BIOD 322 - Module 1: Cellular Neuroscience Exam
2026/2027 UPDATE UPDATED ACTUAL Questions and
CORRECT Answers
1. Which part of the neuron is primarily responsible for receiving incoming
signals from other neurons?
A. Axon
B. Soma
C. Dendrite
D. Axon terminal
Answer: C
Rationale: Dendrites are branch-like structures that extend from the cell body and
function as the primary input zone for receiving chemical or electrical signals.
2. Which glial cell type is responsible for forming the blood-brain barrier (BBB)
in the Central Nervous System?
A. Oligodendrocytes
B. Astrocytes
C. Microglia
D. Schwann cells
Answer: B
Rationale: Astrocytes possess end-feet that wrap around blood vessels, regulating the
passage of substances between the blood and the brain tissue.
,3. What is the typical resting membrane potential of a neuron?
A. +40 mV
B. 0 mV
C. -70 mV
D. -55 mV
Answer: C
Rationale: At rest, the inside of a neuron is typically around -70 mV relative to the outside
due to ion distribution and permeability.
4. The movement of an action potential along a myelinated axon from one Node
of Ranvier to the next is called:
A. Continuous conduction
B. Retrograde transport
C. Saltatory conduction
D. Passive diffusion
Answer: C
Rationale: Saltatory conduction refers to the ‘jumping’ of the action potential between
nodes, which significantly increases signal speed.
5. Which ion is found in higher concentration inside the neuron compared to the
extracellular fluid at rest?
A. Sodium (Na+)
B. Chloride (Cl-)
C. Potassium (K+)
D. Calcium (Ca2+)
Answer: C
Rationale: Potassium ions (K+) are concentrated inside the cell, while Na+, Cl-, and Ca2+
are more concentrated outside.
, 6. Which glial cells provide the myelin sheath for axons in the Peripheral
Nervous System (PNS)?
A. Satellite cells
B. Oligodendrocytes
C. Ependymal cells
D. Schwann cells
Answer: D
Rationale: Schwann cells myelinate a single axon segment in the PNS, whereas
oligodendrocytes myelinate multiple segments in the CNS.
7. The ‘All-or-None’ principle of action potentials implies that:
A. Stronger stimuli produce larger action potentials
B. Neurons fire at a constant rate regardless of stimulus
C. The action potential will occur at full magnitude once threshold is reached
D. Only some axons can conduct action potentials
Answer: C
Rationale: An action potential either happens completely or not at all; its size does not
change based on stimulus intensity.
8. Which phase of the action potential is characterized by a rapid influx of
Sodium (Na+) ions?
A. Repolarization
B. Hyperpolarization
C. Resting phase
D. Depolarization
Answer: D
Rationale: Depolarization occurs when voltage-gated Na+ channels open, allowing Na+ to
rush into the cell, making the interior more positive.
2026/2027 UPDATE UPDATED ACTUAL Questions and
CORRECT Answers
1. Which part of the neuron is primarily responsible for receiving incoming
signals from other neurons?
A. Axon
B. Soma
C. Dendrite
D. Axon terminal
Answer: C
Rationale: Dendrites are branch-like structures that extend from the cell body and
function as the primary input zone for receiving chemical or electrical signals.
2. Which glial cell type is responsible for forming the blood-brain barrier (BBB)
in the Central Nervous System?
A. Oligodendrocytes
B. Astrocytes
C. Microglia
D. Schwann cells
Answer: B
Rationale: Astrocytes possess end-feet that wrap around blood vessels, regulating the
passage of substances between the blood and the brain tissue.
,3. What is the typical resting membrane potential of a neuron?
A. +40 mV
B. 0 mV
C. -70 mV
D. -55 mV
Answer: C
Rationale: At rest, the inside of a neuron is typically around -70 mV relative to the outside
due to ion distribution and permeability.
4. The movement of an action potential along a myelinated axon from one Node
of Ranvier to the next is called:
A. Continuous conduction
B. Retrograde transport
C. Saltatory conduction
D. Passive diffusion
Answer: C
Rationale: Saltatory conduction refers to the ‘jumping’ of the action potential between
nodes, which significantly increases signal speed.
5. Which ion is found in higher concentration inside the neuron compared to the
extracellular fluid at rest?
A. Sodium (Na+)
B. Chloride (Cl-)
C. Potassium (K+)
D. Calcium (Ca2+)
Answer: C
Rationale: Potassium ions (K+) are concentrated inside the cell, while Na+, Cl-, and Ca2+
are more concentrated outside.
, 6. Which glial cells provide the myelin sheath for axons in the Peripheral
Nervous System (PNS)?
A. Satellite cells
B. Oligodendrocytes
C. Ependymal cells
D. Schwann cells
Answer: D
Rationale: Schwann cells myelinate a single axon segment in the PNS, whereas
oligodendrocytes myelinate multiple segments in the CNS.
7. The ‘All-or-None’ principle of action potentials implies that:
A. Stronger stimuli produce larger action potentials
B. Neurons fire at a constant rate regardless of stimulus
C. The action potential will occur at full magnitude once threshold is reached
D. Only some axons can conduct action potentials
Answer: C
Rationale: An action potential either happens completely or not at all; its size does not
change based on stimulus intensity.
8. Which phase of the action potential is characterized by a rapid influx of
Sodium (Na+) ions?
A. Repolarization
B. Hyperpolarization
C. Resting phase
D. Depolarization
Answer: D
Rationale: Depolarization occurs when voltage-gated Na+ channels open, allowing Na+ to
rush into the cell, making the interior more positive.
