, NR 507 Advanced Pathophysiology:
Week 1 High-Yield Questions, Answers,
& Rationales 2026/2027 Update
Question 1: Cellular Adaptation & Injury
A 55-year-old chronic cigarette smoker presents with a
persistent cough. A bronchial biopsy reveals that the normal
pseudostratified ciliated columnar epithelium has been replaced
by stratified squamous epithelium. What cellular adaptation
process has occurred?
A. Atrophy
B. Hypertrophy
C. Metaplasia
D. Dysplasia
Correct Answer: C. Metaplasia.
Explanation: Metaplasia is the reversible replacement of one
mature cell type by another, sometimes less mature, cell type in
response to chronic irritation or injury (such as cigarette smoke
exposing the bronchial lining to toxins). While it protects the
tissue initially, prolonged exposure can lead to dysplasia and
malignancy.
Question 2: Mechanisms of Cellular Injury
During periods of cellular starvation, a cell may undergo
autophagy to survive. Which organelle plays the central role in
digesting cellular components during autophagy?
, A. Mitochondria
B. Golgi apparatus
C. Peroxisomes
D. Lysosomes
Correct Answer: D. Lysosomes
Explanation: Lysosomes contain over 40 distinct hydrolytic
enzymes. During autophagy ("self-eating"), lysosomes fuse with
vacuoles containing damaged organelles or cytosolic proteins,
degrading them into basic building blocks that the cell can reuse
for energy and survival.
Question 3: Inflammation & Chemical Mediators
What is a key functional difference between Cytotoxic T
Lymphocytes (CTLs) and Natural Killer (NK) cells?
A. CTLs require prior antigen sensitization and
presentation via MHC I, whereas NK cells do not require
antigen presentation and can target cells with
downregulated MHC I.
B. NK cells require MHC Class II presentation, while
CTLs require no recognition mechanism.
C. CTLs only attack extracellular bacteria, while NK cells
attack viruses exclusively.
D. NK cells are part of the adaptive immune system,
whereas CTLs are innate.
Correct Answer: A. CTLs require prior antigen sensitization
and presentation via MHC I, whereas NK cells do not
require antigen presentation and can target cells with
downregulated MHC I.
, Question 4: Types of Hypersensitivity Reactions
A client who receives an incompatible blood transfusion
experiences an acute hemolytic reaction characterized by fever,
chills, and hemoglobinuria within minutes. What type of
hypersensitivity reaction is this?
A. Type I (IgE-mediated)
B. Type II (Tissue-specific / Cytotoxic)
C. Type III (Immune complex-mediated)
D. Type IV (Cell-mediated)
Correct Answer: B. Type II (Tissue-specific / Cytotoxic).
Explanation: Type II hypersensitivity reactions involve IgG or
IgM antibodies directed against antigens on cell surfaces or
extracellular matrices (such as ABO blood group antigens). This
triggers cell lysis via complement activation or macrophage-
mediated phagocytosis.
Question 5: Immunodeficiencies & HIV Pathophysiology
What is the specific enzymatic role of reverse transcriptase in
retroviruses such as HIV?
A. It transports viral RNA directly into the host cell
nucleus.
B. It converts single-stranded viral RNA into a double-
stranded DNA version.
C. It cleaves large viral precursor proteins into functional
structural proteins.
D. It integrates the viral genome permanently into the host
chromosome.
Week 1 High-Yield Questions, Answers,
& Rationales 2026/2027 Update
Question 1: Cellular Adaptation & Injury
A 55-year-old chronic cigarette smoker presents with a
persistent cough. A bronchial biopsy reveals that the normal
pseudostratified ciliated columnar epithelium has been replaced
by stratified squamous epithelium. What cellular adaptation
process has occurred?
A. Atrophy
B. Hypertrophy
C. Metaplasia
D. Dysplasia
Correct Answer: C. Metaplasia.
Explanation: Metaplasia is the reversible replacement of one
mature cell type by another, sometimes less mature, cell type in
response to chronic irritation or injury (such as cigarette smoke
exposing the bronchial lining to toxins). While it protects the
tissue initially, prolonged exposure can lead to dysplasia and
malignancy.
Question 2: Mechanisms of Cellular Injury
During periods of cellular starvation, a cell may undergo
autophagy to survive. Which organelle plays the central role in
digesting cellular components during autophagy?
, A. Mitochondria
B. Golgi apparatus
C. Peroxisomes
D. Lysosomes
Correct Answer: D. Lysosomes
Explanation: Lysosomes contain over 40 distinct hydrolytic
enzymes. During autophagy ("self-eating"), lysosomes fuse with
vacuoles containing damaged organelles or cytosolic proteins,
degrading them into basic building blocks that the cell can reuse
for energy and survival.
Question 3: Inflammation & Chemical Mediators
What is a key functional difference between Cytotoxic T
Lymphocytes (CTLs) and Natural Killer (NK) cells?
A. CTLs require prior antigen sensitization and
presentation via MHC I, whereas NK cells do not require
antigen presentation and can target cells with
downregulated MHC I.
B. NK cells require MHC Class II presentation, while
CTLs require no recognition mechanism.
C. CTLs only attack extracellular bacteria, while NK cells
attack viruses exclusively.
D. NK cells are part of the adaptive immune system,
whereas CTLs are innate.
Correct Answer: A. CTLs require prior antigen sensitization
and presentation via MHC I, whereas NK cells do not
require antigen presentation and can target cells with
downregulated MHC I.
, Question 4: Types of Hypersensitivity Reactions
A client who receives an incompatible blood transfusion
experiences an acute hemolytic reaction characterized by fever,
chills, and hemoglobinuria within minutes. What type of
hypersensitivity reaction is this?
A. Type I (IgE-mediated)
B. Type II (Tissue-specific / Cytotoxic)
C. Type III (Immune complex-mediated)
D. Type IV (Cell-mediated)
Correct Answer: B. Type II (Tissue-specific / Cytotoxic).
Explanation: Type II hypersensitivity reactions involve IgG or
IgM antibodies directed against antigens on cell surfaces or
extracellular matrices (such as ABO blood group antigens). This
triggers cell lysis via complement activation or macrophage-
mediated phagocytosis.
Question 5: Immunodeficiencies & HIV Pathophysiology
What is the specific enzymatic role of reverse transcriptase in
retroviruses such as HIV?
A. It transports viral RNA directly into the host cell
nucleus.
B. It converts single-stranded viral RNA into a double-
stranded DNA version.
C. It cleaves large viral precursor proteins into functional
structural proteins.
D. It integrates the viral genome permanently into the host
chromosome.
