Download Nervous System Unit

Pgs. 288-291 in Text
The human body has many
body systems, including …
All of these body systems
are very important!
• Yes, Professor. But
which body system
controls ALL of them?
• That’s Right!
• The Nervous System
This Lesson Will Cover:
1.
2.
3.
4.
5.
6.
7.
8.
9.
Main Parts of the Nervous System
How the Nervous System is Protected
Jobs of the Nervous System
Neurons (Nerve Cells)
3 Types of Neurons
The Brain
The Spinal Cord
Nervous System Problems
Proper Care of the Nervous System
OK, Dexter !
PART 1:
Main Parts of the
Nervous System
Probably!
WHAT ARE THE
MAIN PARTS OF
THE NERVOUS SYSTEM?
1. The BRAIN
2. The SPINAL CORD
3. All the NERVES going
to and from the brain
and spinal cord
WHAT ARE THE
MAIN PARTS OF
THE NERVOUS SYSTEM?
1. The Brain and Spinal Cord
make up the CENTRAL
NERVOUS SYSTEM
2. All the Nerves going
to and from the brain
and spinal cord make
up the PERIPHERAL
NERVOUS SYSTEM
WHICH PART IS MOST
IMPORTANT ?
Let’s explore how the body
protects each part of the
Nervous System …
PART 2:
How the Nervous
System is Protected
• It must be
protected and
kept safe inside
your body
Nervous System tissue is
very soft and delicate.
How does your body
PROTECT all these important
and delicate parts of the
Nervous System?
There are
five ways
1. Bones !
• 22 skull bones
protect the brain
 Cranium = 8 bones
 Face = 14 bones
• 31 vertebrae protect
the spinal cord





8 cervical segments
12 thoracic segments
5 lumbar segments
5 sacral segments
1 coccygeal segment
2. CEREBROSPINAL
FLUID !
• Protects the brain
(under the skull)
• Protects the spinal cord
(inside the vertebrae)
• Average adult has
about 125-150 ml of
cerebrospinal fluid
3. MENINGES !
• The Meninges are
special membranes
which protect the
brain and spinal cord
• Three layers:
– the dura mater,
– the arachnoid mater,
– the pia mater.
4. Cartilage!
• There are discs of
cartilage between the
vertebrae
• They Protect the spinal
cord between each of
the vertebra
• Singular = vertebra
• Plural = vertebrae
5. OTHER WAYS !
• Major nerves
are often
buried deeper
in the body
near bones
and beneath
layers of
muscle and fat
for protection
I should have
sat beneath
a FIG tree …
Hey Isaac: Let’s
explore the jobs or
functions of the
Nervous System!
PART 3:
Jobs (Functions) of the
Nervous System
• The BRAIN is the control
center of your body!
• The BRAIN allows you to
voluntarily control speech,
vision, hearing, emotions,
movement, memories,
and thinking.
The Jobs of
the BRAIN
• The BRAIN also regulates
breathing, heartbeat, and
digestion involuntarily
The Jobs of the SPINAL CORD
• The SPINAL CORD is the
main pathway for all signals
to and from the brain
• The SPINAL CORD also
controls certain reflexes
• If the SPINAL CORD is
damaged, signals to and
from the brain are blocked!
• The NERVES send all the
messages of sight, smell,
taste, hearing, and touch to
the brain so you know what’s
going on around you
• The NERVES also take signals
from your brain to all your
muscles, glands, and organs
so your body can function
The Jobs of the NERVES
That’s correct, Albert.
Let’s see what special
cells make up your
Nervous System
PART 4:
Neurons
(Nerve Cells)
Hey, Anton! You’re the father
of microbiology and pioneer
of the microscope!
What are you looking at?
Just like walls are
made of bricks …
Your body is
made of cells
Your Nervous System is made
of NEURONS (nerve cells)
1.
The main parts
of the Neuron:
= Dendrites
= Nucleus
Cell Body =
3.
2.
What about a
more detailed
Neuron?
4.
= Axon
Let’s label a more
detailed Neuron:
How Do
Neurons
Work?
SIGNALS PASS:
1.
2.
3.
4.
5.
from the Dentrites,
through the Cell Body,
down the Axon,
through the Axon Terminals,
to another Neuron
• The thicker the Myelin Sheath, the faster the
neuron can work
• Some neurons can carry signals as fast as 200
miles per hour!
How fast does this happen?
Pronounced
“SIN NAPS”
Neurons carry
signals all over your
body, all the time
• The signals are
both electrical
and chemical in
nature
• What do you think
Stimulant drugs do?
• How about
Depressant Drugs?
• Hallucinogens?
• Pain Relievers?
Different drugs affect the way
signals go from neuron to
neuron across the synapse
Neurons are cool …
Any last words, Anton?
PART 5:
Three Types of
Neurons
(Nerve Cells)
1) Sensory
2) Connecting
(Interneurons)
(Association)
3) Motor
Spinal Cord
1) Sensory Neurons:
• Take signals to the brain and spinal
cord from the skin, eyes, ears, nose,
mouth, and other organs
2) Connecting: (Interneurons)
(Association)
• Neurons in the brain and
spinal cord
3) Motor Neurons:
• Take signals from the brain and
spinal cord to muscles, glands,
and organs
• There are one way tracks going to the station
• There are tracks in the station
• There are one way tracks going from the station
Your Nervous System’s neurons are
kind of set up like a Train Station:
That “Train Station”
analogy was pretty
good!
• Thanks, Thomas.
Did you invent the
train?
Nope … I invented
almost everything
else, though!
AN EXAMPLE:
1.
2.
3.
4.
5.
Stimulus: Pin jabs your skin
Sensory neuron signal to brain and spinal cord
Association neurons interpret the signal (pain)
Motor neuron signal to muscle
Muscle moves!
ANOTHER EXAMPLE:
I’m not a “Train” guy. I’m
more of a “Chemistry”
guy, myself.
Sorry …
PART 6:
The Brain
• OK, Madame.
• We will avoid
corny brain jokes.
• Has about 100
billion neurons!
• Weighs about
three pounds
(1300-1400 grams)
• The average
human brain is
140 mm wide,
167 mm long,
and 93 mm high.
A Few Brain Facts:
A Few Brain Facts:
• You will become
unconscious
within 8-10
seconds after loss
of blood supply to
the brain
• The brain feels like
a ripe avocado and
looks pink because
of the blood
flowing through it
Let’s examine the
three main areas
of the brain and
the jobs of each
part:
• Breathing and Heartbeat
• Swallowing and
Digestion
• Blood Pressure
• Coughing, Gagging,
Sneezing reflexes
• Alertness, Consciousness
1. Brain Stem:
• Balance
• Posture
• Muscle Tone
• Coordination
of muscle
movements
2. Cerebellum:
3. Cerebrum:
• Five Senses
• Thoughts and
Reasoning
• Emotions
• Memory
• Muscle
Movements
What do you think happens if
neurons get damaged here?
Or here?
Or here?
Lobes of the brain:
Your brain's hemispheres are divided into four lobes.
1. Frontal lobes- control thinking, planning, organizing,
problem solving, short-term memory and movement.
(Voluntary movements, personality, speech)
2. Parietal lobes- interpret sensory information, such as taste,
temperature and touch, body position, heat, cold, pain, touch.
3. Occipital lobes- process images from your eyes and link
that information with images stored in memory. (Vision)
4. Temporal lobes- process information from your senses of
hearing, smell, taste and sound. They also play a role in
memory storage.
This explains
why strokes
affect different
people in
different ways
Which area of the brain is damaged by
the stroke will determine what problems
the person has after the stroke
Can You Label The Brain
and Spinal Cord?
W=
Brain Stem
X=
Spinal Cord
Y=
Cerebellum
Z=
Cerebrum
Your brain has two
sides or hemispheres
• We use both sides
all the time.
• Both sides
“communicate”
with each other
• Each side has
specialties or jobs
it like to do
Left & Right Side
Motor Control
• The left side of your
brain controls the right
side of your body
• The right side of your
brain controls the left
side of your body.
• Do you see why?
But …
Check
out the
specialty
of each
side of
our
brain
Again: We use both sides of
our brains all the time:
Right Brain vs. Left Brain
Leo! You used both sides of
your brain quite well …
PART 7:
The Spinal Cord
• All signals to and
from the brain go
through the Spinal
Cord
• It is very delicate
• It is protected by
the vertebrae and
discs of cartilage
Nerves branch
off the Spinal
Cord to and
from various
body organs
Spinal Reflex
1. Nerve is
hit near
knee
(sensory)
3. Muscles
contract
(motor)
2. Spinal cord
reacts (association)
PART 8:
Nervous System
Problems
There are
hundreds of
problems which
can affect the
nervous system
Some are
more severe
than others
Doesn’t the famous scientist,
Stephen Hawking, have a nervous
system problem?
Correct. He has a motor
neuron disease similar
to ALS: Amyotrophic
Lateral Sclerosis
• Yet his mind
works great!
• In fact, he is a
genius!
I Agree.
His condition has left him almost
completely paralyzed
Some common nervous
system problems include:
1.
2.
3.
4.
5.
6.
7.
Stroke
Spinal Cord Injuries
Concussion
Epilepsy
Multiple Sclerosis
Alzheimer’s
Meningitis
• Stroke is the 4th leading
cause of death in the US
• It is a lack of blood flow
to the brain
• A blood vessel in the
brain breaks or is blocked
LEADING CAUSES OF DEATH:
1) Heart Disease approx 600,000 deaths
2) Cancer 575,000
3) Chronic Lower Respiratory Diseases (Lungs) 138,000
4) Stroke 130,000
5) Accidents 118,000
6) Alzheimer's Disease 83,000
7) Diabetes 69,000
8) Kidney Disease 51,000
9) Influenza and Pneumonia 50,000
10) Suicide 38,000
Stroke is the 4th Leading Cause
of Death in the US
• It is dangerous if the
blood supply to any part
of the brain is cut off
• The brain only weighs 3
pounds (about 1%-3% of
your body weight)
• Yet 15%-20% of the blood
flow from heart goes to
the brain!
• Strokes can be minor or
major in severity
• Strokes can cause
permanent damage to
almost any part of the
brain and lead to death!
• Learn how
to act
F.A.S.T. if
someone
has a
stroke!
• Damage to the
spinal cord is very
serious
• Car accidents, falls,
and other injuries
often are the cause
• See what
can happen
if the spinal
cord is
damaged!
• The damage
is often
permanent
• An injury to the brain
caused by a blow to
the head or by violent
jarring or shaking
• Often involves loss of
consciousness, which
may be momentary
or may last for several
hours
• Concussions
may cause
bruising to
the brain
• They can be
very serious!
• Concussions
are often
caused by
sports injuries
and car
accidents
• A disease involving
seizures
• An area of the brain
sends irregular
signals to the
muscles, causing
involuntary muscle
contractions
• Less severe
seizures are
called Petit Mal
Seizures
• More severe
seizures are
called Grand
Mal Seizures
• People with
epilepsy
often take
medications
to make
seizures less
severe and
happen less
often
• The neuron’s coating
(Myelin Sheath) is
damaged or destroyed
Multiple Sclerosis: When the
nerve coating is destroyed, it is
similar to destroying the coating
of an electrical wire
Can you think of
what problems this
might present?
MS can result in a
variety of problems
almost anywhere
in the body
Causes
 An age-related and
irreversible brain disorder
that occurs gradually
 Results in memory loss,
behavior and personality
changes, and a decline in
thinking abilities.
Causes
 As many as 5.3 million
Americans are
living with Alzheimer’s
disease.
 Every 70 seconds,
someone develops
Alzheimer’s.
Causes

The direct and indirect costs
of Alzheimer's and other
dementias to Medicare,
Medicaid and businesses
amount to more than $148
billion each year

Named for German physician
Alois Alzheimer, who first
described it in 1906.
Causes
 Alzheimer’s Disease is the
SEVENTH Leading Cause of
Death in the US !!
 Check out the following
chart
Alzheimer’s Disease
Causes is the seventh
leading cause of death in the US:
Leading Causes of Death in the US –
1) Heart Disease 631,636 (26% of all deaths)
2) Cancer 559,888 (23.1%)
3) Stroke 137,119 (5.7%)
4) Chronic Lower Respiratory Diseases (Lungs) 124,583 (5.1%)
5) Accidents 121,599 (5%)
6) Diabetes 72,449 (3%)
7) Alzheimer's Disease 72,432 (3%)
8) Influenza Virus and Pneumonia 56,326 (2.3%)
9) Kidney Disease 45,344 (1.9%)
10) Septicemia (infection of the blood) 34,234 (1.4%)
• The meninges
(membranes)
surrounding
the brain or
spinal cord get
infected
• The infection
can be bacterial
or viral
• Can affect brain
or spinal cord
• It is potentially
very serious!
PART 9:
Proper Care of the
Nervous System
“What about me ?”
“I am the
coolest, most
famous
scientist of all”
“Besides … I look like a
young Abe Lincoln!”
OK, Bill.
You can be in the
last segment!
Science
Rules !!!
1.
2.
3.
4.
Get enough sleep and rest
Eat well-balanced meals
Avoid alcohol and other drugs
Wear proper safety equipment
while playing sports
5. Wear a safety belt / helmet
6. Keep both mentally and
physically active
How to properly care for the
nervous system:
1. Get enough sleep
and rest:
 Your nervous system needs
periods of rest to work
properly
 8 hours of sleep per night
is average
 You may need more! Go to
bed earlier!
 Eat a variety of foods,
including fruits and
vegetables
 For your nerves to
work properly, your
body needs the
proper nutrients
 Drink lots of water,
too!
2. Eat well-balanced meals:
REMEMBER:
Food is fuel for your brain
 Drugs and alcohol can
cause permanent
damage to your brain
and nervous system
 In addition, drugs and
alcohol can lead to
accidents and injuries
3. Avoid alcohol and
other drugs:
4. Wear proper safety equipment
while playing sports:
 Competitive sports
and physical
activities are great!
 But be careful!!
Wear proper safety
equipment.
 In a car, buckle your
safety belt!
 On bikes and cycles,
wear a helmet!
 Remember Newton’s
Laws of Motion!
5. Wear a safety belt /
helmet:
6. Keep both mentally and
physically active:
 Physical activity gets
blood and oxygen
flowing to the brain
 Mental activity keeps
your mind stimulated
and helps keep you
sharp and alert
THANKS FOR PAYING
ATTENTION!
• We hope you
learned a few
things this week.
• Can we get a
scientists group
photo?
Wait! We can’t
forget Jane!
Why wasn’t
Jane in the
slide show?
She was monkey-ing around
That was a
really bad joke!
I can’t take any
more bad
scientist jokes!
Group Photo !!!
Why was I not invited?