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Health Psychology
Chapter 3: Biological Foundations of
Health and Illness
Aug 31-Sep 5, 2007
Classes #6-7
Biological Roots of Behavior

Franz Gall (1758-1828)
– Austrian physicist who invented phrenology
– He felt that bumps on the skull could reveal our
mental abilities and character traits
– Introduced as being scientific but its use was
exploited by “quacks on gullible individuals”
– Became similar to that of astrology, palm-reading and
tarot
– Although, ill-fated theory was laughed at by scientific
community of that day – it may have had some
validity
– Localization of brain functions somehow hit the
mark
The Nervous System
Electrochemical communication system
that enables us to think, feel, and behave
 Complex beyond comprehension
 Although, human brains are more complex
our nervous systems and those of animals
operate in a similar fashion – advantage of
this is experimentation

The Nervous System

Allows researchers to study simple animals
such as squids and sea slugs to help us
better understand the organization of our
own brains
Divisions of the Nervous
System

Consists of two systems
– Central Nervous System
 Brain and spinal cord
– Peripheral Nervous System
 Which connects the CNS to the rest of the
body
Organization of the Nervous System
Peripheral Nervous System

Two components:
– Somatic Nervous System
 Transmits sensory input to the CNS from
the outside world and directs motor output
– Autonomic Nervous System
 Controls glands and muscles of our internal
organs – “automatic pilot”
Autonomic Nervous System

Dual system:
– Sympathetic Nervous System
 Arouses the body
– Parasympathetic Nervous System
 Calms us down
Endocrine System: Taking the slow lane
Unlike the speedy nervous system which
zips messages from eyes to brain to hand
in a fraction of a second, endocrine
messages use the slow lane
 May take several seconds or more as
bloodstream carries a hormone from an
endocrine gland to its target tissue

Endocrine System
Hormones are chemical messengers
 Influence all aspects of our lives – growth,
metabolism, reproduction, moods, etc.
 Strives for homeostasis (balance) by
responding to stress, exertion, internal
thoughts, etc.

Epinephrine

Involved in energy and glucose
metabolism
Illnesses Associated With Epinephrine

Depression – too low levels
Norepinephrine
Plays a role in attention and arousal
 Used by sympathetic nervous system to
prepare us for action

Illnesses Associated With
Norepinephrine

Depression
– Chronic stress depletes this neurotransmitter
and can lead to depression

Note:
– Aerobic Exercise is found to protect the brain
from this depletion – so go out and run a mile
or two if your down in the dumps
How does the brain govern
behavior?

3 Principle layers of the brain:
– Brainstem
– Limbic System
 Hippocampus
 Amygdala
 Hypothalamus
– Cerebral Cortex
Brainstem (or Hindbrain)

The brain’s innermost region…
– Begins where the spinal cord enters the skull
and swells slightly forming the medulla
– Towards the rear of the brainstem is the
cerebellum – this is linked to memory and its
major function is muscular control
Limbic System

Hippocampus
– This structure plays a key role in allowing us
to store new information
– Problems here may cause Alzheimer's – these
individuals have trouble processing declarative
memories
– Milner (1968): the classic case of H.M.
Limbic System

Amygdala
– Emotional control center of the brain – major
influence on aggression and fear
– Emotional memories as well
– Alzheimer’s ???
 Kluver and Bucy (1939)
 Demasio (1994)
Limbic System

Hypothalamus
– Major influence on hunger, thirst, body
temperature, and sexual behavior
 Olds and Milner (1954)
Cerebral Cortex

Makes us distinctively human – much higher
developed than in animals
– Motor Cortex – involved in the conscious initiation
of voluntary movements in specific parts of the body
including hand, knee, foot and head
Fritsch and Hitzig (1870)
 Delgado (1969a)
 Delgado (1969b)
 Penfield (1975)

Cerebral Cortex


Sensory Cortex
– receives information from our senses
 Visual cortex
– visual info
 Auditory cortex
– auditory info
 Somatosensory cortex
– info from skin
Association cortex
– involved in complex cognitive tasks associating words
with images
 Broca’s area (aphasia)
 Wernicke’s area (aphasia)
Function of the Cardiovascular
System





Assist in gas transport.
Deliver nutrients, hormones
Remove waste products from the cells
Assist in temperature regulation
Assist in balancing body fluids and helps
prevent dehydration
Systems of the Heart
 The
heart functions to contract
and propel blood through the
two blood transport systems.
 Pulmonary
system
 Systemic system
Pulmonary System
Within the pulmonary system blood is
transported to and from the lungs.
 The right ventricle propels
deoxygenated, carbon dioxide rich,
blood to the lungs where carbon dioxide
is released and oxygen is picked up.
 After gas exchange the blood returns to
the left atrium of the heart.

Impact of Cardiovascular
Disease
Affects more than 60 million
Americans each year
 Results in nearly 1 million deaths
each year
 Cost nearly $275 billion

Cardiovascular Disease
 Cardiovascular
disease (CVD)
is the number one cause of
death in the United States.
 Most reported deaths are
related to coronary artery
disease
Forms of Cardiovascular
Disease







Coronary artery disease
Hypertension (Chronic high blood pressure)
Cerebral vascular accidents (strokes)
Peripheral vascular disease
Valvular heart disease
Congenital heart disease
Congestive heart failure
Coronary Artery Disease
 Primary
form of heart disease
 A disease involving waxy
plaque build-up in the arteries
Coronary Risk Factors

Primary Risk Factors: Factors that have
been definitively associated with or
directly cause coronary artery disease.


Smoking, inactivity, hypertension
Secondary Risk Factors: Factors believed
to contribute to or advance the severity of
CAD.

Gender, age
The Respiratory System


At the level of the individual cell:
respiration involves energy-producing
chemical reactions that require oxygen
At the level of the whole organism,
respiration is the process of taking in
oxygen from the environment and ridding
the body of carbon dioxide.
The Lungs

Left and right
lungs:


are in left and
right pleural
cavities
The base:

inferior portion of
each lung rests on
superior surface of
diaphragm
The Right
Lung

Has 3 lobes:


superior,
middle, and
inferior
separated by
horizontal and
oblique fissures
The Left Lung

Has 2 lobes:


superior and
inferior
are separated by
an oblique
fissure
Relationship between Lungs and
Heart
Figure 23–8
Lung Shape

Right lung:



is wider
is displaced upward by liver
Left lung:


is longer
is displaced leftward by the heart forming
the cardiac notch
Components of
the Digestive System
Digestive Tract



Gastrointestinal
(GI) tract or
alimentary canal
Is a muscular tube
Extends from oral
cavity to anus
6 Functions of the Digestive System
Ingestion:
1.
occurs when materials enter digestive tract via the
mouth

Mechanical processing:
2.
crushing and shearing
makes materials easier to propel along digestive
tract


3.
Digestion:



is the chemical breakdown of food
into small organic fragments
for absorption by digestive epithelium
Secretion:
4.
is the release of water, acids, enzymes, buffers, and salts
by epithelium of digestive tract
by glandular organs



Absorption:
5.
movement of organic substrates, electrolytes, vitamins,
and water
across digestive epithelium
into interstitial fluid of digestive tract



6.
Excretion:

removal of waste products from body fluids
THE IMMUNE SYSTEM
We all get sick sometimes...but then
we get better.
What happens when we get sick?
Why do we get better?
ANATOMY OF THE IMMUNE SYSTEM

The immune system is
localized in several
parts of the body
 immune cells
develop in the
primary organs bone marrow and
thymus (yellow)
 immune responses
occur in the
secondary organs
(blue)
ANATOMY OF THE IMMUNE SYSTEM

Thymus – glandular organ near the heart – where T cells learn
their jobs

Bone marrow – blood-producing tissue located inside certain
bones


blood stem cells give rise to all of the different types of blood cells
Spleen – serves as a filter for the blood


removes old and damaged red blood cells
removes infectious agents and uses them to activate cells called
lymphocytes

Lymph nodes – small organs that filter out dead cells, antigens,
and other “stuff” to present to lymphocytes

Lymphatic vessels – collect fluid (lymph) that has “leaked” out
from the blood into the tissues and returns it to circulation
PASSIVE IMMUNITY
While your immune system was developing, you were
protected by immune defenses called antibodies. These
antibodies traveled across the placenta from the maternal
blood to the fetal blood.
Antibodies (Y) are also found
in breast milk.
The antibodies received
through passive immunity
last only several weeks.
reign invaders - viruses, bacteria, allergens, toxins and
rasites- constantly bombard our body.
YOUR ACTIVE IMMUNE DEFENSES
Innate Immunity
Adaptive Immunity
- invariant (generalized)
- early, limited specificity
- the first line of defense
- variable (custom)
- later, highly specific
- ‘‘remembers’’ infection
What influences one’s
behavior: Nature or Nurture?

The age-old debate:
 Is
it genes or is it the environment?
Twin Studies

Monozygotic


Identical twins (one-egg)
Dizygotic

Not identical (fraternal) twins

Resemble one another as much as any brother or
sister would
“The Jim Twins”

Thomas Bouchard’s University of Minnesota twin studies
 Extraordinary similarities between Jim Springer and
Jim Lewis
 Uncanny coincidences?
 Any limitations to this study?
These guys shared a flushing
the toilet gene…

Bouchard (1979)

Part of Bouchard’s twins study…

Oskar Stohl and Jack Yulfe were raised in
environments with more obvious differences
And you thought it was because
you were incompatible…

Is there a genetic risk of divorce?

McGue and Lykken (1992)
 1516 pairs of same-sex twins
 722 MZ and 794 DZ
 MZ > DZ
What is a gene made out of?

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Genes are made from
chromosomes. People have 23
pairs of chromosomes.
DNA consists of a double helix,
whose parallel strands consist of
both pairs held together by
hydrogen bonds.
Each chromosome in the DNA
contains instructions for
stringing together amino acids.
These instructions are used in
different combinations with the
chemicals adenine (A), thiamine
(T), guanine (G) and cytosine
(C).
Conception


Fertilized egg with two pronuclei


Within 72 hours it’s divided into 8 cells
Once the sperm penetrates the
egg, the two nuclei fuse to
become one, with 23
chromosomes from the father
and 23 chromosome from the
mother
A zygote is the single cell
formed from the fusing of the
sperm and ovum.
After four days there are about
100 cells and it is now called a
blastocyst
The organism’s genetic
inheritance is set for life once
the chromosomes pair up
Is it a boy or a girl?



In the 23rd pair of
chromosomes women
are XX and men are
XY
Every ovum that the
woman produces is XX
Men will produce half
Y sperm and half X
sperm because his
23rd pair contain both

1.
2.
3.
Different factors can
determine the sex of the
embryo such as when:
A man carries a gene
that causes his X or Y
gene to be immobile
The alkaline or acidity
levels of a woman’s
uterus can help either
the X or Y gene
Stress can cause an XY
embryo to be expelled

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
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1.
2.
3.
4.
A zygote may split in the early
stages of development, which
creates separate identical
zygotes
Monozygotic twins are
identical because they originate
from the same zygote
Dizygotic twins are formed
when two separate ova are
fertilized by two separate sperm.
They share half their genes,
similar to siblings.
Factors that can increase the
chances of twins are:
A woman’s age
A woman’s ethnic group
Medical intervention
A family history of having
twins
Let’s split!
Mary-Kate and Ashley Olsen
What else do genes do?



Once the zygote reaches it’s
eight-cell stage, cells begin to
specialize to become different
parts of the body
Genes code protein so that
they can give instructions to
other genes to shut on and off
at different stages of life. For
instance, to absorb
nourishment, to multiply and
to die
Phenotype is a person’s
actual appearance and
behavior, which are the results
of both genetic and
environmental influences
How do gene’s interact?


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Additive genes interact
additively so that there are
fairly equal contributions from
all the genes involved. They
affect traits such as skin color
and height
A dominant gene is the
member of an interacting pair
of alleles whose influence is
more evident in the phenotype
A recessive gene is the
member of an interacting pair
of alleles whose influence is
less evident in the phenotype
X-linked genes are genes
located on the X chromosome
Genotype vs. Phenotype

Genotype is an
organism’s entire genetic
inheritance, or genetic
potential. For instance,
you might have inherited
the genes that could lead
you to become a great
mathematician. Another
example is that you may
have inherited blue eyes.

Phenotype is a person’s
actual appearance and
behavior, which are the
result of both genetic and
environmental influences.
For instance, you might
have the genes to
become a great
mathematician, but
without the right
environment, your talent
may never be recognized.
What is behavior genetics?

Behavior genetics is
the study of the genetic
origins of psychological
characteristics, such as
personality patterns,
psychological disorders
and intellectual abilities
Sadness is one personality trait that is
studied in behavior genetics
Behavioral Genetics

This field studies the relationship between
heredity and behavior…


Research in behavioral genetics has shown
that even newborn infants exhibit differences
in temperament
Some are emotionally placid, others are
emotionally reactive
How it applies to the development
of personality…

Initial differences in temperament might
contribute to the development of differences in
personality…




They might affect how infants respond to other
people and, in turn, how other people respond to
them
For example, a placid infant would be less responsive
to other people
As a consequence, others would be less responsive to
the infant
This might predispose the infant to become less
sociable later in childhood, laying the groundwork for
an introverted adult personality
Conclusion

Which plays a bigger
role in human
development,
heredity or
environment?
Is Kate Hudson’s ability as an actor influenced
by her environment or genes? Do you think
her environment or her genes influenced her
career choice?
Credits




http://www.clt.astate.edu/amooneyhan/WebPresentations/WebCh4Cardio%20SysII-New.PPT
http://www.coe.unt.edu/mcnair/ClassNotes/Spring2006/Ch%2023%20The
%20Respiratory%20System.ppt#4
http://www.coe.unt.edu/mcnair/ClassNotes/Spring2006/Ch%2024%20The
%20Digestive%20System.ppt
http://www.nbtc.cornell.edu/mainstreetscience/immunity_and_you/IMMUN
OLOGY_LECTURES/Lecture_1_Innate_Immunity.ppt#13