/ 2027 QUESTIONS AND CORRECT VERIFIED ANSWERS WITH
RATIONALES | UTA
Question 1
A patient experiences several minutes of severe tissue hypoxia after an
interruption of blood flow. Which intracellular change occurs earliest as a direct
consequence of ATP depletion?
A. Activation of lysosomal enzymes causing membrane rupture
B. Fragmentation of nuclear DNA by endonucleases
C. Irreversible destruction of mitochondrial membranes
D. Failure of the sodium-potassium pump with intracellular sodium and
water accumulation
Answer: D
Rationale: ATP depletion impairs the sodium-potassium ATPase, allowing
sodium and water to accumulate within the cell and producing cellular swelling.
This is a characteristic early, potentially reversible response to hypoxic injury.
More severe mitochondrial and membrane damage develops later if the insult
persists.
Question 2
A 58-year-old patient with years of poorly controlled hypertension develops left
ventricular enlargement on echocardiography. Which cellular adaptation best
explains this finding?
A. Hyperplasia caused by increased cardiomyocyte division
B. Hypertrophy caused by increased workload on existing cardiomyocytes
,C. Metaplasia caused by replacement of cardiac muscle cells
D. Dysplasia caused by abnormal differentiation of myocardial cells
Answer: B
Rationale: Cardiac muscle responds to chronic increased pressure workload
primarily through hypertrophy. Individual cardiomyocytes enlarge by increasing
structural proteins and organelles because mature cardiomyocytes have limited
capacity for proliferative division. The resulting increased wall thickness is a
form of pathologic cardiac remodeling.
Question 3
A patient with chronic gastroesophageal reflux undergoes an endoscopic biopsy
that shows replacement of the normal distal esophageal squamous epithelium
with specialized columnar epithelium containing goblet cells. How should this
cellular change be classified?
A. Dysplasia
B. Hyperplasia
C. Metaplasia
D. Anaplasia
Answer: C
Rationale: Metaplasia is a reversible change in which one mature cell type is
replaced by another mature cell type better able to tolerate chronic stress.
Barrett esophagus is a classic example. Dysplasia involves disordered cellular
growth and maturation and is considered a premalignant abnormality rather than
an adaptive substitution of mature cell types.
,Question 4
During severe cellular injury, intracellular calcium concentration rises
substantially. Which consequence most directly contributes to irreversible cell
injury?
A. Activation of phospholipases, proteases, and endonucleases
B. Increased ATP synthesis through oxidative phosphorylation
C. Stabilization of cellular membranes
D. Suppression of mitochondrial permeability
Answer: A
Rationale: Excess intracellular calcium activates destructive enzymes,
including phospholipases that damage membranes, proteases that degrade
cytoskeletal proteins, and endonucleases that fragment DNA. Mitochondrial
dysfunction and ATP depletion further amplify the injury. This calcium-
mediated cascade is an important pathway toward irreversible cell damage.
Question 5
A laboratory report from a patient with diabetic ketoacidosis shows:
- pH: 7.19
- PaCO₂: 23 mmHg
- HCO₃⁻: 9 mEq/L
Which physiologic response best accounts for the PaCO₂ value?
A. Renal retention of hydrogen ions
B. Hypoventilation to conserve carbonic acid
, C. Increased bicarbonate generation by the lungs
D. Increased alveolar ventilation to reduce PaCO₂
Answer: D
Rationale: The low pH and markedly decreased bicarbonate indicate primary
metabolic acidosis. The low PaCO₂ reflects respiratory compensation through
increased alveolar ventilation, often manifesting as deep, rapid Kussmaul
respirations. The lungs cannot directly generate bicarbonate but can rapidly alter
carbon dioxide elimination.
Question 6
A patient with severe diarrhea develops metabolic acidosis from bicarbonate
loss. Which additional laboratory finding would be most consistent with the
expected cellular response to acidemia?
A. Decreased extracellular potassium concentration caused by intracellular
potassium shift
B. Decreased intracellular hydrogen ion concentration caused by renal
alkalinization
C. Increased extracellular potassium concentration caused by movement of
hydrogen ions into cells
D. Increased extracellular calcium concentration caused by sodium-potassium
exchange
Answer: C
Rationale: In acidemia, hydrogen ions can shift into cells, with potassium
moving out of cells in exchange in many forms of metabolic acidosis. This can
raise serum potassium despite total-body potassium depletion. The magnitude of
the potassium shift varies with the cause of acidosis, so serum potassium should
not be interpreted as a direct measure of total potassium stores.