Download 1.nerve notes

The Nervous
System
-controls the body
through electrical
signals
- is made up of
the brain, spinal
cord & nerves all
over the body
Neurons - are nerve cells
Nerves – are a bundle of neurons
Sensory neurons
control your senses
(taste, touch, see,
hear & smell)
Motor neurons
control your
muscles.
Nucleus
Dendrites –
receive the
message
Cell Body
Axon –
sends the
message
Synapse – open
space between
two neurons
The arrow
shows the
movement of
the message
A myelin sheath (found on
some neurons) allows the
message to travel faster
(like insulation on an
electrical cord )
Multiple Sclerosis - the myelin
sheath is attacked by the immune
system (autoimmune disease)
After the myelin is destroyed it leaves behind
scar tissue (sclerosis means scar). The scar
blocks the message from being sent.
To send a message the neurotransmitters are released into
the synapse they bounce around & hit the receptors to
send on the message.
(like pinball hitting certain spots scores points)
Neurotransmitters are destroyed by enzymes
neurotransmitters
axon
synapse
receptors
Axon
Neurotransmitters
Synapse
Receptors
Dendrite
Nerves and Drugs
What kind of effects can drugs
have?
Axon
What does this have to do with
nerves?
Why do different drugs create
different effects?
Different drugs affect nerves in
different areas of the body
Dendrite
Enzyme destroying
Example – hallucinogens affect the a neurotransmitter
area of the brain that shows a visual
image.
Drugs affect the nerves at the synapse
- They act like neurotransmitters hitting the
receptors.
- They block the enzyme from destroying the
neurotransmitter after the message has
been sent, so they keep sending the
message
The receptors get worn out &
stop working (this is addiction)
Addiction is when the person
physically needs the drug to function
normally.