Question 1

Which of the following best describes the difference between the sympathetic and parasympathetic divisions of the autonomic nervous system?

Accepted Answer

Sympathetic division mediates 'fight-or-flight' responses and primarily uses norepinephrine at postganglionic synapses, while parasympathetic mediates 'rest-and-digest' responses and uses acetylcholine at postganglionic synapses.

Question 2

Which glial cell type is responsible for forming myelin sheaths in the peripheral nervous system?

Accepted Answer

Schwann cells

Question 3

A graded potential that starts above threshold but decreases in strength as it travels through the cell body and is below threshold at the trigger zone will result in:

Accepted Answer

No action potential being generated.

Question 4

Which equation best represents the Nernst equation for calculating the equilibrium potential of an ion?

Accepted Answer

$$E_{ion} = \frac{RT}{zF} \ln \left( \frac{[ion]_{out}}{[ion]_{in}} \right)$$

Question 5

During the rising phase of the action potential, which ion is primarily responsible for the rapid depolarization of the neuron?

Accepted Answer

Sodium ($$Na^+)$$

Question 6

Which of the following scenarios best illustrates temporal summation in a postsynaptic neuron?

Accepted Answer

A single presynaptic neuron fires rapidly in succession, causing graded potentials to overlap and sum.

Question 7

Which neurotransmitter is released at the neuromuscular junction (NMJ) to stimulate skeletal muscle contraction?

Accepted Answer

Acetylcholine

Question 8

A patient with chronic pain due to diabetic neuropathy is prescribed gabapentin. What is the primary mechanism by which gabapentin reduces neuronal excitability?

Accepted Answer

It decreases the density of presynaptic voltage-gated calcium channels, reducing neurotransmitter release.

Question 9

Which of the following best describes the role of the trigger zone in a neuron?

Accepted Answer

It is the region where action potentials are initiated if the membrane potential reaches threshold.

Question 10

Which type of sensory receptor is responsible for detecting changes in temperature?

Accepted Answer

Thermoreceptors

Question 11

Which of the following drugs acts by blocking the reuptake of both serotonin and norepinephrine at the synapse?

Accepted Answer

Amitriptyline

Question 12

In the gate-control model of pain modulation, which of the following is true?

Accepted Answer

Non-painful input can inhibit the transmission of pain signals to the brain.

Question 13

Which of the following best describes the effect of increased extracellular potassium ($$K^+) $$concentration on the resting membrane potential?

Accepted Answer

It makes the resting membrane potential less negative (depolarizes the cell).

Question 14

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

Accepted Answer

Action potential arrives at axon terminal, voltage-gated calcium channels open, neurotransmitter is released into the synaptic cleft.

Question 15

Which of the following is true regarding the integration of excitatory and inhibitory postsynaptic potentials (EPSPs and IPSPs)?

Accepted Answer

Inhibitory inputs can prevent the neuron from reaching threshold even if excitatory inputs are present.

Question 16

Which neurotransmitter is primarily responsible for fast excitatory transmission in the central nervous system?

Accepted Answer

Glutamate

Question 17

Which of the following best describes the effect of temporal summation on action potential generation?

Accepted Answer

It increases the likelihood of reaching threshold by overlapping graded potentials in time.

Question 18

Which of the following is a property of the NMDA receptor at the glutamate synapse?

Accepted Answer

It requires depolarization to remove $$Mg^{2+}$$ block and allow $$Ca^{2+}$$ entry.

Question 19

Which of the following best describes the organization of the autonomic nervous system pathway?

Accepted Answer

Two neurons are involved: a preganglionic neuron synapses in an autonomic ganglion with a postganglionic neuron that innervates the target tissue.

Nerve and Muscle Physiology: An Overview – Study Notes

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