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Unit 1 Lesson 5 The Nervous System
Brainiac!
What is the function of the nervous
system?
• The nervous system is made up of the
structures that control actions and reactions of the
body in response to stimuli in the environment.
• The nervous system has two parts: the central
nervous system (CNS) and the peripheral nervous
system (PNS).
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Unit 1 Lesson 5 The Nervous System
What is the function of the nervous
system?
• The CNS is made up of the brain and spinal cord.
• The brain is the body’s central command organ.
• The spinal cord allows the brain to communicate
with the rest of the body.
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Unit 1 Lesson 5 The Nervous System
What is the function of the nervous
system?
• The PNS connects the CNS to the rest of the body.
• Involuntary processes are those you have no
control over, such as your heart beating.
• Voluntary processes are actions your brain can
control, such as moving an arm or a leg.
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Unit 1 Lesson 5 The Nervous System
What are the parts of the CNS?
• The CNS is made up of the brain and the spinal
cord.
• The cerebrum is the largest part of the brain. It is
where you think, solve problems, and store
memories.
• The cerebrum controls voluntary movements and
processes information from your senses.
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Unit 1 Lesson 5 The Nervous System
What are the parts of the CNS?
• The cerebellum processes information from your
body, keeps track of body position, and
coordinates movements.
• The brain stem connects your brain to the spinal
cord.
• A part of the brain stem called the medulla
controls involuntary processes in the body.
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Unit 1 Lesson 5 The Nervous System
What are the parts of the CNS?
• Describe the part of the brain that made one
activity that you did today possible.
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Unit 1 Lesson 5 The Nervous System
What are the parts of the CNS?
• The spinal cord is a bundle of nerves protected by
bones called vertebrae.
• Nerves are a collection of nerve-cell extensions
bundled together with blood vessels and
connective tissue.
• The spinal cord carries messages to and from the
brain.
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Unit 1 Lesson 5 The Nervous System
You’ve Got Nerves!
How do signals move through the
nervous system?
• The nervous system translates environmental
information into electrical signals.
• A neuron is a special cell that moves messages in
the form of fast-moving electrical energy.
• These messages are called impulses.
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Unit 1 Lesson 5 The Nervous System
How do signals move through the
nervous system?
• Signals move through the CNS and PNS with the
help of glial cells that protect and support
neurons.
• Sensory neurons gather information from in and
around your body and move it to the brain.
• Motor neurons move impulses from the brain and
spinal cord to other parts of the body.
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Unit 1 Lesson 5 The Nervous System
What are the parts of a neuron?
• The cell body of a neuron has a nucleus and
organelles.
• A dendrite is a typically short, branched
extension of the cell body.
• The cell body gathers information from dendrites
and creates an impulse.
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Unit 1 Lesson 5 The Nervous System
What are the parts of a neuron?
• An axon is an extension of the neuron that carries
impulses away from the cell body.
• A neuron has only one axon.
• At the end of the axon is the axon terminal that
changes the electrical signal to a chemical signal,
or neurotransmitter.
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Unit 1 Lesson 5 The Nervous System
What are the parts of a neuron?
• How is a message transformed from an electrical
message to a chemical message in a neuron?
What are disorders of the nervous system?
•Parkinson’s disease, multiple sclerosis, and spinalcord injuries are disorders of the nervous system.
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