KAPLAN PATHOPHYSIOLOGY EXAM PRACTICE TEST QUESTIONS AND CORRECT ANSWERS (VERIFIED ANSWERS) PLUS
RATIONALES 2026 Q&A | INSTANT DOWNLOAD PDF
Core Domains
Cellular Pathophysiology and Genetic Basis of Disease
Cardiovascular System Disorders
Respiratory System Disorders
Renal and Urinary System Disorders
Endocrine and Metabolic Disorders
Neurologic System Disorders
Immune System and Infectious Diseases
Gastrointestinal System Disorders
Hematologic Disorders
Ethics, Legal Compliance, and Professional Standards
Introduction
This practice examination is designed to assess comprehensive knowledge of pathophysiological mechanisms and disease processes across
multiple body systems. The exam evaluates critical clinical reasoning skills, including the ability to identify pathophysiological changes,
understand disease mechanisms, and apply theoretical knowledge to real-world clinical scenarios. Through multiple-choice and scenario-based
questions, candidates demonstrate their mastery of cellular injury, system-specific disorders, and the interrelationships between physiological
systems. The assessment emphasizes clinical decision-making, professional ethics, regulatory compliance, and the application of
pathophysiological concepts to patient care situations encountered in advanced healthcare practice.
Section One: Questions 1–100
Question 1
Which cellular change represents the earliest reversible response to cellular hypoxia?
,A. Nuclear pyknosis
B. Cellular swelling
C. Membrane rupture
D. Karyorrhexis
🟢 B. Cellular swelling
🔴 RATIONALE: Cellular swelling is the first reversible response to cellular hypoxia, resulting from decreased ATP production that impairs the
Na+/K+ ATPase pump, leading to intracellular accumulation of sodium and water. Nuclear pyknosis, karyorrhexis, and membrane rupture are
irreversible changes associated with cell death.
Question 2
A patient presents with metabolic acidosis and elevated lactate levels. Which mechanism primarily contributes to lactic acid accumulation?
A. Increased oxidative phosphorylation
B. Anaerobic glycolysis
C. Enhanced beta-oxidation
D. Increased gluconeogenesis
🟢 B. Anaerobic glycolysis
🔴 RATIONALE: Anaerobic glycolysis occurs when oxygen is insufficient for oxidative phosphorylation, leading to pyruvate conversion to lactate
instead of entering the mitochondria. This process generates lactic acid, causing metabolic acidosis. Increased oxidative phosphorylation, beta-
oxidation, and gluconeogenesis do not produce lactate.
Question 3
Which genetic disorder is characterized by autosomal recessive inheritance and results in abnormal hemoglobin production?
A. Huntington disease
B. Sickle cell disease
C. Marfan syndrome
D. Duchenne muscular dystrophy
🟢 B. Sickle cell disease
,🔴 RATIONALE: Sickle cell disease is an autosomal recessive disorder caused by a mutation in the beta-globin gene (HbS), resulting in abnormal
hemoglobin that distorts red blood cells into a sickle shape. Huntington disease is autosomal dominant, Marfan syndrome is autosomal dominant,
and Duchenne muscular dystrophy is X-linked recessive.
Question 4
A nurse is caring for a patient with third-degree burns. Which type of cell injury is most likely responsible for the tissue damage?
A. Hypoxic injury
B. Chemical toxicity
C. Thermal injury
D. Radiation injury
🟢 C. Thermal injury
🔴 RATIONALE: Third-degree burns result from thermal injury, which causes direct protein denaturation, membrane disruption, and cell death
through heat exposure. Hypoxic injury involves oxygen deprivation, chemical toxicity involves toxic substances, and radiation injury involves
ionizing radiation, none of which are the primary mechanism in burn injuries.
Question 5
Which of the following best describes the pathophysiology of hypernatremia?
A. Excessive sodium intake with adequate water
B. Water deficit relative to sodium gain or loss
C. Sodium loss exceeding water loss
D. Increased renal sodium excretion
🟢 B. Water deficit relative to sodium gain or loss
🔴 RATIONALE: Hypernatremia occurs when there is a water deficit relative to sodium, either from inadequate water intake, excessive water loss, or
sodium gain. This results in serum sodium concentration exceeding 145 mEq/L. Sodium loss exceeding water loss causes hyponatremia, not
hypernatremia.
Question 6
A patient with chronic kidney disease presents with elevated serum potassium. Which mechanism explains this finding?
, A. Increased aldosterone secretion
B. Decreased renal potassium excretion
C. Enhanced gastrointestinal potassium loss
D. Increased cellular potassium uptake
🟢 B. Decreased renal potassium excretion
🔴 RATIONALE: Chronic kidney disease reduces the number of functional nephrons, decreasing the kidney's ability to excrete potassium, leading to
hyperkalemia. Increased aldosterone would increase potassium excretion, enhanced GI loss would decrease potassium, and increased cellular uptake
would lower serum potassium.
Question 7
Which acid-base disorder is most commonly associated with prolonged vomiting?
A. Metabolic acidosis
B. Metabolic alkalosis
C. Respiratory acidosis
D. Respiratory alkalosis
🟢 B. Metabolic alkalosis
🔴 RATIONALE: Prolonged vomiting leads to loss of gastric hydrogen chloride (HCl), resulting in metabolic alkalosis characterized by elevated pH
and increased bicarbonate. Metabolic acidosis occurs with acid loss or base gain, respiratory acidosis with CO2 retention, and respiratory alkalosis
with CO2 loss.
Question 8
A patient with asthma demonstrates wheezing and shortness of breath. Which pathophysiological change is most characteristic of asthma?
A. Fixed airway obstruction
B. Reversible airway obstruction with inflammation
C. Alveolar destruction
D. Pulmonary fibrosis
🟢 B. Reversible airway obstruction with inflammation
RATIONALES 2026 Q&A | INSTANT DOWNLOAD PDF
Core Domains
Cellular Pathophysiology and Genetic Basis of Disease
Cardiovascular System Disorders
Respiratory System Disorders
Renal and Urinary System Disorders
Endocrine and Metabolic Disorders
Neurologic System Disorders
Immune System and Infectious Diseases
Gastrointestinal System Disorders
Hematologic Disorders
Ethics, Legal Compliance, and Professional Standards
Introduction
This practice examination is designed to assess comprehensive knowledge of pathophysiological mechanisms and disease processes across
multiple body systems. The exam evaluates critical clinical reasoning skills, including the ability to identify pathophysiological changes,
understand disease mechanisms, and apply theoretical knowledge to real-world clinical scenarios. Through multiple-choice and scenario-based
questions, candidates demonstrate their mastery of cellular injury, system-specific disorders, and the interrelationships between physiological
systems. The assessment emphasizes clinical decision-making, professional ethics, regulatory compliance, and the application of
pathophysiological concepts to patient care situations encountered in advanced healthcare practice.
Section One: Questions 1–100
Question 1
Which cellular change represents the earliest reversible response to cellular hypoxia?
,A. Nuclear pyknosis
B. Cellular swelling
C. Membrane rupture
D. Karyorrhexis
🟢 B. Cellular swelling
🔴 RATIONALE: Cellular swelling is the first reversible response to cellular hypoxia, resulting from decreased ATP production that impairs the
Na+/K+ ATPase pump, leading to intracellular accumulation of sodium and water. Nuclear pyknosis, karyorrhexis, and membrane rupture are
irreversible changes associated with cell death.
Question 2
A patient presents with metabolic acidosis and elevated lactate levels. Which mechanism primarily contributes to lactic acid accumulation?
A. Increased oxidative phosphorylation
B. Anaerobic glycolysis
C. Enhanced beta-oxidation
D. Increased gluconeogenesis
🟢 B. Anaerobic glycolysis
🔴 RATIONALE: Anaerobic glycolysis occurs when oxygen is insufficient for oxidative phosphorylation, leading to pyruvate conversion to lactate
instead of entering the mitochondria. This process generates lactic acid, causing metabolic acidosis. Increased oxidative phosphorylation, beta-
oxidation, and gluconeogenesis do not produce lactate.
Question 3
Which genetic disorder is characterized by autosomal recessive inheritance and results in abnormal hemoglobin production?
A. Huntington disease
B. Sickle cell disease
C. Marfan syndrome
D. Duchenne muscular dystrophy
🟢 B. Sickle cell disease
,🔴 RATIONALE: Sickle cell disease is an autosomal recessive disorder caused by a mutation in the beta-globin gene (HbS), resulting in abnormal
hemoglobin that distorts red blood cells into a sickle shape. Huntington disease is autosomal dominant, Marfan syndrome is autosomal dominant,
and Duchenne muscular dystrophy is X-linked recessive.
Question 4
A nurse is caring for a patient with third-degree burns. Which type of cell injury is most likely responsible for the tissue damage?
A. Hypoxic injury
B. Chemical toxicity
C. Thermal injury
D. Radiation injury
🟢 C. Thermal injury
🔴 RATIONALE: Third-degree burns result from thermal injury, which causes direct protein denaturation, membrane disruption, and cell death
through heat exposure. Hypoxic injury involves oxygen deprivation, chemical toxicity involves toxic substances, and radiation injury involves
ionizing radiation, none of which are the primary mechanism in burn injuries.
Question 5
Which of the following best describes the pathophysiology of hypernatremia?
A. Excessive sodium intake with adequate water
B. Water deficit relative to sodium gain or loss
C. Sodium loss exceeding water loss
D. Increased renal sodium excretion
🟢 B. Water deficit relative to sodium gain or loss
🔴 RATIONALE: Hypernatremia occurs when there is a water deficit relative to sodium, either from inadequate water intake, excessive water loss, or
sodium gain. This results in serum sodium concentration exceeding 145 mEq/L. Sodium loss exceeding water loss causes hyponatremia, not
hypernatremia.
Question 6
A patient with chronic kidney disease presents with elevated serum potassium. Which mechanism explains this finding?
, A. Increased aldosterone secretion
B. Decreased renal potassium excretion
C. Enhanced gastrointestinal potassium loss
D. Increased cellular potassium uptake
🟢 B. Decreased renal potassium excretion
🔴 RATIONALE: Chronic kidney disease reduces the number of functional nephrons, decreasing the kidney's ability to excrete potassium, leading to
hyperkalemia. Increased aldosterone would increase potassium excretion, enhanced GI loss would decrease potassium, and increased cellular uptake
would lower serum potassium.
Question 7
Which acid-base disorder is most commonly associated with prolonged vomiting?
A. Metabolic acidosis
B. Metabolic alkalosis
C. Respiratory acidosis
D. Respiratory alkalosis
🟢 B. Metabolic alkalosis
🔴 RATIONALE: Prolonged vomiting leads to loss of gastric hydrogen chloride (HCl), resulting in metabolic alkalosis characterized by elevated pH
and increased bicarbonate. Metabolic acidosis occurs with acid loss or base gain, respiratory acidosis with CO2 retention, and respiratory alkalosis
with CO2 loss.
Question 8
A patient with asthma demonstrates wheezing and shortness of breath. Which pathophysiological change is most characteristic of asthma?
A. Fixed airway obstruction
B. Reversible airway obstruction with inflammation
C. Alveolar destruction
D. Pulmonary fibrosis
🟢 B. Reversible airway obstruction with inflammation
