FINAL EXAMS MSG 527 QUESTION AND
GUIDE SOLUTION ANSERS STUDY
GUIDE UPDATED A PLUS
SECTION ONE: CELLULAR
ADAPTATION AND INJURY
Question 1
A patient with a history of chronic alcohol abuse presents with severe
epigastric pain. Lab tests show elevated serum lipase. The pathologist notes
the pancreatic cells have been destroyed by digestive enzymes. What is the
primary intracellular mechanism that allows digestive enzymes to destroy
the pancreas from the inside?
A. The enzymes mutate and become resistant to normal inhibitors.
B. Lysosomal membranes rupture, releasing acid hydrolases that activate
the digestive proenzymes within the acinar cells.
C. The endoplasmic reticulum synthesizes active trypsin instead of
trypsinogen.
D. Apoptosis is triggered, causing programmed release of toxins.
Answer: B
RATIONALE: In acute pancreatitis, such as that caused by alcohol or
gallstones, the primary cellular injury begins with the premature
activation of digestive enzymes. Trypsinogen and other proenzymes are
normally safely packaged in zymogen granules. However, injury causes
lysosomal membranes to fuse with these zymogen granules. The
lysosomal acid hydrolases activate the trypsinogen into trypsin inside the
cell. This active trypsin then activates all other pancreatic enzymes (like
,lipase and amylase) directly within the acinar cell, causing massive
autodigestion, cellular swelling, and necrosis.
Question 2
A biopsy of a smoker's airway shows stratified squamous epithelium
replacing the normal ciliated columnar epithelium. The cells are fully
mature and there is no nuclear atypia. How is this process best described
pathophysiologically?
A. Dysplasia
B. Anaplasia
C. Metaplasia
D. Hyperplasia
Answer: C
RATIONALE: Metaplasia is the reversible replacement of one fully
differentiated adult cell type with another adult cell type. In the
respiratory tract, chronic tobacco exposure destroys the fragile ciliated
columnar cells. To protect the underlying tissue from the chronic irritant,
basal stem cells differentiate into tougher, more resistant stratified
squamous epithelium. Dysplasia would involve atypical, disorganized
cells with nuclear changes, which is a precursor to cancer. Anaplasia
refers to undifferentiated, primitive-looking cells typical of malignancy.
Hyperplasia is simply an increase in the number of normal cells.
Question 3
A patient suffers a massive ischemic stroke. The neurologist explains that
the core infarct is surrounded by a penumbra. Why is the tissue in the
penumbra salvageable, unlike the core?
, A. The penumbra has an alternative blood supply from collateral circulation,
while the core does not.
B. Cells in the penumbra have shifted to anaerobic glycolysis to maintain
their membrane integrity, whereas cells in the core have lost ATP
completely, causing membrane failure and uncontrolled calcium influx.
C. The penumbra is located in the white matter, which is resistant to
ischemia.
D. Glutamate excitotoxicity only affects the core and spares the penumbra.
Answer: B
RATIONALE: In an ischemic stroke, blood flow drops in a gradient. The
core receives almost no blood flow (below 10 mL/100g/min). Without
oxygen, the electron transport chain stops, ATP is depleted, and the
sodium-potassium pump fails. This allows uncontrolled sodium and
calcium influx into the cells, causing acute cellular swelling
(oncosis) and rapid death by necrosis. The penumbra has reduced blood
flow (around 10 to 20 mL/100g/min). This is not enough to generate
action potentials (causing clinical symptoms like paralysis), but it is just
enough ATP to keep the cell membranes intact. If perfusion is restored
(e.g., with tPA), the penumbra cells can recover.
SECTION TWO: IMMUNOLOGY AND INFLAMMATION
Question 4
A patient develops a delayed hypersensitivity reaction to a cosmetic
product, presenting with a red, itchy, vesicular rash 48 hours after
application. Which immune cells and mediators are most responsible for
the tissue damage in this reaction?
GUIDE SOLUTION ANSERS STUDY
GUIDE UPDATED A PLUS
SECTION ONE: CELLULAR
ADAPTATION AND INJURY
Question 1
A patient with a history of chronic alcohol abuse presents with severe
epigastric pain. Lab tests show elevated serum lipase. The pathologist notes
the pancreatic cells have been destroyed by digestive enzymes. What is the
primary intracellular mechanism that allows digestive enzymes to destroy
the pancreas from the inside?
A. The enzymes mutate and become resistant to normal inhibitors.
B. Lysosomal membranes rupture, releasing acid hydrolases that activate
the digestive proenzymes within the acinar cells.
C. The endoplasmic reticulum synthesizes active trypsin instead of
trypsinogen.
D. Apoptosis is triggered, causing programmed release of toxins.
Answer: B
RATIONALE: In acute pancreatitis, such as that caused by alcohol or
gallstones, the primary cellular injury begins with the premature
activation of digestive enzymes. Trypsinogen and other proenzymes are
normally safely packaged in zymogen granules. However, injury causes
lysosomal membranes to fuse with these zymogen granules. The
lysosomal acid hydrolases activate the trypsinogen into trypsin inside the
cell. This active trypsin then activates all other pancreatic enzymes (like
,lipase and amylase) directly within the acinar cell, causing massive
autodigestion, cellular swelling, and necrosis.
Question 2
A biopsy of a smoker's airway shows stratified squamous epithelium
replacing the normal ciliated columnar epithelium. The cells are fully
mature and there is no nuclear atypia. How is this process best described
pathophysiologically?
A. Dysplasia
B. Anaplasia
C. Metaplasia
D. Hyperplasia
Answer: C
RATIONALE: Metaplasia is the reversible replacement of one fully
differentiated adult cell type with another adult cell type. In the
respiratory tract, chronic tobacco exposure destroys the fragile ciliated
columnar cells. To protect the underlying tissue from the chronic irritant,
basal stem cells differentiate into tougher, more resistant stratified
squamous epithelium. Dysplasia would involve atypical, disorganized
cells with nuclear changes, which is a precursor to cancer. Anaplasia
refers to undifferentiated, primitive-looking cells typical of malignancy.
Hyperplasia is simply an increase in the number of normal cells.
Question 3
A patient suffers a massive ischemic stroke. The neurologist explains that
the core infarct is surrounded by a penumbra. Why is the tissue in the
penumbra salvageable, unlike the core?
, A. The penumbra has an alternative blood supply from collateral circulation,
while the core does not.
B. Cells in the penumbra have shifted to anaerobic glycolysis to maintain
their membrane integrity, whereas cells in the core have lost ATP
completely, causing membrane failure and uncontrolled calcium influx.
C. The penumbra is located in the white matter, which is resistant to
ischemia.
D. Glutamate excitotoxicity only affects the core and spares the penumbra.
Answer: B
RATIONALE: In an ischemic stroke, blood flow drops in a gradient. The
core receives almost no blood flow (below 10 mL/100g/min). Without
oxygen, the electron transport chain stops, ATP is depleted, and the
sodium-potassium pump fails. This allows uncontrolled sodium and
calcium influx into the cells, causing acute cellular swelling
(oncosis) and rapid death by necrosis. The penumbra has reduced blood
flow (around 10 to 20 mL/100g/min). This is not enough to generate
action potentials (causing clinical symptoms like paralysis), but it is just
enough ATP to keep the cell membranes intact. If perfusion is restored
(e.g., with tPA), the penumbra cells can recover.
SECTION TWO: IMMUNOLOGY AND INFLAMMATION
Question 4
A patient develops a delayed hypersensitivity reaction to a cosmetic
product, presenting with a red, itchy, vesicular rash 48 hours after
application. Which immune cells and mediators are most responsible for
the tissue damage in this reaction?
