Carry impulses from the Central Nervous
System to perform muscle movement
 Motor Neurons are known as the control
muscle
 They directly or indirectly control the
contraction or relaxation of muscles

Neurons are made up of 3 basic
parts :
Cell Body- contains the nucleus ,
mitochondria and ribosomes
Dendrites- these branch like cells
are located at one or both ends
of the neuron. Dendrites make
connections to other cells
Axons- carry out electrochemical
messages (nerve impulses or
action potentials)
Motor Neurons that control muscle
contraction have a cell body at one
end, a long axon in the middle and
dendrites at the other end.
The impulse is received at the
dendrites and is carried through the
cell till it reaches the muscle
The signal reaching the muscle fiber is
a specialized synapse called the
neuromuscular junction
The neuron will release
neurotransmitters that triggers muscle
response
Most Motor Neurons are located in the
brain and the spinal cord
 Upper Motor Neurons being found in the
brain and Lower Motor Neurons are
found in the spine

Motor Neuron diseases are a group of
disorders that destroys cells that control
muscle activity
 Basic functions such as speaking, walking
and even breathing are effected
 Basic transmissions from the Central
Nervous System are disrupted
 Muscles become weak and uncontrolled

Amyotrophic lateral sclerosis (ALS) is a
common motor neuron disease that
affects the nerve fiber
 ALS is caused by the death of motor
neurons in the spinal cord and brain
 As these motor neurons begin to die off
the muscles cannot move as effectively
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http://science.howstuffworks.com/environmental/life/human-biology/nerve1.htm
http://thebrain.mcgill.ca/flash/d/d_06/d_06_cl/d_06_cl_mou/d_06_cl_mou.html
http://www.bcb.uwc.ac.za/sci_ed/grade10/mammal/nervous.htm
http://www.wisegeek.com/what-is-a-motor-neuron.htm
http://www.sflorg.com/sciencenews/scn080107_02.html
http://www.google.ca/imgres?q=motor+neurons&um=1&hl=en&biw=1024&bih=565&tb
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