NU 650: Advanced Pathophysiology
– Exam 1 Study Guide 2026 questions
with correct answers and
rationale graded A+
Q1. A patient presents with severe ischemia of the lower extremity. At the cellular level, the lack of
oxygen leads to a decrease in mitochondrial ATP production. Which of the following is the direct
consequence of this ATP depletion on intracellular ion concentrations?
A. Decreased intracellular sodium, increased intracellular potassium
B. Increased intracellular sodium, increased intracellular calcium, decreased intracellular potassium
C. Increased intracellular potassium, decreased intracellular calcium
D. Decreased intracellular sodium, decreased intracellular calcium
Correct Answer: B
Rationale: When ATP levels fall due to ischemia, the energy-dependent
N
a
+
/
K
+
Na
+
/K
+
ATPase pump fails, causing sodium to accumulate inside the cell and potassium to diffuse out.
Additionally, the
C
a
,2
+
Ca
2+
ATPase pump fails, preventing the extrusion of calcium and leading to an influx of extracellular
calcium. This intracellular calcium overload activates destructive intracellular enzymes (proteases,
phospholipases, endonucleases), leading to irreversible cellular injury.
Q2. During an autophagic response to nutrient deprivation, which of the following cellular structures
delivers damaged organelles to the lysosome for degradation?
A. Ubiquitin-proteasome system
B. Autophagosome
C. Peroxisome
D. Golgi apparatus
Correct Answer: B
Rationale: Autophagy is a survival mechanism where a cell recycles its own components. Damaged
organelles or proteins are sequestered within a double-membrane vesicle called an autophagosome,
which then fuses with a lysosome (forming an autolysosome) to degrade and recycle the contents.
The ubiquitin-proteasome system degrades individual tagged proteins, not entire organelles.
Q3. A 68-year-old male with a long-standing history of uncontrolled hypertension exhibits left
ventricular hypertrophy on an echocardiogram. This cellular adaptation is best characterized by
which of the following?
A. An increase in the number of myocardial cells
B. An increase in the size of individual myocardial cells due to increased protein synthesis
C. Replacement of myocardial cells with fibrous connective tissue
D. A reversible change where one adult cell type is replaced by another
Correct Answer: B
Rationale: Hypertrophy is an increase in the size of cells (not the number), resulting in an increase in
the size of the organ. Because myocardial cells are permanent and cannot divide (undergo
hyperplasia), they adapt to an increased workload (such as systemic hypertension) by increasing
protein synthesis, leading to larger individual cardiocytes.
Q4. A biopsy of the bronchus of a chronic cigarette smoker reveals that the normal pseudostratified
ciliated columnar epithelium has been replaced by stratified squamous epithelium. What is this
cellular adaptation called?
A. Dysplasia
,B. Anaplasia
C. Metaplasia
D. Hyperplasia
Correct Answer: C
Rationale: Metaplasia is the reversible replacement of one mature cell type by another mature cell
type, usually in response to chronic irritation or inflammation. While the stratified squamous
epithelium is more resilient to smoke, the loss of cilia and mucus secretion compromises respiratory
defenses.
Q5. A pathologist reviews a tissue biopsy showing cell death characterized by nuclear condensation
(pyknosis), fragmentation (karyorrhexis), and dissolution (karyolysis), accompanied by marked
inflammation of the surrounding tissue. Which type of cell death is represented?
A. Apoptosis
B. Autophagy
C. Necrosis
D. Senescence
Correct Answer: C
Rationale: Necrosis is accidental, unregulated cell death characterized by membrane rupture,
enzymatic digestion of cellular components, pyknosis/karyorrhexis/karyolysis, and the release of
intracellular contents that triggers an inflammatory response in surrounding tissues. Apoptosis is
programmed, neat cell death that does not trigger inflammation.
Q6. A patient undergoes an autopsy which reveals soft, liquefied brain tissue with abscess formation
following an ischemic stroke. Which pattern of necrosis is most characteristic of brain tissue
ischemia?
A. Coagulative necrosis
B. Liquefactive necrosis
C. Caseous necrosis
D. Fat necrosis
Correct Answer: B
Rationale: Liquefactive necrosis occurs primarily in the central nervous system (brain) due to
ischemic injury. Brain tissue is rich in lipids and hydrolytic enzymes and contains little connective
tissue, causing the tissue to digest rapidly into a soft, liquid mass. Coagulative necrosis is typical of
ischemic injury in solid organs like the heart, kidneys, and adrenal glands.
Q7. Which of the following processes is the primary initiator of the extrinsic pathway of apoptosis?
, A. Cytochrome c release from the mitochondria into the cytosol
B. Activation of Caspase-9 by the apoptosome
C. Binding of Fas ligand (FasL) to the Fas death receptor (CD95)
D. DNA damage activating the p53 tumor suppressor gene
Correct Answer: C
Rationale: The extrinsic (death receptor-initiated) pathway of apoptosis begins when extracellular
ligands, such as Fas ligand (FasL) or TNF-alpha, bind to transmembrane death receptors like Fas
(CD95). This recruits initiator Caspase-8 or -10. Cytochrome c release and Caspase-9 activation are
characteristic of the intrinsic (mitochondrial) pathway.
Q8. A 45-year-old female presents with signs of premature aging, skin atrophy, and a history of
delayed wound healing. A genetic defect in telomerase is suspected. What is the physiological role of
telomeres in cellular aging?
A. They facilitate the translation of mitochondrial proteins
B. They prevent cellular division by sealing the nuclear membrane
C. They are repetitive DNA sequences that cap chromosomes and shorten with each cell division,
eventually signaling senescence
D. They synthesize ATP during periods of cellular stress
Correct Answer: C
Rationale: Telomeres are repetitive nucleotide sequences at the ends of chromosomes that protect
chromosomes from degradation. With each round of cell division, telomeres shorten. When they
reach a critically short length, they trigger a DNA damage response that leads to cellular senescence
(the Hayflick limit). Telomerase is an enzyme that maintains telomere length, typically active in germ
cells and cancer cells.
Q9. Free radicals cause cellular injury by attacking vital cell components. Which of the following is a
primary mechanism of free radical-induced damage?
A. Epigenetic silencing of histone proteins
B. Lipid peroxidation of chemical bonds in membrane lipids
C. Active transport of sodium out of the cell
D. Decreased intracellular calcium levels
Correct Answer: B
Rationale: Reactive oxygen species (ROS) and free radicals cause damage via three main pathways:
(1) lipid peroxidation of membranes, which damages organelles and plasma membranes; (2)
– Exam 1 Study Guide 2026 questions
with correct answers and
rationale graded A+
Q1. A patient presents with severe ischemia of the lower extremity. At the cellular level, the lack of
oxygen leads to a decrease in mitochondrial ATP production. Which of the following is the direct
consequence of this ATP depletion on intracellular ion concentrations?
A. Decreased intracellular sodium, increased intracellular potassium
B. Increased intracellular sodium, increased intracellular calcium, decreased intracellular potassium
C. Increased intracellular potassium, decreased intracellular calcium
D. Decreased intracellular sodium, decreased intracellular calcium
Correct Answer: B
Rationale: When ATP levels fall due to ischemia, the energy-dependent
N
a
+
/
K
+
Na
+
/K
+
ATPase pump fails, causing sodium to accumulate inside the cell and potassium to diffuse out.
Additionally, the
C
a
,2
+
Ca
2+
ATPase pump fails, preventing the extrusion of calcium and leading to an influx of extracellular
calcium. This intracellular calcium overload activates destructive intracellular enzymes (proteases,
phospholipases, endonucleases), leading to irreversible cellular injury.
Q2. During an autophagic response to nutrient deprivation, which of the following cellular structures
delivers damaged organelles to the lysosome for degradation?
A. Ubiquitin-proteasome system
B. Autophagosome
C. Peroxisome
D. Golgi apparatus
Correct Answer: B
Rationale: Autophagy is a survival mechanism where a cell recycles its own components. Damaged
organelles or proteins are sequestered within a double-membrane vesicle called an autophagosome,
which then fuses with a lysosome (forming an autolysosome) to degrade and recycle the contents.
The ubiquitin-proteasome system degrades individual tagged proteins, not entire organelles.
Q3. A 68-year-old male with a long-standing history of uncontrolled hypertension exhibits left
ventricular hypertrophy on an echocardiogram. This cellular adaptation is best characterized by
which of the following?
A. An increase in the number of myocardial cells
B. An increase in the size of individual myocardial cells due to increased protein synthesis
C. Replacement of myocardial cells with fibrous connective tissue
D. A reversible change where one adult cell type is replaced by another
Correct Answer: B
Rationale: Hypertrophy is an increase in the size of cells (not the number), resulting in an increase in
the size of the organ. Because myocardial cells are permanent and cannot divide (undergo
hyperplasia), they adapt to an increased workload (such as systemic hypertension) by increasing
protein synthesis, leading to larger individual cardiocytes.
Q4. A biopsy of the bronchus of a chronic cigarette smoker reveals that the normal pseudostratified
ciliated columnar epithelium has been replaced by stratified squamous epithelium. What is this
cellular adaptation called?
A. Dysplasia
,B. Anaplasia
C. Metaplasia
D. Hyperplasia
Correct Answer: C
Rationale: Metaplasia is the reversible replacement of one mature cell type by another mature cell
type, usually in response to chronic irritation or inflammation. While the stratified squamous
epithelium is more resilient to smoke, the loss of cilia and mucus secretion compromises respiratory
defenses.
Q5. A pathologist reviews a tissue biopsy showing cell death characterized by nuclear condensation
(pyknosis), fragmentation (karyorrhexis), and dissolution (karyolysis), accompanied by marked
inflammation of the surrounding tissue. Which type of cell death is represented?
A. Apoptosis
B. Autophagy
C. Necrosis
D. Senescence
Correct Answer: C
Rationale: Necrosis is accidental, unregulated cell death characterized by membrane rupture,
enzymatic digestion of cellular components, pyknosis/karyorrhexis/karyolysis, and the release of
intracellular contents that triggers an inflammatory response in surrounding tissues. Apoptosis is
programmed, neat cell death that does not trigger inflammation.
Q6. A patient undergoes an autopsy which reveals soft, liquefied brain tissue with abscess formation
following an ischemic stroke. Which pattern of necrosis is most characteristic of brain tissue
ischemia?
A. Coagulative necrosis
B. Liquefactive necrosis
C. Caseous necrosis
D. Fat necrosis
Correct Answer: B
Rationale: Liquefactive necrosis occurs primarily in the central nervous system (brain) due to
ischemic injury. Brain tissue is rich in lipids and hydrolytic enzymes and contains little connective
tissue, causing the tissue to digest rapidly into a soft, liquid mass. Coagulative necrosis is typical of
ischemic injury in solid organs like the heart, kidneys, and adrenal glands.
Q7. Which of the following processes is the primary initiator of the extrinsic pathway of apoptosis?
, A. Cytochrome c release from the mitochondria into the cytosol
B. Activation of Caspase-9 by the apoptosome
C. Binding of Fas ligand (FasL) to the Fas death receptor (CD95)
D. DNA damage activating the p53 tumor suppressor gene
Correct Answer: C
Rationale: The extrinsic (death receptor-initiated) pathway of apoptosis begins when extracellular
ligands, such as Fas ligand (FasL) or TNF-alpha, bind to transmembrane death receptors like Fas
(CD95). This recruits initiator Caspase-8 or -10. Cytochrome c release and Caspase-9 activation are
characteristic of the intrinsic (mitochondrial) pathway.
Q8. A 45-year-old female presents with signs of premature aging, skin atrophy, and a history of
delayed wound healing. A genetic defect in telomerase is suspected. What is the physiological role of
telomeres in cellular aging?
A. They facilitate the translation of mitochondrial proteins
B. They prevent cellular division by sealing the nuclear membrane
C. They are repetitive DNA sequences that cap chromosomes and shorten with each cell division,
eventually signaling senescence
D. They synthesize ATP during periods of cellular stress
Correct Answer: C
Rationale: Telomeres are repetitive nucleotide sequences at the ends of chromosomes that protect
chromosomes from degradation. With each round of cell division, telomeres shorten. When they
reach a critically short length, they trigger a DNA damage response that leads to cellular senescence
(the Hayflick limit). Telomerase is an enzyme that maintains telomere length, typically active in germ
cells and cancer cells.
Q9. Free radicals cause cellular injury by attacking vital cell components. Which of the following is a
primary mechanism of free radical-induced damage?
A. Epigenetic silencing of histone proteins
B. Lipid peroxidation of chemical bonds in membrane lipids
C. Active transport of sodium out of the cell
D. Decreased intracellular calcium levels
Correct Answer: B
Rationale: Reactive oxygen species (ROS) and free radicals cause damage via three main pathways:
(1) lipid peroxidation of membranes, which damages organelles and plasma membranes; (2)
