WGU D313 ANATOMY AND PHYSIOLOGY II
COMPREHENSIVE 500-QUESTION PRACTICE EXAMINATION
|QUESTIONS WITH CORRECT ANSWERS &
DETAILED RATIONALES
DOMAIN 1: NERVOUS AND SENSORY SYSTEMS (Q1–Q80)
Q1. The resting membrane potential of a typical neuron is approximately:
A) +30 mV
B) -70 mV
C) -55 mV
D) +90 mV
Correct Answer: B
Rationale: The resting membrane potential is approximately -70 mV, maintained
by the Na+/K+ ATPase pump (3 Na+ out, 2 K+ in) and high K+ permeability.
Q2. During depolarization of an action potential, which ion moves across the
membrane and in which direction?
A) K+ moves out
B) Na+ moves in
C) Cl- moves in
D) Ca2+ moves out
Correct Answer: B
Rationale: Depolarization is caused by rapid influx of Na+ through voltage-
gated Na+ channels, making the inside less negative.
Q3. The threshold potential for triggering an action potential is typically:
A) -70 mV
B) -55 mV
C) 0 mV
D) +30 mV
Correct Answer: B
Rationale: The threshold is about -55 mV. If the membrane depolarizes to this
1
,level, voltage-gated Na+ channels open explosively, triggering the action
potential.
Q4. Which of the following increases the speed of action potential conduction?
A) Decreased axon diameter
B) Increased myelination
C) Increased temperature
D) Both B and C
Correct Answer: D (B and C)
Rationale: Myelination allows saltatory conduction (jumping between Nodes of
Ranvier), which speeds conduction. Increased temperature also speeds ion
movement and conduction velocity.
Q5. The synaptic cleft is:
A) The space between the presynaptic and postsynaptic neurons
B) The vesicle containing neurotransmitter
C) The receptor on the postsynaptic membrane
D) The axon hillock
Correct Answer: A
Rationale: The synaptic cleft is the 20-30 nm gap between the presynaptic
terminal and the postsynaptic membrane where neurotransmitters are released.
Q6. Which neurotransmitter is the primary excitatory neurotransmitter in the
CNS?
A) GABA
B) Glycine
C) Glutamate
D) Dopamine
Correct Answer: C
Rationale: Glutamate is the main excitatory neurotransmitter in the CNS. GABA
and glycine are inhibitory; dopamine has both excitatory and inhibitory roles.
Q7. Which neurotransmitter is the primary inhibitory neurotransmitter in the
2
,CNS?
A) Glutamate
B) Acetylcholine
C) GABA
D) Norepinephrine
Correct Answer: C
Rationale: GABA (gamma-aminobutyric acid) is the primary inhibitory
neurotransmitter in the CNS, opening Cl- channels to hyperpolarize the neuron.
Q8. An excitatory postsynaptic potential (EPSP) is characterized by:
A) Hyperpolarization of the postsynaptic membrane
B) Depolarization of the postsynaptic membrane
C) Opening of K+ channels
D) Inhibition of neurotransmitter release
Correct Answer: B
Rationale: EPSPs are graded depolarizations caused by Na+ influx (or Ca2+
influx) that make the postsynaptic neuron more likely to fire.
Q9. An inhibitory postsynaptic potential (IPSP) is characterized by:
A) Depolarization of the postsynaptic membrane
B) Hyperpolarization of the postsynaptic membrane
C) Opening of Na+ channels
D) Exocytosis of synaptic vesicles
Correct Answer: B
Rationale: IPSPs are graded hyperpolarizations caused by Cl- influx or K+
efflux, making the postsynaptic neuron less likely to fire.
Q10. Temporal summation occurs when:
A) Multiple presynaptic neurons stimulate a postsynaptic neuron simultaneously
B) A single presynaptic neuron stimulates a postsynaptic neuron repeatedly in
rapid succession
C) Neurotransmitters are removed from the synaptic cleft
D) The postsynaptic neuron reaches absolute refractory period
3
, Correct Answer: B
Rationale: Temporal summation is the additive effect of multiple action
potentials arriving from the same presynaptic neuron in rapid succession.
Q11. Spatial summation occurs when:
A) Multiple presynaptic neurons stimulate a postsynaptic neuron simultaneously
B) A single presynaptic neuron stimulates repeatedly
C) The axon hillock integrates signals
D) Neurotransmitter reuptake occurs
Correct Answer: A
Rationale: Spatial summation is the additive effect of simultaneous EPSPs from
multiple different presynaptic neurons converging on one postsynaptic neuron.
Q12. The absolute refractory period ensures:
A) The neuron can be stimulated again immediately
B) The action potential propagates in one direction
C) The neuron cannot fire again regardless of stimulus strength
D) Both B and C
Correct Answer: D (B and C)
Rationale: The absolute refractory period (during depolarization and early
repolarization) prevents re-stimulation and ensures unidirectional propagation.
Q13. The relative refractory period corresponds to:
A) Depolarization phase
B) Repolarization phase
C) Hyperpolarization phase
D) Resting state
Correct Answer: C
Rationale: The relative refractory period occurs during hyperpolarization
(after repolarization) when a stronger-than-normal stimulus can trigger an AP.
Q14. Which glial cell is responsible for forming the blood-brain barrier?
A) Oligodendrocyte
4
COMPREHENSIVE 500-QUESTION PRACTICE EXAMINATION
|QUESTIONS WITH CORRECT ANSWERS &
DETAILED RATIONALES
DOMAIN 1: NERVOUS AND SENSORY SYSTEMS (Q1–Q80)
Q1. The resting membrane potential of a typical neuron is approximately:
A) +30 mV
B) -70 mV
C) -55 mV
D) +90 mV
Correct Answer: B
Rationale: The resting membrane potential is approximately -70 mV, maintained
by the Na+/K+ ATPase pump (3 Na+ out, 2 K+ in) and high K+ permeability.
Q2. During depolarization of an action potential, which ion moves across the
membrane and in which direction?
A) K+ moves out
B) Na+ moves in
C) Cl- moves in
D) Ca2+ moves out
Correct Answer: B
Rationale: Depolarization is caused by rapid influx of Na+ through voltage-
gated Na+ channels, making the inside less negative.
Q3. The threshold potential for triggering an action potential is typically:
A) -70 mV
B) -55 mV
C) 0 mV
D) +30 mV
Correct Answer: B
Rationale: The threshold is about -55 mV. If the membrane depolarizes to this
1
,level, voltage-gated Na+ channels open explosively, triggering the action
potential.
Q4. Which of the following increases the speed of action potential conduction?
A) Decreased axon diameter
B) Increased myelination
C) Increased temperature
D) Both B and C
Correct Answer: D (B and C)
Rationale: Myelination allows saltatory conduction (jumping between Nodes of
Ranvier), which speeds conduction. Increased temperature also speeds ion
movement and conduction velocity.
Q5. The synaptic cleft is:
A) The space between the presynaptic and postsynaptic neurons
B) The vesicle containing neurotransmitter
C) The receptor on the postsynaptic membrane
D) The axon hillock
Correct Answer: A
Rationale: The synaptic cleft is the 20-30 nm gap between the presynaptic
terminal and the postsynaptic membrane where neurotransmitters are released.
Q6. Which neurotransmitter is the primary excitatory neurotransmitter in the
CNS?
A) GABA
B) Glycine
C) Glutamate
D) Dopamine
Correct Answer: C
Rationale: Glutamate is the main excitatory neurotransmitter in the CNS. GABA
and glycine are inhibitory; dopamine has both excitatory and inhibitory roles.
Q7. Which neurotransmitter is the primary inhibitory neurotransmitter in the
2
,CNS?
A) Glutamate
B) Acetylcholine
C) GABA
D) Norepinephrine
Correct Answer: C
Rationale: GABA (gamma-aminobutyric acid) is the primary inhibitory
neurotransmitter in the CNS, opening Cl- channels to hyperpolarize the neuron.
Q8. An excitatory postsynaptic potential (EPSP) is characterized by:
A) Hyperpolarization of the postsynaptic membrane
B) Depolarization of the postsynaptic membrane
C) Opening of K+ channels
D) Inhibition of neurotransmitter release
Correct Answer: B
Rationale: EPSPs are graded depolarizations caused by Na+ influx (or Ca2+
influx) that make the postsynaptic neuron more likely to fire.
Q9. An inhibitory postsynaptic potential (IPSP) is characterized by:
A) Depolarization of the postsynaptic membrane
B) Hyperpolarization of the postsynaptic membrane
C) Opening of Na+ channels
D) Exocytosis of synaptic vesicles
Correct Answer: B
Rationale: IPSPs are graded hyperpolarizations caused by Cl- influx or K+
efflux, making the postsynaptic neuron less likely to fire.
Q10. Temporal summation occurs when:
A) Multiple presynaptic neurons stimulate a postsynaptic neuron simultaneously
B) A single presynaptic neuron stimulates a postsynaptic neuron repeatedly in
rapid succession
C) Neurotransmitters are removed from the synaptic cleft
D) The postsynaptic neuron reaches absolute refractory period
3
, Correct Answer: B
Rationale: Temporal summation is the additive effect of multiple action
potentials arriving from the same presynaptic neuron in rapid succession.
Q11. Spatial summation occurs when:
A) Multiple presynaptic neurons stimulate a postsynaptic neuron simultaneously
B) A single presynaptic neuron stimulates repeatedly
C) The axon hillock integrates signals
D) Neurotransmitter reuptake occurs
Correct Answer: A
Rationale: Spatial summation is the additive effect of simultaneous EPSPs from
multiple different presynaptic neurons converging on one postsynaptic neuron.
Q12. The absolute refractory period ensures:
A) The neuron can be stimulated again immediately
B) The action potential propagates in one direction
C) The neuron cannot fire again regardless of stimulus strength
D) Both B and C
Correct Answer: D (B and C)
Rationale: The absolute refractory period (during depolarization and early
repolarization) prevents re-stimulation and ensures unidirectional propagation.
Q13. The relative refractory period corresponds to:
A) Depolarization phase
B) Repolarization phase
C) Hyperpolarization phase
D) Resting state
Correct Answer: C
Rationale: The relative refractory period occurs during hyperpolarization
(after repolarization) when a stronger-than-normal stimulus can trigger an AP.
Q14. Which glial cell is responsible for forming the blood-brain barrier?
A) Oligodendrocyte
4
