McCance & Huether’s Pathophysiology
The Biologic Basis for Disease in Adults
and Children
9th Edition
Author(s)Julia Rogers
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. Laboratory studies
demonstrate impaired leukocyte migration into infected
tissues despite marked neutrophilia in the bloodstream.
, Defective function of which cellular structure most directly
explains this patient’s presentation?
A. Gap junctions
B. Tight junctions
C. Integrins involved in cell adhesion
D. Intermediate filaments
E. Desmosomes
Correct Answer: C
Rationale:
• Clinical Clue: Delayed umbilical cord separation with
recurrent infections strongly suggests defective leukocyte
adhesion and migration.
• Mechanism: Integrins mediate firm adhesion of leukocytes
to vascular endothelium before transmigration into
tissues.
• Why the Correct Answer Is Right: Defective integrin-
mediated adhesion prevents neutrophils from exiting
circulation, causing recurrent infections despite elevated
circulating neutrophils.
• Why the Other Options Are Wrong:
o A: Gap junctions facilitate intercellular ion
communication, not leukocyte migration.
o B: Tight junctions regulate paracellular permeability.
o D: Intermediate filaments provide structural integrity.
, o E: Desmosomes anchor cells mechanically but are not
central to leukocyte extravasation.
• Exam Trap: High neutrophil counts do not exclude
immunodeficiency when migration defects are present.
• High-Yield Clinical Correlation: Leukocyte adhesion
deficiency commonly involves β2-integrin defects.
• Memory Anchor: “Neutrophils stuck in blood = integrin
adhesion failure.”
Q2. A researcher exposes cultured hepatocytes to cyanide,
resulting in abrupt cessation of aerobic ATP production.
Which intracellular process is most directly impaired first?
A. Glycolysis within the cytosol
B. Oxidative phosphorylation in mitochondria
C. Ribosomal protein synthesis
D. Lysosomal degradation
E. DNA replication in the nucleus
Correct Answer: B
Rationale:
• Clinical Clue: Cyanide poisoning rapidly halts aerobic
energy generation.
• Mechanism: Cyanide inhibits cytochrome oxidase in the
mitochondrial electron transport chain, preventing
oxidative phosphorylation.
, • Why the Correct Answer Is Right: Mitochondria are the
primary site of ATP generation through oxidative
phosphorylation.
• Why the Other Options Are Wrong:
o A: Glycolysis continues anaerobically.
o C: Protein synthesis declines later due to ATP
depletion.
o D: Lysosomal activity is not the primary early target.
o E: DNA replication is secondarily affected.
• Exam Trap: ATP depletion from mitochondrial injury
occurs before widespread structural damage becomes
evident.
• High-Yield Clinical Correlation: Severe mitochondrial
dysfunction produces lactic acidosis due to reliance on
anaerobic glycolysis.
• Memory Anchor: “Cyanide shuts down the mitochondrial
power plant.”
Q3. A patient with severe viral hepatitis develops marked
hepatocyte swelling and membrane blebbing. Intracellular
sodium and water accumulation most likely resulted from
failure of which mechanism?
The Biologic Basis for Disease in Adults
and Children
9th Edition
Author(s)Julia Rogers
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. Laboratory studies
demonstrate impaired leukocyte migration into infected
tissues despite marked neutrophilia in the bloodstream.
, Defective function of which cellular structure most directly
explains this patient’s presentation?
A. Gap junctions
B. Tight junctions
C. Integrins involved in cell adhesion
D. Intermediate filaments
E. Desmosomes
Correct Answer: C
Rationale:
• Clinical Clue: Delayed umbilical cord separation with
recurrent infections strongly suggests defective leukocyte
adhesion and migration.
• Mechanism: Integrins mediate firm adhesion of leukocytes
to vascular endothelium before transmigration into
tissues.
• Why the Correct Answer Is Right: Defective integrin-
mediated adhesion prevents neutrophils from exiting
circulation, causing recurrent infections despite elevated
circulating neutrophils.
• Why the Other Options Are Wrong:
o A: Gap junctions facilitate intercellular ion
communication, not leukocyte migration.
o B: Tight junctions regulate paracellular permeability.
o D: Intermediate filaments provide structural integrity.
, o E: Desmosomes anchor cells mechanically but are not
central to leukocyte extravasation.
• Exam Trap: High neutrophil counts do not exclude
immunodeficiency when migration defects are present.
• High-Yield Clinical Correlation: Leukocyte adhesion
deficiency commonly involves β2-integrin defects.
• Memory Anchor: “Neutrophils stuck in blood = integrin
adhesion failure.”
Q2. A researcher exposes cultured hepatocytes to cyanide,
resulting in abrupt cessation of aerobic ATP production.
Which intracellular process is most directly impaired first?
A. Glycolysis within the cytosol
B. Oxidative phosphorylation in mitochondria
C. Ribosomal protein synthesis
D. Lysosomal degradation
E. DNA replication in the nucleus
Correct Answer: B
Rationale:
• Clinical Clue: Cyanide poisoning rapidly halts aerobic
energy generation.
• Mechanism: Cyanide inhibits cytochrome oxidase in the
mitochondrial electron transport chain, preventing
oxidative phosphorylation.
, • Why the Correct Answer Is Right: Mitochondria are the
primary site of ATP generation through oxidative
phosphorylation.
• Why the Other Options Are Wrong:
o A: Glycolysis continues anaerobically.
o C: Protein synthesis declines later due to ATP
depletion.
o D: Lysosomal activity is not the primary early target.
o E: DNA replication is secondarily affected.
• Exam Trap: ATP depletion from mitochondrial injury
occurs before widespread structural damage becomes
evident.
• High-Yield Clinical Correlation: Severe mitochondrial
dysfunction produces lactic acidosis due to reliance on
anaerobic glycolysis.
• Memory Anchor: “Cyanide shuts down the mitochondrial
power plant.”
Q3. A patient with severe viral hepatitis develops marked
hepatocyte swelling and membrane blebbing. Intracellular
sodium and water accumulation most likely resulted from
failure of which mechanism?
