Download The Science of Psychology

The Biological Perspective
Chapter 2
LO 2.1 What are the nervous system, neurons and nerves
Overview of Nervous System
• Nervous System - an extensive network of
specialized cells that carry information to and from all
parts of the body.
• Neuroscience – deals with the structure and function
of neurons, nerves, and nervous tissue.
• Relationship to behavior and learning.
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The Nervous System
Nervous
System
Central
Nervous
System
Peripheral
nervous
system
Autonomic
(Involuntary)
Somatic
(Voluntary)
The Nervous System
Central Nervous System
Peripheral Nervous System
LO 2.3
Brain and spinal cord
Central Nervous System
• Central nervous system (CNS) - part of
the nervous system consisting of the
brain and spinal cord.
• Spinal cord - a long bundle of
neurons that carries messages
• is responsible for very fast,
lifesaving reflexes.
Nervous
System
Central
Nervous
System
Peripheral
nervous
system
Autonomic
(Involuntary)
Somatic
(Voluntary)
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LO 2.3
Brain and spinal cord
The Reflex Arc: Three Types of
Neurons
• Sensory neuron - a neuron that carries information
from the senses to the central nervous system.
• Motor neuron - a neuron that carries messages from
the central nervous system to the muscles of the
body.
• Interneuron - a neuron found in the center of the
spinal cord that receives information from the sensory
neurons and sends commands to muscles via the
motor neurons.
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The Reflex Arc
LO 2.4
Somatic and autonomic nervous systems
Peripheral Nervous System
• Peripheral nervous system (PNS) all nerves and neurons that are not
contained in the brain and spinal
Nervous
System
cord but that run through the body
itself
Central
Peripheral
Nervous
System
• Divided into the:
• Somatic nervous system
• Autonomic nervous system
Autonomic
(Involuntary)
nervous
system
Somatic
(Voluntary)
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LO 2.4 Somatic and Autonomic nervous systems
Autonomic Nervous System
• Autonomic nervous system (ANS) division of the PNS consisting of
nerves that control all of the
involuntary muscles, organs, and
glands
• Composed of:
Sympathetic division Reacts to
stressful events and bodily
arousal.
• Parasympathetic division –
restores body to normal
functioning after arousal
Nervous
System
Central
Nervous
System
Peripheral
nervous
system
Autonomic
(Involuntary)
Somatic
(Voluntary)
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LO 2.4 Somatic and Autonomic nervous systems
Somatic Nervous System
• Somatic nervous system division of the PNS consisting
of nerves that carry
information from the senses to
the CNS and from the CNS to
the voluntary muscles of the
body.
Nervous
System
Central
Nervous
System
Peripheral
nervous
system
Autonomic
(Involuntary)
Somatic
(Voluntary)
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Autonomic Divisions
Sympathetic
Eyes
Lungs
Heart
Stomach
Blood Vessels
Parasympathetic
LO 2.1 What are the nervous system, neurons and nerves
Structure of the Neuron
• Neurons – cells that make up the
nervous system
• receive and send messages within
that system.
• Parts of a Neuron
• Dendrites - branch-like structures
that receive messages.
• Soma - the cell body of the
neuron, maintains the life of the
cell.
• Axon - long tube-like structure that
sends out messages
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Structure of the Neuron
LO 2.1 What are the nervous system, neurons and nerves
Other Types of Brain Cells
• Glial cells - grey fatty cells that:
• Provide support for the neurons to grow
• Deliver nutrients to neurons
• Produce myelin to coat axons
Glial Cell
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Myelin Sheath
Myelin - fatty substances
that coat the axons of
neurons to insulate,
protect, and speed up
the neural impulse.
• Clean up waste
products and
dead neurons.
Myelin
LO 2.1 What are the nervous system, neurons and nerves
Neurons in the Body
• Nerves – bundles of axons in the body that travel
together through the body.
Axon
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LO 2.1 What are the nervous system, neurons and nerves
Generating the Message:
Neural Impulse
• Ions – charged particles.
• Inside neuron – negatively charged.
• Outside neuron – positively charged.
• Resting potential - the state of the neuron when not
firing a neural impulse.
• Action potential - the release of the neural impulse
• All-or-none - referring to the fact that a neuron
either fires completely or does not fire at all.
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Action Potential
Action Potential
LO 2.2
Neuron communication
Neuron Communication
• Excitatory
neurotransmitter neurotransmitter that
causes a receiving cell
to fire.
• Inhibitory
neurotransmitter neurotransmitter that
causes a receiving cell
to stop firing.
Excitatory
Inhibitory
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Neuron Communication
• Chemical substances can affect neuronal
communication.
• Agonists - mimic or enhance the effects of a
neurotransmitter; thus, increasing or decreasing
the activity of a receiving cell
• Antagonists - block or reduce a cell’s response to
neurotransmitters or other chemicals
LO 2.2 Neuron communication
Neurotransmitters
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LO 2.5
Study of the brain
Peeking Inside the Brain
• Deep lesioning – sending electrical current via a
wire, which destroys the brain cells at the tip of the
wire.
• Electrical stimulation of the brain (ESB) – sending
milder electrical current via a wire to explore the
activity of the brain
•
http://www.youtube.com/watchv=IOHtUzW02cg&feature=related
• Electroencephalograph (EEG) – Records brain
wave patterns produced by electrical activity of the
surface of the brain.
•
http://www.youtube.com/watch?v=t6XeCwFQrCA&NR=1
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LO 2.5
Study of the brain
Peeking Inside the Brain
• Computed tomography (CT) - brain-imaging method
using computer controlled X-rays of the brain.
• Magnetic resonance imaging (MRI) - brain-imaging
method using radio waves and magnetic fields. FMRImore detailed
•
http://www.youtube.com/watch?v=Cwda7YWK0WQ
• Positron emission tomography (PET) - brain-imaging
method in which an injected radioactive sugar shows
the activity of the brain with lighter colors indicating
more activity.
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LO 2.6 Structures of the bottom part of brain
The Brain Stem
• Medulla – Forms
the lowest part of
the brain
• Responsible
for lifesustaining
functions such
as breathing,
swallowing,
and heart
rate.
Medulla
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The Brain Stem
• Pons – Structure
above the medulla
• Connects the top
of the brain to the
bottom
• Plays a part in
sleep, dreaming,
left–right body
coordination, and
arousal.
Pons
LO 2.6 Structures of the bottom part of brain
The Brain Stem
• Cerebellum part of the lower
brain located
behind the Pons
• Controls and
coordinates
involuntary,
rapid, fine
Cerebellum
motor
movement.
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LO 2.7 Structures controlling emotion, learning, memory, and motivation
The Limbic System
• Limbic system - a group of several brain structures
involved in learning, emotion, memory, and
motivation.
Thalamus
Hypothalamus
Olfactory
Amygdala Hippocampus
bulbs
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LO 2.7 Structures controlling emotion, learning, memory, and motivation
The Limbic System
• Hypothalamuslocated below the
thalamus and directly
above the pituitary
gland
• Responsible for
motivational
behavior
Hypothalamu
s
• Controls pituitary
gland
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The Limbic System
• Thalamus - part of
the limbic system
located in the center
of the brain
• Relays sensory
information from
the lower part of
the brain to the
proper areas of
the cortex
Thalamus
The Limbic System
• Hippocampus curved structure
located within each
temporal lobe
• Formation of longterm memories
and the storage of
memory for
location of objects.
Hippocampus
The Limbic System
• Amygdala - brain
structure located
near the
hippocampus
• Responsible for
fear responses
and memory of
fear.
Amygdala
The Limbic System
• Olfactory bulbs two projections
just under the
front of the brain
• Receive
information
from the
receptors in
the nose
located just
below.
Olfactory
bulbs
LO 2.7 Structures controlling emotion, learning, memory, and motivation
The Cortex
• Cortex - outermost
covering of the brain
consisting of densely
packed neurons
• responsible for
higher thought
processes and
interpretation of
sensory input.
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The Cortex: Various Primates
LO 2.8 Parts of cortex controlling senses and movement
Cerebral Hemispheres
• Cerebral hemispheres - the two sections of the cortex
on the left and right sides of the brain.
• Corpus callosum - thick band of neurons that
connects the right and left cerebral hemispheres.
Corpus callosum
Corpus callosum
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LO 2.8 Parts of cortex controlling senses and movement
Four Lobes of the Brain
• Occipital lobe – section
containing the visual
centers of the brain.
• Primary visual
cortex – processes
visual information
from the eyes.
• Visual association
cortex – identifies
and makes sense of
visual information.
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Four Lobes of the Brain
• Parietal lobes – sections
containing centers for
touch, taste, and
temperature sensations.
• Somatosensory
cortex – responsible
for processing
information from the
skin and receptors for
touch, temperature,
body position, and
possibly taste.
LO 2.8 Parts of cortex controlling senses and movement
Four Lobes of the Brain
• Temporal lobes – areas
containing the neurons
responsible for the sense
of hearing and
meaningful speech.
• Primary auditory
cortex – processes
auditory information
from the ears.
• Auditory association
cortex – identifies/
makes sense of
auditory information.
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Four Lobes of the Brain
• Frontal lobes – areas
responsible for higher
mental processes,
decision making, and
the production of
fluent speech.
• Motor cortex –
responsible for
sending motor
commands to the
muscles of the
somatic nervous
system.
Four Lobes: Summary
LO 2.9 Parts of cortex responsible for higher thought
Association Areas of Cortex
• Association areas- areas responsible
Wernicke’s aphasia
for interpreting information
Broca’s aphasia
• Broca’s aphasia – result of
damage to Broca’s area-Inability
to speak fluently, to mispronounce
words, and to speak haltingly.
•
http://www.youtube.com/watch?v=Fw6d54gjuvA
• Wernicke’s aphasia – result of
damage to Wernicke’s areaInability to understand or produce
meaningful language.
•
http://www.youtube.com/watch?v=aVhYN7NTIKU&feature=relat
ed
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Association Areas of the Brain
• Spatial neglect - condition produced by damage to
the association areas of the right hemisphere
• Inability to recognize objects or body parts in the
left visual field.
•
http://www.youtube.com/watch?v=ADchGO-0kGo&feature=related
LO 2.10 Left side and right side of brain
Split Brain Research
• Split brain research
• Study of patients with severed corpus callosum.
• Involves sending messages to only one side of the
brain.
• Demonstrates right and left brain specialization.
•
http://www.youtube.com/watch?v=aCv4K5aStdU
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LO 2.10 Left side and right side of brain
Results of Split Brain Research
• Left side of the brain:
• seems to control language, writing, logical
thought, analysis, and mathematical abilities,
• processes information sequentially,
• Right side of the brain
• controls emotional expression, spatial perception,
recognition of faces, patterns, melodies, and
emotions,
• processes information globally
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