100 Practice Questions with Detailed Answers & Rationales | 2026
Study Guide
SECTION 1: CELLULAR INJURY, ADAPTATION, AND DEATH (Questions 1–25)
1. A cell exposed to prolonged hypoxia initially swells due to failure of the sodium-potassium pump.
Which mechanism best explains this finding?
A) Increased intracellular sodium with osmotic water movement
B) Decreased intracellular calcium
C) Enhanced ATP production
D) Increased protein synthesis
Answer: A
Rationale:
Hypoxia depletes ATP, causing failure of the Na⁺/K⁺-ATPase pump. Sodium accumulates intracellularly,
creating an osmotic gradient that draws water into the cell, producing hydropic swelling. ATP depletion also
causes calcium to accumulate intracellularly (not decrease), and protein synthesis is reduced, not enhanced.
2. Which type of cellular adaptation involves a decrease in cell size and function in response to
reduced demand?
A) Hypertrophy
B) Hyperplasia
C) Atrophy
D) Metaplasia
Answer: C
Rationale:
Atrophy is a decrease in cell size and function due to reduced workload, decreased blood supply, or
hormonal withdrawal. Hypertrophy is increased cell size, hyperplasia is increased cell number, and
metaplasia is the reversible replacement of one mature cell type with another.
,3. A 45-year-old smoker's bronchial epithelium undergoes replacement of columnar cells with
stratified squamous cells. This is an example of:
A) Dysplasia
B) Metaplasia
C) Anaplasia
D) Neoplasia
Answer: B
Rationale:
Metaplasia is the reversible replacement of one differentiated cell type with another, often in response to
chronic irritation. In smokers, columnar epithelium is replaced by stratified squamous epithelium as an
adaptive response. Dysplasia involves disordered growth and atypia, anaplasia is lack of differentiation
(malignant), and neoplasia is new growth.
4. Which of the following is the most common cause of irreversible cell injury leading to necrosis?
A) Transient ischemia
B) Severe and prolonged ATP depletion with membrane damage
C) Mild oxidative stress
D) Reversible cell swelling
Answer: B
Rationale:
Irreversible cell injury occurs when ATP depletion is severe and prolonged, leading to loss of membrane
integrity, mitochondrial dysfunction, and release of lysosomal enzymes. Transient ischemia, mild oxidative
stress, and reversible swelling can be recovered from. The key point of no return is membrane damage.
5. A pathologist describes a tissue as showing "coagulative necrosis." Which organ is most likely
affected?
A) Brain
B) Heart
C) Pancreas
D) Lung
Answer: B
Rationale:
Coagulative necrosis is most common in ischemic injury to solid organs such as the heart, kidney, and spleen.
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,The basic tissue architecture is preserved, but cells are dead. The brain undergoes liquefactive necrosis, and
the pancreas undergoes fat necrosis. The lung typically shows caseous necrosis in tuberculosis.
6. Which type of necrosis is characterized by a "cheesy" appearance and is typically associated with
tuberculosis?
A) Coagulative necrosis
B) Liquefactive necrosis
C) Caseous necrosis
D) Fat necrosis
Answer: C
Rationale:
Caseous necrosis is characterized by a "cheesy" (caseous) appearance on gross examination and is classically
associated with tuberculosis. It consists of amorphous, granular debris with a granulomatous inflammatory
reaction. Coagulative necrosis preserves architecture, liquefactive necrosis involves enzymatic digestion
(brain, abscesses), and fat necrosis occurs in the pancreas or breast.
7. During apoptosis, which of the following is a key morphologic feature?
A) Cell swelling and rupture
B) Chromatin condensation and membrane blebbing
C) Inflammatory infiltrate
D) Coagulation of proteins
Answer: B
Rationale:
Apoptosis is programmed cell death characterized by chromatin condensation, nuclear fragmentation,
membrane blebbing, and formation of apoptotic bodies. It does not cause inflammation. Cell swelling and
rupture, inflammatory infiltrate, and protein coagulation are features of necrosis, not apoptosis.
8. Which cellular adaptation is most likely to occur in the liver in response to chronic alcohol
consumption?
A) Atrophy
B) Hyperplasia
C) Hypertrophy and fatty change
D) Metaplasia
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, Answer: C
Rationale:
Chronic alcohol consumption causes hepatocyte hypertrophy and fatty change (steatosis) due to increased
fat synthesis, decreased fat oxidation, and impaired lipoprotein export. Atrophy is a decrease in cell size,
hyperplasia is increased cell number, and metaplasia is replacement of cell type.
9. A biopsy shows dysplastic changes in the cervix. Which statement best describes dysplasia?
A) It is always reversible
B) It is always malignant
C) It involves disordered growth and cellular atypia
D) It is a normal finding
Answer: C
Rationale:
Dysplasia is characterized by disordered growth and maturation with cellular atypia, including nuclear
enlargement, hyperchromasia, and pleomorphism. It is not always reversible (can progress to carcinoma in
situ and invasive cancer) and is not always malignant. It is not a normal finding.
10. Which of the following is a mechanism of cell injury caused by free radicals?
A) Lipid peroxidation of cell membranes
B) DNA repair
C) Increased ATP production
D) Enhanced protein synthesis
Answer: A
Rationale:
Free radicals cause cell injury through lipid peroxidation of membranes, oxidative modification of proteins,
and DNA damage. They do not promote DNA repair, increase ATP production, or enhance protein synthesis.
Antioxidants (e.g., glutathione, superoxide dismutase) counteract free radicals.
11. A patient with a prolonged fever and dehydration develops cellular swelling in multiple organs.
This reversible change is known as:
A) Necrosis
B) Apoptosis
C) Hydropic swelling
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