AP Biology

1
AP Biology

• Nervous Systems
• Part 3

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Synapse and Neurotransmitter
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Nerve Impulse is approaching the axon terminal by
Saltatory Conduction
Schwann cell
Depolarized region (node of Ranvier)
Cell body
Myelin sheath
Axon
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Synapse at the axon terminal
Postsynaptic cell
Presynaptic cell
Na
Neuro- transmitter
K
Synaptic vesicles containing neurotransmitter
Presynaptic membrane
Postsynaptic membrane
Ligand- gated ion channel
Voltage-gated Ca2 channel
Postsynaptic membrane
Ca2
Synaptic cleft
Ligand-gated ion channels
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Post synaptic membrane
Na
Na
Na
Na
K
K
Rising phase of the action potential
Falling phase of the action potential
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Action potential
Na
Na
0
Membrane potential (mV)
Threshold
50
K
Resting potential
100
Time
Depolarization
Na
Na
Potassium channel
Extracellular fluid
Activation gates
Na
K
Plasma membrane
Undershoot
Cytosol
Sodium channel
Inactivation gate
K
Resting state
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Synapse with effector cell
Spinal cord
Motor unit 1
Motor unit 2
Synaptic terminals
Nerve
Motor neuron cell body
Motor neuron axon
Muscle
Muscle fibers
Tendon
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