system that secretes a large
number of hormones.
This gland is located near the “midbrain” and
the Hypothalamus, which monitors the amount
of hormones in the blood and sends messages
to correct the imbalances.
The Endocrine System
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So what do these “hormones” do?
Well, to start off with…Hormones regulate:
- Emotional responses (awwww)
- Motivation (get off your lazy butt)
- Physical Growth (Could you point me in the
direction of the gun show?)
- Metabolism (ahhh, the fat burner!)
- Oh yeah, almost forgot…Sexual arousal (Hey
there…)
Have you bought your tickets to the
gun show?
Ron Burgandy says, “pay attention in psychology class…and learn how to get guns like these!”
The Endocrine System
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Other glands you should know!
The Adrenal Gland: Only becomes active when a
person is angry of frightened! The release of
adrenaline causes the heartbeat and breathing to
increase. This helps a person to generate extra energy!
The Sex Glands: 1.) Testes: Produce the male
hormone “testosterone.” (low levels are also found in
women) 2.) Ovaries: Produce the female hormones
“estrogen” and “progesterone.” (low levels are also
found in men)
The Endocrine System
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Testosterone: is important in the physical development
of males. Testosterone helps to decide the sex of a
fetus. It is also important for the growth of muscles
and male sex characteristics.
Estrogen and Progesterone: Are important in the
growth of female sex characteristics. They regulate the
reproductive cycles of females. The levels of these
hormones can vary, causing premenstrual syndrome
(PMS) which could cause fatigue, irritability, and
depression. (see text pg. 172 if needed)
The Endocrine System
Heredity and Environment
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How much do genetic
factors contribute to our
behavior?
How much do
environmental factors
contribute to our behavior?
Is it possible that a
combination of both
genetic and social factors
have helped us to become
what we are today?
Heredity and Environment
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What is heredity?
Heredity: Is the genetic transmission of characteristics
from parents to their offspring.
For example, do people become good athletes or are
they born that way? Do people learn to do well in
school, or are they simply born good at it?
Why do you think the concept of heredity has caused
so much controversy?
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Change things.
Heredity and Environment
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The argument over the
nature vs. nurture
question has been
going on for centuries!
So what exactly are
these “nature” and
“nurture” terms that
we have been talking
about?
Nature, mad at Nurture, haha
I’m so funny!
Heredity and Environment
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Nature: Refers to the characteristics that a
person inherits – in other words, his or her
biological “makeup.”
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Nurture: Refers to environmental factors, such
as family, culture, education, and individual
experiences.
Sir Francis Galton vs. John Watson
Nature
Nurture
Heredity and Environment
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Genes and Behavior!
Genes are the basic units of heredity! They are
reproduced and passed along from parent to child.
All of the effects that genes have on behavior occur
through their role in building and modifying the
physical structures of the body.
These structures must interact with their environment
to produce behavior.
Musicians example!
Heredity and Environment
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Twin Studies
One of the best ways to find out whether or not a trait
is inherited is to study twins.
Identical Twins: Twins who come from one fertilized
egg; in other words, twins having the same heredity.
Fraternal Twins: Twins who come from 2 different
eggs fertilized by 2 different sperm.
How can studying twins help us to understand Nature
vs. Nurture?
Can Studying Twins help to Explain
Nature vs. Nurture?
Is this behavior a result of heredity or of societal pressures?
Heredity and Environment
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Twins that grow up in the same house share the
same general environment, but identical twins
share the same genes.
Sooooo…if identical twins who grow up
together prove to be more alike on a specific
trait than fraternal twins do, it probably means
that genes are important for that trait!
Nature vs. Nurture - Twins