Physiology Resting Membrane Potential: Nerst Potentials

Front 1

Cell resting membrane potential

Back 1

-60 to -90 mV

Front 2

Process that utilizes resting membrane potential

Back 2

action potential/electrical impulses and absorption and secretion

Front 3

What happens when a cell is 'excited'

Back 3

it generates an electrical impulse

Front 4

What actually causes an electrical impulse?

Back 4

the distribution of ions across the membrane

Front 5

What determines the electrical gradient?

Back 5

the movement of ions on either side of the membrane

Front 6

How can a concentration gradient be opposed?

Back 6

if an electrical gradient is opposite in direction. This results in no net movement of ions (driving force is zero).

Front 7

Define the Nerst potential

Back 7

the membrane potential at which there is no net movement of an ion. (Na+ is +70 mV, if the potential is +70 mV on either side of the membrane, no net movement occurs)

Front 8

How can the Nerst potential be calculated for an ion?

Back 8

by measuring the concentration of the ion inside and outside the cell

Front 9

Where are the following ions found in highest concentration? (K, Na, Ca, and Cl)

Back 9

K - inside the cell
Na, Ca and Cl - outside the cell

Front 10

Which ion's Nerst potential is closest to intracellular resting potential and is most permeable?

Back 10

Potassium (-90 mV)

Front 11

Name two ions that have a positive Nerst potential

Back 11

Sodium and calcium

Front 12

What does the Nerst potential determine?

Back 12

the value of the membrane potential if the membrane is selectively permeable to the ion ONLY

Front 13

Define the equilibrium potential (Ep) for the following:
ENa+
ECa++
ECl-
EK+

Back 13

+70 mV
+122 mV
-47 mV
-88 mV