Resting Potential

Question 1

What is the membrane voltage equation?

Answer 1

V=Q/C

Question 2

How is depolarization achieved?

Answer 2

• Reduction in charge separation

- Less negative membrane potential

Question 3

How is hyperpolarization achieved?

Answer 3

• Increase in charge separation

- More negative membrane potential

Question 4

Which establishes ionic gradients - Ion pumps or ion channels?

Answer 4

Ion pumps ! active transporters which establish ionic gradients

Question 5

Where are the following ions in higher concentration - outside or inside the cell?

1. K+
2. Na+
3. Ca2+

Answer 5

1. K+ is higher inside
2. Na+ is higher outside
3. Ca2+ is MUCH higher outside

Question 6

Is the direction of current flow defined as the direction of net movement of Positive or Negative charge?

Answer 6

POSITIVE

Question 7

What is the nernst equation?

Answer 7

E=RT/zF Log (X)2/(X)1

or just know:
E=61.5 Log (Koutside/Kinside)

Question 8

What is the nernst equation used for ?

Answer 8

To calculate equilibrium potential (theoretical situation mostly)

Question 9

What is the goldmans equation used for?

Answer 9

To calculate a steady state potential –> membrane potential (accounts for permeabilitites)

Question 10

What is the Pna/Pk ratio or alpha of the goldman equation?

Answer 10

alpha =0.05

Question 11

What is a result of interstitial hypokalemia (lower K+ concentration)

Answer 11

Cellular hyperpolarization (more negative)

Question 12

What is the result of intersitial hyperkalemia (higher K+ concentration)?

Answer 12

Cellular depolarization (more positive)