Adaptation, and Injury 2026 |Maryville
1. Which of the following cellular processes is primarily responsible for the
reduction in skeletal muscle size observed in a patient who has had their leg in a
cast for six weeks?
A. Atrophy
B. Hypertrophy
C. Metaplasia
D. Dysplasia
Answer: A
Rationale: Atrophy is the shrinkage in cell size. When skeletal muscle is not used (disuse),
cells shrink via the ubiquitin-proteasome pathway.
2. In response to increased cardiac workload, such as in chronic hypertension,
myocardial cells increase in size. This is known as:
A. Hypertrophy
B. Neoplasia
C. Hyperplasia
D. Metaplasia
Answer: A
Rationale: Hypertrophy is an increase in the size of cells, and consequently the organ,
often due to mechanical load or trophic signals.
,3. A 55-year-old male with chronic gastroesophageal reflux disease (GERD)
shows a change in the lining of his esophagus from stratified squamous
epithelium to columnar epithelium. This is an example of:
A. Dysplasia
B. Metaplasia
C. Anaplasia
D. Hyperplasia
Answer: B
Rationale: Metaplasia is the reversible replacement of one mature cell type by another,
often as an adaptation to chronic irritation.
4. Which cellular adaptation is considered ‘atypical hyperplasia’ and is often a
precursor to invasive neoplasia?
A. Metaplasia
B. Dysplasia
C. Atrophy
D. Physiologic Hyperplasia
Answer: B
Rationale: Dysplasia refers to abnormal changes in the size, shape, and organization of
mature cells and is frequently associated with cancerous transformation.
5. The most common cause of cellular injury is:
A. Free radical formation
B. Hypoxia
C. Chemical toxicity
D. Genetic defects
Answer: B
Rationale: Hypoxia, or lack of sufficient oxygen, is the single most common cause of
cellular injury.
, 6. What is the initial mechanism of cell swelling during hypoxic injury?
A. Failure of the Na+/K+ ATPase pump
B. Increased protein synthesis
C. Increased aerobic metabolism
D. Decreased intracellular sodium concentration
Answer: A
Rationale: Hypoxia leads to ATP depletion, which shuts down the sodium-potassium
pump, causing sodium to accumulate in the cell and water to follow by osmosis.
7. During ischemia-reperfusion injury, cellular damage is significantly
exacerbated by the production of:
A. Antioxidants
B. Glucose
C. Lactic acid
D. Reactive oxygen species (ROS)
Answer: D
Rationale: Reperfusion injury occurs when oxygen restoration leads to the formation of
highly reactive free radicals that damage membranes.
8. Which organelle contains digestive enzymes (hydrolases) that degrade
intracellular debris?
A. Mitochondria
B. Peroxisomes
C. Lysosomes
D. Golgi apparatus
Answer: C
Rationale: Lysosomes are the cell’s digestive system, containing over 40 acid hydrolases to
break down macromolecules.