Chapters 32 & 37

Question 1

What is the resting potential of a neuron?

Answer 1

Resting potential is the membrane potential of a neuron that is not sending signals

Question 2

Where is the concentration of Na+ higher? K+?

Answer 2

(Inside of neuron is more neg. than outside). This is because there is a lot of K+ ions on the outside which are positive.
Inside of membrane is -70 mV.

Question 3

What must you do to achieve an action potential?

Answer 3

A certain level of depolarization must occur.

Question 4

What is depolarization? How does it occur?

Answer 4

Reducing the membrane potential making it more positive. How it occurs: Sodium channels stimulated to open. Sodium moves into the cell. Causes change in membrane potential.

Question 5

What membrane conditions are primarily responsible for maintaining the resting membrane potential?

Answer 5

The gated Na+ and K+ channels are closed. Ungated channels maintain the resting state.

Question 6

What events are primarily responsible for the depolarization or the membrane?

Answer 6

A couple sodium channels are opened by stimulus. The inflow of Na+ through those channels depolarizers the membrane. An action potential is triggered if depolarization reaches the threshold.

Question 7

What events are primarily responsible for the repolarization of the membrane?

Answer 7

K+ outflow is responsible for the repolarization of the membrane. Remember that in the repolarization zone, the sodium channels are inactivated.

Question 8

What events are primarily responsible for the hyper polarization of the membrane?

Answer 8

Hyper polarization is caused from anything that increases the outflow of positive ions or the inflow of negative ions.

Question 9

What forms the myelin sheath?

Answer 9

Schwann cells