Download Nervous System

Chapter 9
Alcohol
Lesson 2
The Nervous System
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 neurons
Cells that make up the nervous system
 central nervous
system
Made up of the brain and the spinal cord
Made up of the nerves that connect the central
 peripheral
nervous system nervous system to all parts of the body
 brain
The command center, or coordinator, of the
nervous system
 spinal cord
A long bundle of neurons that sends messages to
and from the brain and all parts of the body
In this lesson, you will be able to
 list the parts of the nervous system.
 describe problems of the nervous system.
 explain how you can keep your nervous system healthy.
 practice decision-making skills to protect the nervous system.
Video Clip from Kidshealth.org
The Command Center of the Body
The nervous system:
Is your body’s control center
Carries messages to and from your brain
Controls breathing
Controls the flow of blood throughout the body
Can be harmed or permanently damaged by
alcohol
The Command Center of the Body
Neurons are also called nerve cells.
neurons Cells that make up the nervous system
Neurons send and receive messages to and from
the brain in the form of tiny electrical charges.
Three types of neurons as seen on page 273
Sensory Neurons
 Receives messages and passes on information from
outside world
skin, ears, eyes
Motor Neurons
 Sends messages to muscles and glands
Connection Neurons

Relays messages between sensory and motor neurons
What do you think would happen if some
neurons failed to pass on information
received from the outside world?
The Parts of the Nervous System
The two parts of the nervous system are:
The central nervous system (CNS)
The peripheral nervous system (PNS)
central nervous system Made up of the brain and the spinal cord
peripheral nervous system Made up of the nerves that connect the
central nervous system to all parts of the
body
Nervous
System
Central Nervous
System
Peripheral Nervous
System
PNS
CNS
Neurons
Brain
Spinal Cord
Neurons
The Parts of the
Nervous System
The Parts of the Central Nervous System
The brain works with the spinal cord.
brain The command center, or coordinator, or the nervous system
spinal cord A long bundle of neurons that sends messages to and
from the brain and all parts of the body
Central Nervous System CNS
page 274 figure 9.4
Brain
 made up of billions of neurons
 Receives information and sends messages to the other parts of the body
… works with the spinal cord

interprets the messages … helps the body respond to the information it receives from the
senses
 processes thoughts … when you think the neurons in your brain are working
Spinal Cord
 some messages are processed here but most are sent to the brain
 relays messages between the brain and other parts of the body
If you lose or damage CNS neurons your body cannot
make new ones
Your Nervous System
How the Brain Works
Considering everything it does, the human brain is
incredibly compact, weighing just 3 pounds. Its
many folds and grooves, though, provide it with
the additional surface area necessary for storing
all of the body's important information.
The spinal cord, on the other hand, is a long
bundle of nerve tissue about 18 inches long
and ¾ inch thick. It extends from the lower
part of the brain down through spine.
How the Brain Works
Intelligence, Learning, and Memory
When you learn things, messages travel from one neuron to another,
over and over. Then the brain creates connections (or pathways)
between the neurons, so things become easier and you can do them
better and better.
In young children, the brain is highly adaptable. In fact, when one part of
a young child's brain is injured, another part may learn to take over
some of the lost function. But as we age, the brain has to work harder to
make new neural pathways, making it more difficult to master new tasks
or change established behavior patterns. That's why many scientists
believe it's important to keep challenging your brain to learn new things
and make new connections — it helps keep the brain active over the
course of a lifetime.
Peripheral Nervous System PNS page 274 figure 9.4
made up of nerves that connect CNS to all parts of the body
makes possible the movements you can control
– walking
– speaking
handles movements you cannot control … AUTOMATIC actions
– heart beat
– sweating
– digestion
– the change of the pupil of your eyes as they react to light
PNS neurons can regenerate if they are damaged
Your Nervous System
Problems of the Nervous System
The nervous system can become injured, or it may
be affected by diseases and disorders.
Injuries
A brain injury can cause brain damage, loss of
memory, and the loss of some physical abilities.
PROTECT YOUR BRAIN AND SPINAL CORD
Alcohol and Drug Abuse
Alcohol can destroy millions of brain cells, which can
never be replaced.
Other drugs harm the brain by affecting sleeping,
breathing, sleeping, and the way your nervous
system sends and receives messages.
Infections
Some viruses that can harm the nervous system
include:
Polio
Rabies
Meningitis
There are vaccines that help protect people from some of these
illnesses. Other illnesses may be treated with medicine.
Disorders
Multiple Sclerosis
(MS)
MS attacks the central nervous system and damages
the outer part of some nerves.
Cerebral
Palsy
Cerebral palsy is caused by damage to the brain as it
is growing.
Alzheimer’s
Disease
Alzheimer’s causes a loss of memory, mental
deterioration, and death.
Parkinson's
Disease
People with Parkinson’s disease often have shaking
and stiffness of the arms and legs.
Epilepsy
Epilepsy occurs when the signals in the brain aren’t
sent in the normal way, sometimes causing seizures.
Taking Care of Your Nervous System
Follow positive health
practices.
Eat nutritious foods and get enough rest.
Protect yourself from
disease.
Get vaccinated and avoid risky situations.
Protect yourself from
physical injury when playing
sports.
Wear protective gear. Never dive into shallow water.
Have someone spot you when weight lifting.
Follow traffic rules.
Obey all signs and wear a safety belt when in a car.
Practice positive health
behaviors.
Decide never to use alcohol or other drugs.
Lesson 2 Review
What I Learned
Vocabulary Define neuron.
a cell that makes up the nervous system
Lesson 2 Review
What I Learned
Name List the two parts of the nervous system.
central nervous system and peripheral nervous system
Lesson 2 Review
What I Learned
Explain Describe how multiple sclerosis affects the
nervous system.
MS damages the outer part of some nerves so that they cannot send
messages properly.
Lesson 2 Review
What I Learned
Describe How can alcohol damage the nervous
system?
Alcohol can destroy brain cells.
Lesson 2 Review
Thinking Critically
Hypothesize If the PNS stopped working, what would
happen to the CNS?
Sample answer: The central nervous system could not receive
messages from the nerves in the body, so the body could not
respond to what it senses.
Lesson 2 Review
Thinking Critically
Apply What decisions can you make to keep your
nervous system healthy?
Sample answer: Wear a helmet while bicycling or in-line skating and
never use drugs or alcohol.
End of
Chapter 9
Alcohol
Lesson 2
The Nervous System
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