U4L2 Nerve impulse and action potential graph review

Depolarization occurs when

• sodium channels open

• potassium channels open

• sodium channels close

• potassium channels close

When a stimulus approaches the axon, it opens up channels to allow what chemical ion to flow into the axon?

• sodium

• iron

• potassium

• calcium

Returning back to the resting phase is called -

• polarization

• conductivity

• depolarization

• repolarization

Which ions are involved in the electrical nerve impulse?

• Iodine and Sodium
• Potassium and Sodium
• Iron and Sodium
• Calcium and Iodine

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

when does the stimuli cause an action potential?

• when it reaches threshold

• just below the threshold

• just above threshold

When a neuron is resting, the inside of the axon has a ____________ charge.

• positive
• negative

which is the correct pathway of impulse in a voluntary action

• stimulus > effector > brain > affector > response

• stimulus .> affector > brain > effector > response

• stimulus > affector > spinal cord > effector > response

• stimulus > effector > spinal cord > affector > response

To return back to the normal resting phase, a channel on the axon membrane opens up and allows what chemical ion to escape from the axon?

• sodium

• calcium

• potassium

• iron

a signal molecule that transmits nerve impulses across synapses

• neuron
• neurotransmitter
• nerve
• action potential