Understanding Pathophysiology
8th Edition
Author(s)Sue E. Huether
TEST BANK
Q1. A 6-year-old boy develops recurrent bacterial infections,
delayed wound healing, and poor leukocyte migration into
infected tissues. Genetic testing identifies a defect in β2-
integrin expression on neutrophils. The impaired host defense
most directly results from failure of which cellular process?
A. Formation of tight junction barriers between endothelial
cells
B. Adhesion-dependent leukocyte transmigration across
vascular endothelium
C. Intracellular degradation of pathogens within lysosomes
,D. Assembly of collagen fibrils in the extracellular matrix
E. ATP generation through oxidative phosphorylation
Correct Answer: B
Rationale:
Clinical Clue:
Recurrent bacterial infections with defective leukocyte
migration strongly suggests impaired adhesion and
extravasation.
Mechanism:
β2-integrins mediate firm adhesion of leukocytes to endothelial
ICAM molecules during diapedesis.
Why the Correct Answer Is Right:
Without integrin-mediated adhesion, neutrophils cannot
effectively exit the bloodstream and enter tissues.
Why the Other Options Are Wrong:
A. Tight junctions regulate barrier permeability, not leukocyte
migration.
C. Lysosomal degradation occurs after phagocytosis.
D. Collagen assembly relates to connective tissue integrity.
E. ATP production does not specifically explain migration
failure.
Exam Trap (common misconception tested):
Confusing chemotaxis with endothelial adhesion; the defect is
in transmigration, not directional signaling.
,High-Yield Clinical Correlation:
Leukocyte adhesion defects produce neutrophilia because
leukocytes remain trapped in circulation.
Q2. A researcher inhibits Na+/K+-ATPase activity in cultured
myocardial cells. Several minutes later, the cells begin to swell.
The earliest intracellular change most directly responsible for
this swelling is:
A. Increased intracellular sodium concentration
B. Increased intracellular calcium sequestration
C. Activation of mitochondrial apoptosis pathways
D. Enhanced lysosomal membrane permeability
E. Increased extracellular osmotic pressure
Correct Answer: A
Rationale:
Clinical Clue:
Cell swelling after ATPase inhibition reflects disrupted
membrane ion transport.
Mechanism:
Na+/K+-ATPase normally extrudes sodium from cells. Failure
causes sodium accumulation, followed by osmotic water influx.
Why the Correct Answer Is Right:
Intracellular sodium retention creates osmotic forces driving
cellular edema.
, Why the Other Options Are Wrong:
B. Calcium accumulation occurs later and contributes to injury.
C. Apoptosis is not the earliest event.
D. Lysosomal leakage develops with severe injury.
E. Extracellular osmotic pressure is not the primary mechanism.
Exam Trap (common misconception tested):
Assuming water movement occurs independently of ionic
shifts.
High-Yield Clinical Correlation:
Cellular swelling is a hallmark of reversible early hypoxic injury.
Q3. A patient with chronic alcohol use develops hepatocyte
injury associated with impaired protein trafficking and reduced
plasma albumin synthesis. Dysfunction of which organelle best
explains these findings?
A. Smooth endoplasmic reticulum
B. Ribosomes
C. Golgi apparatus
D. Peroxisomes
E. Lysosomes
Correct Answer: C
Rationale:
8th Edition
Author(s)Sue E. Huether
TEST BANK
Q1. A 6-year-old boy develops recurrent bacterial infections,
delayed wound healing, and poor leukocyte migration into
infected tissues. Genetic testing identifies a defect in β2-
integrin expression on neutrophils. The impaired host defense
most directly results from failure of which cellular process?
A. Formation of tight junction barriers between endothelial
cells
B. Adhesion-dependent leukocyte transmigration across
vascular endothelium
C. Intracellular degradation of pathogens within lysosomes
,D. Assembly of collagen fibrils in the extracellular matrix
E. ATP generation through oxidative phosphorylation
Correct Answer: B
Rationale:
Clinical Clue:
Recurrent bacterial infections with defective leukocyte
migration strongly suggests impaired adhesion and
extravasation.
Mechanism:
β2-integrins mediate firm adhesion of leukocytes to endothelial
ICAM molecules during diapedesis.
Why the Correct Answer Is Right:
Without integrin-mediated adhesion, neutrophils cannot
effectively exit the bloodstream and enter tissues.
Why the Other Options Are Wrong:
A. Tight junctions regulate barrier permeability, not leukocyte
migration.
C. Lysosomal degradation occurs after phagocytosis.
D. Collagen assembly relates to connective tissue integrity.
E. ATP production does not specifically explain migration
failure.
Exam Trap (common misconception tested):
Confusing chemotaxis with endothelial adhesion; the defect is
in transmigration, not directional signaling.
,High-Yield Clinical Correlation:
Leukocyte adhesion defects produce neutrophilia because
leukocytes remain trapped in circulation.
Q2. A researcher inhibits Na+/K+-ATPase activity in cultured
myocardial cells. Several minutes later, the cells begin to swell.
The earliest intracellular change most directly responsible for
this swelling is:
A. Increased intracellular sodium concentration
B. Increased intracellular calcium sequestration
C. Activation of mitochondrial apoptosis pathways
D. Enhanced lysosomal membrane permeability
E. Increased extracellular osmotic pressure
Correct Answer: A
Rationale:
Clinical Clue:
Cell swelling after ATPase inhibition reflects disrupted
membrane ion transport.
Mechanism:
Na+/K+-ATPase normally extrudes sodium from cells. Failure
causes sodium accumulation, followed by osmotic water influx.
Why the Correct Answer Is Right:
Intracellular sodium retention creates osmotic forces driving
cellular edema.
, Why the Other Options Are Wrong:
B. Calcium accumulation occurs later and contributes to injury.
C. Apoptosis is not the earliest event.
D. Lysosomal leakage develops with severe injury.
E. Extracellular osmotic pressure is not the primary mechanism.
Exam Trap (common misconception tested):
Assuming water movement occurs independently of ionic
shifts.
High-Yield Clinical Correlation:
Cellular swelling is a hallmark of reversible early hypoxic injury.
Q3. A patient with chronic alcohol use develops hepatocyte
injury associated with impaired protein trafficking and reduced
plasma albumin synthesis. Dysfunction of which organelle best
explains these findings?
A. Smooth endoplasmic reticulum
B. Ribosomes
C. Golgi apparatus
D. Peroxisomes
E. Lysosomes
Correct Answer: C
Rationale:
