Action Potential

Q.

How does the membrane potential inside a neuron change during an action potential?

1. First positive, then negative and again back to positive

2. First negative, then positive and again back to negative

3. First negative, then positive and continue to be positive

4. First positive, then negative and continue to be negative

Q.

After generation of action potential, the recovery process is called _____.

1. Depolarisation

2. Hyperpolarization

3. No change

4. Repolarisation

Q.

The diffusion of potassium ions out of a neuron after depolarisation causes : _____.

1. Depolarization

2. Repolarization

3. Nerve impulse

4. Action potential

Q.

An action potential is caused by an influx of _____ ions into the cell.

1. Sodium

2. Both Potassium and Sodium

3. Potassium

4. Calcium

Q.

An action potential is _____.

1. Outflux of negative ions to depolarize the membrane

2. Initiated by potassium ion movements

3. Outflux of positive ions to depolarize the membrane

4. Essential for nerve impulse propagation

Q.

During the propagation of a nerve impulse, the action potential results from the movement of ______.

1. K+ ion from extra cellular fluid to intra cellular fluid

2. Na+ ions from intra cellular fluid to extra cellular fluid

3. K+ ions from intracellular fluid to extra cellular fluid

4. Na+ ions from extra cellular fluid to intra cellular fluid

Q. Ions diffuse freely along their (i)___, from the region of (ii)___ concentration and (iii)___ charge to the region of (iv)___ concentration and (v)___charge.

1. (i) concentration gradient, (ii) high, (iii) opposite, (iv) low, (v) similar
2. (i) electrochemical gradient, (ii) high, (iii) opposite, (iv) low, (v) similar
3. (i) concentration gradient, (ii) high, (iii) similar, (iv) low, (v) opposite
4. (i) electrochemical gradient, (ii) high, (iii) similar, (iv) low, (v) opposite

Q.

Action potential in a polarised neuron triggers _____.

1. Hyperpolarization

2. No change

3. Repolarisation

4. Depolarisation

Q.

Threshold potential is a state of depolarisation at which _____.

1. All of the above

2. An action potential is sure to fire

3. Voltage gated Na+ channels open

4. Membrane potential is near -55mV

Q.

Fill in the correct sequence for generation of Action potential in a neuron

Stimulus ⟶Inflow of $N{a}^{+}$ ions ⟶ _(i)_____⟶Repolarisation ⟶___(ii)______

1. Transmission of Na+ Inflow of Na+ ions

2. Inflow of Na+ ions Transmission of Na+

3. Hyperpolarization Inflow of Na+ ions

4. Transmission of Na+ & K+ Hyperpolarization & RMP