M&R Session 5- The Cellular Response To Action Potentials Flashcards Preview

SOPHIE'S ESA 2 > M&R Session 5- The Cellular Response To Action Potentials > Flashcards

Flashcards in M&R Session 5- The Cellular Response To Action Potentials Deck (14)
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0
Q

Why does a small amount of calcium influx cause a significant increase in intracellular calcium?

A

Because basal intracellular concentrations of calcium are so low.

1
Q

What is the result of an AP reaching a presynaptic membrane?

A

Causes the opening of voltage gated calcium channels and a calcium influx.

2
Q

What does the entry of calcium trigger?

A

Neurotransmitter release

3
Q

What is the structure of voltage gated calcium channels?

A

Similar to voltage gated sodium channels. 6 transmembrane domains in each of the 4 subunits.

4
Q

How do we know that calcium channels have structural diversity?

A

Because they have different blockers.

5
Q

What is the advantage of blockers being specific to few calcium channels?

A

They allow more localised effects.

6
Q

What are the specific blockers to the L type calcium channel?

A

Dihydropyridines

7
Q

Describe how the influx of calcium causes acetylcholine release.

A

The influx of calcium binds to synaptotagmin.
The vesicle is brought closer to the membrane.
The snare complex makes a fusion pore, which ACh can move out of.

8
Q

How is an end plate potential produced?

A

The released acetylcholine binds to nicotinic acetylcholine receptors on the post synaptic membrane and produces an end plate potential.

9
Q

How many acetylcholine bind to nAChR to open it?

A

2

10
Q

Where do competitive acetylcholine blockers bind?

A

To the acetylcholine recognition site.

11
Q

Give an example of a competitive blocker.

A

Tubocurarine

12
Q

What do depolarising blockers do? What is the consequence for sodium channels?

A

They cause maintained depolarisation at the post synaptic membrane.
They become inactivated due to accommodation.

13
Q

Give an example of a depolarising blocker.

A

Succinylcholine

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