Transcript The Neuron_smetak

The Neuron
The wild wonderful neuron and
the nervous system
The Neuron
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Any of the bundles of fibers
interconnecting the central
nervous system and all parts
of the body, capable of
transmitting sensory stimuli
and motor impulses from
one part of body to another
Nerves can be viewed as
telephone lines connecting
the body telling it what to do
10 trillion in body! 100
billion in brain
in Fetus, develop at 250k
/min.
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an individual nerve cell
each connect to 10k others
messages to and from brain
travel along here
these are chemical-electrical
signals “fired”
can use thousand times a
minute and never stop in
motion
could circle the world 22k
times
Parts of the neuron
Synapse – gap
between neurons
 Receptors- cells that
gather information
from the senses
 Effectors- cells that
work the muscles and
internal organs
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Neurotransmitters
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chemical messages
between neurons <think
of water valves)
messages must travel in
one way till done or
inhibited (stopped)
can be stopped by
nerve damage (MS) or
by other neurons acting
on same one
Types of Neurotransmitters
 ACH-
controls muscle contractions
 Serotonin-emotions and happiness
 Dopamine-adrenaline, heart rate and
blood pressure, balance
 Histamine-stomach acid production
 Peptides- sleepiness and arousal
 Endorphins- released to relieve pain
Parts of the Neuron
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axon - the long extension of a
neuron that carries nerve
impulses away from the body
of the cell.
cell body (soma) - the cell
body of the neuron; it contains
the nucleus.
dendrites - the branching
structure of a neuron that
receives messages.
myelin sheath - a fatty
substance that surrounds and
protects some nerve fibers.
Types of Nervous Systems