BIO 151 Module 7 Exam Nervous System Anatomy &
Physiology I Actual Exam 2026/2027 – Complete 30
Questions with Detailed Rationales | 100% Verified | Pass
Guaranteed – A+ Graded
SECTION A: Nervous System Organization & Neural Tissue (Q1–Q6)
Q1: On the first day of the nervous system unit, students are asked to correctly define
the components of the central nervous system (CNS). Which answer is correct?
A. Cranial nerves and spinal nerves
B. Brain and spinal cord [CORRECT]
C. Peripheral ganglia and sensory receptors
D. Brain, spinal cord, and all peripheral nerves
Correct Answer: B
Rationale: The CNS consists solely of the brain and spinal cord, the body's integration
and command centers. The other options incorrectly include peripheral nerves, ganglia,
or receptors, which are components of the peripheral nervous system.
Q2: A patient sustains a traumatic injury to a peripheral nerve in the arm. When repairing
and remyelinating the damaged axon, which neuroglial cell type will perform the
myelination in this peripheral location?
A. Schwann cells [CORRECT]
B. Oligodendrocytes
C. Microglia
D. Ependymal cells
Correct Answer: A
Rationale: Schwann cells are the myelinating glia of the peripheral nervous system,
wrapping single axon segments and aiding peripheral regeneration. Oligodendrocytes
myelinate only in the CNS, while microglia act as phagocytes and ependymal cells line
the ventricles.
Q3: A student measures conduction speed in a myelinated peripheral axon and finds it
far faster than in an unmyelinated axon of the same diameter. Which mechanism best
explains this difference?
A. Myelinated axons contain more sodium pumps per micron
, B. Myelinated axons lack voltage-gated channels entirely
C. Saltatory conduction, in which the impulse jumps between nodes of Ranvier
[CORRECT]
D. Myelin chemically converts electrical signals to faster chemical signals
Correct Answer: C
Rationale: Myelin insulates the axon so the action potential regenerates only at the
exposed nodes of Ranvier, jumping rapidly from node to node (saltatory conduction).
Voltage-gated channels are actually concentrated at the nodes, and the signal remains
electrochemical throughout.
Q4: During a lab demonstration of membrane potentials, a student is asked what occurs
during the repolarization phase of an action potential. Which response is correct?
A. Sodium channels open and sodium rushes into the cell
B. The membrane potential rises toward +30 mV
C. Ligand-gated channels open, allowing chloride influx
D. Potassium channels open and potassium exits the cell, restoring the resting
membrane potential [CORRECT]
Correct Answer: D
Rationale: Repolarization is driven by opening of voltage-gated potassium channels,
allowing K+ to leave the cell and return the membrane potential toward the resting
negative level. Sodium influx and membrane depolarization toward +30 mV describe the
depolarization phase.
Q5: A student traces the events at an axon terminal during synaptic transmission. Which
event directly triggers the release of neurotransmitter into the synaptic cleft?
A. Potassium efflux from the synaptic knob
B. Influx of calcium ions into the axon terminal through voltage-gated calcium channels
[CORRECT]
C. Hyperpolarization of the postsynaptic membrane
D. Active pumping of sodium out of the synaptic cleft
Correct Answer: B
Rationale: When the action potential reaches the terminal, voltage-gated Ca2+ channels
open, and the calcium influx causes synaptic vesicles to fuse with the membrane and
release neurotransmitter by exocytosis. Potassium flux, postsynaptic potentials, and
cleft pumping do not trigger vesicle release.
Q6: In the organization of the peripheral nervous system, which description correctly
defines the efferent division?
A. Fibers carrying sensory information toward the spinal cord
B. Fibers transmitting impulses from receptors to the brain
Physiology I Actual Exam 2026/2027 – Complete 30
Questions with Detailed Rationales | 100% Verified | Pass
Guaranteed – A+ Graded
SECTION A: Nervous System Organization & Neural Tissue (Q1–Q6)
Q1: On the first day of the nervous system unit, students are asked to correctly define
the components of the central nervous system (CNS). Which answer is correct?
A. Cranial nerves and spinal nerves
B. Brain and spinal cord [CORRECT]
C. Peripheral ganglia and sensory receptors
D. Brain, spinal cord, and all peripheral nerves
Correct Answer: B
Rationale: The CNS consists solely of the brain and spinal cord, the body's integration
and command centers. The other options incorrectly include peripheral nerves, ganglia,
or receptors, which are components of the peripheral nervous system.
Q2: A patient sustains a traumatic injury to a peripheral nerve in the arm. When repairing
and remyelinating the damaged axon, which neuroglial cell type will perform the
myelination in this peripheral location?
A. Schwann cells [CORRECT]
B. Oligodendrocytes
C. Microglia
D. Ependymal cells
Correct Answer: A
Rationale: Schwann cells are the myelinating glia of the peripheral nervous system,
wrapping single axon segments and aiding peripheral regeneration. Oligodendrocytes
myelinate only in the CNS, while microglia act as phagocytes and ependymal cells line
the ventricles.
Q3: A student measures conduction speed in a myelinated peripheral axon and finds it
far faster than in an unmyelinated axon of the same diameter. Which mechanism best
explains this difference?
A. Myelinated axons contain more sodium pumps per micron
, B. Myelinated axons lack voltage-gated channels entirely
C. Saltatory conduction, in which the impulse jumps between nodes of Ranvier
[CORRECT]
D. Myelin chemically converts electrical signals to faster chemical signals
Correct Answer: C
Rationale: Myelin insulates the axon so the action potential regenerates only at the
exposed nodes of Ranvier, jumping rapidly from node to node (saltatory conduction).
Voltage-gated channels are actually concentrated at the nodes, and the signal remains
electrochemical throughout.
Q4: During a lab demonstration of membrane potentials, a student is asked what occurs
during the repolarization phase of an action potential. Which response is correct?
A. Sodium channels open and sodium rushes into the cell
B. The membrane potential rises toward +30 mV
C. Ligand-gated channels open, allowing chloride influx
D. Potassium channels open and potassium exits the cell, restoring the resting
membrane potential [CORRECT]
Correct Answer: D
Rationale: Repolarization is driven by opening of voltage-gated potassium channels,
allowing K+ to leave the cell and return the membrane potential toward the resting
negative level. Sodium influx and membrane depolarization toward +30 mV describe the
depolarization phase.
Q5: A student traces the events at an axon terminal during synaptic transmission. Which
event directly triggers the release of neurotransmitter into the synaptic cleft?
A. Potassium efflux from the synaptic knob
B. Influx of calcium ions into the axon terminal through voltage-gated calcium channels
[CORRECT]
C. Hyperpolarization of the postsynaptic membrane
D. Active pumping of sodium out of the synaptic cleft
Correct Answer: B
Rationale: When the action potential reaches the terminal, voltage-gated Ca2+ channels
open, and the calcium influx causes synaptic vesicles to fuse with the membrane and
release neurotransmitter by exocytosis. Potassium flux, postsynaptic potentials, and
cleft pumping do not trigger vesicle release.
Q6: In the organization of the peripheral nervous system, which description correctly
defines the efferent division?
A. Fibers carrying sensory information toward the spinal cord
B. Fibers transmitting impulses from receptors to the brain
