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28 Cards in this Set
- Front
- Back
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Spontaneously depolarizing cells generate APs in the?
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heart.
A damaged neuron will spont. depolar |
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synapse
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a(place(where(2(cells(communicate(–(when(one(cell(is(a(neuron,(and(the(other(cell( may(or(may(not(be,(you(have(communication(between(known(as(a(synapse(
o one(neuron(releases(a(chemical((transmitter)(that(binds(to(receptors(on(the(2nd(cell,( which(could(be(another(neuron,(a(muscle,(almost(anything(–(and(brings(about(a(change( in(the(functioning(of(the(2nd(cell( |
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Catecholamines
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EP, NE, Dopamine
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transmitter in vesicles are stored where?
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in the interior of the axon. APs cause them to release
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Why don't vesicles get release automatically?
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bc neg charges on vesicles are repelled by the neg
charges on the cell membrane. Brownian motion. If vesicles have a high enough energy to overcome the repulsion they can stick to the membrane. |
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Whats the threshold for Ca ion channels?
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-40mV. The more positive they open, the more negative they stay closed.
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If -35mv, is Ca channels open or closed?
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open. More Ca that comes in helps to neutralize the repulsion.
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If -55mV, are Ca channels open or closed?
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closed
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How does calcium get out of the cell after an AP?
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1. Ca/ATPase in the short run. 1 Ca for 1 ATP
2. Exchange/Antiport. 3NA in for 1 Ca out and it is driven by the Na gradient |
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How are catechoamines get removed?
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by re-uptake.
Acetylcholine by Acetylcholinesterase, which breaks it apart into acetate and choline |
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Are vesicles recycled?
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Yes. via the Kiss and Go model. Vesicle merges with membrane and gets coated with clathrin while being pulled in. It then goes to the golgi and merges where and membrane becomes part of the golgi and a new formed vesicle exits on the other side.
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Transmitter cause the glycoprotein receptor in the post synaptic membrane to bind reversibly to the receptor. The transmitter causes a conformational change to the receptor. The synapse can have what sort of affect?
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1. Change in Ion permeability (ionotropic)
2. Activate/inhibit some enzymes within the cell (metabotropic) |
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Suppose there is an increase in Na permeability, is it EPSP or IPSP?
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EPSP - it's trying to shift the membrane close to +60 mV
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Suppose there is an increase in PK, is it EPSP or IPSP?
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IPSP - It's trying to pull it toward -90mV which will make it harder to reach -55mV
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Suppose there is an increase in the permeability of chloride, is it EPSP or IPSP?
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IPSP
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Suppose there is an decrease in the permeability of chloride, is it EPSP or IPSP?
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EPSP
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Suppose there is an decrease in Na permeability, is it EPSP or IPSP?
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IPSP
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Suppose there is an decrease in PK, is it EPSP or IPSP?
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EPSP
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liminal
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reached the threshold for AP
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subliminal
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did not reach threshold = no AP
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Metabotropic synapse
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many of these affect G-Proteins
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When you activate PLC what happens?
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Activated by Alpha GTP. It cuts the bond and you're left with DAG and the other IP3 goes into the cytoplasm
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What does IP3 do?
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When it encounters a Ca storing internal organelle it tells it to release Ca. Ex. ER
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What does DAG do?
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It aims to increase Ca concentration in the cell as well. When it encounters Ca channels it opens them.
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What does calmodulin do?
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Calcium binding in SM
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Length constant for Unmyelinated axons
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V = sq rt. diamter
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Length constant for Myelinated axons
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V = diameter
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Length constant
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= sq rt of Rm/RL
Rm = current stays in Rl = current leaves |
