Physiology II Actual Exam 2026/2027 – Complete Questions
with Detailed Rationales | 100% Verified | Pass Guaranteed –
A+ Graded
SECTION A: Nervous System Organization & Neural Tissue (Q1–Q6)
Q1: A patient involved in a motorcycle accident has a CT scan showing bleeding
confined within the skull and along the spinal column involving the brain and spinal
cord. Anatomically, which division of the nervous system sustained the injury?
A. The peripheral nervous system
B. The somatic sensory division
C. The central nervous system [CORRECT]
D. The autonomic nervous system
Correct Answer: C
Rationale: The central nervous system consists of the brain and spinal cord; the
peripheral, somatic, and autonomic divisions are composed of nerves and ganglia
outside these structures.
Q2: A research study demonstrates that a specific neuroglial cell maintains the
blood–brain barrier, regulates the chemical environment around neurons, and forms
scar tissue following CNS injury. Which neuroglial cell performs these functions?
A. Oligodendrocytes
B. Astrocytes [CORRECT]
C. Microglia
D. Ependymal cells
Correct Answer: B
Rationale: Astrocytes are the most abundant CNS neuroglia; they form the blood–brain
barrier, control ion and neurotransmitter levels, and form glial scars. Oligodendrocytes
myelinate CNS axons, microglia phagocytose debris, and ependymal cells produce
cerebrospinal fluid.
Q3: A patient with a demyelinating condition demonstrates markedly slowed nerve
conduction in peripheral nerves. Loss of which structure best explains this finding?
A. The nodes of Ranvier, which block ion flow
, B. The axon hillock, which generates myelin
C. The Nissl bodies, which insulate the axon
D. The myelin sheath formed by Schwann cells, which enables rapid saltatory
conduction [CORRECT]
Correct Answer: D
Rationale: Myelin, produced by Schwann cells in the PNS, insulates the axon so the
action potential "jumps" between nodes of Ranvier (saltatory conduction); its loss slows
or blocks impulse transmission. Nodes of Ranvier are gaps that speed conduction, Nissl
bodies perform protein synthesis, and the axon hillock triggers the action potential.
Q4: During the depolarization phase of an action potential, which event is occurring at
the neuronal membrane?
A. Voltage-gated sodium channels open, and sodium rushes into the neuron [CORRECT]
B. Potassium rapidly exits the neuron through open channels
C. The sodium–potassium pump actively reverses the membrane polarity
D. Calcium enters the soma to trigger vesicle release
Correct Answer: A
Rationale: Depolarization occurs when threshold is reached and voltage-gated Na⁺
channels open, allowing sodium influx and reversing the resting membrane potential.
Potassium exit produces repolarization, the pump restores ionic gradients afterward,
and calcium entry occurs at the axon terminal rather than the soma.
Q5: An action potential arrives at the axon terminal. Which event directly triggers the
release of neurotransmitter into the synaptic cleft?
A. Sodium entry into the axon terminal
B. Potassium leakage from the terminal
C. Opening of voltage-gated calcium channels, allowing calcium to trigger synaptic
vesicle fusion [CORRECT]
D. Breakdown of the myelin sheath at the terminal
Correct Answer: C
Rationale: Depolarization of the axon terminal opens voltage-gated Ca²⁺ channels; the
influx of calcium causes synaptic vesicles to fuse with the membrane and release
neurotransmitter by exocytosis. Sodium and potassium movements propagate the
signal but do not directly release transmitter.
Q6: A medication administered during surgery blocks receptors at the neuromuscular
junction, producing skeletal muscle paralysis. Which neurotransmitter's action has been
blocked?
A. Norepinephrine
B. Acetylcholine [CORRECT]