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Groove
your brain!
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Information
Bumpy Activity Book
Bumpy
Brains Activity Book |
Cells of the Nervous
System:
Neurons
Glial Cells
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The Structure of a
Neuron
Guest starring
Nestor the Neuron! |
Each part of Nestor has been
labeled. Below are the descriptions for his parts:
Soma (cell body): contains
cytoplasm, the nucleus and other organelles such as mitochondria.
Nucleus:
contains DNA.
Dendrites:
receive information
from other neurons (known as pre-synaptic neurons). Dendrites
receive information through receptors. Receptors are also found
on the cell body.
Dendritic branch: a branching of the dendrite; also
contains receptors.
Axon hillock: connects the soma to the axon
Axon: carries information to other neurons
(known as post-synaptic neurons).
Myelin
sheath: made up of lipids and proteins, myelin
electrically insulates the axon.
The purpose of myelin is to speed electrical impulses (information
being to sent
to post-synaptic neurons or other non-neuronal cell) down the axon.
Nodes
of Ranvier: gaps
between segments of myelin sheath. Electrical impulses jump from
one node to the next (over the fatty myelin sheaths), thus speeding the
impulse (this is called saltatory conduction).
Schwann cell: in the
peripheral nervous system, a type of glial cell that provides myelin to
axons. In the central nervous system, oligodendrocytes provide
myelin.
Terminal button: also known as the axon terminal; the end
of the axon. This is where the impulse finally ends and
information is transmitted via the release of neurotransmitters.
Neurotransmitters: "chemical messengers" that allow neurons
to communicate with each other.
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Neurons are
also known as
"brain cells," and are a type of cell that make up the nervous
system (along with glial cells).
They are responsible for everything we do, including
walking, talking, eating, sleeping, and thinking!
Neurons differ
from other cells in the body because they have an axon and dendrites
which allow them to send and receive information to and from other
neurons.
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The Structure of a
Neuron: Simplified by Vinny
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neuron
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cells
in NS that communicate
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dendrites
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receive
information
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soma
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cell
body; has DNA and other stuff like mitochondria
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axon
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sends
information
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myelin
sheath
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wraps
around axon (it's really made of oligodendrocytes!);
speeds up
information sending and insulates those messages (because they're
electric)
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Try
it!
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Put
Vinny's neuron back together. Click and drag the structures (to
the right) onto the outlined neuron (on the left).
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Dendrites
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Axon |
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Soma
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Myelin Sheath
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The Synapse
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A synapse is where a
neuron
communicates with a post-synaptic neuron or other non-neuronal
cell. A synapse includes 3 parts:
- Terminal button (axon terminal) of pre-synaptic neuron.
- Synaptic cleft (space between the
cells).
- Dendrites or membrane of the post-synaptic neuron or other cell.
Depending
on the type of signal, synapses can either be electrical or chemical.
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Glial
Cells
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Glial cells, along with neurons,
make up the Nervous System. There are different types of glial
cells, including:
- Astrocytes -
give structure and nutrients for neurons (pictured left)
- Microglia -
clean up the trash in the nervous system (pictured left)
- Oligodendrocytes
- make up myelin in the CNS (pictured below)
- Schwann cells
- make up myelin in the PNS (pictured below)
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The
drawing to the right shows that oligodendrocytes
wrap around axons of many different neurons and schwann cells
wrap around only one axon.
Here
is a comic of this drawing (rated
PG-13).
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Copyright ©
2008-2009, Bumpy Brains - Last
updated on April 12, 2009 |
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