Download The Nervous System - McGraw Hill Higher Education

PsychSmart
INTRODUCTION TO PSYCHOLOGY
1
Copyright © McGraw-Hill, Inc. 2011
CHAPTER TWO:
NEUROSCIENCE AND BEHAVIOR
2
Copyright © McGraw-Hill, Inc. 2011
Neurons: The Basic Units
of the Nervous System

Why do psychologists study the brain and
nervous system?

What are the basic elements of the
nervous system?

How does the nervous system
communicate electrical and chemical
messages from one part to another?
3
Copyright © McGraw-Hill, Inc. 2011
Structure of the Neuron

Neurons (Nerve cells)


Basic elements of the
nervous system
As many as 1 trillion
Figure 1 of Chapter 2
Copyright © McGraw-Hill, Inc. 2011
4
The Structure of the Neuron

Dendrites


Axon



Clusters of fibers that receive messages from other
neurons
Carries messages received by the dendrites to other
neurons
Terminal buttons-send messages to other neurons
Myelin sheath

A protective coating of fat and protein that wraps
around the axon like links of sausage
5
Copyright © McGraw-Hill, Inc. 2011
How Neurons Fire

Transmits an
electrical impulse
along the axon




All-or-none law
Resting state
Action potential
Mirror neurons
Figures 2 and 3 of Chapter 2
Copyright © McGraw-Hill, Inc. 2011
6
Where Neurons Meet:
Bridging the Gap

Synapse

The space between
two neurons where the
axon of a sending
neuron communicates
with the dendrites of a
receiving neuron by
using chemical
messages
Figure 4 of Chapter 2
Copyright © McGraw-Hill, Inc. 2011
7
Where Neurons Meet:
Bridging the Gap

Neurotransmitters

Chemicals that carry messages across the
synapse to a dendrite of a receiving neuron

Excitatory messages


Inhibitory messages


Increase the likelihood that neurons will fire
Decrease the likelihood that neurons will fire
Reuptake

Reabsorption by the terminal button
8
Copyright © McGraw-Hill, Inc. 2011
Neurotransmitters:
Chemical Couriers




Acetylcholine (ACh)
Dopamine (DA)
Serotonin
Endorphins
Figure 5 of Chapter 2
Copyright © McGraw-Hill, Inc. 2011
9
Parts of the Nervous System
Figure 6 of Chapter 2
Copyright © McGraw-Hill, Inc. 2011
10
The Nervous System:
Linking Neurons

Central and Peripheral Nervous Systems

Central nervous system
Brain
 Spinal cord


Reflex
 Sensory (afferent) neurons
 Motor (efferent) neurons
 Interneurons
11
Copyright © McGraw-Hill, Inc. 2011
The Nervous System:
Linking Neurons

Central and Peripheral Nervous Systems

Peripheral Nervous System

Somatic division


Voluntary movements
Autonomic division

Controls organs that function automatically
12
Copyright © McGraw-Hill, Inc. 2011
The Central Nervous System &
the Peripheral Nervous System
Figure 7 of Chapter 2
Copyright © McGraw-Hill, Inc. 2011
13
Activating the Divisions of the
Autonomic Nervous System

Sympathetic Division

Acts to prepare the body for action in stressful
situations by engaging all of the organism’s
resources to run away or confront the threat


“Fight or flight”
Parasympathetic Division

Calms the body after emergency ends
14
Copyright © McGraw-Hill, Inc. 2011
Major Functions of the
Autonomic Nervous System
Figure 8 of Chapter 2
Copyright © McGraw-Hill, Inc. 2011
15
The Evolutionary Foundations
of the Nervous System

Evolutionary Psychology


The branch of psychology that seeks to
identify how behavior is influenced and
produced by our genetic inheritance from our
ancestors
Behavioral Genetics

Studies the effects of heredity on behavior

Behavioral genetics, gene therapy, and genetic
counseling
16
Copyright © McGraw-Hill, Inc. 2011
The Endocrine System:
Hormones and Glands

The chemical
communication
network that sends
messages throughout
the body via the
bloodstream


Hormones
Pituitary gland

“Master gland”
Figure 9 of Chapter 2
Copyright © McGraw-Hill, Inc. 2011
17
The Brain

How do researchers identify the major parts and
functions of the brain?

What are the major parts of the brain, and for
what behaviors is each part responsible? How
do the two halves of the brain operate
interdependently?

How can an understanding of the nervous
system help us find ways to alleviate disease
and pain?
18
Copyright © McGraw-Hill, Inc. 2011
Techniques for Spying on the
Brain

Electroencephalogram (EEG)

Functional Magnetic Resonance Imaging
(fMRI)

Positron Emission Tomography (PET)

Transcranial Magnetic Stimulation (TMS)
19
Copyright © McGraw-Hill, Inc. 2011
Brain Scans Produced
by Different Techniques
Figures 10A, 10B,10C, and 10D
of Chapter 2
Copyright © McGraw-Hill, Inc. 2011
20
Major Structures in the
Brain in Cross-section
Figure 12 of Chapter 2
Copyright © McGraw-Hill, Inc. 2011
21
The Central Core:
Our “Old Brain”

Central Core

Hindbrain

Medulla


Breathing and heartbeat
Pons

Transmitter of motor information

Cerebellum

Balance Reticular formation
Reticular Formation



Passes through the midbrain and into the forebrain
Activates other parts of the brain to produce bodily arousal
22
Copyright © McGraw-Hill, Inc. 2011
The Central Core:
Our “Old Brain”

Central Core

Thalamus


Relay station for information about the senses
Hypothalamus

Maintains a steady internal environment for the
body
23
Copyright © McGraw-Hill, Inc. 2011
The Central Core:
Our “Old Brain”

The Limbic System: Beyond the Central Core

Controls a variety of functions relating to emotions and selfpreservation, like eating, aggression, and reproduction

Includes:


Amygdala
Hippocampus
Figure 13 of Chapter 2
Copyright © McGraw-Hill, Inc. 2011
24
The Cerebral Cortex:
Our “New Brain”

Cerebral Cortex

Provides the ability to
think, evaluate, and
make complex
judgments

Lobes




Frontal
Parietal
Temporal
Occipital
Figure 14 of Chapter 2
Copyright © McGraw-Hill, Inc. 2011
25
The Cerebral Cortex:
Our “New Brain”

The Motor Area of the Cortex


Largely responsible for the body’s voluntary
movement
The Sensory Area of the Cortex

Corresponds to body sensations

Somatosensory area



Touch
Pressure
The greater the amount of brain tissue devoted to a specific
area of the body, the more sensitive that area of the body
26
Copyright © McGraw-Hill, Inc. 2011
The Cerebral Cortex:
Our “New Brain”

The Association Areas of the Cortex

Executive functions

Higher mental processes such as thinking,
language, memory, and speech
27
Copyright © McGraw-Hill, Inc. 2011
The Adaptable Brain

Neuroplasticity


The brain continually reorganizing itself
Neurogenesis

New neurons created in certain areas of the
brain during adulthood
28
Copyright © McGraw-Hill, Inc. 2011
Specialization of the Hemispheres:
Two Brains or One?

Left and right symmetrical halves

Lateralized

Left



Verbal competence
Processes information sequentially
Right





Spatial relationships
Recognition of patterns and drawings
Music
Emotional expression
Processes information globally
29
Copyright © McGraw-Hill, Inc. 2011
The Split Brain: Exploring the
Two Hemispheres

Split-brain patients



The corpus callosum
is surgically cut
The two hemispheres
of the brain no longer
communicate with
each other
The patient cannot
combine the
information of both
hemispheres
Figure 16 of Chapter 2
Copyright © McGraw-Hill, Inc. 2011
30