Action Potential

An electrical impulse within a single neuron is called a

• synapse

• membrane potential

• action potential

• cell body

Which ion is pumped into the axon of a neuron to help maintain the resting potential?

• calcium

• hydrogen

• potassium

• sodium

Which one of the following is involved in maintaining a resting membrane potential?

• Na+/K+ ATPase pump moves 3Na+ in for every 2K+ out

• Na+/K+ ATPase pump moves 3K+ in for every 2Na+ out

• Na+/K+ ATPase pump moves 3Na+ out for every 2K+ in

• Na+/K+ ATPase pump moves 3K+ out for every 2Na+ in

What is a characteristic of axons in motor neurons?

• When there is a resting potential, the outside of the axon is negative relative to the inside.

• During an action potential, Na+ ions diffuse out of the axon.

• K+ ions diffusing out of the axon repolarizes it.

• Impulses in the axon travel towards the cell body.

Depolarization occurs when

• sodium channels open

• potassium channels open

• sodium channels close

• potassium channels close

Depolarization is occuring at number

• 1

• 2

• 4

• 5

What number(s) on the graph represents the Resting Potential?

• 1 and 2
• 1 and 5
• 2 and 3
• 3 and 4

When a membrane potential reaches +30mV, ________ channels open, ________ occurs, and ________ channels close.

• Sodium, depolarization, potassium
• Potassium, depoloarization, sodium
• sodium, repolarization, potassium
• postassium, repolarization, sodium

What number on the graph represents the Hyperpolarization phase?

• 1
• 2
• 3
• 4

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