NURS 6501 Advanced Pathophysiology 2026/2027 | Walden University NURS
6501 Exam Study Guide, Advanced Pathophysiology Exam Prep, Cellular
Injury, Inflammation, Immunity, Genetics, Neoplasia, Cardiovascular,
Respiratory, Renal, Endocrine & Neurological Disorders, Practice Questions,
Answers & Rationales
Question 1: A 42-year-old female presents with fatigue, pallor, and a
hemoglobin of 8.2 g/dL. Bone marrow biopsy reveals megaloblastic anemia with
hypersegmented neutrophils. The pathophysiologic basis of megaloblastic
anemia involves impaired DNA synthesis due to deficiency of:
A. Iron required for hemoglobin production
B. Vitamin B12 or folate required for thymidine synthesis and DNA replication
C. Vitamin K required for coagulation factor synthesis
D. Copper required for ceruloplasmin function
CORRECT ANSWER: B. Vitamin B12 or folate required for thymidine synthesis
and DNA replication
Rationale: Megaloblastic anemia results from impaired DNA synthesis caused by
vitamin B12 or folate deficiency, leading to large, immature erythrocytes. Iron
deficiency causes microcytic anemia, vitamin K deficiency causes bleeding, and
copper deficiency causes neurologic symptoms .
Question 2: A 35-year-old male with a history of recurrent infections is found to
have a genetic defect in the NADPH oxidase enzyme system in his phagocytes.
This defect results in chronic granulomatous disease, which impairs the ability
of phagocytes to:
A. Engulf and internalize bacteria through endocytosis
B. Produce reactive oxygen species needed for intracellular killing of pathogens
C. Present antigens to T lymphocytes via MHC class II molecules
D. Secrete complement proteins that opsonize bacteria
CORRECT ANSWER: B. Produce reactive oxygen species needed for intracellular
killing of pathogens
Rationale: Chronic granulomatous disease results from a defect in NADPH
oxidase, which prevents the respiratory burst needed to generate reactive oxygen
species for killing ingested pathogens. Phagocytosis itself and antigen
,presentation remain intact, and complement is produced by the liver, not
phagocytes .
Question 3: A 28-year-old female presents with a butterfly rash across her
cheeks and nose, joint pain, and proteinuria. Laboratory testing reveals positive
anti-dsDNA antibodies and low complement levels. The underlying
pathophysiologic mechanism in systemic lupus erythematosus involves:
A. Type I hypersensitivity mediated by IgE antibodies
B. Type II hypersensitivity with antibody-mediated cellular destruction
C. Loss of self-tolerance with production of autoantibodies that form immune
complexes depositing in tissues
D. Type IV delayed hypersensitivity mediated by cytotoxic T lymphocytes
CORRECT ANSWER: C. Loss of self-tolerance with production of autoantibodies
that form immune complexes depositing in tissues
Rationale: SLE involves loss of self-tolerance leading to autoantibody production,
and immune complex deposition (type III hypersensitivity) in tissues such as the
kidney, skin, and joints. Type I involves IgE, type II involves direct antibody-
mediated cell destruction, and type IV is T-cell mediated .
Question 4: A 55-year-old male with a 30-pack-year smoking history develops
squamous cell carcinoma of the lung. The cellular adaptation that most
commonly precedes the development of this malignancy in the bronchial
epithelium is:
A. Hyperplasia, an increase in the number of cells
B. Metaplasia, the replacement of one differentiated cell type with another
C. Hypertrophy, an increase in cell size without cell division
D. Dysplasia, disordered cell growth with loss of uniformity
CORRECT ANSWER: B. Metaplasia, the replacement of one differentiated cell
type with another
Rationale: Chronic exposure to cigarette smoke causes squamous metaplasia,
replacing ciliated columnar epithelium with squamous epithelium, which is the
precursor change that can progress to dysplasia and then carcinoma. Hyperplasia
,and hypertrophy do not involve cell type change, and dysplasia follows metaplasia
.
Question 5: The irreversible marker of cell death on electron microscopy is:
A. Cellular swelling
B. Nuclear pyknosis
C. Mitochondrial amorphous (flocculent) densities
D. Membrane blebbing
CORRECT ANSWER: C. Mitochondrial amorphous (flocculent) densities
Rationale: Flocculent densities in the mitochondrial matrix are an irreversible
marker of cell death, indicating severe membrane damage. This is the "point of no
return" where cell death is inevitable even if the stressor is removed .
Question 6: What is the earliest reversible morphologic sign of cell injury?
A. Fatty change
B. Cellular swelling (hydropic change)
C. Nuclear condensation
D. Membrane rupture
CORRECT ANSWER: B. Cellular swelling (hydropic change)
Rationale: Cellular swelling is the earliest reversible sign of cell injury, caused by
ATP depletion leading to failure of the Na+/K+ pump and subsequent water influx.
This is followed by fatty change in some organs .
Question 7: The process where a normal cell becomes a cancer cell is called:
A. Metaplasia
B. Dysplasia
C. Cell transformation
D. Anaplasia
CORRECT ANSWER: C. Cell transformation
Rationale: Cell transformation is the process by which a normal cell acquires the
characteristics of a cancer cell. It involves genetic mutations that lead to
uncontrolled growth, loss of differentiation, and the ability to invade and
metastasize .
, Question 8: Cachexia in cancer patients is primarily mediated by which
cytokine?
A. Interleukin-2 (IL-2)
B. Interferon-gamma (IFN-γ)
C. Tumor Necrosis Factor-alpha (TNF-α)
D. Interleukin-10 (IL-10)
CORRECT ANSWER: C. Tumor Necrosis Factor-alpha (TNF-α)
Rationale: TNF-α, formerly called cachectin, is a key mediator of cancer cachexia.
It promotes fat and muscle wasting, anorexia, and systemic inflammation seen in
advanced malignancies .
Question 9: The "two-hit hypothesis" applies to which type of genes?
A. Proto-oncogenes
B. Tumor suppressor genes
C. Oncogenes
D. DNA repair genes
CORRECT ANSWER: B. Tumor suppressor genes
Rationale: The two-hit hypothesis states that both alleles of a tumor suppressor
gene must be inactivated (mutated or deleted) for cancer to develop. Examples
include the retinoblastoma (Rb) and p53 genes .
Question 10: What is the primary cause of hypokalemia during treatment of
diabetic ketoacidosis (DKA)?
A. Vomiting from acidosis
B. Insulin driving potassium into cells
C. Renal loss of potassium
D. Increased aldosterone secretion
CORRECT ANSWER: B. Insulin driving potassium into cells
Rationale: During DKA treatment, insulin administration activates the Na+/K+-
ATPase pump, driving potassium from the extracellular space into cells. This can
cause life-threatening hypokalemia even if initial potassium levels are normal or
elevated .
6501 Exam Study Guide, Advanced Pathophysiology Exam Prep, Cellular
Injury, Inflammation, Immunity, Genetics, Neoplasia, Cardiovascular,
Respiratory, Renal, Endocrine & Neurological Disorders, Practice Questions,
Answers & Rationales
Question 1: A 42-year-old female presents with fatigue, pallor, and a
hemoglobin of 8.2 g/dL. Bone marrow biopsy reveals megaloblastic anemia with
hypersegmented neutrophils. The pathophysiologic basis of megaloblastic
anemia involves impaired DNA synthesis due to deficiency of:
A. Iron required for hemoglobin production
B. Vitamin B12 or folate required for thymidine synthesis and DNA replication
C. Vitamin K required for coagulation factor synthesis
D. Copper required for ceruloplasmin function
CORRECT ANSWER: B. Vitamin B12 or folate required for thymidine synthesis
and DNA replication
Rationale: Megaloblastic anemia results from impaired DNA synthesis caused by
vitamin B12 or folate deficiency, leading to large, immature erythrocytes. Iron
deficiency causes microcytic anemia, vitamin K deficiency causes bleeding, and
copper deficiency causes neurologic symptoms .
Question 2: A 35-year-old male with a history of recurrent infections is found to
have a genetic defect in the NADPH oxidase enzyme system in his phagocytes.
This defect results in chronic granulomatous disease, which impairs the ability
of phagocytes to:
A. Engulf and internalize bacteria through endocytosis
B. Produce reactive oxygen species needed for intracellular killing of pathogens
C. Present antigens to T lymphocytes via MHC class II molecules
D. Secrete complement proteins that opsonize bacteria
CORRECT ANSWER: B. Produce reactive oxygen species needed for intracellular
killing of pathogens
Rationale: Chronic granulomatous disease results from a defect in NADPH
oxidase, which prevents the respiratory burst needed to generate reactive oxygen
species for killing ingested pathogens. Phagocytosis itself and antigen
,presentation remain intact, and complement is produced by the liver, not
phagocytes .
Question 3: A 28-year-old female presents with a butterfly rash across her
cheeks and nose, joint pain, and proteinuria. Laboratory testing reveals positive
anti-dsDNA antibodies and low complement levels. The underlying
pathophysiologic mechanism in systemic lupus erythematosus involves:
A. Type I hypersensitivity mediated by IgE antibodies
B. Type II hypersensitivity with antibody-mediated cellular destruction
C. Loss of self-tolerance with production of autoantibodies that form immune
complexes depositing in tissues
D. Type IV delayed hypersensitivity mediated by cytotoxic T lymphocytes
CORRECT ANSWER: C. Loss of self-tolerance with production of autoantibodies
that form immune complexes depositing in tissues
Rationale: SLE involves loss of self-tolerance leading to autoantibody production,
and immune complex deposition (type III hypersensitivity) in tissues such as the
kidney, skin, and joints. Type I involves IgE, type II involves direct antibody-
mediated cell destruction, and type IV is T-cell mediated .
Question 4: A 55-year-old male with a 30-pack-year smoking history develops
squamous cell carcinoma of the lung. The cellular adaptation that most
commonly precedes the development of this malignancy in the bronchial
epithelium is:
A. Hyperplasia, an increase in the number of cells
B. Metaplasia, the replacement of one differentiated cell type with another
C. Hypertrophy, an increase in cell size without cell division
D. Dysplasia, disordered cell growth with loss of uniformity
CORRECT ANSWER: B. Metaplasia, the replacement of one differentiated cell
type with another
Rationale: Chronic exposure to cigarette smoke causes squamous metaplasia,
replacing ciliated columnar epithelium with squamous epithelium, which is the
precursor change that can progress to dysplasia and then carcinoma. Hyperplasia
,and hypertrophy do not involve cell type change, and dysplasia follows metaplasia
.
Question 5: The irreversible marker of cell death on electron microscopy is:
A. Cellular swelling
B. Nuclear pyknosis
C. Mitochondrial amorphous (flocculent) densities
D. Membrane blebbing
CORRECT ANSWER: C. Mitochondrial amorphous (flocculent) densities
Rationale: Flocculent densities in the mitochondrial matrix are an irreversible
marker of cell death, indicating severe membrane damage. This is the "point of no
return" where cell death is inevitable even if the stressor is removed .
Question 6: What is the earliest reversible morphologic sign of cell injury?
A. Fatty change
B. Cellular swelling (hydropic change)
C. Nuclear condensation
D. Membrane rupture
CORRECT ANSWER: B. Cellular swelling (hydropic change)
Rationale: Cellular swelling is the earliest reversible sign of cell injury, caused by
ATP depletion leading to failure of the Na+/K+ pump and subsequent water influx.
This is followed by fatty change in some organs .
Question 7: The process where a normal cell becomes a cancer cell is called:
A. Metaplasia
B. Dysplasia
C. Cell transformation
D. Anaplasia
CORRECT ANSWER: C. Cell transformation
Rationale: Cell transformation is the process by which a normal cell acquires the
characteristics of a cancer cell. It involves genetic mutations that lead to
uncontrolled growth, loss of differentiation, and the ability to invade and
metastasize .
, Question 8: Cachexia in cancer patients is primarily mediated by which
cytokine?
A. Interleukin-2 (IL-2)
B. Interferon-gamma (IFN-γ)
C. Tumor Necrosis Factor-alpha (TNF-α)
D. Interleukin-10 (IL-10)
CORRECT ANSWER: C. Tumor Necrosis Factor-alpha (TNF-α)
Rationale: TNF-α, formerly called cachectin, is a key mediator of cancer cachexia.
It promotes fat and muscle wasting, anorexia, and systemic inflammation seen in
advanced malignancies .
Question 9: The "two-hit hypothesis" applies to which type of genes?
A. Proto-oncogenes
B. Tumor suppressor genes
C. Oncogenes
D. DNA repair genes
CORRECT ANSWER: B. Tumor suppressor genes
Rationale: The two-hit hypothesis states that both alleles of a tumor suppressor
gene must be inactivated (mutated or deleted) for cancer to develop. Examples
include the retinoblastoma (Rb) and p53 genes .
Question 10: What is the primary cause of hypokalemia during treatment of
diabetic ketoacidosis (DKA)?
A. Vomiting from acidosis
B. Insulin driving potassium into cells
C. Renal loss of potassium
D. Increased aldosterone secretion
CORRECT ANSWER: B. Insulin driving potassium into cells
Rationale: During DKA treatment, insulin administration activates the Na+/K+-
ATPase pump, driving potassium from the extracellular space into cells. This can
cause life-threatening hypokalemia even if initial potassium levels are normal or
elevated .
