$$\text{Voltage} = \text{current} \times \text{resistance}$$

Question 1

Which structure in a multipolar neuron is primarily responsible for receiving incoming signals from other neurons?

Accepted Answer

Dendrites

Question 2

What is the main function of the Nissl bodies found in the soma of a neuron?

Accepted Answer

Protein synthesis

Question 3

During the resting membrane potential (RMP), which ion is most abundant inside the cell?

Accepted Answer

K$$^+$$

Question 4

Which equation correctly relates membrane potential, charge separation, and voltage?

Accepted Answer

$$	ext{Voltage} = 	ext{current} 	imes 	ext{resistance}$$

Question 5

A patient is given Novocain during a dental procedure. What is the primary effect of Novocain on neuronal function?

Accepted Answer

It blocks voltage-gated Na$$^+$$ channels, preventing action potential propagation.

Question 6

Which of the following best describes the 'all or none' response in neurons?

Accepted Answer

A neuron fires only if the stimulus is above a certain threshold, and the action potential is always the same size.

Question 7

Which ion channel type is always open and is important for maintaining the resting membrane potential?

Accepted Answer

Leakage ion channels

Question 8

During the depolarization phase of an action potential, which event occurs first?

Accepted Answer

Voltage-gated Na$$^+$$ channels open

Question 9

What is the main role of the Na$$^+/K$^+$$ ATPase pump in neurons?

Accepted Answer

To maintain the concentration gradients of Na$$^+$$ and K$$^+ by $$pumping Na$$^+$$ out and K$$^+ in $$against their gradients

Question 10

A neuron is exposed to a threshold stimulus. Which of the following best describes what happens next?

Accepted Answer

Voltage-gated Na$$^+$$ channels open, causing Na$$^+$$ influx and depolarization

Question 11

Which of the following is TRUE regarding the refractory period in neurons?

Accepted Answer

It is the time when a neuron cannot transmit another impulse in response to a second stimulus.

Question 12

Which of the following best explains why the inside of a neuron is negatively charged at rest?

Accepted Answer

There are more K$$^+$$ leakage channels than Na$$^+$$ leakage channels, and negatively charged proteins are trapped inside.

Question 13

Which of the following is a correct sequence of events during synaptic transmission at a chemical synapse?

Accepted Answer

Depolarization of the axon terminus opens voltage-gated Ca$$^{2+}$$ channels, causing neurotransmitter release

Question 14

Which neurotransmitter is released at the neuromuscular junction to stimulate muscle contraction?

Accepted Answer

Acetylcholine (ACh)

Question 15

A neuron is exposed to a toxin that blocks voltage-gated K$$^+$$ channels. What effect would this have on the action potential?

Accepted Answer

The neuron would not repolarize properly, leading to prolonged depolarization.

Question 16

Which of the following best describes the role of the axon hillock in a neuron?

Accepted Answer

It is the site where action potentials are initiated if threshold is reached.

Question 17

Which of the following equations correctly represents Ohm's Law as applied to neurons?

Accepted Answer

$$V = I 	imes R$$

Question 18

During the repolarization phase of an action potential, which ion moves out of the neuron?

Accepted Answer

K$$^+$$

Question 19

Which of the following is TRUE about the propagation of an action potential along a neuron?

Accepted Answer

It moves in one direction due to the refractory period.

Neuronal Physiology: Structure, Function, and Signal Transmission

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