Ch 12: 3-D Physiology: Membrane Potentials: Graded and Action Potentials

If I can block neurotransmitters attaching to chemically-gated sodium channels, what will be the result? The cell will become hyperactive The cell will die An action potential will not be produced The cell will depolarize but not repolarize

An action potential will not be produced

A single graded potential can produce an action potential. True False

False

What results in the depolarization of the cell membrane? Voltage-gated potassium channels open allowing potassium ions to diffuse out of the cell taking their positive charges with them. Chemically-gated potassium channels open allowing potassium ions to diffuse out of the cell causing the inside of the membrane to become more negative. Mechanically-gated channels open to allow potassium ions to diffuse into the cell causing the membrane to become more negatively charged inside. Voltage-gated sodium channels open allowing sodium ions to enter the cell to cancel negative charges on the inside of the membrane.

Voltage-gated sodium channels open allowing sodium ions to enter the cell to cancel negative charges on the inside of the membrane

When the threshold of voltage-gated channels is reached and voltage-gated channels open, the resulting change in membrane potential is known as a(n) action potential. induction mode. graded potential. transition state.

action potential.

The principle which states that once an action potential begins, all of the output zone will depolarize and repolarize is known as the membrane integrity principle. cellular hysteresis principle. polarity principle. all-or-none principle.

all-or-none principle.

When the electrical potential on the inside of the cell membrane is uncharged, reaches 0 mv, the inside of the membrane is considered to be neutral. repolarized. depolarized. polarized.

depolarized.

When a neurotransmitter attaches to a chemically-gated sodium channel, the sodium channel briefly opens to allow sodium ions to diffuse in. This action produces what type of graded potential? depolarizing graded potential hyperpolarizing graded potential polarizing graded potential repolarizing graded potential

depolarizing graded potential

Resting membrane potential is maintained by leak channels. leak channels and sodium-Potassium pumps. sodium-Potassium pumps. chemically-gated channels.

leak channels and sodium-Potassium pumps.

The depolarization of one area of the cell membrane provides enough positive charge to cause neighboring voltage-gated channels to reach threshold allowing the action potential to spread across the membrane. True False

true

If the accumulation of graded potentials in the trigger zone reaches threshold, the result is voltage-gated channels open. the cell is blocked from any further action. mechanically-gated channels must close. the cell membrane goes to its resting state.

voltage-gated channels open.