Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Human physiology > Membrane potentials and action potentials > Flashcards

Membrane potentials and action potentials Flashcards

1
Q

At what voltage will the number of potassium ions leaving the cell be equal to the number entering the cell?

A

-94 millivolts

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

At rest what are nerve fibers on the outside of the cell, electropositive or electronegative?

A

Electropositive

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

At rest what are nerve fibers on the inside of the cell, electropositive or electronegative?

A

Electronegative

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

What are the 2 forces that move ions?

A

Chemical
Electric

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

Where is potassium more concentrated? (inside or outside the cell)

A

Inside

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

Where is sodium more concentrated? (inside or outside the cell)

A

Outside

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

At what voltage will the number of sodium ions leaving the cell be equal to the number entering the cell?

A

+61 millivolts

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

What can the Nernst equation do?

A

Can quantify forces acting on ions

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

What does the diffusion potential of a membrane permeable to different ions depend on? (3)

A

Polarity of the electrical charge of each ions
Permeability of the membrane to each ion
The concentration of the respective ions inside and outside of the cell membrane

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

Which equation is used to figure out the conditions of a cell membrane which has multiple ions permeable?

A

The Goldman equation

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

Why is the Nernst equation not sufficient to learn about the condition of a cell membrane?

A

As it is permeable to multiple ions, all of which need to be taken into account

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

At what voltage is all ions leaving the cell equal to all ions entering the cell? (nerve cell)

A

-70 millivolts

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

Definition of resting membrane potential

A

Estimation of voltage when forces are 0

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

Is the resting membrane potential in all cells?

A

No it varies as ion vary and their permeability varies depending on type of cell and its function

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

What causes the variation in membrane potential of cells?

A

Structure of membrane
Concentration of ions

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

What is the driving force equal to?
Vdf=?

A

Difference between the membrane potential and equilibrium potential of the ion
Vdf= Vm-Veq

17
Q

A less than 0 Vdf of cations predicts what?

A

Outward movement of ions

18
Q

A less than 0 Vdf of anions predicts what?

A

Inward movement of ions

19
Q

A more than 0 Vdf of cations predicts what?

A

Inward movement of ions

20
Q

A more than 0 Vdf of anion predicts what?

A

Outward movement of ions

21
Q

What kind of pump is the sodium potassium pump?

A

Electrogenic pump

22
Q

Which is bigger, potassium or sodium?

A

Potassium

23
Q

When are leak channels open?

A

Always

24
Q

Which is easier, for the sodium to enter the cell or potassium to leave the cell?

A

Potassium to leave the cell

25
Q

Why is the resting potential of neurons closer to the potassium membrane potential than the sodium membrane potential?

A

Because the membrane is more permeable to the potassium, it easier for it to leave the cell than it is for sodium to enter

26
Q

3 states of a voltage gated channel

A

Resten/closed
Activated/open
Inactivated

27
Q

What is conductance?

A

Current of the ions that determine a specific voltage

28
Q

What kind of feedback loop is the cycle of membrane depolarisation during the active potential?

A

Positive feedback loop

29
Q

What happens to the permeability of Na+ when a nerve fiber is increased?

A

It increases

30
Q

What happens to the potential of the heart muscle fibers before depolarisation begins?

A

Remains at a plateau

31
Q

Why does the heart muscle fibers remain at a plateau?

A

Calcium channels manage to maintain the voltage for some time

32
Q

What does rhythmical discharge cause? (3)

A

Beat of the heart
Peristalsis of intestines
Control of breathing

Human physiology (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions