A&P 1: Chapters 12 & 13 Practice Action Potential with animations and questions

TRUE or FALSE Individual EPSPs and IPSPs determine whether or not a neuron fires and the rate of firing by stimulating or inhibiting the production of more action potentials.

-FALSE-

TRUE or FALSE The sodium-potassium pump uses bulk transport to move the sodium and potassium ions.

-FALSE-

TRUE or FALSE The voltage-gated potassium channels close before the membrane potential is brought back to its resting level.

-FALSE-

Increasing the intensity of a stimulus may increase which of the following? Select two answers from the list below.

-Number of activated neurons -Firing frequency of individual neurons

TRUE or FALSE After the passage of the action potential, the sodium-potassium pump re-establishes the resting membrane potential.

-TRUE

TRUE or FALSE Fast retrograde transport returns used synaptic vesicles and other materials to the soma and informs the soma of conditions at the axon terminals.

-TRUE-

2PART QUESTION 1) A resting membrane potential of -70 mV indicates that the ________________. 2) Normally, sodium and potassium leakage channels differ because ___________________.

1) charges lining the inside of the plasma membrane are negative compared to the charges lining the outside 2) sodium ions diffuse through leakage channels into the cell, but potassium ions diffuse through leakage channels out of the cell

3 PART QUESTION 1) Action potentials occur ____________________________. 2) Demyelinating diseases cause a(n) ______________ in the conduction velocity of action potentials. 3) If demyelination occurs, why don't action potentials occur at regions of the axon that were previously myelinated?

1) in the unmyelinated regions of an axon 2) decrease 3) These regions lack the appropriate concentration of voltage-gated sodium channels.

2 PART QUESTION 1)When voltage-gated sodium channels are open, sodium flows _____________ the neuron, making the inside of the cell more _______________. 2) The following information best describes the _____________ phase of an action potential. • A membrane potential reading of +10 mV • Inactivated voltage-gated sodium channels • Open voltage-gated potassium channels

1) into; positive 2) repolarization

2 PART QUESTION 1) Graded potentials result from the opening of ________________. 2) An inhibitory postsynaptic potential results from the opening of____________________.

1) ligand-gated channels 2) potassium and/or chloride channels

2 PART QUESTION 1) Graded potentials are produced within the _______________________ segment of a neuron. 2) Graded potentials result from the opening of ________________.

1) receptive 2) ligand-gated channels

At resting membrane potential, which of the following statements about the voltage-gated sodium ion channels is true?

Activation gates are closed, and inactivation gates are open.

Why does depolarization occur?

More Na+ diffuse into the cell than K+ diffuse out of it.

Why does depolarization occur?

More sodium ions diffuse into the cell than potassium ions diffuse out of it.

During depolarization, which of the following statements about voltage-gated ion channels is true?

Na+ gates open before K+ gates.

Which ion has the greatest influence on the resting membrane potential of most neurons?

Potassium

Why does repolarization occur?

Potassium ions continue to diffuse out of the cell after the inactivation gates of the voltage-gated sodium ion channels begin to close.

TRUE or FALSE The nerve impulse is an electrical current that travels along dendrites or axons.

TRUE

TRUE or FALSE The sodium-potassium pump is involved in establishing the resting membrane potential.

TRUE

Which of the following statements about the resting membrane potential is true?

The exterior of the cell has a net positive charge, and the interior has a net negative charge.

Why does hyperpolarization occur?

The increased potassium ion permeability lasts slightly longer than the time required to bring the membrane potential back to its resting level.

What is the most important mechanism for transmitting qualitative information?

The labeled line code

The resting membrane potential is negative due to which of the following?

There are more negatively charged particles on the inside of the membrane than on the outside.