Nerves 2 Flashcards

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

How do neurones send electrical signals?

A
  • Action potentials: transmit signals over long distances
  • Graded potentials: decide when an action potential should be fired
  • Resting membrane potential: keeps cell ready to respond
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is RMP?

A

-70mV

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

What is the equilibrium potential?

A

The membrane potential at which the electrical gradient is exactly equal and opposite to the concentration gradient

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

What equation predicts the equilibrium potential for a single ion species?

A

The Nernst equation

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

Why are bananas dangerous?

A
  • Bananas contain high [K]
  • Reduction in concentration gradient
  • This sustains a smaller electrical gradient at equilibrium
  • RMP is reduced as the cell depolarises
  • Stresses the importance of the blood brain barrier
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What can an increase in [K] lead to?

A

Hyperkalaemia which leads to ventral fibrillation

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

How is the blood brain barrier protective?

A
  • Capillaries of the brain are especially tight
  • Due to astrocytes and tight junctions between endothelial cells
  • This protects the brain from changes in plasm [K]
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What has the biggest effect on the RMP?

A

Leaky K channels

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

What equation predicts the equilibrium potential generated by several ions?

A

The Goldman equation

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

Why is the RMP nearer -70mV than -90mV?

A
  • Other leaky channels, Na and Cl especially
  • Electrogenic nature of the Na/K
  • Large intracellular -ve charged molecules
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

When does the cell hyperpolarise?

A

When there is an increase in negative charge within the cell

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

When does the cell depolarise?

A

When there is an increase in positive charge within the cell

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