Action Potential Conduction

Question 1

Na channels open? inactive? closed?

K channels open?

Answer 1

Question 2

Na channels open? inactive? closed?

K channels open?

Answer 2

Question 3

Refractory period

Answer 3

absolute: absolutely cannot get another action potential because Na+ channels are inactivated (closed).
relative: can get action potential if have enough depolarization (Na deinactivating)

Question 4

Axon hillock

Answer 4

place that had to reach threshold for action potnetial to occur. decision is made here

Question 5

Propagation of action potential

Answer 5

Na channels open and Na rushes into the cell causing depolarization. Na moves to the right in the axon because the Na channels on the left are inactive. More Na channels to the right open. Na channels on the left inactive through ball and chain mechanism. K+ channels open and K rushes out of axon.

Question 6

Factors affecting rate of propagation

Answer 6

Axon diameter: smaller axon = higher internal resistance = slower rate of propagation.

Membrane resistaace: less leak channels = higher membrane resistance = faster rate of propagation

Myelination: saltatory conduction through nodes of ranvier allow you to not have to generate the action potential as frequently so it can propagate faster