Action Potenial

What is the charge on the outside of the axon during the resting membrane potential?

• +

• -

• neutral

Where is the concentration of sodium ions higher during the resting membrane potential?

• Outside

• Inside

What structure is used to maintain the resting membrane potential?

• Na/K pump

• leakage channels

• voltage gated channels

• secretory vessicles

During an action potential, _____ ions flow INTO the axon and _____ ions flow out of the axon.

• Na, K

• K, Na

• Na, Cl

• Cl, Na

During repolarization _____ ions flow ______ the axon

• K, into

• K, out of

• Na, into

• Na, out of

What term describes the movement of excess K ions such that the membrane potential becomes more negative than -70Mv?

• hyperpolarization

• repolarization

• subthreshold

• threshold

What happens if not enough Na+ enters the axon to reach the threshold potential?

• nothing

• a weak impulse

• a slow impulse

• a full impulse

The depolarization of the axon stimulates the opening of adjacent ion channels, which causes the depolarization of that area of the axon resulting in the opening of other ion channels. This describes...

• Positive Feedback

• Negative Feedback

• Threshold Stimulus

• Subthreshold Stimulus

What 2 forces cause the sodium ions to move into the axon during depolarization?

• Concentration Gradient

• Electrical Gradient

• Na/K pump

• Voltage Gated Channels

What is the numerical value of the resting membrane potential of an axon?

• -70mV

• 70mV

• 7.35-7.45

• 30 puffballs