Understanding Pathophysiology
8th Edition
Author(s)Sue E. Huether
TEST BANK
Q1. A 6-year-old boy presents with recurrent bacterial
infections, delayed wound healing, and poor leukocyte
migration into infected tissues. Genetic analysis reveals a defect
in integrin-mediated adhesion between leukocytes and vascular
endothelium. The impaired immune response is most directly
attributable to failure of which cellular process?
A. Receptor-mediated endocytosis
B. Cell-to-cell adhesion signaling
C. Mitochondrial oxidative phosphorylation
D. Lysosomal enzyme activation
E. DNA proofreading during replication
,Correct Answer: B
Rationale:
Clinical Clue:
Recurrent infections with impaired leukocyte migration strongly
suggests defective adhesion molecule function.
Mechanism:
Integrins mediate leukocyte attachment to endothelial cells
during extravasation. Failure of adhesion disrupts cellular
communication required for inflammatory migration.
Why the Correct Answer Is Right:
Cell-to-cell adhesion signaling enables leukocytes to tether,
adhere, and migrate through vascular endothelium toward
infected tissues.
Why the Other Options Are Wrong:
A. Endocytosis affects uptake, not migration.
C. Oxidative phosphorylation defects cause energy failure
rather than selective migration impairment.
D. Lysosomal dysfunction impairs intracellular killing, not
endothelial adhesion.
E. DNA proofreading defects predispose to mutations, not
defective leukocyte trafficking.
Exam Trap (common misconception tested):
Confusing intracellular killing defects with defects in leukocyte
recruitment.
,High-Yield Clinical Correlation:
Leukocyte adhesion defects produce neutrophilia because
leukocytes remain trapped in circulation.
Q2. A hepatocyte exposed to prolonged hypoxia develops
intracellular swelling before irreversible injury occurs. The
earliest pathophysiologic change most likely involves disruption
of which membrane transport mechanism?
A. Secondary active transport of glucose
B. Sodium-potassium ATPase activity
C. Facilitated diffusion of oxygen
D. Calcium-dependent exocytosis
E. Receptor-mediated pinocytosis
Correct Answer: B
Rationale:
Clinical Clue:
Cellular swelling is an early reversible manifestation of ATP
depletion.
Mechanism:
Hypoxia reduces ATP production, impairing energy-dependent
ion pumps.
Why the Correct Answer Is Right:
Failure of the sodium-potassium ATPase allows intracellular
sodium and water accumulation, producing cellular edema.
, Why the Other Options Are Wrong:
A. Glucose transport disruption is secondary.
C. Oxygen diffusion is passive and not ATP dependent.
D. Exocytosis impairment does not primarily cause swelling.
E. Pinocytosis abnormalities are not the major mechanism.
Exam Trap (common misconception tested):
Attributing swelling to membrane rupture rather than pump
failure.
High-Yield Clinical Correlation:
Cellular swelling is typically reversible if oxygen delivery is
restored before membrane integrity is lost.
Q3. A rapidly proliferating malignant tumor demonstrates
marked genomic instability and accumulation of chromosomal
abnormalities. Dysfunction of which cell-cycle checkpoint most
directly predisposes to propagation of damaged DNA?
A. G0 checkpoint
B. Mitotic spindle checkpoint
C. G1/S checkpoint
D. Cytokinesis checkpoint
E. Ribosomal assembly checkpoint
Correct Answer: C
Rationale:
8th Edition
Author(s)Sue E. Huether
TEST BANK
Q1. A 6-year-old boy presents with recurrent bacterial
infections, delayed wound healing, and poor leukocyte
migration into infected tissues. Genetic analysis reveals a defect
in integrin-mediated adhesion between leukocytes and vascular
endothelium. The impaired immune response is most directly
attributable to failure of which cellular process?
A. Receptor-mediated endocytosis
B. Cell-to-cell adhesion signaling
C. Mitochondrial oxidative phosphorylation
D. Lysosomal enzyme activation
E. DNA proofreading during replication
,Correct Answer: B
Rationale:
Clinical Clue:
Recurrent infections with impaired leukocyte migration strongly
suggests defective adhesion molecule function.
Mechanism:
Integrins mediate leukocyte attachment to endothelial cells
during extravasation. Failure of adhesion disrupts cellular
communication required for inflammatory migration.
Why the Correct Answer Is Right:
Cell-to-cell adhesion signaling enables leukocytes to tether,
adhere, and migrate through vascular endothelium toward
infected tissues.
Why the Other Options Are Wrong:
A. Endocytosis affects uptake, not migration.
C. Oxidative phosphorylation defects cause energy failure
rather than selective migration impairment.
D. Lysosomal dysfunction impairs intracellular killing, not
endothelial adhesion.
E. DNA proofreading defects predispose to mutations, not
defective leukocyte trafficking.
Exam Trap (common misconception tested):
Confusing intracellular killing defects with defects in leukocyte
recruitment.
,High-Yield Clinical Correlation:
Leukocyte adhesion defects produce neutrophilia because
leukocytes remain trapped in circulation.
Q2. A hepatocyte exposed to prolonged hypoxia develops
intracellular swelling before irreversible injury occurs. The
earliest pathophysiologic change most likely involves disruption
of which membrane transport mechanism?
A. Secondary active transport of glucose
B. Sodium-potassium ATPase activity
C. Facilitated diffusion of oxygen
D. Calcium-dependent exocytosis
E. Receptor-mediated pinocytosis
Correct Answer: B
Rationale:
Clinical Clue:
Cellular swelling is an early reversible manifestation of ATP
depletion.
Mechanism:
Hypoxia reduces ATP production, impairing energy-dependent
ion pumps.
Why the Correct Answer Is Right:
Failure of the sodium-potassium ATPase allows intracellular
sodium and water accumulation, producing cellular edema.
, Why the Other Options Are Wrong:
A. Glucose transport disruption is secondary.
C. Oxygen diffusion is passive and not ATP dependent.
D. Exocytosis impairment does not primarily cause swelling.
E. Pinocytosis abnormalities are not the major mechanism.
Exam Trap (common misconception tested):
Attributing swelling to membrane rupture rather than pump
failure.
High-Yield Clinical Correlation:
Cellular swelling is typically reversible if oxygen delivery is
restored before membrane integrity is lost.
Q3. A rapidly proliferating malignant tumor demonstrates
marked genomic instability and accumulation of chromosomal
abnormalities. Dysfunction of which cell-cycle checkpoint most
directly predisposes to propagation of damaged DNA?
A. G0 checkpoint
B. Mitotic spindle checkpoint
C. G1/S checkpoint
D. Cytokinesis checkpoint
E. Ribosomal assembly checkpoint
Correct Answer: C
Rationale:
