GCU PATHOPHYSIOLOGY MIDTERM EXAM
TEST | ALL QUESTIONS AND SOLUTIONS
(RATIONALES) 2026 | EXAM PREP TEST
1. A patient with a long history of poorly controlled hypertension presents for a routine
checkup. Echocardiography reveals significant left ventricular hypertrophy. Which
cellular adaptation process best accounts for this structural change in cardiac muscle cells?
A. Hyperplasia
B. Hypertrophy
C. Metaplasia
D. Dysplasia
Answer: B
Rationale: Hypertrophy refers to an increase in individual cell size resulting in enlarged tissue
mass, commonly seen in cardiac myocytes responding to increased workload and systemic
vascular resistance in chronic hypertension. Hyperplasia involves an increase in the actual
number of cells, which does not occur in adult cardiac myocytes. Metaplasia is the reversible
replacement of one mature cell type by another, while dysplasia represents disordered
cellular growth and differentiation.
2. A 45-year-old female patient with chronic gastroesophageal reflux disease (GERD)
undergoes an upper endoscopy. Biopsy reports show that normal squamous epithelial cells
of the lower esophagus have been replaced by columnar epithelial cells. Which cellular
modification is described?
A. Atrophy
B. Hyperplasia
C. Metaplasia
D. Anaplasia
Answer: C
Rationale: Metaplasia is the adaptive transformation of one fully differentiated adult cell
type into another type better suited to withstand chronic harsh environments, such as acid
,exposure in Barrett esophagus. Atrophy involves cell size reduction, hyperplasia indicates an
increased cell count, and anaplasia represents loss of cellular differentiation typical of
malignant neoplasia.
3. During ischemia, cellular swelling occurs due to a lack of ATP production. Which
biochemical failure directly causes intracellular sodium accumulation and subsequent
cellular edema?
A. Inactivation of the sodium-potassium ATPase pump
B. Activation of intracellular lysosomal enzymes
C. Intracellular influx of excess potassium ions
D. Lactic acid depletion within the cytoplasm
Answer: A
Rationale: Ischemia leads to hypoxia and depleted ATP synthesis. Without adequate ATP, the
membrane-bound Na+/K+ ATPase pump fails, allowing sodium to enter and accumulate
inside the cell. Osmotic pressure then draws water inward, causing hydropic swelling.
Lysosomal breakdown occurs secondary to prolonged swelling and membrane damage, while
intracellular potassium decreases as it leaks out down its concentration gradient.
4. A nurse reviews the lab results of a critically ill trauma patient and notes elevated
intracellular ionized calcium levels. What is the major pathophysiological consequence of
excessive free cytosolic calcium?
A. Suppression of mitochondrial permeability transition pores
B. Activation of destructive intracellular enzymes like phospholipases and endonucleases
C. Hyperpolarization of the cell membrane, preventing necrosis
D. Accelerated synthesis of structural proteins to repair cell damage
Answer: B
Rationale: Pathological increases in intracellular free calcium activate membrane-damaging
phospholipases, protein-degrading proteases, endonucleases that fragment DNA, and
ATPases that accelerate energy depletion, triggering cellular necrosis or apoptosis. Excessive
calcium disrupts mitochondrial function rather than suppressing permeability pores and leads
to membrane damage rather than hyperpolarization or structural repair.
,5. A biopsy of a pulmonary nodule from a patient with active tuberculosis shows a soft,
cheese-like central area of tissue destruction surrounded by epithelioid histiocytes. What
specific form of necrosis is present?
A. Coagulative necrosis
B. Liquefactive necrosis
C. Caseous necrosis
D. Fat necrosis
Answer: C
Rationale: Caseous necrosis is characteristic of tuberculous lung lesions, featuring dead cells
disintegrated into a soft, friable, yellowish-white "cheesy" mass surrounded by
granulomatous inflammation. Coagulative necrosis typically occurs in hypoxic infarction of
solid organs like the kidney or heart, liquefactive necrosis occurs in brain tissue or bacterial
abscesses, and fat necrosis results from enzymatic destruction of adipose tissue.
6. Which mechanisms distinguish apoptosis from necrosis in human tissue pathology?
A. Apoptosis induces a widespread inflammatory response, whereas necrosis does not.
B. Apoptosis involves programmed, energy-dependent cell shrinkage and intact plasma
membranes.
C. Necrosis involves organized chromatin cleavage orchestrated by intracellular caspases.
D. Necrosis preserves cell membrane integrity, resulting in quiet phagocytosis without lysis.
Answer: B
Rationale: Apoptosis is a strictly regulated, ATP-dependent process characterized by cell
shrinkage, nuclear fragmentation, and apoptotic body formation with intact cell membranes,
preventing inflammation. Necrosis is passive and uncoordinated, leading to cell swelling,
membrane rupture, leakage of cellular contents, and local acute inflammation.
7. A patient with severe peripheral arterial disease presents with a cool, blackened,
shriveled lower leg with a clear line of demarcation between viable and dead tissue. Which
clinical diagnosis is most appropriate?
A. Dry gangrene
B. Wet gangrene
, C. Gas gangrene
D. Liquefactive necrosis
Answer: A
Rationale: Dry gangrene typically results from severe arterial ischemia without severe
bacterial infection; tissue undergoes coagulative necrosis, turns black/shriveled, and exhibits
a well-defined line of demarcation. Wet gangrene involves superadded bacterial infection,
rapid tissue liquefaction, swelling, and severe inflammation without a distinct border. Gas
gangrene is caused by Clostridium species producing toxin and subcutaneous gas bubbles.
8. An individual exposed to severe oxidative stress accumulates excess reactive oxygen
species (ROS). Which cellular enzyme plays a critical role in neutralizing superoxide
radicals into hydrogen peroxide?
A. Catalase
B. Superoxide dismutase
C. Glutathione peroxidase
D. Myeloperoxidase
Answer: B
Rationale: Superoxide dismutase (SOD) specifically converts superoxide free radicals (O2-)
into hydrogen peroxide (H2O2) and oxygen. Catalase and glutathione peroxidase
subsequently decompose hydrogen peroxide into water and molecular oxygen.
Myeloperoxidase converts hydrogen peroxide and chloride into hypochlorous acid within
neutrophils.
9. A patient is evaluated for severe hypokalemia. Which physiological cellular change
occurs when extracellular potassium drops significantly below normal levels?
A. Resting membrane potential becomes more negative (hyperpolarized), decreasing cell
excitability.
B. Resting membrane potential moves closer to threshold, increasing cell excitability.
C. Intracellular calcium efflux increases rapidly, initiating voluntary muscle spasm.
D. Sodium ions enter cells spontaneously, triggering continuous rapid action potentials.
Answer: A
TEST | ALL QUESTIONS AND SOLUTIONS
(RATIONALES) 2026 | EXAM PREP TEST
1. A patient with a long history of poorly controlled hypertension presents for a routine
checkup. Echocardiography reveals significant left ventricular hypertrophy. Which
cellular adaptation process best accounts for this structural change in cardiac muscle cells?
A. Hyperplasia
B. Hypertrophy
C. Metaplasia
D. Dysplasia
Answer: B
Rationale: Hypertrophy refers to an increase in individual cell size resulting in enlarged tissue
mass, commonly seen in cardiac myocytes responding to increased workload and systemic
vascular resistance in chronic hypertension. Hyperplasia involves an increase in the actual
number of cells, which does not occur in adult cardiac myocytes. Metaplasia is the reversible
replacement of one mature cell type by another, while dysplasia represents disordered
cellular growth and differentiation.
2. A 45-year-old female patient with chronic gastroesophageal reflux disease (GERD)
undergoes an upper endoscopy. Biopsy reports show that normal squamous epithelial cells
of the lower esophagus have been replaced by columnar epithelial cells. Which cellular
modification is described?
A. Atrophy
B. Hyperplasia
C. Metaplasia
D. Anaplasia
Answer: C
Rationale: Metaplasia is the adaptive transformation of one fully differentiated adult cell
type into another type better suited to withstand chronic harsh environments, such as acid
,exposure in Barrett esophagus. Atrophy involves cell size reduction, hyperplasia indicates an
increased cell count, and anaplasia represents loss of cellular differentiation typical of
malignant neoplasia.
3. During ischemia, cellular swelling occurs due to a lack of ATP production. Which
biochemical failure directly causes intracellular sodium accumulation and subsequent
cellular edema?
A. Inactivation of the sodium-potassium ATPase pump
B. Activation of intracellular lysosomal enzymes
C. Intracellular influx of excess potassium ions
D. Lactic acid depletion within the cytoplasm
Answer: A
Rationale: Ischemia leads to hypoxia and depleted ATP synthesis. Without adequate ATP, the
membrane-bound Na+/K+ ATPase pump fails, allowing sodium to enter and accumulate
inside the cell. Osmotic pressure then draws water inward, causing hydropic swelling.
Lysosomal breakdown occurs secondary to prolonged swelling and membrane damage, while
intracellular potassium decreases as it leaks out down its concentration gradient.
4. A nurse reviews the lab results of a critically ill trauma patient and notes elevated
intracellular ionized calcium levels. What is the major pathophysiological consequence of
excessive free cytosolic calcium?
A. Suppression of mitochondrial permeability transition pores
B. Activation of destructive intracellular enzymes like phospholipases and endonucleases
C. Hyperpolarization of the cell membrane, preventing necrosis
D. Accelerated synthesis of structural proteins to repair cell damage
Answer: B
Rationale: Pathological increases in intracellular free calcium activate membrane-damaging
phospholipases, protein-degrading proteases, endonucleases that fragment DNA, and
ATPases that accelerate energy depletion, triggering cellular necrosis or apoptosis. Excessive
calcium disrupts mitochondrial function rather than suppressing permeability pores and leads
to membrane damage rather than hyperpolarization or structural repair.
,5. A biopsy of a pulmonary nodule from a patient with active tuberculosis shows a soft,
cheese-like central area of tissue destruction surrounded by epithelioid histiocytes. What
specific form of necrosis is present?
A. Coagulative necrosis
B. Liquefactive necrosis
C. Caseous necrosis
D. Fat necrosis
Answer: C
Rationale: Caseous necrosis is characteristic of tuberculous lung lesions, featuring dead cells
disintegrated into a soft, friable, yellowish-white "cheesy" mass surrounded by
granulomatous inflammation. Coagulative necrosis typically occurs in hypoxic infarction of
solid organs like the kidney or heart, liquefactive necrosis occurs in brain tissue or bacterial
abscesses, and fat necrosis results from enzymatic destruction of adipose tissue.
6. Which mechanisms distinguish apoptosis from necrosis in human tissue pathology?
A. Apoptosis induces a widespread inflammatory response, whereas necrosis does not.
B. Apoptosis involves programmed, energy-dependent cell shrinkage and intact plasma
membranes.
C. Necrosis involves organized chromatin cleavage orchestrated by intracellular caspases.
D. Necrosis preserves cell membrane integrity, resulting in quiet phagocytosis without lysis.
Answer: B
Rationale: Apoptosis is a strictly regulated, ATP-dependent process characterized by cell
shrinkage, nuclear fragmentation, and apoptotic body formation with intact cell membranes,
preventing inflammation. Necrosis is passive and uncoordinated, leading to cell swelling,
membrane rupture, leakage of cellular contents, and local acute inflammation.
7. A patient with severe peripheral arterial disease presents with a cool, blackened,
shriveled lower leg with a clear line of demarcation between viable and dead tissue. Which
clinical diagnosis is most appropriate?
A. Dry gangrene
B. Wet gangrene
, C. Gas gangrene
D. Liquefactive necrosis
Answer: A
Rationale: Dry gangrene typically results from severe arterial ischemia without severe
bacterial infection; tissue undergoes coagulative necrosis, turns black/shriveled, and exhibits
a well-defined line of demarcation. Wet gangrene involves superadded bacterial infection,
rapid tissue liquefaction, swelling, and severe inflammation without a distinct border. Gas
gangrene is caused by Clostridium species producing toxin and subcutaneous gas bubbles.
8. An individual exposed to severe oxidative stress accumulates excess reactive oxygen
species (ROS). Which cellular enzyme plays a critical role in neutralizing superoxide
radicals into hydrogen peroxide?
A. Catalase
B. Superoxide dismutase
C. Glutathione peroxidase
D. Myeloperoxidase
Answer: B
Rationale: Superoxide dismutase (SOD) specifically converts superoxide free radicals (O2-)
into hydrogen peroxide (H2O2) and oxygen. Catalase and glutathione peroxidase
subsequently decompose hydrogen peroxide into water and molecular oxygen.
Myeloperoxidase converts hydrogen peroxide and chloride into hypochlorous acid within
neutrophils.
9. A patient is evaluated for severe hypokalemia. Which physiological cellular change
occurs when extracellular potassium drops significantly below normal levels?
A. Resting membrane potential becomes more negative (hyperpolarized), decreasing cell
excitability.
B. Resting membrane potential moves closer to threshold, increasing cell excitability.
C. Intracellular calcium efflux increases rapidly, initiating voluntary muscle spasm.
D. Sodium ions enter cells spontaneously, triggering continuous rapid action potentials.
Answer: A
