Action Potentials

Question 1

A rapid depolarization is followed by a ____

Answer 1

rapid repolarization

Question 2

Neuron re-polarizes at about ___ mV

Answer 2

+20 mV

Question 3

Depolarization is caused by what?

Answer 3

Increase in cytosolic Na concentraion

Question 4

Typical resting potential is what?

Answer 4

-65 mV

Question 5

At +20 mv, the Na ____ force is outward while the Na ___ force is inward.

Answer 5

electrical

concentration

Question 6

At +20 mv Sodium channels ____ to keep pumping out sodium using electrical force.

Answer 6

close

Question 7

To repolarize what direction does K+ flow?

Answer 7

outward

Question 8

At +20mv, what direction is the K+ chemical and electrical force?

Answer 8

Both are outward

Question 9

Once at -65 mV concentration what direction is the K+ chemical and electrical force?

Answer 9

The electrical force is inward but the concentration force is outward.

Question 10

At -65 mV concentration what happens to the K+ channels?

Answer 10

The K+ channels close

Question 11

What structure allows for a change in membrane potential triggering an action potential?

Answer 11

Voltage gated channels

Question 12

What is the threshold for action potential?

Answer 12

-55mV

Question 13

What is the period in which a neuron is inactive and will remain inactive until the membrane is at resting potential

Answer 13

Refractory period

Question 14

What is it called when a current enter and spreads throughout the membrane

Answer 14

Electron-tonic conduction

Question 15

Propagation speed is dependent on what two factors?

Answer 15

mylination and diameter size

Question 16

Which axon will have a high propagation speed? The one with the larger diameter or smaller diameter?

Answer 16

The one with larger diameter

Question 17

The Axon hillock originates what?

Answer 17

depolarization

Question 18

Axon specifically identify what?

Answer 18

Pathways of communication

Question 19

Sodium channels have two gates ____ and ____

Answer 19

Inactivation gate and Activation gate

Question 20

At -65mv the sodium inactivation gate is ___

Answer 20

open

Question 21

At -65mv the sodium activation gate is ___

Answer 21

Closed

Question 22

At threshold (-55mv) the sodium activation gate is ___

Answer 22

Open

Question 23

At threshold (-55mv) the sodium inactivation gate is ___

Answer 23

Open

Question 24

At +20mv the sodium activation gate is ___

Answer 24

Open

Question 25

At +20mv the sodium inactivation gate is ___

Answer 25

Closed

Question 26

At re-polarization the sodium inactivation gate ___

Answer 26

opens

Question 27

At re-polarization the sodium activation gate ___

Answer 27

Closes

Question 28

What is the function of an action potential?

Answer 28

It is to communicate with other neurons