NU 641 ADVANCED
PATHOPHYSIOLOGY EXAM REVIEW
QUESTIONS AND ANSWERS AND
EXPLANATIONS | LATEST - REGIS
1. Which process involves the reversible replacement of one mature cell type by another, less
mature cell type to better withstand an adverse environment?
A. Atrophy
B. Metaplasia
C. Dysplasia
D. Hyperplasia
Answer: B
Conceptual Explanation: Metaplasia is the reversible replacement of one mature cell by
another, often as an adaptation to chronic irritation, such as the change from ciliated
columnar to stratified squamous epithelium in smokers.
2. During cellular injury, a decrease in ATP production leads to the failure of the sodium-
potassium pump. What is the immediate consequence within the cell?
A. Cellular shrinkage due to water loss
B. Intracellular acidosis and calcium efflux
,C. Cellular swelling due to influx of sodium and water
D. Increased protein synthesis to repair the pump
Answer: C
Conceptual Explanation: When the Na-K pump fails, sodium accumulates inside the cell.
Because water follows sodium osmotically, the cell swells (oncosis), which can lead to
organelle damage.
3. Which epigenetic mechanism involves the addition of a methyl group to a cytosine base,
typically leading to gene silencing?
A. Histone acetylation
B. RNA interference
C. DNA methylation
D. Translation inhibition
Answer: C
Conceptual Explanation: DNA methylation typically occurs at CpG islands and results in
the silencing of gene expression by preventing the binding of transcription factors.
4. In the extrinsic pathway of apoptosis, which molecule acts as the ‘death receptor’ on the
cell surface?
A. Caspase-9
B. Bcl-2
, C. Fas receptor
D. Cytochrome c
Answer: C
Conceptual Explanation: The extrinsic pathway is triggered by the binding of ligands (like
Fas ligand) to death receptors such as Fas or TNF-R1 on the cell membrane.
5. A patient presents with a Type I hypersensitivity reaction. Which immunoglobulin is
primarily responsible for triggering mast cell degranulation?
A. IgG
B. IgM
C. IgE
D. IgA
Answer: C
Conceptual Explanation: Type I hypersensitivity is mediated by IgE, which binds to high-
affinity receptors on mast cells and basophils, leading to the release of histamine upon re-
exposure to an allergen.
6. Which component of the complement system is known as the ‘anaphylatoxin’ that induces
rapid mast cell degranulation?
A. C3b
B. C5a
PATHOPHYSIOLOGY EXAM REVIEW
QUESTIONS AND ANSWERS AND
EXPLANATIONS | LATEST - REGIS
1. Which process involves the reversible replacement of one mature cell type by another, less
mature cell type to better withstand an adverse environment?
A. Atrophy
B. Metaplasia
C. Dysplasia
D. Hyperplasia
Answer: B
Conceptual Explanation: Metaplasia is the reversible replacement of one mature cell by
another, often as an adaptation to chronic irritation, such as the change from ciliated
columnar to stratified squamous epithelium in smokers.
2. During cellular injury, a decrease in ATP production leads to the failure of the sodium-
potassium pump. What is the immediate consequence within the cell?
A. Cellular shrinkage due to water loss
B. Intracellular acidosis and calcium efflux
,C. Cellular swelling due to influx of sodium and water
D. Increased protein synthesis to repair the pump
Answer: C
Conceptual Explanation: When the Na-K pump fails, sodium accumulates inside the cell.
Because water follows sodium osmotically, the cell swells (oncosis), which can lead to
organelle damage.
3. Which epigenetic mechanism involves the addition of a methyl group to a cytosine base,
typically leading to gene silencing?
A. Histone acetylation
B. RNA interference
C. DNA methylation
D. Translation inhibition
Answer: C
Conceptual Explanation: DNA methylation typically occurs at CpG islands and results in
the silencing of gene expression by preventing the binding of transcription factors.
4. In the extrinsic pathway of apoptosis, which molecule acts as the ‘death receptor’ on the
cell surface?
A. Caspase-9
B. Bcl-2
, C. Fas receptor
D. Cytochrome c
Answer: C
Conceptual Explanation: The extrinsic pathway is triggered by the binding of ligands (like
Fas ligand) to death receptors such as Fas or TNF-R1 on the cell membrane.
5. A patient presents with a Type I hypersensitivity reaction. Which immunoglobulin is
primarily responsible for triggering mast cell degranulation?
A. IgG
B. IgM
C. IgE
D. IgA
Answer: C
Conceptual Explanation: Type I hypersensitivity is mediated by IgE, which binds to high-
affinity receptors on mast cells and basophils, leading to the release of histamine upon re-
exposure to an allergen.
6. Which component of the complement system is known as the ‘anaphylatoxin’ that induces
rapid mast cell degranulation?
A. C3b
B. C5a
