Download The Nervous System

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Chapter Introduction
Section 1: The Nervous System:
The Basic Structure
Section 2: Studying the Brain
Section 3: The Endocrine
System
Chapter Preview 1
The Nervous System: The
Basic Structure
Understand that the nervous
system helps us know how
messages that are sent to and
from the brain cause behavior.
Chapter Preview 2
Studying the Brain
Discuss the many parts of the
brain that work together to
coordinate movement and
stimulate thinking and emotions.
Chapter Preview 3
The Endocrine System
Explain how the endocrine system
controls and excites growth and
affects emotions and behavior.
Section 1-Main Idea
Main Idea
Learning about the nervous system helps us
know how messages that are sent to and
from the brain cause behavior.
Section 1-Key Terms
Vocabulary
• central nervous
system (CNS)
• neurotransmitters
• spinal cord
• somatic nervous
system (SNS)
• peripheral nervous
system (PNS)
• automatic nervous
system (ANS)
• neurons
• synapse
Section 1-Objectives
Objectives
• Identify the parts of the nervous system.
• Describe the functions of the nervous
system.
How the Nervous System Works
• The nervous system controls your
emotions, movements, thinking, and
behavior—almost everything you do.
• It is divided into two parts:
– The central nervous system (CNS)—the
brain and spinal cord.
– The peripheral nervous system (PNS)—
these small branches of nerves conduct
information from the bodily organs to the CNS
and take information back to the organs.
How the Nervous System Works (cont.)
• All parts of the nervous system are
protected in some way (the skull protects
the brain and so forth).
How the Nervous System Works (cont.)
• Neurons are the long, thin cells of nerve
tissues along which messages travel to
and from the brain (much like a flame
travels along a firecracker fuse).
• Transmission between neurons, or nerve
cells, occurs whenever the cells are
stimulated past a minimum point and emit
a signal.
How the Nervous System Works (cont.)
• Neurons have four basic parts:
– Dendrites
– Cell body
– An axon
– Axon terminals
How the Nervous System Works (cont.)
• A white, fatty substance called the myelin
sheath insulates and protects the axon
from some neurons.
• A synapse is a junction or connection
between the neurons.
How the Nervous System Works (cont.)
• A neuron transmits its impulse or message
to another neuron across the synapse by
releasing neurotransmitters.
– Neurotransmitters can excite the next
neuron or stop it from transmitting.
– The synapse only allows signals to
move in one direction.
How the Nervous System Works (cont.)
• There are many different neurotransmitters
including:
– Norepinephrine
– Endorphin
– Acetylcholine
– Dopamine
– Serotonin
How the Nervous System Works (cont.)
• The actual destination of nerve impulses is
limited by what tract in the nervous system
they are on.
– Ascending tracts carry sensory impulses
to the brain.
– Descending tracts carry motor impulses
from the brain.
How the Nervous System Works (cont.)
• There are different types of neurons:
– Afferent (sensory)—relay messages
from the sense organs to the brain.
– Efferent (motor)—send signals from the
brain to the glands and muscles.
– Interneurons—process signals
connecting only to other neurons.
How the Nervous System Works (cont.)
• Somatic nervous system (SNS)—the
part of the peripheral nervous system that
controls voluntary movement of skeletal
muscles.
• Autonomic nervous system (ANS)—the
part of the peripheral nervous system that
controls involuntary internal biological
functions.
How the Nervous System Works (cont.)
• The ANS has two parts:
– The sympathetic nervous system
– The parasympathetic nervous system
Section 2-Main Idea
Main Idea
There are many parts in the human brain
that work together to coordinate movement
and stimulate thinking and emotions.
Section 2-Key Terms
Vocabulary
• hindbrain
• midbrain
• forebrain
• lobes
• positron emission
tomography (PET)
• magnetic
resonance imaging
(MRI)
• electroencephalograph (EEG)
• computerized axial tomography (CT)
Section 2-Objectives
Objectives
• Identify the structure and functions of the
human brain.
• Discuss the different ways psychologists
study the brain.
Section
The Three Brains
2
• The brain is composed of three parts:
– The hindbrain
– The midbrain
– The forebrain
Section
The Three Brains
(cont.)
2
• The higher thinking processes are located in
the forebrain:
– Cerebral cortex
– Cerebrum
– Limbic system
Section
The Three Brains
(cont.)
2
• The forebrain includes the:
– Hypothalamus
– Amyglada
– Thalamus
– Hippocampus
The Three Brains (cont.)
• The cerebrum is two hemispheres
connected by a band of fibers called the
corpus callosum.
• Each cerebral hemisphere has deep
grooves, some of which mark regions, or
lobes (the different regions into which the
cerebral cortex is divided).
The Three Brains (cont.)
• There are four lobes:
– Occipital lobe
– Parietal lobe
– Temporal lobe
– Frontal lobe
The Three Brains (cont.)
• The right and left hemispheres of the brain
complement and help each other.
• They are roughly mirror images of each other.
The Three Brains (cont.)
• Each hemisphere is connected to one-half
the body in crisscrossed fashion (the right
side of the brain controls the left side of
the body and vice versa).
The Three Brains (cont.)
• The right side controls:
– Visual and spatial relations
– Perceptual tasks
– Recognition of patterns
– Creativity and intuition
The Three Brains (cont.)
• The left side controls:
– Speech
– Mathematical ability
– Calculation
– Logic
The Three Brains (cont.)
• Severing the corpus callosum can decrease
the severity and amount of grand mal
seizures a person is experiencing.
• This results in a split brain—the person
has two brains that operate independently
of each other.
How Psychologists Study the Brain
• Psychologists who study the brain are
known as physiological psychologists,
psychobiologists, or neuroscientists.
How Psychologists Study the Brain
(cont.)
• The methods used to explore the brain
include:
– Recording with an electroencephalograph
(EEG)
– Stimulation
– Lesioning
– Accidents
How Psychologists Study the Brain
(cont.)
• Imaging is also used to study the brain:
– Computerized axial tomography (CT)
– Positron emission tomography (PET)
– Magnetic resonance imaging (MRI)
Section 3-Main Idea
Main Idea
The endocrine system controls and excites
growth and affects emotions and behavior in
people.
Section 3-Key Terms
Vocabulary
• endocrine system
• hormones
• pituitary gland
Section 3-Objectives
Objectives
• Describe the endocrine system.
• Identify hormones and their function in the
endocrine system.
The Endocrine Glands
• The endocrine system is a chemical
communication system that uses hormones
to send messages through the bloodstream.
• Hormones—chemical substances that
carry messages through the body in blood.
The Endocrine Glands (cont.)
• Hormones affect:
– your behavior.
– the growth of bodily structures such as
muscles and bones.
– your metabolic processes.
– how your body acts in a stressful situation.
– the brain (your moods and drives).
– the differences between boys and girls.
The Endocrine Glands (cont.)
• The pituitary gland is the center of control
of the endocrine system and secrets a
large number of hormones.
• It is directed by the hypothalamus.
The Endocrine Glands (cont.)
• These hormone messages regulate cell
metabolism and control growth and
reproduction.
• The thyroid gland produces the hormone
thyroxine, which stimulates certain
chemical reactions that are important for
all tissues of the body.
The Endocrine Glands (cont.)
• The adrenal glands become active when a
person is angry or frightened.
• They release epinephrine and
norepinephrine, which cause the heartbeat
and breathing to increase.
The Endocrine Glands (cont.)
• There are two types of sex glands:
– Testes—these produce sperm and
testosterone.
– Ovaries—these produce eggs and
estrogen and progesterone.
Hormones Vs. Neurotransmitters
• Neurotransmitter—a chemical used as a
neurotransmitter is released right beside
that cell that it is to excite or inhibit.
• Over time, this system developed to send
rapid and specific messages.
Hormones Vs. Neurotransmitters (cont.)
• Hormone—when a chemical is used as a
hormone it is released into the blood,
which diffuses it throughout the body.
• Over time, this system developed to send
slow and widespread communication.