BIOD 171 Human Pathophysiology Midterm Exam Practice
Questions and Detailed Solutions Latest Update 2026/2027 |
Cellular Injury, Organ System Diseases, Verified Answers - 190
Questions
This midterm examination assesses advanced understanding of cellular injury mechanisms and organ system
pathophysiology, emphasizing integrative reasoning, clinical application, and interpretation of diagnostic data.
Questions require synthesis across molecular, cellular, and systemic levels of disease processes. It contains 190
multiple-choice questions, each with four distractors and a fully worked rationale that explains why the keyed
answer is correct. Questions are organized into clearly labelled sections that mirror the major content areas of
the course. Targeted learning outcomes include: Analyze mechanisms of cellular injury and adaptation in
response to pathological stimuli.; Integrate pathophysiological principles across organ systems to explain disease
manifestations.; Evaluate diagnostic and therapeutic approaches based on underlying pathophysiology.; Interpret
clinical scenarios and data to make evidence-based decisions in complex cases.. Every item has been reviewed for
clinical accuracy, current guidelines, and clarity so that students can study with confidence and self-correct as
they work through the bank. Use it as a high-yield review immediately before the exam, or as a structured practice
tool during the unit - the rationales double as concise teaching notes. The recommended writing time is 3 hours,
with a passing score of 70%. Aligned with Aligned with standards of US medical education accreditation (LCME)
and rigorous university examination protocols. standards and reflects the question style commonly seen on
accredited program examinations. Students consistently achieving above the cut score on this bank have
Section 1: General (Questions 1-190)
1 A cell undergoing severe ATP depletion shifts to anaerobic
metabolism. Which consequence directly impairs the Na+/K+
ATPase, leading to cellular swelling?
A) Increased intracellular calcium
B) Decreased ATP availability
C) Accumulation of lactic acid
D) Mitochondrial permeability transition
Answer: B
Rationale: Na+/K+ ATPase is ATP-dependent; ATP depletion directly
reduces its activity, causing sodium and water influx. Increased
calcium and mitochondrial changes are downstream effects, while
lactic acid contributes to pH changes but not directly to pump failure.
2 In reperfusion injury, which reactive oxygen species is generated by
xanthine oxidase during the conversion of hypoxanthine to
xanthine?
,A) Hydroxyl radical
B) Superoxide anion
C) Hydrogen peroxide
D) Nitric oxide
Answer: B
Rationale: Xanthine oxidase produces superoxide anion (O2•") when it
converts hypoxanthine to xanthine. Hydroxyl radical forms via Fenton
reaction, hydrogen peroxide via dismutation, and nitric oxide from
NOS.
3 Which type of cellular adaptation is characterized by a reversible
change in which one adult cell type is replaced by another adult cell
type, often in response to chronic irritation?
A) Hyperplasia
B) Metaplasia
C) Dysplasia
D) Hypertrophy
Answer: B
Rationale: Metaplasia is the replacement of one differentiated cell type
with another, e.g., squamous metaplasia in smokers. Hyperplasia is
increased cell number, hypertrophy is increased cell size, and
dysplasia is disordered growth.
4 A patient with chronic heart failure has elevated B-type natriuretic
peptide (BNP). Which pathophysiological mechanism directly
stimulates BNP secretion from ventricular myocytes?
A) Increased sympathetic tone
B) Ventricular wall stretch
C) Renin-angiotensin-aldosterone activation
D) Hypoxia-induced gene expression
Answer: B
Rationale: BNP is released in response to ventricular volume and
pressure overload causing wall stretch. Sympathetic and RAAS
,activation are compensatory but not direct stimuli for BNP release.
Hypoxia may contribute but is not the primary direct trigger.
5 In acute respiratory distress syndrome (ARDS), which
pathophysiological feature is most directly responsible for refractory
hypoxemia?
A) Pulmonary vasoconstriction
B) Intrapulmonary shunting
C) Decreased lung compliance
D) Surfactant dysfunction
Answer: B
Rationale: Intrapulmonary shunting (blood perfusing non-ventilated
alveoli) causes venous admixture and hypoxemia unresponsive to
oxygen. Vasoconstriction and compliance changes contribute to
ventilation-perfusion mismatch but shunting is the key mechanism.
6 A patient with chronic kidney disease develops hyperphosphatemia.
Which secondary response is most likely to occur due to decreased
renal phosphate excretion?
A) Increased calcitriol synthesis
B) Decreased parathyroid hormone secretion
C) Metastatic calcification in soft tissues
D) Increased intestinal calcium absorption
Answer: C
Rationale: Hyperphosphatemia leads to calcium-phosphate product
elevation, causing metastatic calcification. It suppresses calcitriol
synthesis and stimulates PTH secretion (secondary
hyperparathyroidism), not decreases. Intestinal calcium absorption is
reduced due to low calcitriol.
7 Which of the following best describes the pathophysiological
sequence in the development of hepatic encephalopathy?
, A) Impaired urea cycle -> hyperammonemia -> astrocyte swelling ->
altered neurotransmission
B) Hepatocyte necrosis -> bile duct proliferation -> cholestasis ->
pruritus
C) Portal hypertension -> splenomegaly -> thrombocytopenia ->
bleeding
D) Fibrosis -> sinusoidal resistance -> ascites -> spontaneous
bacterial peritonitis
Answer: A
Rationale: Hepatic encephalopathy results from liver failure causing
impaired urea cycle, leading to hyperammonemia. Ammonia crosses
the blood-brain barrier, causes astrocyte swelling and neurotransmitter
imbalance. The other options describe other complications of
cirrhosis.
8 A patient with type 1 diabetes mellitus has a HbA1c of 9.5%. Which
pathophysiological mechanism is most directly responsible for the
elevated HbA1c?
A) Increased insulin receptor sensitivity
B) Non-enzymatic glycosylation of hemoglobin
C) Enhanced renal glucose reabsorption
D) Increased hepatic gluconeogenesis
Answer: B
Rationale: HbA1c reflects average blood glucose over 2-3 months via
non-enzymatic glycosylation of hemoglobin. Insulin resistance and
hepatic gluconeogenesis contribute to hyperglycemia but not directly
to HbA1c formation. Renal reabsorption affects glucose excretion.
9 A patient with sepsis develops disseminated intravascular
coagulation (DIC). Which laboratory finding is most consistent with
the consumption of clotting factors and platelets?
A) Elevated fibrinogen
B) Elevated D-dimer
Questions and Detailed Solutions Latest Update 2026/2027 |
Cellular Injury, Organ System Diseases, Verified Answers - 190
Questions
This midterm examination assesses advanced understanding of cellular injury mechanisms and organ system
pathophysiology, emphasizing integrative reasoning, clinical application, and interpretation of diagnostic data.
Questions require synthesis across molecular, cellular, and systemic levels of disease processes. It contains 190
multiple-choice questions, each with four distractors and a fully worked rationale that explains why the keyed
answer is correct. Questions are organized into clearly labelled sections that mirror the major content areas of
the course. Targeted learning outcomes include: Analyze mechanisms of cellular injury and adaptation in
response to pathological stimuli.; Integrate pathophysiological principles across organ systems to explain disease
manifestations.; Evaluate diagnostic and therapeutic approaches based on underlying pathophysiology.; Interpret
clinical scenarios and data to make evidence-based decisions in complex cases.. Every item has been reviewed for
clinical accuracy, current guidelines, and clarity so that students can study with confidence and self-correct as
they work through the bank. Use it as a high-yield review immediately before the exam, or as a structured practice
tool during the unit - the rationales double as concise teaching notes. The recommended writing time is 3 hours,
with a passing score of 70%. Aligned with Aligned with standards of US medical education accreditation (LCME)
and rigorous university examination protocols. standards and reflects the question style commonly seen on
accredited program examinations. Students consistently achieving above the cut score on this bank have
Section 1: General (Questions 1-190)
1 A cell undergoing severe ATP depletion shifts to anaerobic
metabolism. Which consequence directly impairs the Na+/K+
ATPase, leading to cellular swelling?
A) Increased intracellular calcium
B) Decreased ATP availability
C) Accumulation of lactic acid
D) Mitochondrial permeability transition
Answer: B
Rationale: Na+/K+ ATPase is ATP-dependent; ATP depletion directly
reduces its activity, causing sodium and water influx. Increased
calcium and mitochondrial changes are downstream effects, while
lactic acid contributes to pH changes but not directly to pump failure.
2 In reperfusion injury, which reactive oxygen species is generated by
xanthine oxidase during the conversion of hypoxanthine to
xanthine?
,A) Hydroxyl radical
B) Superoxide anion
C) Hydrogen peroxide
D) Nitric oxide
Answer: B
Rationale: Xanthine oxidase produces superoxide anion (O2•") when it
converts hypoxanthine to xanthine. Hydroxyl radical forms via Fenton
reaction, hydrogen peroxide via dismutation, and nitric oxide from
NOS.
3 Which type of cellular adaptation is characterized by a reversible
change in which one adult cell type is replaced by another adult cell
type, often in response to chronic irritation?
A) Hyperplasia
B) Metaplasia
C) Dysplasia
D) Hypertrophy
Answer: B
Rationale: Metaplasia is the replacement of one differentiated cell type
with another, e.g., squamous metaplasia in smokers. Hyperplasia is
increased cell number, hypertrophy is increased cell size, and
dysplasia is disordered growth.
4 A patient with chronic heart failure has elevated B-type natriuretic
peptide (BNP). Which pathophysiological mechanism directly
stimulates BNP secretion from ventricular myocytes?
A) Increased sympathetic tone
B) Ventricular wall stretch
C) Renin-angiotensin-aldosterone activation
D) Hypoxia-induced gene expression
Answer: B
Rationale: BNP is released in response to ventricular volume and
pressure overload causing wall stretch. Sympathetic and RAAS
,activation are compensatory but not direct stimuli for BNP release.
Hypoxia may contribute but is not the primary direct trigger.
5 In acute respiratory distress syndrome (ARDS), which
pathophysiological feature is most directly responsible for refractory
hypoxemia?
A) Pulmonary vasoconstriction
B) Intrapulmonary shunting
C) Decreased lung compliance
D) Surfactant dysfunction
Answer: B
Rationale: Intrapulmonary shunting (blood perfusing non-ventilated
alveoli) causes venous admixture and hypoxemia unresponsive to
oxygen. Vasoconstriction and compliance changes contribute to
ventilation-perfusion mismatch but shunting is the key mechanism.
6 A patient with chronic kidney disease develops hyperphosphatemia.
Which secondary response is most likely to occur due to decreased
renal phosphate excretion?
A) Increased calcitriol synthesis
B) Decreased parathyroid hormone secretion
C) Metastatic calcification in soft tissues
D) Increased intestinal calcium absorption
Answer: C
Rationale: Hyperphosphatemia leads to calcium-phosphate product
elevation, causing metastatic calcification. It suppresses calcitriol
synthesis and stimulates PTH secretion (secondary
hyperparathyroidism), not decreases. Intestinal calcium absorption is
reduced due to low calcitriol.
7 Which of the following best describes the pathophysiological
sequence in the development of hepatic encephalopathy?
, A) Impaired urea cycle -> hyperammonemia -> astrocyte swelling ->
altered neurotransmission
B) Hepatocyte necrosis -> bile duct proliferation -> cholestasis ->
pruritus
C) Portal hypertension -> splenomegaly -> thrombocytopenia ->
bleeding
D) Fibrosis -> sinusoidal resistance -> ascites -> spontaneous
bacterial peritonitis
Answer: A
Rationale: Hepatic encephalopathy results from liver failure causing
impaired urea cycle, leading to hyperammonemia. Ammonia crosses
the blood-brain barrier, causes astrocyte swelling and neurotransmitter
imbalance. The other options describe other complications of
cirrhosis.
8 A patient with type 1 diabetes mellitus has a HbA1c of 9.5%. Which
pathophysiological mechanism is most directly responsible for the
elevated HbA1c?
A) Increased insulin receptor sensitivity
B) Non-enzymatic glycosylation of hemoglobin
C) Enhanced renal glucose reabsorption
D) Increased hepatic gluconeogenesis
Answer: B
Rationale: HbA1c reflects average blood glucose over 2-3 months via
non-enzymatic glycosylation of hemoglobin. Insulin resistance and
hepatic gluconeogenesis contribute to hyperglycemia but not directly
to HbA1c formation. Renal reabsorption affects glucose excretion.
9 A patient with sepsis develops disseminated intravascular
coagulation (DIC). Which laboratory finding is most consistent with
the consumption of clotting factors and platelets?
A) Elevated fibrinogen
B) Elevated D-dimer
