2026/2027 Wilkes University
Q1. Loss of mitochondrial oxidative phosphorylation during severe
cellular hypoxia most directly causes which early biochemical
change?
A) Increased intracellular ATP production
B) Depletion of cellular ATP
C) Increased protein synthesis
D) Accelerated DNA replication
Correct Answer: B) Depletion of cellular ATP
Rationale: Oxygen deprivation impairs mitochondrial oxidative
phosphorylation, reducing ATP production. ATP depletion disrupts energy-
dependent processes such as the sodium-potassium pump, protein
synthesis, and calcium regulation. Persistent energy failure contributes to
progressive cellular injury and may eventually produce irreversible damage.
Q2. Failure of the sodium-potassium ATPase during reversible cell
injury produces cellular swelling primarily through which
mechanism?
A) Sodium accumulates intracellularly and draws water into the cell
B) Potassium accumulates extracellularly and draws water from the cell
C) Calcium leaves the cytoplasm and increases extracellular osmolality
D) Proteins diffuse from the cytoplasm into the extracellular fluid
Correct Answer: A) Sodium accumulates intracellularly and draws water
into the cell
Rationale: ATP depletion reduces sodium-potassium pump activity. Sodium
consequently accumulates inside the cell, increasing intracellular osmotic
pressure and promoting water influx. Cellular and organelle swelling are
characteristic early manifestations of reversible injury associated with
impaired energy-dependent ion transport.
Q3. Skeletal muscle decreases in size after prolonged
immobilization of an extremity. Which cellular adaptation best
explains this change?
, A) Hyperplasia
B) Metaplasia
C) Atrophy
D) Dysplasia
Correct Answer: C) Atrophy
Rationale: Atrophy is a reduction in cell size and functional activity in
response to diminished workload, reduced stimulation, inadequate nutrition,
or other stresses. Prolonged immobilization decreases mechanical demand
on skeletal muscle, resulting in reduced protein synthesis and progressive
loss of cellular mass.
Q4. Chronic pressure overload causes cardiac muscle fibers to
enlarge without producing a substantial increase in the number of
cardiomyocytes. What adaptation has occurred?
A) Metaplasia
B) Hyperplasia
C) Dysplasia
D) Hypertrophy
Correct Answer: D) Hypertrophy
Rationale: Hypertrophy is an increase in cell size that enlarges an organ or
tissue. It is particularly important in tissues composed of cells with limited
proliferative capacity, such as cardiac muscle. Increased workload stimulates
greater synthesis of structural proteins and cellular components.
Q5. Replacement of one mature differentiated cell type by another
mature cell type in response to persistent environmental stress is
termed what?
A) Anaplasia
B) Metaplasia
C) Hyperplasia
D) Neoplasia
Correct Answer: B) Metaplasia