1t- Generation of a nerve impulse Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

What is the resting membrane potential?

A

The state where there is no net flow of ions across the membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What does the transmission of a nerve impulse require?

A

Changes in the membrane potential of the neurons plasma membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is an action potential?

A

A wave of electrical excitation along a neurons plasma membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How do neurons initiate a response?

A

By binding to their receptors at a synapse

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How can neurotransmitters be described?

A

As ligand-gated ion channels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What does depolaristation as the result of the entry of positive ions trigger?

A

The opening of voltage-gated sodium channels, and further depolarisation occurring

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is depolarisation?

A

A change in the membrane potential to a less negative value inside

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What restores the resting membrane potential?

A

Inactivation of the sodium channels and the opening of potassium channels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What does the binding of a neurotransmitter trigger?

A

The opening of ligand-gated ion channels at a synapse

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What occurs after the opening of ligand gated ion channels at a synapse?

A

Ion movement occurs and there is a depolarisation of the plasma membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What happens if sufficient ion movement occurs, and the membrane is depolarised beyond a threshold value?

A

The opening of voltage-gated sodium channels is triggered and sodium ions enter the cell down their electrochemical gradient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What does the entering of sodium ions through voltage-gated sodium channels into the cell lead to?

A

A rapid and large change in the membrane potential

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What happens a short time after the sodium channels open?

A

They become inactivated and then voltage-gated potassium channels open to allow potassium ions to move out of the cell to restore the resting membrane potential

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What does the depolarisation of a patch of membrane cause to happen?

A

Neighbouring regions of membrane to depolarise and go through the same cycle, as adjacent voltage-gated sodium channels are opened

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What happens when the action potential reaches the end of the neuron?

A

It cause vescicles containing neurotransmitter to fuse with the membrane- this releases neurotransmitter, which stimulates a response in a connecting cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What two things does the restoration of the resting membrane potential allow to happen?

A
  • the inactive voltage-gated sodium channels return to a conformation that allows
    them to open again in response to further depolaristaion of the membrane
  • ion concentration gradients are re-established by the sodium-potassium pump,
    which actively transports excess ions in and out of the cell