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What are the 6 steps in signal transmission between neurons?
- 1. Action potential is created at the Axon hillock
- 2. Signal moves through the axon to the terminal buotons, calcium channels open, CA+ rushes in
- 3. This causes vesicles to fuse (dock) with the presynaptic membrane
- 4. Vesicles release neurotransmitter into synaptic cleft, (exocytosis) neurotransmitters open the receiving channels on the post-synaptic cell
- 5. Ions flow through cleft to post-synaptic neuron
- 6. Change in potential of post-synaptic membrane (depolarize or hyperpolarize)
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What does the Action potential activate at the axon terminal?
Calcium voltage-gated channels
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What does CA+ cause in the presynaptic cell?
Vesicles to dock with the presynaptic membrane, and encourages neurotransmitters to be released
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When neurotransmitters are released into the synaptic cleft, this is called:
exocytosis
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1. What are the two major classes of neurotransmitters?
2. What are the functions of both?
- 1. Small Molecule and large molecule
- 2. Small: point to point effects, large: wide-spread effects
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What type of gated channel does a neurotransmitter open?
Ligand-gated channel
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The neurotransmitter _______ across the cleft and binds to ________ in the postsynaptic membrane. _______-gated receptors open and _____ flow through channels, causing a change in the ____-synaptic membrane potential. This change is the __________ ______ which will be integrated with others in the cell body
- diffuse
- receptors
- ligand
- ions
- post
- postsynaptic potential (PSP)
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Postsynaptic potentials can _______ or ______ the postsynaptic neuron.
- depolarize (excite)
- hyperpolarize (inhibit)
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The neurotransmitter effect depends on the _________ _______.
postsynaptic receptors
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Each neuron has ____ type of ligand-gated channel on its membrane for each ____________ that it receives
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Excitatory Postsynaptic Potentials:
Result from ____ flooding the cell
which causes a ____________
this can lead to an _______ _________
- NA+depolarization
- action potential
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Inhibitory Postsynaptic Potentials:
Result from ____ flooding the cell or ____ leaving the cell
Causes a ____________
Can prevent the production of an ______ ______
- CL- K+
- hyperpolarization
- action potential
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Different inputs _______ or _______ when they reach the cell body. If the combination of signals is excitatory, ____ channels will open and an action potential can occur, if the signal is inhibitory the action potential will not occur.
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Each postsynaptic potential is usually less than ___ mV, and an action potential can be over ___ mV.
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Postsynaptic Potentials are _______ _______.
Graded potentials
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Graded Potential:
_______-channel activated
______-distance
Magnitude is dependent on ______
Signal travels by ______ current flow
Magnitude _______ over moves away from stimulus site
Initiated at synapses of ____ _____ and _______
result in ________ or __________
- ligand
- short
- stimulus
- local
- dissipates
- cell body
- dendrites
- depolarization, hyperpolarization
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Activated by _______-gated channels
____-distance
Magnitude is _____ ___ _____
Signal can travel be _____ current or _________ _________.
Magnitude of signal is __________.
Initiated at _____ _____
Results in __________ only.
- voltage
- long
- all-or-none
- local
- saltatory conduction
- maintained
- axon hillock
- depolarization
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What are the two types of summations?
Explain:
Temporal (one stimulus site, many signals over time) and Spatial (many stimulus sites, many signals)
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In a ______ pathway, one presynaptic neuron branches to affect a larger number of postsynaptic neurons.
Divergent (one-to-many)
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In a _______ pathway many presynaptic neurons influence a smaller number of postsynaptic neurons.
Convergent (many-to-one)
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