Do now
Grade Brainpop!
1. What is a neuron?
2. What is the nervous system?
3. What makes up your nervous system?
4. What does your nervous system control?
Monday/Tuesday, April 8th, 2013
Your Learning Goal:
Students will be able to explain why people become
paralyzed when they break their back using the terms
motor neuron, axon, dendrite, and neurotransmitter.
Standard: 5a. Levels of organization
5b. Students know that organ systems function because of the
contributions of individual organs, tissues, and cells. The failure of
any part can affect the entire system
Table of Contents: 7.3 Nervous System
Agenda:
Homework:
See next page
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Do-Now: Reading
Notes on neurons
Wipe board races
Notes on neuron communication
Reflex Activity if time
Start HW if time
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Assignments that must be completed when we
return from spring break
Assigned 4/10 or 4/11
Due 4/21 or 4/22
7.02 Musculoskeletal Worksheet and Lever Arm
7.1 Be perfect Reading
7.1 Be Perfect Webquest
7.2 Neuron Brainpop
7.3 Nervous System Worksheet
7.3 Nervous System Flashcards
– 18 Terms
• Will Post an extra credit assignment on the website
this weekend. Spent all night in the hospital
without internet
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New Vocab Words
Nervous System
Brain
Spinal Chord
Nerve
Neuron
Central Nervous System
Peripheral Nervous System
Neuron
Sensory neurons
Motor Neurons
Interneurons
Dendrite
Cell Body
Nucleus
Axon
Axon Terminals
Neurotransmitter
Synapse
Spinal Cord Injury TPS
• When someone breaks their back, why do you
think they become paralyzed? Why can’t they
move from the waste down (paraplegic) or the
neck down (quadriplegic)?
I think that people become paralyzed because….
Levels of Organization: The Nervous
System
• Our bodies are organized into different sized groups:
-CellsTissuesOrgansOrgan SystemsOrganism
(smallest)
(largest)
-All organisms are made up of cells.
-The same cell working together make up tissues. Neurons work together to
make nervous tissue!
-Groups of tissues make up organs (eye, stomach, brain). Nerves are an organ
made up of nervous tissue and other connective tissues.
-An organ system is a group of organs that work together (Nervous system is
made up of the brain, spinal chord, and nerves).
Brain
What is the Nervous System
• Nervous system: The organ
system responsible for sending
and receiving information
in the body
Spinal
cord
– Tells muscles to contract and
relax
– Time to move
– Info from the external
environment
– “IT SMELLS LIKE DINNER IS
READY”
– Info from inside the body
– “I NEED MORE OXYGEN”
Nerves
3 Organs OF THE
NERVOUS SYSTEM
1. Brain: The ‘control center’ of
the body; controls and
interprets all information in
the body
2. Spinal cord: major network of
nerves in the body; connects to the
brain to the rest of the body. The
spinal chord is responsible for
sending information from the brain
to the rest of the body (and viceversa)
3. Nerve: A group of neurons (and
other cell tissues) that carry
information from the spinal chord
to the rest of the body (and viceverca)
Brain
Spinal
cord
Nerves
The nervous system is
split into 2 parts
1. The Central Nervous System
(CNS) is made up of the brain
and spinal cord and its job is
to control the entire body.
2. The peripheral nervous
system is made up of all of
the nerves that carry
messages to and from the
central nervous system (all
of the neurons outside of
the brain and spinal cord).
CNS
CNS
PNS
Check Point: Questions You will see
1. Which organ of the nervous system connects your brain to
the rest of your body?
2. Which organ of the nervous systeis the command center
of your body?
3. Which organ of the nervous system sends and receives
information to your limbs?
4. Which part of the nervous system is your spinal chord in?
PNS or CNS?
5. Which part of your nervous system are your nerves in?
PNS or CNS?
6. Which part of your nervous system is your Brain in? PNS
or CNS?
What is a Neuron

A neuron is a nerve cell. Neurons carry information through the
nervous system. Neurons Communicate through electrochemical
signals

The neuron basic unit of the nervous system and is the cell we are
talking about when we talk about nerves.
What are the 3 types of neurons
in our bodies:
Sensory
neuron
Motor neuron
Interneuron
Spinal cord
Receptor in skin
Direction
of impulse
Muscle
contracts
Reflex: Before the brain even gets information
from touching the hot bowl, you jerk your hand
back. After your reflex, the message makes it to
your brain.
1. Sensory neurons carry
messages from your body
to your brain or spinal
cord. (from the spinal
cord, the interneurons
take the message to the
brain)
2. Motor neurons carry
messages from your brain
to the muscles in your
body telling them to
contract and move.
3. Interneurons carry
messages inside your brain
and spinal cord.
TYPE OF NEURONS CFU
• Wipe Board Races!
What kind of neuron is this?
Carries messages from the brain to muscles in the
face, making the baby smile.
What kind of neuron is this?
What kind of neuron is this?
Brain sends message to muscles in the leg so that they kick.
What kind of neuron is this?
Finger sends touch message to neuron which takes the
message to the brain.
Spinal Cord
What kind of neuron is this?
A neuron that sends information in
the brain and spinal cord.
What kind of neuron is this?
Neurons receive a
message from Kayne’s
brain and take it to the
muscles in his face so
that he sings.
What kind of neuron is this?
-Works inside the
spinal cord.
What kind of neuron is this?
Neurons in the dog’s ear send
pain message to the brain.
What kind of neuron is this?
Works inside brain and
spinal cord.
What kind of neuron is this?
Neurons in a man’s hand sends
the heat message to the brain.
What kind of neuron is this?
What Happens in a relay
• How do you think neurons relate to a relay
race?
Relaying an impulse
1. Receptors in the neuron
sense a touch.
2. Sensory neurons carry the
touch message to the brain.
3. The brain interprets the message
from the sensory neurons. A response is
sent to the motor neurons.
4. Motor neurons carry a message
back to the muscles in your neck.
5. The neck muscles are activated and the
neck turns.

The nervous
system sorts and
interprets
incoming
information before
directing a
response.
What are the parts of a Neuron (Nerve
Cell)?
• Dendrites- receives chemical messages called
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neurotransmitters from other neurons. This starts the
electrical impulse in the neuron!
Cell Body: Holds the Nucleus and other organelles
Nucleus: Holds the DNA
Axon- sends electrical impulses through the neuron (signals)
Axon Terminals- : Sends message to another neuron releases
neurotransmitters to the dendrites of other neuron (or muscle)
CFU Neuron (Nerve Cell)
Connections
between neurons
Dendrite
Axon
-Although neurons lie end to end,
they do not touch!!!
Impulse
- Synapse: That gape between
neurons!
-The axon of the presynaptic
neuron (the neuron in front of the
synapse) sends a neurotransmitter
across the synapse to the dendrite
of the post synaptic neuron (the
neuron after the synapse)
Synapse
Dendrite
Impulse
Axon
Neurotransmitter: The baton
messenger
• A neurotransmitter is a
chemical that activates
(starts) an electrical
impulse (wave) in a
neuron (or makes a
muscle contract for motor
neurons).
• Electrochemical Signal:.
Electrical Impulse goes
down the axon and gets to
the end and releases a
chemical signal (the
neurotransmitter)
How do impulses get across the synapse?
Dendrite
Impulse
Axon
Synapse
Dendrite
Axon
Impulse
Axon
Synaptic
space
Dendrite
When an impulse
reaches the end of
a neuron, the
neuron releases
neurotransmitters
which diffuse, or
move, across the
gap between the
neurons. These
neurotransmitters
then activate the
next neuron.
How does it all get started?
• If neurotransmitters relay the message from
neuron to neuron and to the neurons in the
brain or cells in the muscle, How do these
messages start?
• I think the messages start when…
Cutaneous Receptors
• Sensory information is received on the skin by
special receptors that start signals in sensory
neurons. These receptors send
neurotransmitters to the first dendrite of the
sensory neuron!
– Mechanoreceptor: Feels pressure
– Thermoreceptor: Feels temperature
– Nociceptor: feels pain
So why can’t someone move their legs
when they break their back?
Exit Slip
2. What type of neuron sends a message to your muscles
telling it to contract?
3. What type of neuron send messages other neurons in
your body?
4. What’s the difference between a dendrite and an
axon?
a. The dendrite releases neurotransmitters and the axon
receives neurotransmitters?
b. The axon releases the neurotransmitter and the dendrite
receives the neurotransmitter
c. The dendrite is an electrical signal
d. The axon is a chemical signal.
How does this work?
Reflexes
-Sometimes a stimulus results in an automatic response that you can’t
control. This is called a reflex. The sensory neuron sends a
neurotransmitter to a motor neuron in the spinal cord. The motor neuron
sends a message to make the muscle contract
Sensory neuron
Direction of
impulse
Motor
neuron
Flexor muscle contracts
and withdraws part
being stimulated
Pain receptors in skin
Reflexes in the Somatic Nervous System
-Sometimes a stimulus results in an automatic response that you
can’t control. This is called a reflex. The sensory neuron sends a
neurotransmitter to a motor neuron in the spinal cord.
Sensory neuron
Direction of
impulse
Motor
neuron
Flexor muscle contracts
and withdraws part
being stimulated
Pain receptors in skin
Neuron Relay Team