Transcript The Nervous System

The
Nervous
System
Key Concepts
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Know the function and divisions
of the nervous system (CNS &
PNS)
Describe the structure of a neuron
Sensory
Identify and know the function of
Neuron
the three types of neurons and the
describe neurotransmission
Know the main parts of the brainSkin receptors
and explain their functions
Identify the lobes of the cerebral
cortex
Brain
Motor
Neuro
n
Interneuron
Muscle
Funtion of the Nervous System
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Receive information
externally and internally
Respond to stimuli
Maintain stable internal
conditions.
Neurons
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Neurons are the cells that carry
nerve impulses through your
nervous system
There are 3 kinds of neurons
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Interneuron -connects motor and
sensory neurons; what the brain
is mostly made of
Sensory – picks up stimuli from
internal and external sources
Motor – sends message to muscle
to produce an action or
movement
Neuron Structure
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A neuron is made up of 3
main parts
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Cell body – where the nucleus
and organelles are found
Dendrites – extensions that
pick up nerve impulses and
carry to the cell body
Axon – carries the nerve
impulse away from the cell
body and to another neuron
Nerve impulses travel in only
ONE direction
Neurotransmission
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Message travels form the dendrites
through the cell body and to the end
of the axon.
The message causes chemicals,
neurotransmitters, to be released
from the end of the axon into the
space between the axon of one
neuron and the dendrites of another
The neurotransmitters then travel
across the synapse on the receptors
on the dendrites of another neuron.
Once the neurotransmitters have
attached to the receptors the impulse
is passed on.
The neurotransmitters are released
from the receptors.
Divisions of the Nervous System
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Central Nervous System (CNS)
Brain
 Spinal cord
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Peripheral Nervous System (PNS)
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All of the nerves located OUTSIDE of the CNS
(senses)
Main Parts of the Brain
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Cerebrum
Cerebellum
Brain Stem
Peripheral Nervous System
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Consists of a
network of nerves
that branch out from
the CNS.
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Somatic system –
control voluntary
actions
Autonomic system –
controls involuntary
actions
Reflex
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Automatic response
that occurs very
rapidly without
conscious control
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Nerve impulse goes
to spinal cord but
NOT the brain; helps
to speed up the
reaction