Understanding Pathophysiology
8th Edition
Author(s)Sue E. Huether
TEST BANK
Q1. A 6-year-old boy presents with recurrent bacterial
infections, poor wound healing, and delayed separation of the
umbilical cord after birth. Neutrophil counts are markedly
elevated. Flow cytometry demonstrates absent expression of
β2-integrins on leukocytes. The patient’s recurrent infections
are most directly explained by failure of which cellular process?
A. Intracellular lysosomal fusion
B. Leukocyte transendothelial migration
C. Antigen-dependent clonal expansion
D. Neutrophil oxidative phosphorylation
E. Complement-mediated opsonization
Correct Answer: B
,Rationale:
Clinical Clue:
Delayed umbilical cord separation with recurrent bacterial
infections strongly suggests leukocyte adhesion deficiency.
Mechanism:
β2-integrins mediate firm leukocyte adhesion to endothelial
ICAM molecules before diapedesis.
Why the Correct Answer Is Right:
Without integrin-mediated adhesion, neutrophils cannot exit
the bloodstream efficiently and migrate into infected tissues.
Why the Other Options Are Wrong:
A. Lysosomal fusion defects cause Chediak-Higashi syndrome,
characterized by albinism and neuropathy.
C. Clonal expansion is a lymphocyte function not responsible for
neutrophil migration.
D. Oxidative phosphorylation defects do not specifically impair
adhesion.
E. Opsonization remains intact in leukocyte adhesion
deficiency.
Exam Trap (common misconception tested):
Confusing impaired leukocyte migration with impaired
phagocytic killing.
High-Yield Clinical Correlation:
Persistent neutrophilia in the setting of recurrent infections
,often indicates defective tissue migration rather than defective
neutrophil production.
Q2. A researcher inhibits Na+/K+-ATPase activity in cultured
myocardial cells. Within minutes, the cells begin to swell. The
earliest intracellular change most directly responsible for this
finding is:
A. Increased intracellular sodium concentration
B. Enhanced mitochondrial ATP synthesis
C. Decreased membrane permeability to water
D. Increased extracellular potassium concentration
E. Activation of lysosomal hydrolases
Correct Answer: A
Rationale:
Clinical Clue:
Acute cellular swelling after ATPase inhibition indicates
disrupted osmotic regulation.
Mechanism:
Na+/K+-ATPase normally extrudes sodium from cells. Pump
failure causes intracellular sodium accumulation, drawing water
inward osmotically.
Why the Correct Answer Is Right:
Sodium retention increases intracellular osmolarity, causing
water influx and hydropic swelling.
, Why the Other Options Are Wrong:
B. ATP synthesis decreases rather than increases.
C. Water permeability is not the primary issue.
D. Extracellular potassium changes are secondary.
E. Lysosomal activation occurs later during irreversible injury.
Exam Trap (common misconception tested):
Assuming water accumulation is primary rather than secondary
to ionic imbalance.
High-Yield Clinical Correlation:
Cellular swelling is typically the earliest morphologic
manifestation of reversible injury.
Q3. A woman with metastatic breast carcinoma develops
cachexia despite adequate caloric intake. Tumor analysis
reveals marked upregulation of glycolytic pathways even in
highly oxygenated regions. This metabolic adaptation most
directly benefits the tumor by promoting:
A. Enhanced oxidative phosphorylation efficiency
B. Increased intracellular calcium sequestration
C. Rapid biosynthetic substrate generation
D. Reduced lactate production
E. Decreased glucose transporter expression
Correct Answer: C
Rationale:
8th Edition
Author(s)Sue E. Huether
TEST BANK
Q1. A 6-year-old boy presents with recurrent bacterial
infections, poor wound healing, and delayed separation of the
umbilical cord after birth. Neutrophil counts are markedly
elevated. Flow cytometry demonstrates absent expression of
β2-integrins on leukocytes. The patient’s recurrent infections
are most directly explained by failure of which cellular process?
A. Intracellular lysosomal fusion
B. Leukocyte transendothelial migration
C. Antigen-dependent clonal expansion
D. Neutrophil oxidative phosphorylation
E. Complement-mediated opsonization
Correct Answer: B
,Rationale:
Clinical Clue:
Delayed umbilical cord separation with recurrent bacterial
infections strongly suggests leukocyte adhesion deficiency.
Mechanism:
β2-integrins mediate firm leukocyte adhesion to endothelial
ICAM molecules before diapedesis.
Why the Correct Answer Is Right:
Without integrin-mediated adhesion, neutrophils cannot exit
the bloodstream efficiently and migrate into infected tissues.
Why the Other Options Are Wrong:
A. Lysosomal fusion defects cause Chediak-Higashi syndrome,
characterized by albinism and neuropathy.
C. Clonal expansion is a lymphocyte function not responsible for
neutrophil migration.
D. Oxidative phosphorylation defects do not specifically impair
adhesion.
E. Opsonization remains intact in leukocyte adhesion
deficiency.
Exam Trap (common misconception tested):
Confusing impaired leukocyte migration with impaired
phagocytic killing.
High-Yield Clinical Correlation:
Persistent neutrophilia in the setting of recurrent infections
,often indicates defective tissue migration rather than defective
neutrophil production.
Q2. A researcher inhibits Na+/K+-ATPase activity in cultured
myocardial cells. Within minutes, the cells begin to swell. The
earliest intracellular change most directly responsible for this
finding is:
A. Increased intracellular sodium concentration
B. Enhanced mitochondrial ATP synthesis
C. Decreased membrane permeability to water
D. Increased extracellular potassium concentration
E. Activation of lysosomal hydrolases
Correct Answer: A
Rationale:
Clinical Clue:
Acute cellular swelling after ATPase inhibition indicates
disrupted osmotic regulation.
Mechanism:
Na+/K+-ATPase normally extrudes sodium from cells. Pump
failure causes intracellular sodium accumulation, drawing water
inward osmotically.
Why the Correct Answer Is Right:
Sodium retention increases intracellular osmolarity, causing
water influx and hydropic swelling.
, Why the Other Options Are Wrong:
B. ATP synthesis decreases rather than increases.
C. Water permeability is not the primary issue.
D. Extracellular potassium changes are secondary.
E. Lysosomal activation occurs later during irreversible injury.
Exam Trap (common misconception tested):
Assuming water accumulation is primary rather than secondary
to ionic imbalance.
High-Yield Clinical Correlation:
Cellular swelling is typically the earliest morphologic
manifestation of reversible injury.
Q3. A woman with metastatic breast carcinoma develops
cachexia despite adequate caloric intake. Tumor analysis
reveals marked upregulation of glycolytic pathways even in
highly oxygenated regions. This metabolic adaptation most
directly benefits the tumor by promoting:
A. Enhanced oxidative phosphorylation efficiency
B. Increased intracellular calcium sequestration
C. Rapid biosynthetic substrate generation
D. Reduced lactate production
E. Decreased glucose transporter expression
Correct Answer: C
Rationale:
