2026 WGU D236 Pathophysiology OA V2 – Complete
Practice Questions with Rationales
Question 1: A pathologist examines a tissue sample and notes an area of
brain tissue that has been replaced by a cavity filled with debris and
inflammatory cells. This is most consistent with which type of necrosis?
A) Coagulative necrosis
B) Liquefactive necrosis
C) Caseous necrosis
D) Fat necrosis
Correct Answer: B) Liquefactive necrosis
Rationale: Liquefactive necrosis is characteristic of the central nervous system
(brain) and occurs when cellular enzymes and inflammatory cells liquefy
dead tissue, forming a cystic cavity filled with debris. Coagulative necrosis
preserves tissue architecture (seen in ischemia of solid organs), caseous
necrosis is cheesy (seen in TB), and fat necrosis occurs in adipose tissue.
Question 2: Which of the following is a characteristic of reversible cell
injury?
A) Cellular swelling and fatty change
B) Nuclear fragmentation
C) Membrane rupture
D) Mitochondrial calcification
Correct Answer: A) Cellular swelling and fatty change
,Rationale: Reversible cell injury is characterized by cellular swelling (due to
failure of the Na+/K+ pump) and fatty change (lipid accumulation). Nuclear
fragmentation, membrane rupture, and mitochondrial calcification are
features of irreversible injury and necrosis.
Question 3: In which phase of wound healing does angiogenesis and new
blood vessel formation primarily occur?
A) Inflammatory phase
B) Proliferative phase
C) Maturation phase
D) Hemostasis phase
Correct Answer: B) Proliferative phase
Rationale: Angiogenesis (new blood vessel formation) occurs during the
proliferative phase of wound healing, along with fibroblast proliferation and
collagen deposition. The inflammatory phase involves hemostasis and
immune cell recruitment. The maturation phase involves collagen remodeling
and wound contraction.
Question 4: Which of the following is a function of the complement
system?
A) Direct killing of pathogens by phagocytosis
B) Opsonization, chemotaxis, and cell lysis
C) Production of antibodies
D) Activation of T lymphocytes
Correct Answer: B) Opsonization, chemotaxis, and cell lysis
,Rationale: The complement system has multiple functions: opsonization (C3b
coats pathogens for phagocytosis), chemotaxis (C5a attracts immune cells),
and cell lysis (membrane attack complex). Antibodies are produced by B cells,
and T cell activation involves antigen presentation, not complement directly.
Question 5: A patient with a bacterial infection has an elevated white blood
cell count with a predominance of neutrophils. This is most characteristic of:
A) A viral infection
B) A parasitic infection
C) An acute bacterial infection
D) A chronic allergic reaction
Correct Answer: C) An acute bacterial infection
Rationale: Neutrophilia (elevated neutrophils) is the hallmark of acute
bacterial infections. Viral infections typically cause lymphocytosis. Parasitic
infections often cause eosinophilia. Allergic reactions are associated with
eosinophilia and basophilia.
Question 6: The type of hypersensitivity reaction that involves IgE-
mediated mast cell degranulation and is responsible for anaphylaxis is:
A) Type I hypersensitivity
B) Type II hypersensitivity
C) Type III hypersensitivity
D) Type IV hypersensitivity
Correct Answer: A) Type I hypersensitivity
Rationale: Type I hypersensitivity is IgE-mediated and involves mast cell
degranulation, leading to anaphylaxis, allergic rhinitis, and asthma. Type II is
, antibody-mediated (cytotoxic), Type III is immune complex-mediated, and
Type IV is T-cell mediated (delayed-type).
Question 7: A patient with chronic inflammation has a granuloma
formation. This is most characteristic of:
A) Acute bacterial infection
B) Viral infection
C) Foreign body reaction or mycobacterial infection
D) Allergic reaction
Correct Answer: C) Foreign body reaction or mycobacterial infection
Rationale: Granulomas are organized collections of macrophages (epithelioid
cells) that form in response to persistent, non-degradable antigens, such as
Mycobacterium tuberculosis (TB), fungi, or foreign bodies. They are a
hallmark of chronic inflammation.
Question 8: The process by which neutrophils migrate from the
bloodstream to the site of tissue injury is called:
A) Diapedesis
B) Opsonization
C) Chemotaxis
D) Phagocytosis
Correct Answer: A) Diapedesis
Rationale: Diapedesis (extravasation) is the process by which leukocytes
(including neutrophils) squeeze through the endothelial cell junctions to exit
the bloodstream and enter tissues. Chemotaxis is the movement toward a
chemical signal, and phagocytosis is the engulfment of particles.
Practice Questions with Rationales
Question 1: A pathologist examines a tissue sample and notes an area of
brain tissue that has been replaced by a cavity filled with debris and
inflammatory cells. This is most consistent with which type of necrosis?
A) Coagulative necrosis
B) Liquefactive necrosis
C) Caseous necrosis
D) Fat necrosis
Correct Answer: B) Liquefactive necrosis
Rationale: Liquefactive necrosis is characteristic of the central nervous system
(brain) and occurs when cellular enzymes and inflammatory cells liquefy
dead tissue, forming a cystic cavity filled with debris. Coagulative necrosis
preserves tissue architecture (seen in ischemia of solid organs), caseous
necrosis is cheesy (seen in TB), and fat necrosis occurs in adipose tissue.
Question 2: Which of the following is a characteristic of reversible cell
injury?
A) Cellular swelling and fatty change
B) Nuclear fragmentation
C) Membrane rupture
D) Mitochondrial calcification
Correct Answer: A) Cellular swelling and fatty change
,Rationale: Reversible cell injury is characterized by cellular swelling (due to
failure of the Na+/K+ pump) and fatty change (lipid accumulation). Nuclear
fragmentation, membrane rupture, and mitochondrial calcification are
features of irreversible injury and necrosis.
Question 3: In which phase of wound healing does angiogenesis and new
blood vessel formation primarily occur?
A) Inflammatory phase
B) Proliferative phase
C) Maturation phase
D) Hemostasis phase
Correct Answer: B) Proliferative phase
Rationale: Angiogenesis (new blood vessel formation) occurs during the
proliferative phase of wound healing, along with fibroblast proliferation and
collagen deposition. The inflammatory phase involves hemostasis and
immune cell recruitment. The maturation phase involves collagen remodeling
and wound contraction.
Question 4: Which of the following is a function of the complement
system?
A) Direct killing of pathogens by phagocytosis
B) Opsonization, chemotaxis, and cell lysis
C) Production of antibodies
D) Activation of T lymphocytes
Correct Answer: B) Opsonization, chemotaxis, and cell lysis
,Rationale: The complement system has multiple functions: opsonization (C3b
coats pathogens for phagocytosis), chemotaxis (C5a attracts immune cells),
and cell lysis (membrane attack complex). Antibodies are produced by B cells,
and T cell activation involves antigen presentation, not complement directly.
Question 5: A patient with a bacterial infection has an elevated white blood
cell count with a predominance of neutrophils. This is most characteristic of:
A) A viral infection
B) A parasitic infection
C) An acute bacterial infection
D) A chronic allergic reaction
Correct Answer: C) An acute bacterial infection
Rationale: Neutrophilia (elevated neutrophils) is the hallmark of acute
bacterial infections. Viral infections typically cause lymphocytosis. Parasitic
infections often cause eosinophilia. Allergic reactions are associated with
eosinophilia and basophilia.
Question 6: The type of hypersensitivity reaction that involves IgE-
mediated mast cell degranulation and is responsible for anaphylaxis is:
A) Type I hypersensitivity
B) Type II hypersensitivity
C) Type III hypersensitivity
D) Type IV hypersensitivity
Correct Answer: A) Type I hypersensitivity
Rationale: Type I hypersensitivity is IgE-mediated and involves mast cell
degranulation, leading to anaphylaxis, allergic rhinitis, and asthma. Type II is
, antibody-mediated (cytotoxic), Type III is immune complex-mediated, and
Type IV is T-cell mediated (delayed-type).
Question 7: A patient with chronic inflammation has a granuloma
formation. This is most characteristic of:
A) Acute bacterial infection
B) Viral infection
C) Foreign body reaction or mycobacterial infection
D) Allergic reaction
Correct Answer: C) Foreign body reaction or mycobacterial infection
Rationale: Granulomas are organized collections of macrophages (epithelioid
cells) that form in response to persistent, non-degradable antigens, such as
Mycobacterium tuberculosis (TB), fungi, or foreign bodies. They are a
hallmark of chronic inflammation.
Question 8: The process by which neutrophils migrate from the
bloodstream to the site of tissue injury is called:
A) Diapedesis
B) Opsonization
C) Chemotaxis
D) Phagocytosis
Correct Answer: A) Diapedesis
Rationale: Diapedesis (extravasation) is the process by which leukocytes
(including neutrophils) squeeze through the endothelial cell junctions to exit
the bloodstream and enter tissues. Chemotaxis is the movement toward a
chemical signal, and phagocytosis is the engulfment of particles.
