Action Potentials

What is the normal resting potential of a neuron cell membrane?

• +40mV
• -30mV
• +55mV
• -70mV

Which ions are involved in an action potential?

• Na; Cl
• Na; K
• K; Cl
• Na; Ca

At which point on the diagram does depolarisation of the axon occur? 

• A
• B
• C
• D

A membrane potential becoming less negative is called

• hyperpolarization
• depolarization
• repolarization
• polarization

In resting potential, neurons have more _________ on the outside of the cell membrane.

• K+
• NaCl
• Na+
• Cl-

What number(s) on the graph represents the THRESHOLD level of stimulus?

• 1 and 5

• 2

• 3

• 6

Why is -55 mV a significant number?

• This is the largest charge achieved during an action potential
• This is the threshold required to complete an action potential
• This is the resting charge of a neuron
• This is the charge when all the sodium is inside the cell

The sodium-potassium pump....

• Sends (Na⁺) into the cell
• Sends (K⁺) into the cell
• Exchanges (K⁺) & (Na⁺) during depolarization
• Exchanges (K⁺) & (Na⁺) during hyperpolarization

At what stage are both ions present in large concentrations INSIDE the neuron?

• Depolarizarion
• Repolarization
• Hyperpolarization
• Resting Potential

What number on the graph represents the Hyperpolarization phase?

• 1
• 2
• 3
• 4