Q: Which of the following best explains why action potentials only travel in one direction along an axon?

Na\textsuperscript{+} channels become inactivated after depolarization, preventing backward propagation.

Q: During the absolute refractory period, which of the following is TRUE?

Voltage-gated Na\textsuperscript{+} channels are inactivated and cannot be reopened.

Q: What is the primary effect of opening voltage-gated K\textsuperscript{+} channels during an action potential?

It repolarizes the membrane by allowing K\textsuperscript{+} to exit the cell.

Q: Which of the following best describes the process of neurotransmitter release at a chemical synapse?

Neurotransmitter release requires Ca\textsuperscript{2+} entry into the presynaptic cell.

Q: Which of the following is a consequence of hyperkalemia (increased plasma K\textsuperscript{+}) on neuronal resting membrane potential?

Less K\textsuperscript{+} leaves the cell, shifting the membrane potential closer to threshold.

Question 1

Which of the following best explains why action potentials only travel in one direction along an axon?

Accepted Answer

Na	extsuperscript{+} channels become inactivated after depolarization, preventing backward propagation.

Question 2

During the absolute refractory period, which of the following is TRUE?

Accepted Answer

Voltage-gated Na	extsuperscript{+} channels are inactivated and cannot be reopened.

Question 3

What is the primary effect of opening voltage-gated K	extsuperscript{+} channels during an action potential?

Accepted Answer

It repolarizes the membrane by allowing K	extsuperscript{+} to exit the cell.

Question 4

Which equation best represents the Nernst potential for K	extsuperscript{+} ions?

Accepted Answer

$$E_K = \frac{RT}{zF} \ln \left( \frac{[K^+]_{out}}{[K^+]_{in}} \right)$$

Question 5

A neuron is exposed to a neurotransmitter that opens K	extsuperscript{+} channels. What is the most likely effect?

Accepted Answer

The neuron becomes hyperpolarized and less likely to fire.

Question 6

Which of the following statements about myelinated axons is correct?

Accepted Answer

Myelination increases resistance to ion leakage, speeding up conduction.

Question 7

Which of the following best describes the process of neurotransmitter release at a chemical synapse?

Accepted Answer

Neurotransmitter release requires Ca	extsuperscript{2+} entry into the presynaptic cell.

Question 8

Which of the following is a consequence of hyperkalemia (increased plasma K	extsuperscript{+}) on neuronal resting membrane potential?

Accepted Answer

Less K	extsuperscript{+} leaves the cell, shifting the membrane potential closer to threshold.

Question 9

Which of the following is TRUE regarding graded potentials?

Accepted Answer

They fade quickly and can be summed spatially and temporally.

Question 10

Temporal summation in neurons occurs when:

Accepted Answer

EPSPs occur close together in time and sum before fading.

Question 11

Which of the following is NOT a function of the hypothalamus?

Accepted Answer

Integration of voluntary motor movement.

Question 12

Which structure is responsible for coordinating execution of movement and maintaining equilibrium and balance?

Accepted Answer

Cerebellum

Question 13

Which of the following statements about the blood-brain barrier is correct?

Accepted Answer

Lipid-soluble molecules can cross the blood-brain barrier.

Question 14

Which of the following best describes the role of the thalamus?

Accepted Answer

It acts as a relay station integrating sensory information.

Question 15

Which hormone is secreted by the anterior pituitary and stimulates the thyroid gland?

Accepted Answer

Thyroid-stimulating hormone (TSH)

Question 16

Which of the following is TRUE about the organization of the spinal cord?

Accepted Answer

Ventral roots carry efferent signals to muscles and glands.

Question 17

Which area of the cerebral cortex is responsible for processing somatic sensory information such as touch, pain, and temperature?

Accepted Answer

Primary somatosensory cortex

Question 18

Which of the following best describes the effect of long-term potentiation (LTP) at a synapse?

Accepted Answer

It produces sustained increases in synaptic strength, believed to underlie learning.

Question 19

Which of the following is a correct statement about the conduction of action potentials in unmyelinated axons?

Accepted Answer

Conduction is slow because each adjacent region must be depolarized.

Question 20

Which equation best describes the relationship between membrane potential and ion concentrations according to the Goldman-Hodgkin-Katz equation?

Accepted Answer

$$V_m = \frac{RT}{F} \ln \left( \frac{P_{K^+}[K^+]_{out} + P_{Na^+}[Na^+]_{out} + P_{Cl^-}[Cl^-]_{in}}{P_{K^+}[K^+]_{in} + P_{Na^+}[Na^+]_{in} + P_{Cl^-}[Cl^-]_{out}} \right)$$

Neurons: Cellular and Network Properties – Action Potentials and Signal Conduction

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