Biological Psychology Lecture Outline
Key to understanding Human behavior is to examine the
Biological systems:
Brain focus of 1990s research—recent tools have aided
information explosion
Brain has two types of cells (trillions!):
1. Nerve cells--called Neurons-size: 1/100th of a period.
2. Glial cells (Greek meaning “glue”) holds together, shields,
protects and moves nutrients to neurons
Brain Development:
 First 4 months of gestation the brain builds up to 200
billion brain cells
 At 8 months of gestation--brain prunes itself
 Adult brain (18-25 years old)—100 billion neurons
 Neurons located in the brain—mostly in the cortex (outer
layer of brain that is wrinkled where logic, memory
processing and storage, reasoning abilities occur) 3-5
mm deep in the cortex there are approximately 6
layers of neurons –not myelinated—therefore it is the
“grey matter”. Interior of brain has long, myelinated
axons that connect cortex “white matter”.
 CORTEX—has wrinkles, but if flattened would be 3-4
sheets of paper large (3 square feet). Brain is
folded/creased and are the home to the most
memories.
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Biological Psychology Lecture Outline
VISUAL: Show picture of Adam and God from the Sistine
Chapel—how is it like a neuron?
NEUROANATOMY: the study of the parts and functions of
neurons.
The Structure and Function of Nerve Cells: The basic unit
of the nervous system is the neuron (nerve cell).
Communication (“wiring”) between the brain and body is
done with special cells called neurons.
 DENDRITES are specialized for input (receiving signals
from other neurons). Greek word meaning “tree”. Tens of
thousands of branches from the core of the cell continue to
grow until adult (25 years)
 CELL BODY (also called soma) is specialized for
integration (combining all signals together) contains
cytoplasm and the nucleus: directs the synthesis of
neurotransmitters
 AXON is specialized for output (sending a signal out to
other neurons) Greek word for “axis”—long fiber, one per
cell, up to 3 feet long. Messages travel 200-300 mph. Axon
has terminal buttons that contain neurotransmitters.
 MYELIN SHEATH: fatty white material that surrounds
and insulates the axon. Increases the speed continues to
grow until adult (25 years)
 SYNAPSE (Greek work “to join together”) gap between
the axon terminal of one cell and the dendrite of another
cell. The brain has about 1,000 trillion synapses. There are
more synaptic connections in one brain than there are
atoms in the universe.
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The signal that travels within a neuron is ELECTRICAL:
electricity can “flow” within a neuron due to properties of
the CELL MEMBRANE. Impulses travel along neurons
electrochemically at 250-2500 impulses per second (6 ft.
person—2/10 of a second).
 Electricity travels within the cell—electricity does
not jump between the neurons!
 SEMI-PERMEABLE CELL (selectively permeable): some
things can go through (“permeate”) the membrane
passively, on their own, but other things are “trapped”
either on the inside or outside
 PUMPS: spend energy to force things to go into or out of a
neuron
 CHANNELS: are proteins with holes in them; they sit in
the cell membrane and they can change their shape. When
they do, they let certain things flow into or out of the cell.
By moving things with (+) or (-) electrical charge (“fire”) into or
out of the neuron, an electrical difference can exist across the
cell membrane.
 IONS: are atoms that carry units of (+) or (-) electrical
charge.
 SODIUM (Na+) is a (+) charged ion that tends to be
concentrated outside of cells.
 POTASSIUM (K+) is a (+) charged ion that tends to be
concentrated inside of cells.
DESCRIBE: Potato Chip Analogy—if you lick it, you taste salt
on the outside and potato (potassium) on the inside
RESTING MEMBRANE POTENTIAL: A “potential” or a
“polarity” is any kind of electrical difference. At rest, when a
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neuron is not being stimulated and is not sending out signals, the
inside of the neuron is electrically negative relative to the
outside.
DEPOLARIZATION: A net (+) electrical charge goes into the
cell, reducing polarity.
Polarized neuron has (-) ions inside and (+) ions on outside. In a
resting state the neuron is therefore mostly negative.
When the DENDRITES get signal to CELL BODY and it gets
EXCITED! The positive ions enter the membrane through the
gates and push out negative ions. The Depolarized neuron has
(+) ions on inside and (-) ions on the outside.
The BOTTOM LINE is: A neuron must depolarize past a
THRESHOLD to trigger an ACTION POTENTIAL.
View Video at:
http://www.lunatim.com/kinart/videos/videos.htm
VISUAL: Demonstrate how a row of dominoes fall down and
the time it takes to set them all back up before you are able to
knock them over again.
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ACTION POTENTIAL (“nerve impulse”—electric message
firing): An action potential is the basic unit of information
that a neuron has to work with. Action Potential has the
following characteristics:
1. THRESHOLD (enough neurotransmitters are received to
send a message to take action): depolarization is needed to
trigger.
2. It occurs “ALL OR NONE” principle (Neuron either fires
completely or it does not fire at all!)
3. It is followed by an ABSOLUTE REFRACTORY
PERIOD, during which nothing can cause another action
potential.
4. The absolute refractory period is followed by a relative
refractory period, during which a larger than usual amount
of depolarization is needed to trigger another action
potential.
5. Action potentials begin at the cell body of the neuron at the
AXON HILLOCK.
6. SELF-PROPAGATION: Action potentials are actively
regenerated as they move down the axon, away from the
cell body. This is conduction without decay.
7. MYELIN SHEATH: is a white material wrapped around
some axons. It helps action potentials go along an axon
faster (200 mph)!
If myelin sheath is damaged, signals fade and disease
could occurs.
Two Examples:
 Multiple Sclerosis (MS)—lesions on axon bundles in
brain, spinal cord and optic nerves, as adult—
muscular weakness, lack coordination, impaired vision
and speech
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 Guillain-Barre syndrome—slow action potential and
paralyzes
The signal that travels between two neurons is CHEMICAL.
One neuron “talks” to another neuron at a SYNAPSE.
 Action potentials cause PRESYNAPTIC VESICLES in the
AXON TERMINAL (also called terminal buttons or synaptic
knobs) to release NEUROTRANSMITTERS (chemicals
stored in the Axon Terminal inside synaptic vesicles that
enable neurons to communicate) into the SYNAPTIC CLEFT
(gap between the axon of one cell and the dendrite of another
cell)
 Neurotransmitters diffuse (“float”) across the synaptic cleft.
Some neurotransmitters excite the next cell into firing and
some inhibit the next cell from firing.
 Specific neurotransmitters “bind” with specific
POSTSYNAPTIC RECEPTORS.
1. “Lock and Key” model
2. Neurotransmitter—receptor binding causes
postsynaptic changes
3. ION CHANNEL: closely “tied” to a receptor can
open or close when the receptor binds a
neurotransmitter
4. Second Messenger Systems are enzymatic
chemical reactions that can be triggered in a
neuron by a neurotransmitter-receptor binding.
Ultimately, these can have several effects, one of
which might be to increase many ion channels.
5. POSTSYNAPTIC POTENTIAL (PSP): (+) or (-)
electrical charges move into the postsynaptic
neuron, causing either:
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a. Depolarization (excitatory PSP= EPSP) or
b. Hyperpolarization (inhibitory PSP= IPSP).
 Released neurotransmitters are eventually removed from
the synapse by RE-UPTAKE.
 PSPs spread passively via conduction with decay, along the
dendrites and cell body.
 The EPSPs and IPSPs that arrive at the axon hillock
summate, and if the net result is a threshold or greater amount
of depolarization, an action potential occurs.
VISUAL: Hold up Electrical wire—similarities to axon
(insulation, send electrical impulse) and the main difference: no
continuous signals/bursts of activity with periods to reset the
chemicals involved
Student activity—complete the map of the neuron by naming the
parts and describing the functions of the parts of the neurons
(handout).
NEUROTRANSMITTERS:
Here are some examples of the most commonly discussed
neurotransmitters, what their function is and any problems or
diseases that may be associated with the chemical.
1. Endorphins (pain control, brain’s pain killer)
Problems: Involved in addictions
2. Dopamine (controls complex movement, motor movement,
synthesizes hormones and alertness, plays role in the
pleasure and reward system in brain) Problems:
Parkinson’s disease-, schizophrenia+
3. Acetylcholine (Ach) 1st NT identified (motor movement,
contracts muscles, regulates heart, encode memory)
Problems: Alzheimer’s disease-, paralysis Womble AP Psychology Page 7
Biological Psychology Lecture Outline
4. Serotonin (mood control, sleep, appetite, anxiety,
depression, sexual activity, concentration and attention,
temperature regulation, ) in pons Problems: clinical
depression-, LSD+ (prevents reuptake)
5. Norepinephrine (regulate sleep, mood, pay attention,
emotional arousal)
Problems: Anti-Depressants -, Cocaine +
6. Gamma-aminobutyric acid (GABA) (inhibits firing of
neurons—you relax, sleep) Valium increase activity of
GABA Problems: Huntington’s disease-, seizures
(malfunction GABA)
7. Glutamote (emote and think)
8. Epinephrine (control blood pressure)
Normal Nervous System Transmission of Messages:
ALL of your behavior begins with the actions of your
neurons! (AMAZINGLY COMPLEX)
 AFFERENT or Sensory Neurons: incoming (from sensory
neurons, up the spinal cord, to the brain stem, and to the
brain cortex interneurons)
 EFFERENT or Motor Neurons: outgoing (from the brain’s
interneurons, down the spinal cord, to the muscles –
mnemonic: “Exits the brain” or Effort response)
ONE EXCEPTION: Reflexes—spine sends the message and the
brain finds out after the response—keeps us from harming
ourselves and helps us survive, therefore the trait has been
passed on to our children. E.g. knee jerk, sneeze, blink, etc.
What fuels the brain and neuron activity?
1. Oxygen (deep breathing—need 1 eight oz. glass of water
for every 25 pounds of weight a person has to keep lungs
moist and transfers oxygen to blood
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2. Glucose (sugar—fruit)
Structure and Function of the Nervous System
The Nervous System is composed of “highways” and “cities”.
Different structures are specialized for input, integration, and
output.
HIGHWAYS: pathways that carry information form one
place to another. Composed of AXONS collectively called
“white matter” since the myelin covering looks whitish in color.
Specific pathways are often called NERVES, TRACTS, or
COLUMNS.
CITIES: areas that process or transform signals and
information, perform “computations”. Composed mostly of
CELL BODIES and DENDRITES collectively called “gray
matter” since there is less whitish myelin. Specific areas are
sometimes called NUCLEI, GANGLIA or CORTEX.
OVERALL ORGANIZATION OF THE NERVOUS
SYSTEM
PERIPHERAL NERVOUS SYSTEM (PNS): consists of all
the other nerves in the body not encased in bone that carry
sensory information to and motor information away from the
central nervous system via spinal and nerves. Student Activity:
Concept Map
SOMATIC NERVOUS SYSTEM (SNS)-controls
voluntary (skeletal) muscle movements. Motor cortex sends
messages to the SNS to control muscles that allow us to move.
Sensory Division
Motor Division
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AUTONOMIC NERVOUS SYSTEM (ANS)-controls
automatic functions of the body (heart, lungs, internal organs,
glands, etc.) These nerves control our response to stress—the
FIGHT or FLIGHT RESPONSE that prepares our body to
respond to a threat.
 SYMPATHETIC NERVOUS SYSTEM—The alert
system of the body. Mobilizes our body to
respond to stress. ACCELERATES functions
(heart rate, blood pressure, respiration, dilate
pupil, glucose release from liver, secret
adrenalin) and conserves resources needed for
response by slowing down other functions
(digestion).
 PARASYMPATHETIC NERVOUS SYSTEM-The brake
pedal that SLOWS DOWN and calms down the
ANS, it s responsible for slowing down
our body after a stress response (e.g.
return pupils to normal, stimulate tear
glands, restore normal digestive
processes, and normal bladder
contractions).
 (Mnemonic: parachute—ride it down!)
ACTIVITY: Students create a neuron firing chain and time
different connections of impulses (hand to hand, shoulder to
shoulder, leg to leg, etc.)
Central Nervous System=Brain (skull) + Spinal Cord
(vertebrae)
Protective membranes called MENINGES.
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SPINAL CORD: bundle of
nerves that run through the center of
the spine that transmits information
from the rest of the body to the brain
BRAIN: there are several ways
to divide the brain into sections to
study:
Hindbrain, Midbrain, Forebrain
Evolutionary Model-Reptilian Brain, Old Mammalian Brain
(Limbic System), Neocortex (New Mammalian)
Four Lobes: Frontal Lobes, Parietal lobes, Occipital lobes,
Temporal Lobes
Hemispheres: Right and Left
Brain Parts and Functions
MEDULLA OBLONGATA (Hindbrain)
PONS (Hindbrain)
CEREBELLUM (Hindbrain)
THALAMUS (Limbic-Forebrain)
HYPOTHALAMUS (limbic-Forebrain)
HIPPOCAMPUS (Limbic-Forebrain)
AMYGDALA (Limbic-Forebrain)
OLFACTORY
RETICULAR FORMATION
PITUITARY GLAND
CORPUS CALLOSUM-Connects Left and Right side of CORTEX
CEREBRAL CORTEX
1. Looks folded and wrinkled. Bumps are called GYRI and
folds are called SULCI
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2. Each hemisphere is divided into four lobes: Frontal,
Parietal, Occipital, Temporal
3. Sensory and motor cortical areas tend to have
TOPOGRAPHICAL organization and represent the
CONTRALATERAL side of the world
4. Association Areas
FRONTAL LOBES
 Motor Cortex
 Brocas Area (on the
left)
PARIETAL LOBES
 Somatosensory
Cortex
OCCIPITAL LOBES
 Visual Cortex
TEMPORAL LOBES
 Wernicke’s Area (on
the left)
 Auditory Cortex
What is the only direct extension of the brain you normally
see?
EYES (brain analyzes data from body)
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