Questions with Correct Answers
100 questions
1. A person working outdoors in extreme heat develops heat stroke. Cellular injury occurs
because:
A. Cold causes ice crystals in cells
B. High temperatures denature proteins and increase metabolic demand beyond oxygen supply
C. Radiation breaks DNA strands
D. Sodium is pumped out too quickly
Correct Answer: B. High temperatures denature proteins and increase metabolic demand
beyond oxygen supply
Rationale: Hyperthermia increases metabolic rate, denatures enzymes and damages membranes,
leading to multiorgan injury. Ice crystals occur in frostbite, and radiation injury involves ionizing energy.
Heat stroke is an emergency requiring rapid cooling.
2. A patient with severe anemia has fatigue because:
A. Excess oxygen damages cells
B. Reduced oxygen-carrying capacity limits ATP production in tissues
C. Glucose cannot enter cells
D. Sodium channels are blocked
Correct Answer: B. Reduced oxygen-carrying capacity limits ATP production in tissues
Rationale: Anemia reduces hemoglobin available to carry oxygen, causing tissue hypoxia and reduced
aerobic energy production. The body compensates with tachycardia. The other mechanisms are unrelated
to anemia.
3. Pathologic calcification of the aortic valve in older adults contributes to:
A. Mitral regurgitation
B. Pericarditis
C. Pulmonary embolism
D. Aortic stenosis
Correct Answer: D. Aortic stenosis
Rationale: Dystrophic calcification of the aortic valve stiffens the leaflets, narrowing the outflow tract and
causing aortic stenosis. It does not typically cause mitral regurgitation, pericarditis or embolism.
,4. A sign of irreversible cell injury is:
A. Mild cellular swelling
B. Loss of microvilli only
C. Fatty change
D. Rupture of the plasma membrane and lysosomes with nuclear changes such as karyolysis
Correct Answer: D. Rupture of the plasma membrane and lysosomes with nuclear changes
such as karyolysis
Rationale: Severe membrane damage, mitochondrial failure and nuclear dissolution (pyknosis,
karyorrhexis, karyolysis) mark the point of no return. Swelling, microvilli loss and fatty change are
reversible early changes if the stress ends.
5. When cells shift to anaerobic metabolism during hypoxia, the accumulation of lactic acid
causes:
A. Increased ATP production
B. Alkalosis inside the cell
C. Decreased intracellular pH, which damages enzymes and chromatin
D. Improved protein synthesis
Correct Answer: C. Decreased intracellular pH, which damages enzymes and chromatin
Rationale: Anaerobic glycolysis produces much less ATP and generates lactic acid, lowering pH, which
clumps nuclear chromatin and impairs enzyme function. It reduces, not increases, ATP. Detachment of
ribosomes also decreases protein synthesis.
6. Cellular edema of reversible injury is also called:
A. Atrophy
B. Apoptosis
C. Calcification
D. Hydropic degeneration
Correct Answer: D. Hydropic degeneration
Rationale: Hydropic degeneration is cell swelling from water influx due to failed ion pumps, an early
reversible change. Atrophy is shrinkage, apoptosis is programmed death, and calcification is mineral
deposition.
,7. Liquefactive necrosis occurs in:
A. Myocardial infarction
B. Brain infarcts and bacterial abscesses
C. Tuberculosis granulomas
D. Breast trauma
Correct Answer: B. Brain infarcts and bacterial abscesses
Rationale: Hydrolytic enzymes digest the tissue into a liquid mass, as in the brain, which is rich in
enzymes and lipids, and in abscesses where neutrophil enzymes liquefy tissue. MI is coagulative, TB is
caseous, and breast trauma often causes fat necrosis.
8. Hemosiderin accumulates in tissues when there is:
A. Excess fat
B. Excess iron, such as from repeated transfusions or hemorrhage
C. Calcium deficiency
D. Low protein intake
Correct Answer: B. Excess iron, such as from repeated transfusions or hemorrhage
Rationale: Hemosiderin is a storage form of iron that accumulates locally after bleeding (for example, a
bruise turning brown) or systemically with transfusions or hemochromatosis. Fat, calcium and protein
disturbances do not produce hemosiderin.
9. Spina bifida risk is reduced by:
A. Avoiding all vitamins
B. Adequate maternal folic acid intake before and in early pregnancy
C. Increasing vitamin A to high doses
D. Taking aspirin
Correct Answer: B. Adequate maternal folic acid intake before and in early pregnancy
Rationale: Folic acid supports neural tube closure in the first month of pregnancy, reducing neural tube
defects by up to 70%. High-dose vitamin A is teratogenic. Aspirin has no role in preventing neural tube
defects.
, 10. Marfan syndrome results from a defect in fibrillin and places patients at risk for:
A. Severe anemia
B. Hypoglycemia
C. Aortic dilation and dissection, lens dislocation, and long limbs
D. Short stature
Correct Answer: C. Aortic dilation and dissection, lens dislocation, and long limbs
Rationale: Fibrillin is part of connective tissue, so Marfan syndrome affects the aorta, eyes and skeleton,
with tall stature, arachnodactyly and joint laxity. Aortic dissection is the leading cause of death. It is
autosomal dominant and not associated with anemia or hypoglycemia.
11. Genetic testing results should be discussed with genetic counseling because:
A. Results have implications for family members, insurance, and reproductive decisions
B. Results are always simple to interpret
C. Genetic results never change care
D. Counseling is required only for adults over 80
Correct Answer: A. Results have implications for family members, insurance, and
reproductive decisions
Rationale: Genetic results can affect relatives' risk and raise ethical, psychological and privacy concerns;
counseling supports informed decisions. The Genetic Information Nondiscrimination Act protects against
discrimination in health insurance and employment, but not life or long-term care insurance.
12. Women with PKU who plan pregnancy must:
A. Stop all protein completely
B. Resume strict dietary control before conception to prevent fetal harm
C. Avoid pregnancy forever
D. Take extra phenylalanine supplements
Correct Answer: B. Resume strict dietary control before conception to prevent fetal harm
Rationale: High maternal phenylalanine causes microcephaly, heart defects and intellectual disability in
the fetus (maternal PKU syndrome), so tight control before and during pregnancy is needed. Complete
protein avoidance is harmful, and pregnancy is possible with control.