Body and
Behavior
The Nervous System: The Basic
Structure
The nervous system is divided into two parts:
• Central Nervous System (CNS) : the brain and
spinal cord
• Spinal Cord : nerves that run down the length
of the back and transmit most messages
between the body and brain
• Peripheral Nervous System (PNS): nerves
branching out from the spinal cord
Neurons
Neurons: the long, thin
cells of nerve tissue along
which messages travel to
and from the brain
Neurotransmitters: the
chemicals released by
neurons, which
determine the rate at
which other neurons
fire.
Synapse
• Synapse: the
gap that exists
between
individual
nerve cells
Voluntary and Involuntary Activities
• Somatic Nervous System (SNS) : refers to the
part of the peripheral nervous system that
controls voluntary activities.
• Autonomic Nervous System (ANS) : the part of
the peripheral nervous system that controls
internal biological functions
Studying the Brain
• Hindbrain: a part of the brain located at the
rear base of the skull that is involved in the
basic processes of life.
• Midbrain : a small part of the brain above the
pons that integrates sensory information and
relays it upward
• Forebrain : a part of the brain that covers the
brain’s central core
The Lobes of the Brain
• Lobes: the different regions into which the
cerebral cortex is divided
Left and Right Hemispheres
How Psychologists Study the Brain
• Electroencephalograph (EEG): a machine used
to record the electrical activity of large
portions of the brain
Brain Stimulation
Lesions
Accidents
Images
• Computerized Axial Tomography (CAT) : An
imaging technique used to study the brain to
pinpoint injuries and brain deterioration.
• Positron Emission Tomography (PET): An
imaging technique used to see which brain
areas are being activated while performing
tasks
• Magnetic
resonance
imaging (MRI):
An imaging
technique
used to study
brain
structure and
activity
The Endocrine System
Endocrine System: a
chemical communication
system, using hormones,
by which messages are
sent through the
bloodstream
Hormones: chemical
substances that carry
messages through the
body in blood
• Pituitary Gland: the center of control of the
endocrine system that secretes a large
number of hormones
• Thyroid Gland: produces the hormone thyroxine
which stimulates certain chemical reactions that
are important for all tissues of the body.
• Adrenal Glands: become active when a person
is angry or frightened, they release
epinephrine and norepinephrine into the
bloodstream
Heredity and Environment
Twin Studies
• Identical Twins:
twins who come
from one
fertilized egg;
twins having the
same heredity
Genes: the basic
building blocks of
heredity
• Fraternal Twins:
twins who come
from two different
eggs fertilized by
two different
sperm