1
NR507 / NR 507 Midterm Exam
(Latest 2025/2026 Update) Advanced
Pathophysiology Questions and
Verified Answers | 100% Correct | Grade
A – Chamberlain
Question 1: Which immune mechanism is primarily responsible for
the immediate hypersensitivity reaction seen in anaphylaxis?
A. Type I hypersensitivity involving IgE-mediated mast cell
degranulation.
B. Type II hypersensitivity with antibody-mediated cytotoxicity.
C. Type III hypersensitivity due to immune complex deposition.
D. Type IV hypersensitivity involving T-cell activation.
Correct Answer: A
Rationale: Anaphylaxis is a classic Type I hypersensitivity reaction
where allergens cross-link IgE on mast cells and basophils, triggering
rapid degranulation and release of histamine, leukotrienes, and
prostaglandins, leading to vasodilation, bronchoconstriction, and
hypotension. Clinically, this manifests within minutes as hives,
angioedema, or shock. Option B involves IgG/IgM against cell surfaces
(e.g., hemolytic anemia). Option C causes serum sickness from
complexes in tissues. Option D is delayed, cell-mediated (e.g., contact
dermatitis).
Question 2: In cellular injury, what is the primary biochemical
change during reversible hypoxic injury?
A. ATP depletion leading to Na+/K+ ATPase failure and cellular
swelling.
B. Mitochondrial permeability transition pore opening causing
apoptosis.
, 2
C. Lysosomal enzyme rupture leading to necrosis.
D. Free radical generation overwhelming antioxidant defenses.
Correct Answer: A
Rationale: Hypoxic injury initially depletes ATP, impairing the Na+/K+
pump, causing sodium influx, water entry, and cellular swelling
(hydropic change), which is reversible if oxygen is restored. Clinically,
this underlies early ischemic injury in myocardial infarction. Option B
occurs in irreversible injury or apoptosis. Option C leads to necrosis.
Option D is oxidative stress in reperfusion injury.
Question 3: A patient with severe diarrhea develops hyponatremia.
This is primarily due to:
A. Loss of sodium-rich fluid from the gastrointestinal tract.
B. Excessive ADH secretion causing water retention.
C. Renal sodium wasting from aldosterone deficiency.
D. Shift of sodium into cells due to hyperglycemia.
Correct Answer: A
Rationale: Diarrheal fluid is sodium-rich (isotonic), leading to
proportional loss of sodium and water, but if hypotonic fluids are
replaced, hyponatremia ensues from relative water excess. Clinically,
this causes neurological symptoms like confusion. Option B is SIADH.
Option C is Addison's disease. Option D is diabetic ketoacidosis.
Question 4: During acute inflammation, which cell type is the first
responder to the site of injury?
A. Neutrophils migrating via chemotaxis.
B. Macrophages for phagocytosis.
C. Lymphocytes for adaptive immunity.
D. Eosinophils for parasitic defense.
Correct Answer: A
Rationale: Neutrophils are the earliest responders in acute
inflammation, attracted by chemotactic factors like C5a and IL-8, where
, 3
they phagocytose debris and release enzymes. This is seen in bacterial
infections with pus formation. Option B dominates chronic
inflammation. Option C is for specific immunity. Option D targets
allergens/parasites.
Question 5: In autosomal dominant polycystic kidney disease
(ADPKD), the primary genetic defect involves:
A. Mutation in PKD1 gene leading to cyst formation in kidneys.
B. Trisomy 21 causing renal anomalies.
C. X-linked recessive mutation in Alport syndrome.
D. Mitochondrial DNA defect affecting renal function.
Correct Answer: A
Rationale: ADPKD results from PKD1 or PKD2 mutations, causing
defective polycystin proteins, leading to epithelial cell proliferation and
fluid-filled cysts that impair renal function over time. Clinically, it
presents with hypertension and hematuria. Option B is Down syndrome.
Option C affects basement membranes. Option D is rare for kidneys.
Question 6: A patient with type 1 diabetes mellitus has ketoacidosis
due to:
A. Absolute insulin deficiency leading to lipolysis and ketone
production.
B. Insulin resistance with beta-cell exhaustion.
C. Glucagon excess stimulating glycogenolysis.
D. Cortisol elevation from stress response.
Correct Answer: A
Rationale: Type 1 DM involves autoimmune destruction of beta cells,
causing insulin absence, unchecked lipolysis in adipose tissue, and
hepatic ketogenesis from free fatty acids, resulting in acidosis.
Clinically, Kussmaul respirations compensate. Option B is type 2 DM.
Option C contributes but is secondary. Option D worsens but isn't
primary.
NR507 / NR 507 Midterm Exam
(Latest 2025/2026 Update) Advanced
Pathophysiology Questions and
Verified Answers | 100% Correct | Grade
A – Chamberlain
Question 1: Which immune mechanism is primarily responsible for
the immediate hypersensitivity reaction seen in anaphylaxis?
A. Type I hypersensitivity involving IgE-mediated mast cell
degranulation.
B. Type II hypersensitivity with antibody-mediated cytotoxicity.
C. Type III hypersensitivity due to immune complex deposition.
D. Type IV hypersensitivity involving T-cell activation.
Correct Answer: A
Rationale: Anaphylaxis is a classic Type I hypersensitivity reaction
where allergens cross-link IgE on mast cells and basophils, triggering
rapid degranulation and release of histamine, leukotrienes, and
prostaglandins, leading to vasodilation, bronchoconstriction, and
hypotension. Clinically, this manifests within minutes as hives,
angioedema, or shock. Option B involves IgG/IgM against cell surfaces
(e.g., hemolytic anemia). Option C causes serum sickness from
complexes in tissues. Option D is delayed, cell-mediated (e.g., contact
dermatitis).
Question 2: In cellular injury, what is the primary biochemical
change during reversible hypoxic injury?
A. ATP depletion leading to Na+/K+ ATPase failure and cellular
swelling.
B. Mitochondrial permeability transition pore opening causing
apoptosis.
, 2
C. Lysosomal enzyme rupture leading to necrosis.
D. Free radical generation overwhelming antioxidant defenses.
Correct Answer: A
Rationale: Hypoxic injury initially depletes ATP, impairing the Na+/K+
pump, causing sodium influx, water entry, and cellular swelling
(hydropic change), which is reversible if oxygen is restored. Clinically,
this underlies early ischemic injury in myocardial infarction. Option B
occurs in irreversible injury or apoptosis. Option C leads to necrosis.
Option D is oxidative stress in reperfusion injury.
Question 3: A patient with severe diarrhea develops hyponatremia.
This is primarily due to:
A. Loss of sodium-rich fluid from the gastrointestinal tract.
B. Excessive ADH secretion causing water retention.
C. Renal sodium wasting from aldosterone deficiency.
D. Shift of sodium into cells due to hyperglycemia.
Correct Answer: A
Rationale: Diarrheal fluid is sodium-rich (isotonic), leading to
proportional loss of sodium and water, but if hypotonic fluids are
replaced, hyponatremia ensues from relative water excess. Clinically,
this causes neurological symptoms like confusion. Option B is SIADH.
Option C is Addison's disease. Option D is diabetic ketoacidosis.
Question 4: During acute inflammation, which cell type is the first
responder to the site of injury?
A. Neutrophils migrating via chemotaxis.
B. Macrophages for phagocytosis.
C. Lymphocytes for adaptive immunity.
D. Eosinophils for parasitic defense.
Correct Answer: A
Rationale: Neutrophils are the earliest responders in acute
inflammation, attracted by chemotactic factors like C5a and IL-8, where
, 3
they phagocytose debris and release enzymes. This is seen in bacterial
infections with pus formation. Option B dominates chronic
inflammation. Option C is for specific immunity. Option D targets
allergens/parasites.
Question 5: In autosomal dominant polycystic kidney disease
(ADPKD), the primary genetic defect involves:
A. Mutation in PKD1 gene leading to cyst formation in kidneys.
B. Trisomy 21 causing renal anomalies.
C. X-linked recessive mutation in Alport syndrome.
D. Mitochondrial DNA defect affecting renal function.
Correct Answer: A
Rationale: ADPKD results from PKD1 or PKD2 mutations, causing
defective polycystin proteins, leading to epithelial cell proliferation and
fluid-filled cysts that impair renal function over time. Clinically, it
presents with hypertension and hematuria. Option B is Down syndrome.
Option C affects basement membranes. Option D is rare for kidneys.
Question 6: A patient with type 1 diabetes mellitus has ketoacidosis
due to:
A. Absolute insulin deficiency leading to lipolysis and ketone
production.
B. Insulin resistance with beta-cell exhaustion.
C. Glucagon excess stimulating glycogenolysis.
D. Cortisol elevation from stress response.
Correct Answer: A
Rationale: Type 1 DM involves autoimmune destruction of beta cells,
causing insulin absence, unchecked lipolysis in adipose tissue, and
hepatic ketogenesis from free fatty acids, resulting in acidosis.
Clinically, Kussmaul respirations compensate. Option B is type 2 DM.
Option C contributes but is secondary. Option D worsens but isn't
primary.
