THE NERVE IMPULSE

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THE NERVE IMPULSE
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NEURON AT REST
outside
Na/K pump
Na Voltage Gated Pump
K Voltage Gated Pump
inside
3
What is the charge of the neuron at rest?
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NERVE IMPULSE
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1. SODIUM GATED CHANNELS OPEN
Na
Na
Na
outside
Na/K pump
K Voltage Gated Pump
inside
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2. POTASSIUM GATED CHANNELS OPEN
outside
Na/K pump
Na Voltage Gated Pump
K Voltage Gated Pump
K
K
inside
K
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3. HYPERPOLARIZATION
K
Na
Na
Na
outside
K
K
Na/K pump
Na Voltage Gated Pump
K Voltage Gated Pump
K
inside
K
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4. RETURN TO RESTING MEMBRANE POTENTIAL
K
K
Na
Na
Na
outside
K
K
Na/K pump
Na Voltage Gated Pump
K Voltage Gated Pump
K
inside
K
9
Threshold value
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PROPAGATION

• the change in potential in one area causes the
  adjacent channels to open

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SULTATORY CONDUCTION
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TRANSMISSION FROM ONE NEURON TO ANOTHER CELL
Post synaptic cell (e.g. dendrite of another
neuron)
Pre-synaptic cell
Synaptic cleft
Axon end
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STEPS INVOLVED
7.
2.
8.
1.
Ca2
3.
5.
Ach
Ach
Ach
4.
Ach
Ach
6.
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EFFECT ON TARGET CELL
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DRUG EFFECT ON NEUROTRANSMITTERS
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NEUROTRANSMITTERS

• Acetylcholine
• Excitatory and inhibitory effect depending on
  where it binds
• Muscle cells contain nicotinic receptors
• CNS contain both nicotinic and muscarinic
  receptors

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• Dopamine
• Movement, attention and learning
• Decrease can cause Parkinsons disease
• Increase can cause Schizophrenia
• Adrenalin
• Increase heart rate
• Noradrenalin
• Involved in alertness and wakefulness
• Seratonin
• Inhibitory post-synaptic potentials
• Regulation of mood control of eating control of
  sleep and arousal regulation of pain control of
  dreaming
• LSD interferes causing dreaming while awake