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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 in our Bodies
-Our bodies are organized into different sized groups:
-CellsTissuesOrgansOrgan SystemsOrganisms(smallest) (largest)
-All organisms are made up of cells.
-The same cells working together make up tissues.
-Groups of different tissues make up organs (eye, stomach, brain).
-An organ system is a group of organs that work together (digestive system).
What is the Nervous System• Nervous system: The organ system
responsible for sending and receiving information in the body– 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”
Brain
Spinal cord
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 vice-versa)
3. Nerve: A group of neurons (and other cell tissues) that carry information from the spinal chord to the rest of the body (and vice-verca)
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
CFU
• What is the command center of your brain?• Which part of the nervous system is your brain
in?• Which part of the nervous system sends and
receives information to your limbs?• Which part of the nervous system is your
spinal chord in?
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 is a Neuron
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.
Interneuron
Spinal cord
Receptor in skinMotor neuron
Sensory neuron
Direction of impulse
Muscle contracts
What are the 3 types of neurons in our bodies:
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.
TYPE OF NEURONS CFU
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.
What kind of neuron is this?
A neuron that sends information in the brain and spinal cord.
Spin
al C
ord
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?
The nervous system sorts and interprets incoming information before directing a response.
Relaying an impulse1. 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.
What are the parts of a Neuron (Nerve Cell)?• Dendrites- receive nerve impulses (Signals)• Cell Body: Holds the Nucleus and other organelles• Nucleus: Holds DNA• Axon- sends nerve impulses (signals)• Axon Terminals- contact receptors of other cells:
releases neurotransmitters
CFU Neuron (Nerve Cell)
Connections between neurons Dendrite
Axon
Impulse
Synapse
Impulse
Dendrite
Axon
-Although neurons lie end to end, they do not touch!!!
-There is a gap between the neurons called a synapse.
-The axon of the presynaptic neuron sends a neurotransmitter across the synapse to the dendrite of the post synaptic neurotransmitter
Neurotransmitter: The baton messenger
• A neurotransmitter is a chemical that activates (starts) an electrical impulse 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
AxonImpulse
Synapse
Impulse
Dendrite
Axon
Axon
Dendrite
Synaptic space
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 this work?
Sensory neuron
Direction of impulse
Motor neuron
Flexor muscle contracts and withdraws part
being stimulated
Pain receptors in skin
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
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. – Mechanoreceptor: Feels pressure – Thermoreceptor: Feels temperature– Nociceptor: feels pain
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.
Neuron Relay Team
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 neurotransmitterc. The dendrite is an electrical signald. The axon is a chemical signal.
