Unit 3:
Biological Bases
of Behavior
Mr. McCormick
A.P. Psychology
Essential Question
How are human thought and
behavior affected by the following:
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•
•
•
The Nervous System
The Endocrine System
The Brain
Genetics
Unit 3-A (A):
The Neuron
Mr. McCormick
A.P. Psychology
Do-Now
(Discussion)

What is Biological Psychology?

What parts of the body do Biological Psychologists
primarily study?

In understanding psychology, why do you think it is
important to understand biological processes?
Biological Psychology

Biological Psychology:

A branch of Psychology
concerned with the links
between biology and behavior

Biological Psychologists:
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Behavioral Neuroscientists
Neuropsychologists
Behavior Geneticists
Physiological Psychologists
Biopsychologists
Biological Psychology
The Neuron

Neuron:
Nerve cell
 Basic building block of the nervous system

The Neuron

Types of Neurons:
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Sensory Neurons:
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Motor Neurons:
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Carry incoming information from sensory receptors to the brain/spinal
cord
E.g. Perceiving something as “hot”
Carry outgoing information from the brain/spinal cord to the
muscles/glands
E.g. Clenching a fist
Interneurons:


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Located within the brain/spinal cord
Communicate internally between sensory inputs and motor outputs
E.g. Reflexes
The Neuron
 Provide
an example of information that
sensory neurons may transmit.
 Provide
an example of information that
motor neurons may transmit.
 Provide
an example of information that
interneurons may transmit.
Parts of the Neuron
The Firing of a Neuron

Neurons transmit messages when stimulated by our senses, or
triggered by chemicals of other neurons

Resting Potential:

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Threshold:

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Fluid interior of axon: negatively charged ions
Fluid exterior of axon membrane: positively charged ions
Level of stimulation required to trigger a neural impulse (action potential)
Excitatory signals (accelerator) minus inhibitory signals (brakes) must reach
minimum intensity
Action Potential:

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
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Neural impulse
Depolarization occurs
Brief electrical charge that travels down an axon
“All-or-None” Response
The Firing of a Neuron
Review

What is a neuron?

Differentiate between the 3 types of neurons:




Discuss the functions of the following parts of the neuron:
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Sensory Neurons
Motor Neurons
Interneurons
Dendrites
Axon
Myelin Sheath
Terminal Branches
What causes neurons to fire?
Homework

Research Study # 2: “More Experience =
Bigger Brain” (Pgs. 11-18)

Unit 3-A FRQ:

Unit 3-A Quiz: “The Neuron”