Pathophysiology Comprehensive
Exam 100% Correct. Exam – Practice
Questions, Answers & Rationales
(2026/2027 Edition)
Cellular Adaptation, Injury, & Neoplasia (Q 1-15)
1. A patient with chronic gastroesophageal reflux has
columnar epithelium replacing the stratified squamous
epithelium in the lower esophagus. This process is best
described as:
A. Dysplasia
B. Metaplasia
C. Hyperplasia
D. Anaplasia
Answer: B. Metaplasia
Rationale: Metaplasia is the reversible replacement of one
differentiated cell type with another, often due to chronic irritation.
This is a protective mechanism, but predisposes to dysplasia/cancer.
2. In irreversible cell injury, the earliest morphological change
visible by electron microscopy is:
A. Nuclear pyknosis
B. Swelling of the endoplasmic reticulum
C. Rupture of lysosomal membranes
D. Formation of amorphous densities in mitochondria
Answer: D. Formation of amorphous densities in
mitochondria
,Rationale: Irreversible injury is marked by severe mitochondrial
damage, including the appearance of amorphous calcium
phosphate densities within the matrix. This indicates failure of
oxidative phosphorylation.
3. A pathologist notes "liquefactive necrosis" in the brain of a
stroke patient. What process causes this appearance?
A. Coagulation of structural proteins
B. Enzymatic digestion by hydrolytic enzymes
C. Deposition of immune complexes
D. Caseous granulomatous inflammation
Answer: B. Enzymatic digestion by hydrolytic enzymes
Rationale: In the brain, ischemic injury triggers rapid release of
lysosomal enzymes from microglia and neutrophils, literally
dissolving the tissue into a liquid viscous mass.
4. Which of the following is a hallmark of apoptosis compared
to necrosis?
A. Loss of membrane integrity
B. Inflammation of surrounding tissue
C. Chromatin condensation and formation of apoptotic bodies
D. Random cell swelling and lysis
Answer: C. Chromatin condensation and formation of
apoptotic bodies
Rationale: Apoptosis is a regulated, energy-dependent process
where the cell breaks into membrane-bound fragments (apoptotic
bodies) that are phagocytosed without inflammation. Necrosis
involves swelling, lysis, and inflammation.
5. The tumor suppressor gene p53 is known as the "guardian
of the genome" because it:
,A. Repairs damaged DNA directly
B. Induces cell cycle arrest or apoptosis in response to DNA
damage
C. Activates proto-oncogenes
D. Inhibits angiogenesis in tumors
Answer: B. Induces cell cycle arrest or apoptosis in response
to DNA damage
*Rationale: p53 is a transcription factor. In response to DNA
damage, it halts the cell cycle (at G1/S) to allow repair; if damage
is irreparable, it triggers apoptosis.*
6. A 60-year-old smoker has a lung tumor. Biopsy shows
malignant cells that produce keratin pearls. This is most likely:
A. Small cell carcinoma
B. Adenocarcinoma
C. Squamous cell carcinoma
D. Large cell carcinoma
Answer: C. Squamous cell carcinoma
Rationale: Squamous cell carcinomas attempt to differentiate into
stratified squamous epithelium, resulting in "keratin pearls"
(concentric layers of keratinized cells) and intercellular bridges.
7. Which type of necrosis is classically associated with
tuberculosis?
A. Fat necrosis
B. Coagulative necrosis
C. Caseous necrosis
D. Fibrinoid necrosis
Answer: C. Caseous necrosis
Rationale: Caseous necrosis appears as a soft, friable, "cheese-like"
, material. It is a combination of coagulative and liquefactive
necrosis, often seen in TB granulomas.
8. Hypertrophy is most likely to occur in which of the
following tissues?
A. Skeletal muscle
B. Myocardium (cardiac muscle)
C. Liver
D. All of the above
Answer: D. All of the above (Technically, Skeletal and Cardiac
primarily hypertrophy, liver can do both)
Rationale: While the classic answer is myocardium (e.g.,
hypertensive heart disease) and skeletal muscle (exercise), the liver
can also hypertrophy (enzyme induction). For the exam,
hypertrophy occurs in permanent or stable tissues under increased
workload.
9. Free radical injury causes cell damage primarily by:
A. Inhibiting sodium-potassium ATPase
B. Lipid peroxidation of cell membranes
C. Activating the complement cascade
D. Depleting intracellular calcium
Answer: B. Lipid peroxidation of cell membranes
Rationale: Free radicals (ROS) abstract hydrogen atoms from
polyunsaturated fatty acids in membranes, initiating a chain
reaction of lipid peroxidation that destroys membrane integrity and
function.
10. A patient has chronic biliary obstruction. You would
expect to find necrosis in which organ?
A. Heart
Exam 100% Correct. Exam – Practice
Questions, Answers & Rationales
(2026/2027 Edition)
Cellular Adaptation, Injury, & Neoplasia (Q 1-15)
1. A patient with chronic gastroesophageal reflux has
columnar epithelium replacing the stratified squamous
epithelium in the lower esophagus. This process is best
described as:
A. Dysplasia
B. Metaplasia
C. Hyperplasia
D. Anaplasia
Answer: B. Metaplasia
Rationale: Metaplasia is the reversible replacement of one
differentiated cell type with another, often due to chronic irritation.
This is a protective mechanism, but predisposes to dysplasia/cancer.
2. In irreversible cell injury, the earliest morphological change
visible by electron microscopy is:
A. Nuclear pyknosis
B. Swelling of the endoplasmic reticulum
C. Rupture of lysosomal membranes
D. Formation of amorphous densities in mitochondria
Answer: D. Formation of amorphous densities in
mitochondria
,Rationale: Irreversible injury is marked by severe mitochondrial
damage, including the appearance of amorphous calcium
phosphate densities within the matrix. This indicates failure of
oxidative phosphorylation.
3. A pathologist notes "liquefactive necrosis" in the brain of a
stroke patient. What process causes this appearance?
A. Coagulation of structural proteins
B. Enzymatic digestion by hydrolytic enzymes
C. Deposition of immune complexes
D. Caseous granulomatous inflammation
Answer: B. Enzymatic digestion by hydrolytic enzymes
Rationale: In the brain, ischemic injury triggers rapid release of
lysosomal enzymes from microglia and neutrophils, literally
dissolving the tissue into a liquid viscous mass.
4. Which of the following is a hallmark of apoptosis compared
to necrosis?
A. Loss of membrane integrity
B. Inflammation of surrounding tissue
C. Chromatin condensation and formation of apoptotic bodies
D. Random cell swelling and lysis
Answer: C. Chromatin condensation and formation of
apoptotic bodies
Rationale: Apoptosis is a regulated, energy-dependent process
where the cell breaks into membrane-bound fragments (apoptotic
bodies) that are phagocytosed without inflammation. Necrosis
involves swelling, lysis, and inflammation.
5. The tumor suppressor gene p53 is known as the "guardian
of the genome" because it:
,A. Repairs damaged DNA directly
B. Induces cell cycle arrest or apoptosis in response to DNA
damage
C. Activates proto-oncogenes
D. Inhibits angiogenesis in tumors
Answer: B. Induces cell cycle arrest or apoptosis in response
to DNA damage
*Rationale: p53 is a transcription factor. In response to DNA
damage, it halts the cell cycle (at G1/S) to allow repair; if damage
is irreparable, it triggers apoptosis.*
6. A 60-year-old smoker has a lung tumor. Biopsy shows
malignant cells that produce keratin pearls. This is most likely:
A. Small cell carcinoma
B. Adenocarcinoma
C. Squamous cell carcinoma
D. Large cell carcinoma
Answer: C. Squamous cell carcinoma
Rationale: Squamous cell carcinomas attempt to differentiate into
stratified squamous epithelium, resulting in "keratin pearls"
(concentric layers of keratinized cells) and intercellular bridges.
7. Which type of necrosis is classically associated with
tuberculosis?
A. Fat necrosis
B. Coagulative necrosis
C. Caseous necrosis
D. Fibrinoid necrosis
Answer: C. Caseous necrosis
Rationale: Caseous necrosis appears as a soft, friable, "cheese-like"
, material. It is a combination of coagulative and liquefactive
necrosis, often seen in TB granulomas.
8. Hypertrophy is most likely to occur in which of the
following tissues?
A. Skeletal muscle
B. Myocardium (cardiac muscle)
C. Liver
D. All of the above
Answer: D. All of the above (Technically, Skeletal and Cardiac
primarily hypertrophy, liver can do both)
Rationale: While the classic answer is myocardium (e.g.,
hypertensive heart disease) and skeletal muscle (exercise), the liver
can also hypertrophy (enzyme induction). For the exam,
hypertrophy occurs in permanent or stable tissues under increased
workload.
9. Free radical injury causes cell damage primarily by:
A. Inhibiting sodium-potassium ATPase
B. Lipid peroxidation of cell membranes
C. Activating the complement cascade
D. Depleting intracellular calcium
Answer: B. Lipid peroxidation of cell membranes
Rationale: Free radicals (ROS) abstract hydrogen atoms from
polyunsaturated fatty acids in membranes, initiating a chain
reaction of lipid peroxidation that destroys membrane integrity and
function.
10. A patient has chronic biliary obstruction. You would
expect to find necrosis in which organ?
A. Heart
