Q: Which equation correctly represents the electrochemical gradient for an ion across a membrane?

$$ E = \frac{RT}{zF} \ln \left( \frac{[\text{ion outside}]}{[\text{ion inside}]} \right) $$

Q: Which equation represents the change in membrane potential during depolarization?

$$ \Delta V = V_{\text{final}} - V_{\text{initial}} $$

Question 1

Which of the following best describes the function of the sodium-potassium exchange pump in maintaining the resting membrane potential of a neuron?

Accepted Answer

It actively transports 3 Na+ ions out of the cell and 2 K+ ions into the cell, using ATP to maintain a negative resting potential.

Question 2

During the generation of an action potential, what is the significance of the 'all-or-none' principle?

Accepted Answer

Once threshold is reached, the action potential is always the same size and strength, regardless of stimulus intensity.

Question 3

Which equation correctly represents the electrochemical gradient for an ion across a membrane?

Accepted Answer

$$ E = \frac{RT}{zF} \ln \left( \frac{[	ext{ion outside}]}{[	ext{ion inside}]} ight) $$

Question 4

A patient is experiencing muscle rigidity and tremors. Which neurotransmitter is most likely deficient, and which disease is associated with this deficiency?

Accepted Answer

Dopamine; Parkinson's disease

Question 5

Which of the following best explains why myelinated axons conduct action potentials faster than unmyelinated axons?

Accepted Answer

Myelin insulates the axon, causing the action potential to jump from node to node (saltatory propagation), reducing ion leakage and increasing speed.

Question 6

During the repolarization phase of an action potential, which channels are open and what is the direction of ion movement?

Accepted Answer

Potassium channels are open; K+ ions move out of the cell.

Question 7

Which type of peripheral nerve fiber is responsible for carrying rapid, critical motor impulses to skeletal muscles?

Accepted Answer

Type A α (alpha) fibers

Question 8

A neuron receives multiple excitatory postsynaptic potentials (EPSPs) and inhibitory postsynaptic potentials (IPSPs) simultaneously. What determines whether an action potential will be generated?

Accepted Answer

The net effect of all EPSPs and IPSPs at the axon hillock reaching threshold

Question 9

Which neurotransmitter is most associated with regulating sleep, mood, and appetite, and is targeted by drugs like Prozac?

Accepted Answer

Serotonin

Question 10

What is the primary effect of inhibitory neurotransmitters on the postsynaptic membrane?

Accepted Answer

They cause hyperpolarization, suppressing action potentials.

Question 11

Which of the following best describes temporal summation?

Accepted Answer

Multiple EPSPs occur at the same location in rapid succession, increasing the likelihood of reaching threshold.

Question 12

Which equation represents the change in membrane potential during depolarization?

Accepted Answer

$$ \Delta V = V_{	ext{final}} - V_{	ext{initial}} $$

Question 13

Which of the following is true regarding the absolute refractory period?

Accepted Answer

No action potential can be generated, regardless of stimulus strength, because Na+ channels are open or inactivated.

Question 14

Which neurotransmitter is released at all neuromuscular junctions with skeletal muscle fibers and is essential for muscle contraction?

Accepted Answer

Acetylcholine

Question 15

A drug that acts as an agonist at GABA synapses would most likely have which effect?

Accepted Answer

Reduce anxiety and neural activity

Question 16

Which of the following best describes the process of saltatory propagation?

Accepted Answer

Action potentials jump from node to node along myelinated axons, increasing speed and efficiency.

Question 17

Which type of postsynaptic potential results in a graded depolarization of the postsynaptic membrane?

Accepted Answer

Excitatory postsynaptic potential (EPSP)

Question 18

Which of the following is a direct effect of a neurotransmitter on a postsynaptic cell?

Accepted Answer

Opening or closing gated ion channels (ionotropic effect)

Question 19

Which equation best represents the relationship between axon diameter and resistance to ion movement?

Accepted Answer

$$ R \propto \frac{1}{d} $$

Transmembrane Potential and Action Potentials in Neurons

스터디 가이드 - 연습 문제

학습 가이드 - 플래시카드